Anatomy of the Upper and Lower Limb ANA 201 PDF

Anatomy of the Upper and Lower Limb ANA 201 Anatomy of the Upper and Lower Limb -ANA 201 Page 2 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Miva Open University Headquarters Plot 1059 O.P. Fingesi Road, Utako, Abuja...

Anatomy of the Upper and Lower Limb ANA 201 Anatomy of the Upper and Lower Limb -ANA 201 Page 2 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Miva Open University Headquarters Plot 1059 O.P. Fingesi Road, Utako, Abuja Page 3 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Course Development Team Content Editor: Chidubem Eze B.Sc Microbiology Language Editor: Udochi Obiukwu MA English Language Instructional Designer: Assoc. Prof. Kennedy A. Osakwe Adakporia PhD, MPH, MBA, MSc, BDS Page 4 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Table of Contents Table of Contents 5 Table of Figures 6 Study Session 1: Introduction to General Anatomy 8 Introduction 8 Learning Outcomes for Study Session 1 8 1.1. Introduction to Anatomy 9 1.2. Anatomical Planes 11 1.3. Anatomical Relationships 13 1.4. Anatomical Positions 14 1.5. Anatomical Regions 16 1.6. Anatomical directions 18 1.7. Anatomical Terms of Laterality 20 1.8. Anatomical terms of movement 21 1.9. Anatomical cavities 22 Summary 25 Conclusion 26 Tutor-Marked Assignment 27 Study Session 2: General Organisation of Body Systems 28 Introduction 28 Learning Outcomes for Study Session 2 28 2.1 Integumentary System 28 2.2 Skeletal System 29 2.3 Muscular System 30 2.4 Nervous System 31 2.5 Endocrine System 33 2.6 Cardiovascular System 34 2.7 Lymphatic System 36 2.8 Immune System 37 2.9 Respiratory System 38 2.10 Digestive System 40 2.11 Urinary System 42 Page 5 of 86  Anatomy of the Upper and Lower Limb -ANA 201 2.12 Reproductive System 44 Summary 46 Conclusion 47 Tutor Marked Assignment 49 Study Session 3: Appendicular Skeleton 50 Introduction 50 Learning Outcomes for Study Session 3 50 3.1 Appendicular skeleton 50 3.2 Bones of the Upper Limbs 51 3.3 Bones of the Lower Limb 61 Summary 68 Conclusion 70 Tutor Marked Assessment 70 Study Session 4: Muscles of the Upper and Lower Limbs 71 Introduction 71 Learning Outcomes for Study Session 4 71 4.1 Structure of Muscles 71 4.2 Major Muscles of the Upper Limbs 74 Summary 80 Conclusion 82 Tutor Marked Assignment 83 References 84 Glossary 85 Page 6 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Table of Figures Figure 2.1: Anatomy of the Skin 29 Figure 2.2 The Human Skeletal System 30 Figure 2.3 Muscular System 31 Figure 2.4 Nervous System 32 Figure 2.5 Endocrine system 33 Figure 2.6 Cardiovascular System 35 Figure 2.7 Lymphatic system 36 Figure 2.8 Immune system 38 Figure 2.9 Respiratory system 39 Figure 2.10 Digestive System 41 Figure 2.11 Urinary System 43 Figure 2.12 Male and Female Reproductive System 44 3.1 Appendicular skeleton 51 Figure 3.2 Clavicle 52 Figure 3.3 Scapular 52 Figure 3.4 Humerus 54 Figure 3.5 Tibia and Fibula 56 Figure 3.6 Bones of the Right Hand 59 Figure 3.7 The Pelvic Girdle 62 Figure 3.8 Femur 63 Figure 3.9 Tibia & Fibula 64 Figure 4.1 Skeletal Muscle 72 Figure 4.2 Rotator Cuff Muscles 74 Figure 4.3 Rotator Cuff Muscles 76 Figure 4.4 Trapezius Muscles 77 Figure 4.5 Trapezius Muscles 79 Page 7 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Study Session 1: Introduction to General Anatomy Introduction Welcome to this study session, where you are going to study basic concepts in anatomy. In this study session, you will learn different descriptive terminologies used in anatomy. Learning Outcomes for Study Session 1 At the end of this session, you should be able to describe: 1.1. Introductory Concepts in Anatomy 1.2. Anatomical Planes 1.3. Anatomical Relationships 1.4. Anatomical position 1.5. Anatomical regions 1.6. Anatomical directions 1.7. Anatomical terms of laterality 1.8. Anatomical terms of movement 1.9. Anatomical cavities Page 8 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.1. Introduction to Anatomy Anatomy is the branch of science that deals with the study of the structure of living organisms. In the context of human biology, it focuses specifically on the structure of the human body. This field of study is crucial for various medical professions, as it provides the foundation for understanding how the body is organised and how its different parts interact. 1.1.1. Importance of Anatomy 1. Medical Practice: For doctors, nurses, and other healthcare professionals, a profound knowledge of anatomy is indispensable. Understanding the body's structure helps in diagnosing diseases, interpreting symptoms, and performing surgeries. 2. Research: Anatomical knowledge is fundamental in medical research. Researchers study the body's structures to learn about diseases, develop new treatments, and improve existing medical procedures. 3. Education: Anatomy is a core subject in medical education. Medical students and aspiring healthcare professionals learn about the human body's intricacies to provide effective patient care. 1.1.2. Branches of Anatomy 1. Gross Anatomy: This involves the study of visible body structures without the aid of a microscope. It includes systemic anatomy, where the body is studied system by system, and regional anatomy, where specific regions of the body are studied in detail. Page 9 of 86  Anatomy of the Upper and Lower Limb -ANA 201 2. Microscopic Anatomy: Also known as histology, this branch deals with the study of tissues, cells, and organs on a microscopic level. It is essential for understanding the body's functions at a cellular level. 3. Developmental Anatomy: This branch focuses on the development of the human body from conception to adulthood. It explores how organs and structures form and mature over time. 4. Comparative Anatomy: Comparative anatomy involves comparing the anatomical structures of different species. By understanding the similarities and differences, scientists can gain insights into evolutionary relationships. 1.1.3. Basic Concepts in Anatomy 1. Cells: Cells are the basic units of life. Understanding their structure and function is fundamental to anatomy. 2. Tissues: Groups of similar cells form tissues, such as muscle tissue and nerve tissue. Different tissues combine to create organs. 3. Organs: Organs are structures composed of multiple tissues that work together to perform specific functions. For example, the heart is an organ composed of cardiac muscle tissue and connective tissue. 4. Systems: Organs with related functions are grouped into systems. For instance, the heart, blood, and blood vessels form the cardiovascular system. Page 10 of 86  Anatomy of the Upper and Lower Limb -ANA 201 5. Anatomical Terminology: To communicate effectively, anatomists use specific terms to describe the body and its parts. Understanding this terminology is essential for precise communication in the field of anatomy. Anatomy is a vital scientific discipline that provides the foundation for medical knowledge and practice. It encompasses a wide range of topics, from the structure of cells to the organisation of complex organ systems. As our understanding of anatomy advances, so does our ability to diagnose, treat, and prevent diseases, ultimately improving healthcare outcomes for people around the world. 1.2. Anatomical Planes In anatomy, understanding anatomical planes is crucial for describing the body's structure and the relationships between its parts. Anatomical planes are imaginary flat surfaces used as references to divide the body into sections for descriptive and diagnostic purposes. These planes are essential for precise communication among healthcare professionals. 1.2.1 Main Anatomical Planes 1. Sagittal Plane: The sagittal plane divides the body into left and right halves. It runs vertically from front to back, creating a right and a left side. Types of sagittal planes include a. Midsagittal (or Median) Plane: Divides the body into equal left and right halves. b. Parasagittal Plane: Divides the body into unequal left and right portions, offset from the midline. Page 11 of 86  Anatomy of the Upper and Lower Limb -ANA 201 2. Frontal (Coronal) Plane: The frontal plane divides the body into front (anterior) and back (posterior) portions. It runs vertically from side to side, perpendicular to the sagittal plane. Frontal sections reveal internal structures from the front and back perspectives. 3. Transverse (Horizontal) Plane: The transverse plane divides the body into upper (superior) and lower (inferior) portions. It runs horizontally, perpendicular to both the sagittal and frontal planes. Transverse sections provide views from the top and bottom, showcasing internal structures at different levels. 1.2.2. Clinical Importance of Anatomical Planes 1. Diagnostic Imaging: Radiologists use these planes as references when interpreting imaging studies like MRI, CT scans, and X-rays. Knowledge of these planes helps in accurately diagnosing conditions. 2. Surgical Procedures: Surgeons plan incisions and approaches based on these planes, ensuring precise and effective surgeries. 3. Communication: Healthcare professionals use these terms to communicate specific locations of structures or abnormalities within the body accurately. Understanding these planes is fundamental in various medical fields. They provide a standardised way to describe the body's structures and facilitate clear communication among healthcare providers, ultimately contributing to accurate diagnoses and effective treatments. Page 12 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.3. Anatomical Relationships This refers to the spatial arrangement and connections between different structures within the human body. These relationships are crucial for understanding the functioning of organs, tissues, and systems. Here are some fundamental anatomical relationships: 1. Anterior and Posterior: Anterior refers to the front of the body, while posterior refers to the back. For instance, the chest is anterior to the spine. 2. Superior and Inferior: Superior means above or closer to the head, whereas inferior means below or closer to the feet. The head is superior to the neck. 3. Proximal and Distal: Proximal refers to a point closer to the body's centre, usually the trunk, while distal refers to a point farther away. For example, the shoulder is proximal to the hand. 4. Medial and Lateral: Medial means closer to the midline of the body, whereas lateral means farther away from the midline. The nose is medial to the eyes. 5. Superficial and Deep: Superficial refers to a structure closer to the surface of the body, while deep refers to a structure farther beneath the surface. The skin is superficial to the muscles. 