General Anatomy & Embryology PDF

General Anatomy & Embryology Paramedian plane Median plane Horizontal plane Coronal plane Horizontal plane 3 ...

General Anatomy & Embryology Paramedian plane Median plane Horizontal plane Coronal plane Horizontal plane 3  General Anatomy & Embryology Terms of relations: - Anterior (ventral): towards the front of the body or nearer to it. - Posterior (dorsal): towards the back of the body or nearer to it. - Superior (upper – cranial – cephalic – rostral): towards the head or the upper end of the structure. - Inferior (lower – caudal): towards the feet – away from the head or the lower end of the structure. - Medial: near to the median plane. - Lateral: away from the median plane. - Intermediate: between medial and lateral positions. - Proximal: towards the trunk or the root of the limb. - Distal: away from the trunk or the end of the limb. - Superficial: near to the surface of the body. - Deep: away from the surface of the body. - Middle: a position between two points. - External (outer): towards the surface of the cavity of the organ. - Internal (inner): towards the cavity of the organ. - Ipsilateral: the same side. - Contralateral: the opposite side. 4  General Anatomy & Embryology Summary  Definition of Anatomy  Classification of anatomy:  Macroscopic (gross) anatomy  Microscopic anatomy (histology)  Anatomical Terms:  Terms of position  Terms of planes  Terms of relations Formative Assessment Choose the correct answer: -The median plane is a vertical plane that divides the body into which of the following parts? A. Upper and lower. B. Superficial and deep. C. Right and left. D. Anterior and posterior. 5  General Anatomy & Embryology Systems Of The Body The human body is formed of cells, tissues, organs and systems. The cell is the basic structure of every part of the body. The tissue is a group of cells of similar shape and function. The different tissues that unite in special way and perform specific function form an organ. A group of organs that associated to perform certain function form a system. There are four main tissues in the body: 1. Epithelial tissue 2. Connective tissue 3. Muscular tissue 4. Nervous tissue The human body has the following systems: 1. The skeletal system (bones). 2. The articular system (joints). 3. The muscular system (muscles). 4. The circulatory system. 5. The respiratory system. 6. The digestive system. 7. The genital system. 8. The urinary system. 9. The nervous system. 10.The endocrine system. 6  General Anatomy & Embryology Skeletal System SLO: By the end of this course, each student should be able to describe skeletal system, function, classification, surface markings, blood supply and nerve supply. The study of bones is called (osteology). The bone is formed of bone cells (osteocytes) and intercellular matrix (collagen fibers, organic and inorganic salts). Function of bones: - The skeleton gives shape, central axis and support to the body. - The bones give protection to the vital organs as the brain, spinal cord and lungs. - The bones give attachment to muscles and provide levers for muscles to move the joints. - The bones are the major stores for calcium salts. - The bone marrow is the main source for blood cells. Classification of bones: 1. Regional: axial (skull & vertebral column) and appendicular (upper & lower limbs). 2. Developmental: membranous, cartilaginous and mixed. 3. Structural: compact (hard) and cancellous (spongy). 4. Morphological: long, short, flat, irregular and sesamoid. Long Short Flat Irregular Morphological types of bones 7  General Anatomy & Embryology Gross anatomy of the long bone: - A long bone consists of shaft (diaphysis) and two expanded ends called epiphysis. - The part of the diaphysis lying close to the epiphysis is called metaphysis. - The shaft (diaphysis) is formed of an outer cortex (compact bone) and a central medullary (marrow) cavity. The cavity is filled with soft vascular tissues called bone marrow. - The shaft is covered by a fibrous tissue called periosteum. - The epiphysis of the long bone is formed of a cancellous bone covered by a thin layer of compact bone and has a smooth articular surface for the joint. Articular cartilage Epiphysis Epiphyseal cartilage Metaphysis Nutrient canal Diaphysis Medullary cavity Epiphyseal line 8  General Anatomy & Embryology Blood supply of the bones: 1. Nutrient artery: enters the shaft near the middle to reach the medullary cavity then divides into ascending and descending branches. 