6. Ventral and Dorsal: Ventral refers to the front or belly side of the body, and dorsal refers to the backside. In humans, ventral and anterior are often used interchangeably, as are dorsal and posterior. 7. Cranial and Caudal: These terms are often used in reference to animals. Cranial means towards the head, and caudal means towards the tail. Page 13 of 86  Anatomy of the Upper and Lower Limb -ANA 201 8. Ipsilateral and Contralateral: Ipsilateral refers to structures on the same side of the body, while contralateral refers to structures on opposite sides. For example, the right arm and right leg are ipsilateral. Understanding these relationships is vital in various fields such as medicine, biology, and anatomy, as they provide a standardised way to describe the location of structures within the body. 1.4. Anatomical Positions Anatomical position is the standard way of viewing the body. It refers to the specific body orientation used when describing an individual’s anatomy. 1.4.1. Anatomic Position The standard anatomical position is characterised by: i. The person stands upright. ii. The feet are parallel and flat on the ground. iii. The arms hang by the sides of the body. iv. The palms of the hands face forward. v. The head is level and facing forward. vi. The eyes are also looking straight ahead. vii. The fingers are extended and pointed down towards the ground. The anatomical position serves as a universal reference point for describing the positions and relationships of various body parts. It provides a consistent framework for anatomical descriptions, ensuring clear communication among healthcare professionals and scientists when discussing the human body. Page 14 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.4.2. Prone Position In the prone position, a person lies flat on their stomach with their face down and their back up. The arms can be positioned alongside the body, stretched out in front, or bent at the elbows with the hands under the head or chin. The legs are usually straight, but they can also be slightly bent at the knees. The toes are pointed, and the tops of the feet are flat against the surface. The prone position is often used in medical settings for certain procedures and surgeries, particularly those involving the back or spine. It provides healthcare professionals with access to the posterior parts of the body for examinations, treatments, or interventions. This position is different from the anatomical position, where the person is standing upright with arms by the sides and palms facing forward. 1.4.3. Supine Position In the supine position, a person lies flat on their back with their face up and their front side facing upward. The arms can be positioned alongside the body, resting on the surface, or bent at the elbows with the hands near the head or chest. The legs are straight, and the feet are flat on the surface. The supine position is commonly used in medical examinations, procedures, and surgeries. It allows healthcare professionals easy access to the front of the body, making it especially useful for interventions involving the chest, abdomen, and limbs. In contrast to the prone position (where the person lies face down), the supine position provides a clear view of the face and facilitates breathing and airway management during medical procedures. Page 15 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.5. Anatomical Regions The human body can be divided into two main anatomical regions: the axial region and the appendicular region. 1.5.1 Axial Anatomical Regions The axial region comprises the central axis of the human body and includes the following regions: 1. Head: Contains the skull, face, and sensory organs such as eyes, ears, nose, and mouth. Protects the brain and facilitates various sensory functions. 2. Neck: Connects the head to the trunk and houses important structures like the throat (pharynx), voice box (larynx), and the cervical portion of the spine. Supports the head and allows for movement and flexibility. 3. Trunk: i. Thoracic Region: upper part of the trunk containing the ribcage, heart, lungs, and major blood vessels. Protects vital organs and facilitates respiration and circulation. ii. Abdominal Region: The lower part of the trunk houses organs like the stomach, liver, intestines, and kidneys. Important for digestion and nutrient absorption. iii. Pelvic Region: Below the abdominal region, it contains reproductive organs, the urinary bladder, and part of the large intestine. Provides support for the body when sitting. Page 16 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.5.2 Appendicular Anatomical Regions: The appendicular region comprises the limbs and girdles (shoulder and hip) that attach the limbs to the axial skeleton. It includes the following regions: 1. Upper Limbs i. Shoulder: Connects the upper arm to the axial skeleton and allows a wide range of arm movements. ii. Arm: extends from the shoulder to the elbow and includes the humerus bone. iii. Forearm: extends from the elbow to the wrist and includes the radius and ulna bones. iv. Hand: includes the palm, fingers, and thumb. 2. Lower Limbs: i. Hip: Connects the legs to the axial skeleton and supports body weight. ii. Thigh: extends from the hip to the knee and includes the femur bone. iii. Leg: extends from the knee to the ankle and includes the tibia and fibula bones. iv. Foot: includes the sole, toes, and heel. Understanding the axial and appendicular regions is fundamental in anatomical studies and medical practice. These divisions provide a systematic way to study and describe the human body's structure, aiding healthcare professionals in diagnosing and treating various conditions. Page 17 of 86  Anatomy of the Upper and Lower Limb -ANA 201 1.6. Anatomical directions Anatomical directions are standardised terms used to describe the relative positions and movements of body parts in relation to one another. These terms are crucial in anatomy, nursing, and medicine as they provide a clear and consistent way to communicate about the human body. Here are some key anatomical directions: 1. Anterior (or Ventral): Towards the front of the body. For example, the sternum (breastbone) is located anteriorly. 2. Posterior (or Dorsal): Towards the back of the body. The shoulder blades are located posteriorly. 3. Superior: Towards the head or upper part of a structure or the body. For instance, the head is superior to the neck. 4. Inferior: Towards the feet or lower part of a structure or the body. The feet are inferior to the knees. 5. Proximal: Closer to the point of attachment or the trunk of the body. The elbow is proximal to the wrist. 6. Distal: Farther away from the point of attachment or the trunk of the body. The fingers are distal to the hand. 7. Medial: Towards the midline of the body, dividing it into left and right halves. The nose is medial to the eyes. 8. Lateral: Away from the midline of the body, towards the sides. The ears are located laterally on the head. Page 18 of 86  Anatomy of the Upper and Lower Limb -ANA 201 9. Superficial: Toward or at the body surface. The skin is the body's most superficial organ. 10. Deep: Away from the body surface; more internal. The heart is deep within the chest cavity. 11. Ipsilateral: On the same side of the body. The right hand and right foot are ipsilateral. 12. Contralateral: On the opposite sides of the body. The right hand and left foot are contralateral. Understanding these anatomical directions is vital for accurate communication among healthcare professionals, scientists, and anatomists. They provide a standardised way to describe the location, movements, and relationships of various body structures. 1.7. Anatomical Terms of Laterality Anatomical terms of laterality are used to describe the specific location of structures or body parts in relation to the body's midline. These terms are crucial in medical contexts for accurately describing the side of the body where certain structures are located. Here are the key terms related to laterality: 1. Ipsilateral: Refers to structures or body parts that are on the same side of the body. For example, the right hand and right foot are ipsilateral. 2. Contralateral: Refers to structures or body parts that are on opposite sides of the body. For example, the right arm and left leg are contralateral. Page 19 of 86  Anatomy of the Upper and Lower Limb -ANA 201 3. Unilateral: Refers to structures or body parts found only on one side of the body. For instance, the appendix is a unilateral structure. 4. Bilateral: Refers to structures or body parts that are present on both sides of the body. For example, humans have bilateral symmetry in their hands and feet. 5. Lateral: Denotes structures or body parts that are situated away from the midline of the body. The ears are located laterally on the head. 6. Medial: Indicates structures or body parts that are closer to the midline of the body. The nose is located medially on the face. Understanding these terms is vital in medical diagnoses, surgical procedures, and anatomical descriptions, as they provide a precise way to communicate about the location and relationships of body structures. 1.8. Anatomical terms of movement Anatomical terms of movement are used to describe the actions and motions of various body parts relative to the anatomical position. These terms help provide a standardised and precise way to communicate about human body movements. Here are some important anatomical terms for movement: i. Flexion: Decreasing the angle between two body parts. For example, bending the elbow is flexion of the forearm on the upper arm. ii. Extension: Increasing the angle between two body parts or straightening a flexed joint. For example, straightening the elbow from a bent position is an extension. Page 20 of 86  Anatomy of the Upper and Lower Limb -ANA 201 iii. Abduction: Moving a body part away from the midline of the body or another reference point. For instance, raising the arm sideways away from the body is abduction. iv. Adduction: Moving a body part towards the midline of the body or another reference point. Bringing the arm back to the body's side from a raised position is adduction. v. Rotation: Turning or pivoting a body part around its axis. For example, turning the head from side to side involves rotation of the neck. vi. Internal Rotation: Rotating a limb or joint inward towards the midline of the body. For example, rotating the shoulder inward is internal rotation. vii. External Rotation: Rotating a limb or joint outward away from the midline of the body. For example, rotating the shoulder outward is an external rotation. viii. Dorsiflexion: Flexion at the ankle joint, pointing the toes upward toward the shin. ix. Plantar flexion: Extension at the ankle joint, pointing the toes downward away from the shin, as in standing on tiptoe. x. Pronation: Rotating the forearm so that the palm faces downward. For example, when you turn your hand to place it on a table with the palm down, it's pronation. xi. Supination: Rotating the forearm so that the palm faces upward. For example, turning your hand to hold a bowl of soup with the palm up is supination. Page 21 of 86  Anatomy of the Upper and Lower Limb -ANA 201 xii. Eversion: Turning the sole of the foot outward away from the midline of the body. xiii. Inversion: Turning the sole of the foot inward towards the midline of the body. These terms are essential for healthcare professionals, athletes, and researchers, as they enable precise communication about various body movements and positions during activities, exercises, and medical assessments. 1.9. Anatomical cavities Anatomical cavities are hollow spaces within the human body that contain and protect internal organs. These cavities provide a framework for organising the body's internal structures and are important for medical professionals to understand when diagnosing and treating health conditions. The major anatomical cavities in the human body include: 1. Cranial Cavity: The cranial cavity is located within the skull and encases the brain. It provides protection and support for the brain, shielding it from external trauma. 2. Spinal (Vertebral) Canal: This long, bony canal is formed by the vertebral column (spine) and houses the spinal cord. The spinal canal protects the spinal cord, a vital component of the central nervous system. 3. Thoracic Cavity: The thoracic cavity is surrounded by the ribcage and contains the heart, lungs, oesophagus, and major blood vessels. It is divided into two smaller cavities: Page 22 of 86  Anatomy of the Upper and Lower Limb -ANA 201 4. Pericardial Cavity: Surrounds the heart and contains the pericardial fluid, which lubricates and protects the heart. 5. Pleural Cavities: Each pleural cavity surrounds a lung and contains pleural fluid, allowing the lungs to expand and contract during breathing. 6. Abdominal Cavity: The abdominal cavity is located below the diaphragm and above the pelvic cavity. It houses organs such as the liver, stomach, intestines, and kidneys. The abdominal cavity is crucial for digestion and nutrient absorption. 7. Pelvic Cavity: The pelvic cavity is located below the abdominal cavity and is bound by the pelvic bones. It contains reproductive organs (such as the uterus and ovaries in females and the prostate gland in males) and parts of the large intestine and urinary bladder. Understanding these anatomical cavities is essential for healthcare professionals to assess and diagnose medical conditions accurately. Medical imaging techniques, such as X-rays, CT scans, and MRI scans, are often used to visualise these cavities and the organs within them, aiding in the diagnosis and treatment of various diseases and injuries. Page 23 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Summary 1. Anatomical planes are used to visualise body structures. 2. Anatomical relationships describe how body parts interact within these planes. 3. The standard anatomical position is an upright posture with arms at the sides and palms forward. 4. Anatomical regions divide the body into specific areas for clear communication. 5. Anatomical directions (superior, inferior, anterior, and posterior) describe the location of body parts relative to each other. 6. Anatomical terms of laterality distinguish the left and right sides of the body. 7. Anatomical terms of movement (flexion, extension, abduction, and adduction) describe muscle actions. 8. Knowledge of anatomical cavities (cranial, thoracic, and abdominal) helps understand internal organ organisation. 9. These concepts are crucial for healthcare professionals, researchers, and educators for effective communication and understanding of the human body. Page 24 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Conclusion Understanding anatomical planes, anatomical relationships, anatomical position, anatomical regions, anatomical directions, anatomical planes, anatomical terms of laterality, anatomical terms of movement, and anatomical cavities is essential to describing and locating the site of diagnosis, procedures, and treatment in nursing and medical practice. Self-Assessment Questions (SAQ) SAQ1.1. (Test L.O 1.1) Why is anatomy important for medical practice, research, and education? SAQ1.2.(Test L.O 1.2) Why are anatomical planes important in the fields of anatomy and medicine? SAQ1.3. (Test L.O 1.8) Explain the difference between flexion and extension and provide examples of activities that involve these movements. Self-Assessment Answers (SAA) Answer 1.1: For doctors, nurses, and other healthcare professionals, a profound knowledge of anatomy is indispensable. For medical practices, understanding the body's structure helps in diagnosing diseases, interpreting symptoms, and performing surgeries. In research, anatomical knowledge is fundamental, as understanding the body's structures enables us to learn about diseases, develop new treatments, and improve existing medical procedures. Anatomy is a core subject in medical education. Medical students and aspiring healthcare Page 25 of 86  Anatomy of the Upper and Lower Limb -ANA 201 professionals learn about the human body's intricacies to provide effective patient care. Answer 1.2: Understanding anatomical planes is crucial for describing the body's structure and the relationships between its parts, as these planes are crucial for precise communication among healthcare professionals. Answer1.3: Flexion is decreasing the angle between two body parts; for example, bending the elbow is flexion of the forearm on the upper arm, while extension involves increasing the angle between two body parts or straightening a flexed joint; for example, straightening the elbow from a bent position is an extension. Tutor-Marked Assignment 1. How do anatomical cavities assist healthcare professionals in diagnosing and treating health conditions, and what medical imaging techniques are used to visualise them? 2. Explain the significance of understanding the anatomical regions in diagnosing and treating medical conditions. 3. What is the standard anatomical position, and why is it important in anatomy and healthcare? 4. What are the main branches of anatomy, and how do they differ in their focus? Page 26 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Study Session 2: General Organisation of Body Systems Introduction In the previous study session, we discussed anatomical terms used in the description of structures, organs, systems, positions, cavities, planes, relationships, and comparisons. In this unit, we shall discuss the different systems that constitute the human body. Learning Outcomes for Study Session 2 When you have studied this session, you should be able to discuss the following body systems: 2.1. Integumentary system 2.2. Skeletal system 2.3. Muscular system 2.4. Nervous system 2.5. Endocrine system 2.6. Cardiovascular system 2.7. Lymphatic system 2.8. Immune system 2.9. Respiratory system 2.10. Digestive system 2.11. Urinary system 2.12. Reproductive system Page 27 of 86  Anatomy of the Upper and Lower Limb -ANA 201 2.1 Integumentary System The integumentary system is the largest organ system in the human body, encompassing the skin and its associated structures such as hair, nails, and glands. The general functions of the system include protection (physical barrier, protecting internal organs and tissues from physical injury and pathogens), sensation, thermoregulation, excretion, immune defence, synthesis of Vitamin D, blood reservoir, and sensory reception. The skin is one of the components of the system consisting of three layers, namely, epidermis, dermis and subcutaneous layer (see Figure 1.1). Figure 2.1: Anatomy of the Skin 2.2 Skeletal System The skeletal system is the framework of bones and cartilage that provides support, protection, and movement to the human body. The human skeleton has two main subdivisions, the axial, which consists of the vertebral column and much of the skull, and the appendicular, to which the pelvic girdles and the bones and cartilages of the limbs belong (see Figure 1.2). An overview he the Page 28 of 86  Anatomy of the Upper and Lower Limb -ANA 201 functions of the skeletal system include Support, Protection of vital organs, Movement, Mineral Storage, Blood Cell Formation, Energy Storage, and Endocrine Regulation. Figure 2.2 The Human Skeletal System 2.3 Muscular System The muscular system is an organ system consisting of skeletal, smooth, and cardiac muscle (see Figure 1.3). It facilitates movement of the body, maintains posture, heat production, respiration, and digestion, and circulates blood throughout the body. Muscular activities are controlled through the nervous system although some muscles can be completely autonomous. Page 29 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 2.3 Muscular System 2.4 Nervous System The nervous system is a complex network of nerves and cells that transmit signals between different parts of the body. It is the body's control centre, regulating and coordinating various functions to maintain balance and respond to the environment. The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS) (see Figure 1.4). Page 30 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 2.4 Nervous System The CNS consists of the brain and the spinal cord. It serves as the main processing centre for the entire nervous system. Functions of the CNS include Integration of sensory information received from the peripheral nervous system and formulation of appropriate responses; Control of voluntary movements, thoughts, and emotions. The CNS is also responsible for higher cognitive functions such as learning, memory, and decision-making. It is the centre for language, creativity, and problem-solving. The PNS consists of all the nerves outside the CNS. It further divides into the somatic nervous system (SNS) and the autonomic nervous system (ANS). The SNS controls voluntary movements by carrying sensory information to the CNS and motor commands from the CNS to the muscles. It enables conscious movements and responses to external stimuli. The ANS regulates involuntary bodily functions, such as heartbeat, digestion, and respiratory rate. It operates automatically, without conscious effort. Page 31 of 86  Anatomy of the Upper and Lower Limb -ANA 201 The ANS further divides into the sympathetic and parasympathetic systems, which have contrasting effects on various bodily functions. The basic unit of the nervous system is the neuron, a specialized cell that can receive, process, and transmit electrical and chemical signals. Neurons communicate through neurotransmitters, chemical messengers that transmit signals across synapses, the tiny gaps between neurons. The nervous system receives, integrates, and processes sensory Input, motor output, learning and memory. 