2. Epiphyseal and metaphyseal arteries: to the epiphysis & metaphysis. 3. Periosteal arteries: for the periosteum. Nerve supply of the bones: Bones are supplied by sensory nerves and vasomotor nerves that enter the bone together with the blood vessels. Summary  Definition  Functions of bones  Classification of bones  Gross anatomy of long bone  Blood supply of the bones  Nerve supply of the bones Formative Assessment Choose the correct answer: - Concerning the cancellous bone, it is included in which one of the following bone classification? A. Regional. B. Developmental. C. Structural. D. Morphological. 9  General Anatomy & Embryology Muscular System SLO: By the end of this course, each student should be able to describe muscular system, types of muscles: skeletal, cardiac and smooth muscles Myology means the study of the muscles. Muscle is a contractile tissue i.e. becomes short in response to a proper stimulus. The presence of special proteins e.g. actin & myosin and high excitability of the muscle cell are responsible for contractility of muscles. Types of muscles: There are three types of muscles: skeletal (somatic), smooth (visceral) and cardiac. (A) Skeletal (somatic or striated) muscle: - The skeletal muscles form about 40-45% of the body weight. - The skeletal muscles are attached to the skeleton and are derived from the somites. - They are voluntary muscles i.e. they contract under voluntary control. - They show marked longitudinal and cross striations. - They are supplied by somatic nerves and therefore under voluntary control. - The skeletal muscle consists of muscle fibers which are arranged in bundles. - The skeletal muscle fiber is multinucleated cell with peripheral nuclei. The cell membrane is called sarcolemma, the cytoplasm is called sarcoplasm. Parts of skeletal muscle: 1. Origin: It is the less mobile end of the muscle during its contraction. It is usually the proximal end in the limb muscles. It may not be single as in biceps, triceps, and quadriceps muscles. 2. Insertion: It is the more mobile end of the muscle and usually the distal end of the limb muscles. Normally, contraction of a muscle approximates the insertion towards the origin, thus producing movement at the related joint. 11  General Anatomy & Embryology Origin Sarcolemma Insertion Nucleus Skeletal muscle Types of attachment: The skeletal muscles may be attached directly by the fleshy fibers or by a tendon to any of the following structures: 1. Bones: commonest way of attachment. 2. Cartilages: e.g. popliteus muscle is attached to the menisci of the knee joint. 3. Skin and superficial fascia: muscles of the face. 4. Deep fascia: muscles of the thigh are inserted into fascia lata. Forms of muscles: The muscle fibers are arranged either obliquely or parallel with the line of pull of the muscle (line of pull is the line that extends between the origin and insertion). Skeletal muscles are classified according to the arrangement of fibers as follows: 11  General Anatomy & Embryology a- Parallel fibers: 1. Quadrate:e.g. quadratus femoris. 2. Strap:e.g. sartorius muscle. 3. Fusiform:e.g. lumbericals muscles. b- Oblique fibers: 1. Unipennate: fibers lie on one side of the tendon. 2. Bipennate: fibers lie on opposite sides of the tendon. 3. Multipennate: muscle fibers are formed of multiple bipennate units close together. 4. Circumpennate: muscle fibers are attached all around the tendon. There are skeletal muscles with oblique fibers but are not pennate muscles: 1. Triangular:e.g. temporalis muscle. 2. Spiral:e.g. supinator muscle. 3. Cruciate:e.g. masseter muscle. Strap Quadrate Fusiform 12  General Anatomy & Embryology Unipennate Bipennate Multipennate Circumpennate Spiral Triangular Cruciate Nomination of muscles: The skeletal muscles are named according to the following: 1. Attachment:e.g. sterno–thyroid muscle. 2. Position:e.g. supra–spinatus muscle. 3. Shape:e.g. rhomboids muscle. 4. Structure: e.g. semimembranosus. 5. Action: e.g. extensors, flexors, abductors, supinators, pronators and adductors. 6. Fibers arrangement: e.g. tranversus abdominis muscle. 7. Length: e.g. flexor digitorum longus and brevis. 8. Size: e.g. Gluteus maximus, medius and minimus muscles. 