2.5 Endocrine System The endocrine system is a complex network of glands and organs in the body that produces and secretes hormones (see Figure 1.5). Figure 2.5 Endocrine system These hormones are chemical messengers that regulate various physiological functions, including growth and development, metabolism, mood, and reproductive processes. Unlike the nervous system, which uses electrical Page 32 of 86  Anatomy of the Upper and Lower Limb -ANA 201 signals for communication, the endocrine system uses hormones to relay information between cells and organs. The system includes several major glands, such as the pituitary gland, thyroid gland, adrenal glands, pancreas, and gonads (ovaries in females and testes in males). These glands secrete hormones directly into the bloodstream. Hormones are chemical substances produced by endocrine glands. They travel through the bloodstream to target organs and tissues, where they influence various functions. Different hormones have specific roles, and their balance is crucial for maintaining overall health. An overview of the functions of the endocrine system includes regulation of Metabolism, Growth and Development, Reproductive processes, Response to Stress, Maintenance of Electrolyte Balance, Mood and activities of the Immune System. 2.6 Cardiovascular System The cardiovascular system, also known as the circulatory system, is a network of organs and blood vessels that transports blood, oxygen, nutrients, hormones, and waste products throughout the body (see Figure 1.6). Page 33 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 2.6 Cardiovascular System It plays a vital role in maintaining homeostasis, supporting the body's various functions, and ensuring the delivery of essential substances to cells and tissues. The heart is a muscular organ that functions as a pump. It contracts and relaxes rhythmically to propel blood throughout the body. The heart is divided into four chambers, namely two atria (upper chambers) and two ventricles (lower chambers). The cardiovascular system includes a vast network of blood vessels, including arteries, veins, and capillaries. Arteries carry oxygenated blood away from the heart to the body's tissues, while veins carry deoxygenated blood back to the heart. Capillaries are tiny blood vessels where oxygen and nutrients are exchanged with body cells. Blood is the transport medium of the cardiovascular system. It consists of red blood cells (which carry oxygen), white blood cells (which are part of the immune system), platelets (which help in blood clotting), and plasma (a liquid component that carries cells, nutrients, hormones, and Page 34 of 86  Anatomy of the Upper and Lower Limb -ANA 201 waste products). An overview of the function of the cardiovascular system includes the transportation of oxygen in the body, delivery of hormones, regulation of body temperature, blood pressure, clotting, excretion and immune response. 2.7 Lymphatic System The lymphatic system is a vital part of the circulatory system and the body's immune defence mechanism. It is a complex network of tissues, organs, vessels, and nodes that work together to transport a colourless fluid called lymph throughout the body (see Figure 1.7). Figure 2.7 Lymphatic system The lymphatic system plays several crucial roles in maintaining health and protecting the body from infections and diseases. Key components include the lymph, lymphatic vessels, lymph nodes, and lymphatic organs. Page 35 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Lymph: Lymph is a clear fluid that contains white blood cells (lymphocytes) and waste products. It circulates through the lymphatic vessels, carrying immune cells and draining excess fluids from tissues. Lymphatic Vessels: Lymphatic vessels are a network of thin tubes that carry lymph throughout the body. These vessels parallel the veins and arteries and help in maintaining fluid balance by collecting excess fluids from tissues and returning them to the bloodstream. Lymph Nodes: Lymph nodes are small, bean-shaped structures located along the lymphatic vessels. They act as filters, trapping and destroying harmful substances (such as bacteria and viruses) and cancer cells. Lymph nodes also contain immune cells that help fight infections. Lymphatic Organs: The lymphatic system includes various organs, such as the spleen, thymus, and tonsils. These organs house immune cells and contribute to the body's defence against pathogens. 2.8 Immune System The immune system is a complex network of cells, tissues, and organs that work together to defend the body against harmful invaders, such as bacteria, viruses, fungi, and other foreign substances (see Figure 1.8). Its primary purpose is to recognize and eliminate these pathogens, protecting the body from infections and diseases. The immune system also plays a role in identifying and destroying abnormal or damaged cells, including cancer cells. The main components of Page 36 of 86  Anatomy of the Upper and Lower Limb -ANA 201 immune system include the white Blood cells, Lymphocytes, Antibodies, Bone marrow, Lymphatic system, Spleen, and Thymus. Figure 2.8 Immune system When the immune system detects a foreign invader, it mounts a response. This response can involve the production of antibodies, activation of white blood cells, and other immune processes designed to neutralize or eliminate the threat. 2.9 Respiratory System The respiratory system is a complex biological system that facilitates the exchange of gases with their environment. This involves the intake of oxygen and the removal of carbon dioxide, crucial processes for sustaining life. The main component of the respiratory system includes the Nose and Nasal Cavities, Pharynx, Larynx, Trachea, Bronchi, Lungs and Diaphragm (see Figure 1.9). Page 37 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 2.9 Respiratory system An overview of the function of the respiratory system includes gaseous exchange, oxygen and carbon dioxide transport, speech production, defence mechanism, and pH Regulation. Gas Exchange: The primary function of the respiratory system is the exchange of gases between the body and the environment. Oxygen is taken in from the air and transported to cells throughout the body via the bloodstream. At the same time, carbon dioxide, a waste product of cellular metabolism, is removed from the body by exhalation. Oxygen Transport: Oxygen is essential for cellular respiration, where cells use it to produce energy through a process called aerobic metabolism. Oxygen is carried by red blood cells, bound to a molecule called haemoglobin, to tissues and organs where it is needed. pH Regulation: The respiratory system helps regulate the body's pH (acidity or alkalinity) by controlling the levels of carbon dioxide. Carbon dioxide can Page 38 of 86  Anatomy of the Upper and Lower Limb -ANA 201 combine with water to form carbonic acid, which influences the body's acid-base balance. Speech Production: The respiratory system, particularly the larynx, is crucial for speech production. The movement of air over the vocal cords produces sounds that can be shaped into speech. Defence Mechanism: The respiratory system contains mucus-producing cells and tiny hair-like structures called cilia, which trap and remove dust, bacteria, and other particles that enter the respiratory tract, preventing them from reaching the lungs. 2.10 Digestive System The digestive system is a complex and intricate network of organs, glands (see Figure 1.10), and processes responsible for breaking down food into nutrients, which the body can then absorb and utilize for energy, growth, and repair. This system also plays a crucial role in eliminating waste products from the body. Page 39 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 2.10 Digestive System Mouth: Digestion begins in the mouth, where food is broken down into smaller pieces by chewing and mixed with saliva. Saliva contains enzymes that start the chemical digestion process. Oesophagus: The oesophagus is a muscular tube that transports chewed food from the mouth to the stomach through a series of coordinated muscle contractions called peristalsis. Stomach: In the stomach, food is mixed with gastric juices containing acids and enzymes. This acidic environment helps break down proteins and other complex molecules into simpler forms. Page 40 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Small Intestine: Most of the digestion and nutrient absorption occurs in the small intestine. Enzymes from the pancreas and bile from the liver further break down food, allowing nutrients to be absorbed through the intestinal walls into the bloodstream. Pancreas: The pancreas produces digestive enzymes that help break down carbohydrates, proteins, and fats in the small intestine. It also regulates blood sugar levels by producing insulin and glucagon. Liver: The liver produces bile, a substance that emulsifies fats, breaking them down into smaller droplets. Bile is stored in the gallbladder and released into the small intestine when needed. Large Intestine (Colon): The remaining undigested food, water, and electrolytes pass into the large intestine, where water and electrolytes are absorbed, forming faeces. The colon also contains beneficial bacteria that help break down some remaining nutrients and produce certain vitamins. Rectum and Anus: Faeces are stored in the rectum until they are eliminated from the body through the anus during the process of defecation. 2.11 Urinary System The urinary system, also known as the renal system, is responsible for eliminating waste products and excess substances from the bloodstream in the form of urine. Key components include the kidneys, ureters, bladder, and urethra (see Figure 1.11). Page 41 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Kidneys: The kidneys are bean-shaped organs located near the middle of the back, just below the rib cage. They filter waste products and excess substances, such as water, salts, and urea, from the blood to form urine. Ureters: These are thin tubes that carry urine from the kidneys to the urinary bladder. There is one ureter connected to each kidney. Figure 2.11 Urinary System Urinary Bladder: The urinary bladder is a muscular sac that stores urine until it is ready to be expelled from the body. It can expand and contract to accommodate varying amounts of urine. Urethra: The urethra is a tube through which urine is expelled from the body. In males, it also serves as the passage for semen during ejaculation. Key functions of the urinary system include removal of waste products, regulation of blood pressure, red blood cell production, water and electrolyte regulation, and metabolism of vitamin D. Page 42 of 86  Anatomy of the Upper and Lower Limb -ANA 201 2.12 Reproductive System The reproductive system is a complex network of organs and tissues that work together to enable sexual reproduction, allowing the human species to reproduce and sustain itself. Key components of the male reproductive system include the Testes, Epididymis, Vas Deferens, Seminal Vesicle, Urethra and Penis (see Figure 1.12). Key components of the female reproductive system include the Ovaries, Fallopian Tubes, Uterus, Cervix, Vagina, Labia and Clitoris (see Figure 1.12). Figure 2.12 Male and Female Reproductive System 2.12.1 Male Reproductive System Testes: The testes, or testicles, are male reproductive glands that produce sperm cells and testosterone, the primary male sex hormone. Epididymis: Sperm produced in the testes mature and are stored in the epididymis, a coiled tube located on the back of each testicle. Page 43 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Vas Deferens: The vas deferens are muscular tubes that carry mature sperm from the epididymis to the urethra during ejaculation. Seminal Vesicles, Prostate Gland, and Bulbourethral Glands: These glands produce seminal fluids, which nourish and support sperm, forming semen. Urethra: The urethra is a tube that carries both urine from the bladder and semen from the reproductive system out of the body. Penis: The penis is the male external sexual organ. It becomes erect during sexual arousal and is used to introduce sperm into the female reproductive system during sexual intercourse. 2.12.2 Female Reproductive System Ovaries: The ovaries are the female reproductive glands. They produce eggs (ova) and hormones, including oestrogen and progesterone. Fallopian Tubes: Also known as oviducts, these tubes connect the ovaries to the uterus. Fertilization occurs in the fallopian tubes if sperm meets a mature egg. Uterus: The uterus, or womb, is a muscular organ where a fertilized egg implants and develops into a foetus during pregnancy. Cervix: The cervix is the lower part of the uterus that connects to the vagina. It acts as a passage for sperm to enter the uterus and protects the uterus from infections. Page 44 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Vagina: The vagina is a muscular tube that connects the cervix to the external genitals. It serves as the birth canal during childbirth and also receives the penis during sexual intercourse. Labia and Clitoris: The labia are folds of skin that protect the vaginal and urethral openings, while the clitoris is a highly sensitive organ that plays a role in sexual arousal. Summary 1. The Integumentary System encompasses the skin and its associated structures, serving multiple functions, including protection, thermoregulation, and sensory reception. 2. The Skeletal System provides support, and protection, and enables movement through its axial and appendicular subdivisions. 3. The Muscular System, consisting of different muscle types, facilitates bodily movement, heat production, and various physiological processes. 4. The Nervous System, divided into the central and peripheral nervous systems, controls bodily functions, including voluntary movements, emotions, and cognitive processes. 5. The Endocrine System produces and secretes hormones, regulating growth, metabolism, mood, and immune responses. 6. The Cardiovascular System circulates blood throughout the body, maintaining homeostasis and supporting essential functions, such as oxygen transportation and immune responses. Page 45 of 86  Anatomy of the Upper and Lower Limb -ANA 201 7. The Lymphatic System transports lymph and plays a critical role in immune defence, involving lymph, lymphatic vessels, lymph nodes, and lymphatic organs. Conclusion The human body is a marvel of complexity, composed of various interrelated systems that work harmoniously to sustain life and maintain homeostasis. The integumentary system, with its protective functions, and the skeletal system, providing structural support, form the body's physical framework. The muscular system enables movement and plays a vital role in various physiological processes. The nervous system, with its central and peripheral components, governs control and coordination. The endocrine system regulates numerous bodily functions through hormonal signalling. The cardiovascular system ensures the distribution of oxygen and nutrients throughout the body, while the lymphatic system and the immune system collaborate to protect against invaders. The respiratory system facilitates gas exchange and regulates pH. The digestive system processes and extracts nutrients from food, while the urinary system eliminates waste products. Lastly, the reproductive system ensures the continuation of the human species through sexual reproduction. Page 46 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Self-Assessment Questions (SAQs) SAQ 3.1 What are the main functions of the integumentary system, and what are the components of the skin? SAQ 3.2 Name the two main subdivisions of the skeletal system and briefly describe their functions. SAQ 3.3 What are the primary functions of the nervous system, and how is it divided anatomically? Self-Assessment Answers(SAAs) Answer 1: The integumentary system serves functions including protection, sensation, thermoregulation, excretion, immune defence, synthesis of Vitamin D, blood reservoir, and sensory reception. The skin consists of three layers: epidermis, dermis, and subcutaneous layer. Answer 2: The skeletal system has two main subdivisions: the axial, which includes the vertebral column and much of the skull, and the appendicular, which includes the pelvic girdles and bones of the limbs. The skeletal system provides support, protection of vital organs, movement, mineral storage, blood cell formation, energy storage, and endocrine regulation. Answer 3: The nervous system regulates and coordinates body functions, maintaining balance and responding to the environment. It is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord, while the PNS further divides into the Page 47 of 86  Anatomy of the Upper and Lower Limb -ANA 201 somatic nervous system (SNS) and the autonomic nervous system (ANS), regulating voluntary and involuntary functions, respectively. Tutor Marked Assignment 1. What are the major functions of the endocrine system, and how does it communicate compared to the nervous system? 2. Explain the primary functions of the respiratory system and describe its role in maintaining the body's pH. Page 48 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Study Session 3: Appendicular Skeleton Introduction In the previous unit, we discussed general body systems. We explored the composition and function of the systems. In this session, we shall discuss the appendicular skeleton. Learning Outcomes for Study Session 3 At the end of this session, you should be able to: 3.1 Discuss appendicular skeleton 3.2 Understand bones of the Upper Limbs 3.3 Discuss bones of the Lower Limbs 3.1 Appendicular skeleton The appendicular skeleton is one of two major bones categories in the human body. It consists of the upper and lower extremities, with shoulder girdle and pelvis inclusive. The shoulder girdle and pelvis connect the appendicular skeleton to the axial skeleton. A total of 126 bones form the appendicular skeleton. The bones that contribute to the appendicular skeleton include the bones of the hands, feet, upper extremity, lower extremity, shoulder girdle, and pelvic bones. These bones are primarily responsible for movements. Page 49 of 86  Anatomy of the Upper and Lower Limb -ANA 201 3.1 Appendicular skeleton These bones articulate with each other and with the multitude of tendons, tendons and ligaments to form the appendicular skeleton. There are also protuberances and bony prominences that serve as muscle attachment sites on the surfaces of these bones. Comparatively, the appendicular skeleton is designed for a greater range of motion than the axial skeleton. 3.2 Bones of the Upper Limbs The Upper Limbs consist of the shoulder girdle (scapula and clavicle), humerus, two forearm bones (radius and ulna), eight carpal bones 14 phalanges (proximal, intermediate, and distal), and five metacarpals. 3.2.1 Pectoral Girdle: The pectoral girdle, also known as the shoulder girdle, is the set of bones in the human body that connects the upper limbs (arms) to the Page 50 of 86  Anatomy of the Upper and Lower Limb -ANA 201 axial skeleton. It is composed of two main bones: the clavicle (collarbone) and the scapula (shoulder blade). These bones form the foundation for the attachment of the upper limbs and allow for a wide range of movements in the arms, such as lifting, reaching, and rotating. Figure 3.2 Clavicle Figure 3.3 Scapular Page 51 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Clavicle: The clavicle is an S-shaped bone, which is slightly curved. It has a lateral curve (convex outward) and medial curve (concave inward) (see Figure 3.2). It has two ends, namely, lateral end (also known as the acromial end) and the medial end (sternal end). The acromial end articulates with the acromion process of the scapula, forming the acromioclavicular joint. The sternal end attaches to the sternum, forming the sternoclavicular joint. It provides support for the shoulder, helps in the transmission of forces from the upper limb to the axial skeleton, and protects underlying nerves and blood vessels. Muscles, such as the deltoid and trapezius, attach to the acromial end and help in shoulder movements. Ligaments, such as the coracoclavicular ligament, provide stability to the acromioclavicular joint. Scapular: The scapula, also known as the shoulder blade, is a large, roughly flat triangular bone located in the upper back (see Figure 3.3). It is a crucial part of the pectoral girdle, connecting the upper arm bone (humerus) with the collarbone (clavicle) and the muscles of the upper back. The scapula has prominent bony processes, namely, the acromion, spine, and coracoid process, each serving as attachment points for muscles and ligaments. The scapula forms important joints with the clavicle and the humerus. The acromion process articulates with the clavicle to form the acromioclavicular joint, and the head of the humerus fits into the shallow glenoid cavity of the scapula, forming the glenohumeral joint, which is the main joint of the shoulder. Muscles like the deltoid, trapezius, and rotator cuff muscles (supraspinatus, infraspinatus, teres Page 52 of 86  Anatomy of the Upper and Lower Limb -ANA 201 minor, and subscapularis) have their origins or insertions on the scapula, enabling actions such as lifting, rotating, and retracting the shoulder. 