13  General Anatomy & Embryology Action of muscles: The action of muscles depends on the length and the number of the active muscle fibers. The skeletal muscles have a rapid response but easily fatigued. They are classified according to their action into: prime movers (agonists), antagonists (opponents), fixators and synergists. 1. Prime movers: The muscles which are responsible for initiation of a particular movement are called prime movers e.g. brachialis initiates flexion of the elbow. 2. Antagonists: These are the muscles which oppose the prime movers e. g. triceps opposes the brachialis muscle (triceps muscle is the prime extensor of the elbow). 3. Fixators (stabilizers): The muscles which help the prime mover to act efficiently by stabilizing or fixing its origin and the joint upon which it acts. 4. Synergists: During contraction of the muscles to move a joint, undesired movements are eliminated by muscles other than the prime mover; those muscles are called synergists. Therefore, synergists help the prime mover to act efficiently on the joint. Blood supply of the skeletal muscles: The muscles receive muscular branches from the surrounding arteries; the fleshy belly is highly vascular while the tendon is less vascular. 14  General Anatomy & Embryology (B) Smooth (none striated – plain) muscle: - The muscle fiber is spindle shaped cell (fusiform), with large, single and central nucleus. - The smooth muscles are innervated by autonomic nerves (sympathetic & parasympathetic), therefore they contract involuntarily. - They respond slowly and not easily fatigued. - They are present in the wall of viscera and blood vessels. Smooth muscle (C) Cardiac muscle - It is found only in the myocardium of the heart. - It is made of bundles of cells; each has a single central nucleus. The cells branch and join to form a characteristic network of the myocardium (syncytium). - It shows transverse striations. - The whole heart contracts as one unit,the cardiac muscle is involuntary muscle supplied by autonomic nerves and is controlled also by special conducting system present in the myocardium. 15  General Anatomy & Embryology Cardiac muscle Comparison between the muscles: Muscle type Skeletal Smooth Cardiac Site Attached to skeleton Viscera & blood Heart vessels Striation Striated Non- striated Striated Contraction Voluntary Involuntary Involuntary Nerve supply Somatic Autonomic Autonomic Muscle cell Multinucleated Fusiform with single Branch & fuse nucleus together 16  General Anatomy & Embryology Summary  Definition  Types of muscles: Skeletal , Cardiac and Smooth Parts of skeletal muscles Types of Attachment Forms of Muscles Nomination of muscles Action of muscles Blood supply of the skeletal muscles Formative Assessment Choose the correct answer: - Regarding the cardiac muscle, choose the incorrect statement. A. It is present in the wall of heart. B. It has no striation. C. It is under autonomic control. D. It is responsible for rhythmic contractions of heart. 17  General Anatomy & Embryology Articular System SLO: By the end of this course, each student should be able to describe articular system, definition, classification, stability, blood supply and terms of movement. A joint is the meeting between two bones or more, not all joints allow movement. Joints are classified according to the tissue between the articulating bones into three types: fibrous, cartilaginous and synovial. 1. Fibrous joints: The articulating bones are connected together by fibrous tissue; the joints are commonly immobile or allow very limited range of movement. Examples: sutures between bones of the skull and joints between the teeth and their bony sockets (gomphosis). Fibrous tissue bone bone 2. Cartilaginous joints: The articulating bones are connected by a disc of cartilage. There are two types of cartilaginous joints: primary and secondary. a. Primary cartilaginous joint: It is not a permanent joint, there is a temporary plate of hyaline cartilage between the articulating bones that disappears by ossification later and there is no movement at all. Examples: epiphyseal plate of cartilage intervening between the epiphysis and metaphysis of long bones. 18  General Anatomy & Embryology Epiphysis Epiphyseal plate of cartilage Metaphysis b. Secondary cartilaginous joint: The articulating bones are connected by a disc of white fibrocartilage. It is a permanent joint and allows a slight movement. The secondary cartilaginous joints lie in the median plane of the body. Examples: intervertebral discs. vertebra I.V.D. Vertebra 19  General Anatomy & Embryology 3. Synovial joints: Most joints of the body are synovial and they are freely mobile. Structure of synovial joint: 1. The joint is surrounded by a fibrous capsule and lined by a synovial membrane. 2. The joint has a cavity filled with the synovial fluid. 3. The articular surfaces are covered by hyaline cartilages. 4. The joint cavity may contain intra–articular structures e.g. discs or ligaments. Bone Fibrous capsule Synovial membrane Articular cartilage Bone Synovial joint 21  General Anatomy & Embryology Types of synovial joints: Synovial joints are classified according to: a. Number of articulating bones. b. Shape of articulating bones. c. Number of axes and possible movements. A- Number of articulating bones: Synovial joints are classified according to the number of articulating bones into three types: simple, compound and complex. 1. Simple joint: consists of two bones only e. g. shoulder joint. 2. Compound joint: between more than two bones e.g. elbow and wrist joints. 3. Complex joint: the joint cavity contains intra articular discs e.g. knee joint. Simple joint (shoulder joint) Compound joint (elbow joint) B- Shape of articulating bones: Synovial joints are classified according to the shape of articulating bones into: Plane, hinge, pivot, bicondylar, ellipsoid, saddle and ball & socket. 1. Plane joints: the articulating surfaces are flat e.g. tarsal and carpal joints. 21  General Anatomy & Embryology 2. Hinge joints: the articulating surfaces resemble the hinge of the door e.g. elbow joint. 3. Pivot joints: the articulating surfaces consist of a bony pivot and a ring of bone and ligaments e.g. atlanto–axial joint and superior radio–ulnar joint. 4. Bicondylar joints: the articulating surfaces comprise two convex condyles articulate with two concave surfaces (concavo–convex articulation) e.g. knee joint. 5. Ellipsoid joint: the articulating surfaces form a convex oval surface and an elliptical concave surface e.g. wrist joint. 6. Saddle joint: the articulating surfaces are reciprocally concavo- convex. (concavo–convex surface in one bone fits into the convex- concave surface in other bone) e.g. carpo-metacarpal joint of the thumb. 7. Ball and socket joint: the articulating surfaces consist of a round head (ball) and a cup shaped concave socket e.g. hip & shoulder joints. Plane (carpal joint) Hinge (elbow joint) 22  General Anatomy & Embryology Pivot (S.R.U.J.) Bicondylar (knee joint) Ellipsoid (wrist joint) Saddle (C/M joint of the thumb) Ball & Socket (hip joint) 23  General Anatomy & Embryology C-Number of axes of movements: Synovial joints are classified according to the number of axes of movements into three types: uni-axial, bi-axial and multi-axial. 1. Uni-axial joint: The movements are allowed around a single axis. a. Transverse axis as in hinge joint (elbow joint) allowing flexion and extension. b.Vertical axis as in pivot joint (atlanto-axial) allowing rotational movements. 2. Bi-axial joint: The movements are allowed around two axes (one is perpendicular to the other). a. Bi-condylar (condylar) joints e.g. knee joint, there are two axes (transverse and vertical) allowing flexion, extension and little rotation. b. Ellipsoid joint e.g. wrist joint, there are two axes (transverse and antero– posterior) allowing flexion, extension, adduction and abduction movements but no rotation is allowed. c. Saddle joint e.g. carpo–metacarpal joint of the thumb, there are two axes like ellipsoid joint but there is a little degree of rotation. 3. Multi–axial joint: There are many axes passing through one center allowing flexion, extension, abduction, adduction, medial rotation, lateral rotation and circumduction. e.g. shoulder joint. Uni-axial (elbow joint) Bi-axial (knee joint) Multi-axial (hip joint) 24  General Anatomy & Embryology Factors affecting stability of joints: 1. Shape of the articulating bones. 2. Muscles surrounding the joint. 3. Strength of the ligaments. Nerve supply of the joints: Joints are innervated by the nerves which supply the surrounding muscles, they are sensory nerves and end in the fibrous capsule and the ligaments and they are sensitive to pain and movement. Blood supply of the joints: Joints are supplied by articular arteries from the surrounding muscular arteries. Terms of Movements: 1. Flexion: bending the joint. 