3.2.2 Humerus: The humerus is a long bone located in the upper arm, between the shoulder and the elbow (see Figure 3.4). Figure 3.4 Humerus It plays a key role in various movements of the arm. Key features of the humerus include: Head: The rounded, ball-like structure at the proximal end of the humerus fits into the glenoid cavity of the scapula, forming the shoulder joint. Greater Tubercle: This is a bony prominence on the lateral side of the humerus, just below the head. It serves as an attachment site for muscles and tendons. Lesser Tubercle: Located on the anterior surface of the humerus, this smaller projection also provides attachment points for muscles and tendons. Deltoid Tuberosity: This rough, V-shaped area in the middle of the lateral surface of the humerus is where the deltoid muscle attaches. Page 53 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Shaft: The long, cylindrical part of the humerus between the tubercles and the condyles. Surgical Neck: This is a constriction in the bone just below the tubercles. It is a common site for fractures. Medial and Lateral Epicondyles: These are bony projections at the distal end of the humerus and serve as attachment points for various forearm muscles. Trochlea: The smooth, grooved articular process located on the medial side of the humerus. It articulates with the ulna, forming part of the elbow joint. Capitulum: The rounded, smooth knob-like structure on the lateral side of the humerus. It articulates with the head of the radius, contributing to the elbow joint. Coronoid Fossa and Olecranon Fossa: These are indentations on the anterior and posterior aspects of the humerus's distal end, respectively. They accommodate parts of the ulna when the elbow is flexed or extended. 3.2.3 Forearm bones: The forearm is made up of two long bones, namely, the radius and the ulna (see Figure 3.5). These bones run parallel to each other and articulate with the humerus at the elbow joint, forming the skeletal structure of the forearm and facilitating various movements of the hand and arm. Radius: The radius is one of the two long bones located in the forearm, along with the ulna. It runs parallel to the ulna and is situated on the thumb side (lateral side) of the forearm. Key features of the Radius include: Page 54 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Location: The radius extends from the elbow to the wrist and runs alongside the ulna. Figure 3.5 Tibia and Fibula Head: The proximal end of the radius has a rounded structure called the head, which articulates with the capitulum of the humerus. This joint allows for the rotational movement of the forearm. Neck: Below the head, there is a narrowed portion called the neck. Shaft: The shaft of the radius is the long, slender part of the bone between the head and the distal end. It provides attachment points for muscles and ligaments. Radial Tuberosity: Located on the medial side of the radius, just below the head, this is the point where the biceps muscle attaches. Page 55 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Styloid Process: The distal end of the radius features a pointed bony prominence called the styloid process. This process provides stability to the wrist joint and serves as an attachment point for ligaments. Articulation: At the distal end, the radius forms a joint with the bones of the wrist, allowing for movements of the hand. Specifically, it articulates with the scaphoid and lunate bones of the wrist. Function: The radius plays a crucial role in the movement of the forearm and wrist. It allows for rotation of the forearm (pronation and supination) and works in conjunction with the ulna to enable various movements of the hand and arm. Ulnar: The ulna is one of the two long bones in the forearm, the other being the radius (see Figure 3.5). It is located on the medial (pinky finger) side of the forearm and runs parallel to the radius. Key features of the Ulnar include Location: The ulna extends from the elbow to the wrist and runs alongside the radius. Olecranon Process: The proximal end of the ulna features a bony prominence called the olecranon process, which forms the bony tip of the elbow. Coronoid Process: Another projection on the ulna's proximal end, located anteriorly (toward the front), just below the olecranon process. The coronoid process fits into the coronoid fossa of the humerus when the elbow is flexed. Trochlear Notch: The area between the olecranon and coronoid processes forms a U-shaped structure called the trochlear notch. It articulates with the trochlea of the humerus, forming the hinge joint of the elbow. Page 56 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Shaft: The shaft of the ulna is the long, slender part of the bone between the proximal and distal ends. It provides support and structure to the forearm. Styloid Process: The distal end of the ulna features a pointed bony prominence called the styloid process. It provides stability to the wrist joint and serves as an attachment point for ligaments. Articulation: At the distal end, the ulna forms a joint with the bones of the wrist, including the triangular fibrocartilage complex (TFCC) and the ulnar notch of the radius. This joint allows for movements of the hand and wrist. Function: The ulna, along with the radius, enables various movements of the forearm and hand. It plays a crucial role in stabilizing the elbow joint and allowing for flexion and extension of the arm. Additionally, the ulna provides support to the muscles and soft tissues of the forearm. 3.2.4 Bones of the Hand The human hand is a complex structure consisting of 27 bones. These bones can be categorized into three groups: carpals, metacarpals, and phalanges (see Figure 3.6). Page 57 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 3.6 Bones of the Right Hand Carpals (8 bones): The carpal bones are the eight small bones that form the wrist (carpus) and connect the forearm to the hand. These bones are arranged in two rows, with four bones in each row. i. Scaphoid - Located on the thumb side of the wrist, it is the largest carpal bone. ii. Lunate - It is crescent-shaped and sits next to the scaphoid. iii. Triquetrum - Positioned on the little finger side of the wrist, it is pyramidal in shape. iv. Pisiform - A small, pea-shaped bone located on the palmar surface of the ulna. v. Trapezium - Found at the base of the thumb, it is shaped like a four-sided pyramid. vi. Trapezoid - Positioned next to the trapezium, it is smaller and wedge-shaped. Page 58 of 86  Anatomy of the Upper and Lower Limb -ANA 201 vii. Capitate - The largest of the carpal bones, it is located at the centre of the wrist. viii. Hamate - Situated on the little finger side, it has a hook-like process called the hamulus. Metacarpals (5 bones): Metacarpals are the five long bones in the middle part of the hand, connecting the wrist (carpals) to the fingers (phalanges) (see Figure 3.6). They are numbered from 1 to 5, starting with the metacarpal of the thumb, which is Metacarpal 1, and progressing to the little finger, which is Metacarpal 5. These bones provide structural support to the hand and are crucial for grasping and manipulating objects. Each metacarpal bone has a base, body, and head, and they articulate with the carpals at the base and the phalanges at the head, forming the framework of the palm and fingers. i. Metacarpal 1 (also known as the thumb metacarpal) ii. Metacarpal 2 (index finger metacarpal) iii. Metacarpal 3 (middle finger metacarpal) iv. Metacarpal 4 (ring finger metacarpal) v. Metacarpal 5 (little finger metacarpal) Phalanges (14 bones): Each finger (except the thumb) has three phalanges, namely proximal phalanx, middle phalanx, and distal phalanx (see Figure 3.6). The thumb has only two phalanges: the proximal phalanx and the distal phalanx. These bones, along with various joints, ligaments, tendons, and muscles, work Page 59 of 86  Anatomy of the Upper and Lower Limb -ANA 201 together to provide the hand with its incredible range of motion and dexterity, allowing us to perform various tasks with precision and skill. 3.3 Bones of the Lower Limb The lower limb of the human body consists of several bones, provide structure, support, and mobility. Major bones of the lower limb include the Pelvic Girdle, Femur, Tibia, Patella, Fibula, Tarsal, Metatarsal, and Phalanges. 3.3.1 Pelvic Girdle: The pelvic girdle, also known as the hip girdle or simply the pelvis, is a bony structure located in the lower part of the vertebrate spine (see Figure 3.1). It is composed of several bones, including the two large hip bones (ossa coxae or innominate bones) and the sacrum, which is a triangular-shaped bone located at the base of the spine. The hip bones, each made up of three fused bones – the ilium, ischium, and pubis – form a sturdy ring-like structure that supports the weight of the upper body and provides a foundation for the spine. The sacrum fits between the two hip bones, completing the pelvic girdle and forming a protective basin for internal organs in the pelvic region, such as the reproductive and urinary organs. Page 60 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 3.7 The Pelvic Girdle The pelvic girdle is essential for various functions, including providing stability and support to the body, facilitating movement, and protecting internal organs. It also plays a crucial role in walking, standing, and maintaining balance. During childbirth, the pelvic girdle expands slightly to allow the passage of the baby through the birth canal. 