2. Extension: straightening of the joint. 3. Adduction: moving towards the middle line. 4. Abduction: moving away from the middle line. 5. Rotation: medial or lateral around vertical axis. 6. Circumduction: combination of movements (flexion, abduction, extension, adduction). 7. Gliding: sliding movements. 25  General Anatomy & Embryology Summary  Definition  Classification: 1. Fibrous 2. Cartilaginous: Primary - Secondary 3. Synovial  Structure of the synovial joint  Types of synovial joints  Factors affecting stability  Nerve supply  Blood supply  Terms of movement Formative Assessment Choose the correct answer: - Which of the following is a fibrous joint? A. Epiphyseal plate. B. Intervertebral disc. C. Sutures. D. Symphysis pubis. - The intervertebral disc is a: A. Fibrous joint. B. Synovial joint. C. Primary cartilaginous joint. D. Secondary cartilaginous joint. 26  General Anatomy & Embryology Digestive System SLO: By the end of this course, each student should be able to describe the digestive system, mouth cavity, pharynx, esophagus, stomach, small intestine, large intestine and digestive glands. It is the system concerned with food supply to the body, absorption of food and removal of the waste products of digestion. It is formed of digestive tube and organs (glands). (A) Digestive tube (alimentary canal): It extends from the mouth to the anus and it is about nine meters long. It includes: Palate Naso-pharynx mouth Oro-pharynx Tongue Laryngo-pharynx larynx Cervical part Thoracic part Oesophagus Abdominal part Stomach Dudenum Transverse colon Jejunum & ileum Ascending colon Descending colon Caecum & appendix Sigmoid colon Rectum Anal canal 27  General Anatomy & Embryology 1. Mouth cavity: It is divided into: the vestibule (space between the teeth and cheek) and the mouth cavity proper, it contains the followings: a- Palate: It is hard and soft ending by the uvula; it separates the mouth cavity form the nasal cavity. The soft palate shuts off the mouth cavity from the pharynx so that air can enter the larynx, but in swallowing it closes the nasopharynx and the food passes to the oesophagus. b-The tongue: It is a muscular organ used in speaking, chewing, swallowing and taste. It has root, tip and body. It carries different types of papillae especially on the anterior 2/3 (filiform – fungiform - vallate). c- Teeth. d- Openings of salivary glands. Nasal cavity Palate Nasopharynx Mouth cavity Tongue Oropharynx Laryngopharynx Larynx Oesophagus Trachea 28  General Anatomy & Embryology 2. Pharynx: It is a muscular tube, which is divided into three parts: a- Nasopharynx: behind the nasal cavity and above the soft palate (air passage). b- Oropharynx: behind the mouth cavity and contains palatine tonsils (air & food passage). c- Laryngopharynx: behind the larynx (food passage). 3. Oesophagus: It is a muscular tube extending from the lower end of the pharynx, descends through the thorax, and pierces the diaphragm to end in the cardiac opening of the stomach (25 cm long). 4. Stomach: The most dilated part of the digestive tube and lies to the left of the median plane. It is formed of: fundus – body – pylorus (antrum, canal and sphincter), and it has: -2 openings (cardiac & pyloric). -2 borders (lesser & greater curvatures). -2 surfaces (anterior & posterior) Oesophagus Fundus Cardiac orifice Lesser curvature Body Pyloric sphincter Greater curvature Duodenum Pyloric canal Pyloric antrum 29  General Anatomy & Embryology 5. Small intestine: It extends from the pyloric opening of the stomach to the caecum of the large intestine (6 meters long), it is divided into: a. Duodenum: C shaped, 25 cm long, lies around the head of the pancreas and receives the openings of the bile and pancreatic ducts. b. Jejunum and ileum: attached to the posterior abdominal wall by the mesentry, the proximal 2/5 is the jejunum and the distal 3/5 is the ileum. Pancreas Pancreas Dudenum Duodenum Jejunum J &Jejunum ileum Ileum 6. Large intestine (colon): It is wider than the small intestine (about one and half meter long), Its wall shows sacculations and divided into: 1. Caecum and appendix 2. Ascending colon 3. Transverse colon 4. Descending colon 5. Pelvic (sigmoid) colon 6. Rectum and anal canal 31