3.3.2 Femur: The femur, also known as the thigh bone, is the longest and strongest bone in the human body. Page 61 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Figure 3.8 Femur It extends from the hip joint to the knee joint and is a key component of the human skeletal system. The femur is classified as a long bone and plays a crucial role in various activities, including standing, walking, running, and supporting the body's weight. The femur has several important parts, including the head, neck, shaft, and condyles: Head: The rounded, ball-shaped portion of the femur that fits into the hip socket (acetabulum) to form the hip joint. The head allows for a wide range of movements in the hip joint. Neck: The neck is a narrower section just below the head. It connects the head to the shaft of the femur. Shaft: The long, straight portion of the femur, also known as the diaphysis. It provides structural support and strength to the bone. Page 62 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Condyles: The lower end of the femur has two large, rounded projections called condyles. These condyles articulate with the tibia, the larger of the two lower leg bones, forming the knee joint. The femur is essential for the body's mobility and stability. It is a weight-bearing bone that withstands significant forces during activities like walking and running. In addition to its mechanical functions, the femur also houses the bone marrow, where blood cells are produced. 3.3.3 Tibia The tibia, also known as the shinbone, is one of the two long bones located in the lower leg, the other being the fibula. Figure 3.9 Tibia & Fibula Page 63 of 86  Anatomy of the Upper and Lower Limb -ANA 201 It is the larger and stronger of the two, playing a crucial role in supporting body weight and providing stability during various activities such as standing, walking, and running. Key features of the tibia include Proximal End: The upper part of the tibia connects to the knee joint. It has two important structures called the medial and lateral condyles, which articulate with the corresponding condyles of the femur to form the knee joint. Shaft: The shaft, or body, of the tibia, is the long, straight portion of the bone. It provides structural support and serves as an attachment point for muscles and ligaments. Medial Malleolus: The medial malleolus is a bony prominence located on the inner side of the ankle. It can be felt just above the ankle joint and provides stability to the ankle. Distal End: The lower part of the tibia forms the medial side of the ankle joint and articulates with the talus bone of the foot. It also has a bony prominence called the medial malleolus. The tibia works in conjunction with the fibula to support the leg and facilitate movements. While the tibia bears most of the body's weight, the fibula provides additional support and serves as an attachment site for muscles. Tibia fractures are common and can range from minor stress fractures to more severe breaks. Proper medical evaluation and treatment are necessary for these injuries to ensure proper healing and restore functionality to the leg. Page 64 of 86  Anatomy of the Upper and Lower Limb -ANA 201 3.3.4 Bones of the Foot: The human foot is a complex structure made up of 26 bones, which are categorized into three main groups: tarsal bones, metatarsal bones, and phalanges (see Figure 3.4). Figure 3.10 Bones of the right foot Tarsal Bones (7 bones): These tarsal bones form the complex structure of the ankle and midfoot, providing support, flexibility, and shock absorption during activities like walking and running (see Figure 3.4). They are interconnected by ligaments and work in coordination with the muscles of the foot to facilitate various movements. ▪ Calcaneus (Heel Bone): The largest tarsal bone, located at the back of the foot. It forms the foundation of the heel. ▪ Talus: Positioned above the calcaneus, it plays a crucial role in ankle joint movements. Page 65 of 86  Anatomy of the Upper and Lower Limb -ANA 201 ▪ Navicular: A boat-shaped bone located in the middle of the foot, articulating with the talus and several other bones. ▪ Cuboid: Cube-shaped bone on the outer side of the foot, connecting with the calcaneus and metatarsal bones. ▪ Three Cuneiform Bones: These are the medial cuneiform, intermediate cuneiform, and lateral cuneiform bones. They are wedge-shaped and articulate with the metatarsal bones. Metatarsal Bones (5 bones): Each metatarsal bone corresponds to a toe and is numbered from 1 to 5, starting with the bone connected to the big toe and ending with the bone connected to the little toe (see Figure 3.4). These bones form the structure of the midfoot and provide support for body weight during walking and standing. Phalanges (Toe Bones - 14 bones): The phalanges of the foot are the bones that make up the toes (see Figure 3.4). Like the fingers, each toe, except the big toe, consists of three phalanges: proximal, middle, and distal phalanges. The big toe, also known as the hallux, has two phalanges: proximal and distal phalanges. Each Toe (except the big toe) has three phalanges: ▪ Proximal Phalanx: The bone closest to the metatarsal bone. ▪ Middle Phalanx: The middle bone of the toe. ▪ Distal Phalanx: The bone at the tip of the toe. Big Toe (Hallux) has two phalanges: ▪ Proximal Phalanx: The bone connecting to the metatarsal bone. ▪ Distal Phalanx: The bone at the tip of the big toe. Page 66 of 86  Anatomy of the Upper and Lower Limb -ANA 201 These bones work together, along with ligaments, tendons, and muscles, to provide support, balance, and flexibility to the foot. The arrangement of these bones allows for a wide range of movements and activities, from walking and running to various forms of physical activity. Summary 1. The appendicular skeleton includes the upper and lower extremities, with the shoulder girdle and pelvis, and consists of 126 bones responsible for movement. 2. The appendicular skeleton is designed for greater mobility compared to the axial skeleton. 3. The upper limb bones include the shoulder girdle, humerus, forearm bones (radius and ulna), carpal bones, metacarpals, and phalanges. 4. The pectoral girdle, or shoulder girdle, comprises the clavicle and scapula, providing a foundation for upper limb attachment and movement. 5. The humerus features important parts like the head, tubercles, shaft, and condyles, facilitating arm movements. 6. The forearm bones, radius and ulna, run parallel, supporting wrist and hand movements. 7. The hand consists of carpals, metacarpals, and phalanges, enabling a wide range of hand and finger motions. Page 67 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Self-assessment Questions (SAQs) SAQ 3.1 What is the role of the pectoral girdle in the human body, and which bones make up the pectoral girdle? SAQ 3.2 Question 2: What are the key features of the femur, and what is its role in the human body? Self-assessment Answers (SAAs) Answer 1: The pectoral girdle, also known as the shoulder girdle, plays a crucial role in connecting the upper limbs (arms) to the axial skeleton. It provides the foundation for the attachment of the upper limbs and allows for a wide range of arm movements, such as lifting, reaching, and rotating. The pectoral girdle consists of two main bones: the clavicle (collarbone) and the scapula (shoulder blade). Answer 2: The femur, also known as the thigh bone, is the longest and strongest bone in the human body. It features the following key parts: Head: The rounded, ball-shaped portion of the femur that forms the hip joint. Neck: The narrower section just below the head, connecting it to the shaft. Shaft: The long, straight part of the femur that provides structural support. Condyles: The lower end of the femur has two large, rounded projections called condyles, which articulate with the tibia to form the knee joint. The femur plays a vital role in supporting the body's weight, facilitating various activities such as standing, walking, and running, and enabling a wide range of movements in the hip joint. Page 68 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Conclusion The appendicular skeleton plays a pivotal role in the human body's structure and mobility. It comprises the upper and lower extremities, connecting to the axial skeleton through the shoulder girdle and pelvis. A total of 126 bones make up the appendicular skeleton, including those in the hands, feet, upper and lower extremities, shoulder girdle, and pelvic region. These bones are essential for facilitating a wide range of movements, from basic everyday activities to complex physical functions. The upper limb, which includes the pectoral girdle, humerus, forearm bones (radius and ulna), carpals, metacarpals, and phalanges, enables various tasks, such as lifting, reaching, and rotating. On the other hand, the lower limb, consisting of the pelvic girdle, femur, tibia, patella, fibula, tarsal bones, metatarsals, and phalanges, provides support, stability, and the ability to walk and engage in activities involving the legs. The human hand, with its 27 bones in the carpals, metacarpals, and phalanges, showcases incredible dexterity and precision in carrying out tasks. Tutor Marked Assessment 1. How many bones make up the human hand, and what are the three categories into which these hand bones are classified? Page 69 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Study Session 4: Muscles of the Upper and Lower Limbs Introduction In the previous session, we discussed the bones of the upper and lower limbs. We did mention the various features of the bones including sites for insertion of muscles. In this session, we shall discuss the major muscles of the upper and lower limbs. Learning Outcomes for Study Session 4 At the end of this session, you should be able to describe: 4.1 Structure of muscles 4.2 Major Muscles of the upper limbs 4.3 Major Muscles of the lower limbs 4.1 Structure of Muscles The human muscular system is a complex network of tissues that enables movement, provides support, maintains posture, and generates heat. Muscles are made up of specialized cells called muscle fibres, and they come in various shapes and sizes. Skeletal muscles are a type of muscle tissue attached to bones in the human body, allowing for voluntary movement. These muscles work in pairs, with one muscle contracting (shortening) while the other relaxes (lengthens) to create movement around joints. Skeletal muscles are responsible for various actions, including walking, talking, and breathing. Page 70 of 86  Anatomy of the Upper and Lower Limb -ANA 201 4.1.1 Muscle Fibre: Muscle fibres, also known as muscle cells or muscle cells, are the basic units of muscle tissue in the human body. These fibres are specialized cells designed to contract, producing movement in the body. Muscle fibres are long, cylindrical cells that can vary in length from a few millimetres to several centimetres, depending on their location in the body (see Figure 4.1). Figure 4.1 Skeletal Muscle Sarcolemma: The plasma membrane of a muscle fibre, which surrounds and protects the cell. Sarcoplasm: The cytoplasm of a muscle fibre, containing the cell's organelles and myofibrils. Myofibrils: Thread-like structures within the sarcoplasm, made up of repeating units called sarcomeres. These are the contractile units of muscle cells. Sarcomeres: The functional units of a myofibril, responsible for muscle contraction. Sarcomeres contain overlapping filaments of actin and myosin proteins. Page 71 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Actin Filaments: Thin filaments composed of the protein actin. They contain binding sites for myosin heads during muscle contraction. Myosin Filaments: Thick filaments composed of the protein myosin. Myosin heads attach to actin filaments and generate the force required for muscle contraction. Z-Lines (Z-Discs): Structures that define the boundaries of sarcomeres. Actin filaments are anchored to Z-lines. Sarcoplasmic Reticulum: Specialized endoplasmic reticulum in muscle cells, which stores and releases calcium ions (Ca2+). Calcium ions play a crucial role in muscle contraction. T-Tubules (Transverse Tubules): Invaginations of the sarcolemma that penetrate the interior of the muscle fibre. T-tubules help transmit the action potential (nerve signal) deep into the muscle fibre. 4.1.2 Muscle organisation: The structure of the muscle is organised as follows: ▪ Fascicles: Bundles of muscle fibres wrapped together. ▪ Perimysium: Connective tissue surrounding fascicles. ▪ Epimysium: Connective tissue surrounding the entire muscle. ▪ Tendons: Connect muscle to bone, enabling movement. Page 72 of 86  Anatomy of the Upper and Lower Limb -ANA 201 4.2 Major Muscles of the Upper Limbs Muscles of the upper limb can be divided into four groups, namely, the muscles of the rotator cuff muscles or shoulder, arm, muscles of the forearm, and muscles of the hand. 4.2.1 Major Muscles of the Shoulder: The shoulder is a complex joint with several major muscles responsible for its movements and stability. Rotator Cuff Muscles: The rotator cuff is a group of four muscles and their associated tendons located in the shoulder (see Figure 4.2). Figure 4.2 Rotator Cuff Muscles These muscles and tendons work together to stabilize the shoulder joint and allow for a wide range of motion in the arm. i. Supraspinatus: This muscle is located on the top of the shoulder blade and is involved in the initiation of arm abduction (lifting the arm away from the body). It helps in the first 15 degrees of raising the arm. Page 73 of 86  Anatomy of the Upper and Lower Limb -ANA 201 ii. Infraspinatus: Situated on the back of the shoulder blade, this muscle is responsible for the external rotation of the arm. It also helps in stabilizing the shoulder joint. iii. Teres Minor: Found below the infraspinatus, the teres minor muscle also contributes to the external rotation of the arm and provides stability to the shoulder joint. iv. Subscapularis: Positioned on the front of the shoulder blade, this muscle allows for the internal rotation of the arm. It plays a significant role in various shoulder movements and stability. Other muscles that support your shoulder include Rhomboids: The rhomboid muscles are a pair of muscles located in the upper back, beneath the trapezius muscles (see Figure 4.3). There are two rhomboid muscles: the rhomboid major and the rhomboid minor. Rhomboid Major: It originates from the spinous processes of the thoracic vertebrae T2 to T5. It inserts into the medial border of the scapula, from about the level of the spine to the inferior angle of the scapula. The rhomboid major retracts the scapula, pulling it toward the spine. It also helps in rotation and downward movement of the scapula. Rhomboid Minor: It originates from the lower part of the ligamentum nuchae (a ligament in the back of the neck) and the spinous process of the seventh cervical (C7) vertebra. It inserts into the medial border of the scapula, just above the insertion of the rhomboid major. The rhomboid minor has a similar function to Page 74 of 86  Anatomy of the Upper and Lower Limb -ANA 201 the rhomboid major. It retracts and stabilizes the scapula against the thoracic wall. Both the rhomboid major and minor muscles are innervated by the dorsal scapular nerve (C5 nerve root), which arises from the brachial plexus. Figure 4.3 Rotator Cuff Muscles Trapezius: The trapezius muscle is a large, triangular muscle located in the upper back and neck area. It extends from the base of the skull down to the middle of the spine and out to the shoulder blades. The trapezius muscle is divided into three parts based on its function and location: Upper Trapezius: This part of the trapezius muscle originates from the base of the skull and extends down to the outer third of the clavicle (collarbone). Its primary function is to elevate the shoulder girdle, as in shrugging the shoulders. Middle Trapezius: The middle part of the trapezius runs from the spine down to the scapula (shoulder blade). It is responsible for retracting or pulling the shoulder blades toward the spine, as in squeezing them together. Page 75 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Lower Trapezius: This portion of the trapezius muscle originates from the spine and extends down to the lower portion of the scapula. It aids in depressing the scapula, which is the movement of lowering the shoulder blades downward. The trapezius muscle plays a crucial role in various movements of the shoulder and neck, and it is involved in actions like lifting, lowering, and stabilizing the shoulders. Additionally, it helps maintain proper posture by keeping the shoulder blades in the correct position. The innervation of the trapezius muscle comes from the accessory nerve (cranial nerve XI) and the spinal nerves from the cervical region of the spine (C3-C4). This innervation allows for voluntary control of the muscle's movements. Figure 4.4 Trapezius Muscles Deltoid: The deltoid muscle is on the outside of your shoulder (see Figure 4.3). It helps you move your arm forward, backwards and to the side. The deltoid muscle is a large, triangular muscle that covers the shoulder joint. It is responsible for lifting the arm away from the body and giving the shoulder its rounded shape. It consists of anterior, middle and posterior portions. The origin of the anterior Page 76 of 86  Anatomy of the Upper and Lower Limb -ANA 201 portion is from the anterior surface of the lateral third of the clavicle. The anterior deltoid is responsible for flexion and internal rotation of the shoulder joint. It assists in bringing the arm forward and across the body. The origin of the middle portion is the acromion process of the scapula. The middle deltoid is responsible for the abduction of the arm, meaning it raises the arm laterally away from the body. It is a key muscle involved in movements like lifting the arm to the side. The origin of the posterior deltoid is from the Spine of the scapula. The posterior deltoid is responsible for the extension and external rotation of the shoulder joint. It helps in pulling the arm backwards and rotating it externally. The deltoid muscle is primarily innervated by the axillary nerve (C5-C6), which arises from the brachial plexus. This nerve controls the muscle's movements and is essential for the muscle's function. Other muscles include Page 77 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Pectoralis Major: The pectoralis major is a large chest muscle that connects the upper arm to the chest. It assists in the flexion, adduction, and inward rotation of the arm. Figure 4.5 Trapezius Muscles Latissimus Dorsi: The latissimus dorsi is a large, flat muscle in the back that is responsible for several movements of the shoulder and upper arm. It is the widest muscle in the human body and is sometimes referred to as the "lats." The latissimus dorsi muscles are located on both sides of the back and are shaped like a triangle (see Figure 4.6). They originate from the lower spine and the back of the pelvis and insert into the upper arm bone (humerus). Figure 4.6 Back Muscles - Latissimus dorsi Page 78 of 86  Anatomy of the Upper and Lower Limb -ANA 201 Understanding these major shoulder muscles is important for athletes, fitness enthusiasts, and medical professionals, as they play a crucial role in various arm movements and shoulder stability. Summary 1. The human muscular system is composed of specialized cells called muscle fibres, which enable movement, support, posture maintenance, and heat generation. Skeletal muscles, attached to bones, facilitate voluntary movement by working in pairs. 2. Muscle fibres have distinct components, including the sarcolemma (plasma membrane), sarcoplasm (cytoplasm), myofibrils (thread-like structures with sarcomeres), sarcomeres (functional units for muscle contraction with actin and myosin filaments), and the sarcoplasmic reticulum (specialized endoplasmic reticulum storing and releasing calcium ions). T-tubules help transmit nerve signals deep into muscle fibres. 3. Muscle organization involves fascicles (bundles of muscle fibres), perimysium (connective tissue around fascicles), epimysium (connective tissue around the entire muscle), and tendons (connecting muscles to bones). 4. The upper limb muscles can be categorized into the muscles of the rotator cuff, arm, forearm, and hand. 5. Major muscles of the shoulder, specifically the rotator cuff, include the supraspinatus, infraspinatus, teres minor, and subscapularis. Additional Page 79 of 86  Anatomy of the Upper and Lower Limb -ANA 201 shoulder muscles include the rhomboid major and minor, trapezius (upper, middle, and lower portions), and the deltoid (anterior, middle, and posterior portions). Pectoralis major and latissimus dorsi are also involved in shoulder and arm movements. 6. The deltoid muscle covers the shoulder joint and aids in arm movement in various directions, including flexion, abduction, and extension. 7. Latissimus dorsi, a large, flat muscle in the back, is responsible for several shoulder and upper arm movements, making it essential to understand for athletes, fitn