Introduction to Anatomy

Introduction to Anatomy

• Anatomy is the study of the structure and function of the body.
• The term "anatomy" comes from the Greek words "anatome," meaning "dissection," and "logos," meaning "study of."
• Anatomy is directly applied to medicine and surgery.

Approaches to the Study of Anatomy

• Regional Anatomy: Focuses on specific regions of the body.
• Surface Anatomy: Visualizes structures visible from the surface. It can be used to distinguish unusual findings that are palpable and enhance knowledge from dissection.
• Systemic Anatomy: Studies organ systems that work together to perform complex functions.

Divisions of Anatomy

• Gross Anatomy: Examines structures visible to the naked eye, such as muscles, bones, and organs.

Levels of Anatomic Organization

• The body is organized into multiple levels, starting from cells and ending with the organism.

Different Body Systems

• Cardiovascular System: Composed of the heart and blood vessels, functions to pump blood throughout the body.
• Lymphatic/Immune System: Consists of lymphatic vessels, lymph nodes, spleen, tonsils, thymus, and bone marrow. It recovers fluid for tissue drainage, cleanses the blood, and houses cells involved in immunity.
• Nervous System: Includes the brain, spinal cord, nerves, and sensory receptors. It responds to external and internal signals, controlling and coordinating the activities of different organ systems.
• Endocrine System: Comprises the pituitary, thyroid, parathyroid, thymus, pancreas, pineal, ovary, and testes. It directs long-term changes using hormones, aiding in growth, reproduction, food use, and metabolism.
• Respiratory System: Consists of the lungs and airways. It facilitates gas exchange between the body and the environment.
• Digestive System: Made up of the mouth, esophagus, stomach, intestines, and accessory organs. Its role is to break down food and absorb nutrients.
• Urinary System: Includes the kidneys, ureters, bladder, and urethra. It removes waste products and regulates fluid balance.
• Muscular System: Composed of skeletal, smooth, and cardiac muscles. It enables movement, maintains posture, and generates heat.
• Skeletal System: Consists of bones, cartilage, ligaments, and joints. It provides support, protection, and movement.
• Integumentary System: The skin, hair, and nails. It protects the body, regulates temperature, and is involved in sensory perception.
• Reproductive System: Differing structures for males and females. The male system includes testes, scrotum, penis, accessory glands, and duct system. The female includes the ovaries, uterine tubes, uterus, and vagina. The primary function is the production of sex cells and hormones to create progeny.

Anatomical Terminology

• Anatomical Position: A standard reference position with the body upright, head, gaze, and toes facing forward, arms at the sides with palms facing anteriorly, and lower limbs together, feet parallel.
• Planes and Sections:
  • Sagittal Planes: Vertical planes that divide the body into right and left sides.
  • Frontal Planes: Vertical planes that divide the body into anterior (front) and posterior (back) parts.
  • Transverse Planes: Horizontal planes that divide the body into superior (upper) and inferior (lower) parts.
• Terms of Relationship and Comparison:
  • Anterior (Ventral): Front of the body.
  • Posterior (Dorsal): Back of the body.
  • Medial: Structure closer to the median plane of the body.
  • Lateral: Structure farther away from the median plane than another.
  • Superior (Cranial, Cephalic): High or low with reference to the upper and lower ends of the body.
  • Inferior (Caudal): Low or high with reference to the upper and lower ends of the body.
  • Proximal: Closer to the point of attachment of an appendage.
  • Distal: Farther from the point of attachment of an appendage.
  • Palmar vs. Dorsal: Palm of the hand (anterior) is referred to as palmar, while the back of the hand (posterior) is referred to as dorsal.
  • Plantar vs. Dorsal: The sole of the foot (inferior) is referred to as plantar, and the top of the foot (superior) is referred to as dorsal.
• Body Cavities:
  • Dorsal Cavity: Contains the cranial cavity (housing the brain) and the vertebral canal (housing the spinal cord).
  • Ventral Cavity: Contains the thoracic cavity (superior, demarcated by the diaphragm) and the abdominal cavity (inferior).

Introduction to Anatomy

• Anatomy is the study of the structure and function of the body
• The word "anatomy" originates from Greek words "anatome" meaning dissection and "logos" meaning study
• Early examples of anatomy include:
  • Plate tablets from Ancient Mesopotamia
  • Work by Babylonians and Assyrians
  • Edwin Smith Papyrus from Ancient Egypt (describes embalming techniques)
• Herophilus: considered the Father of Anatomy
  • Performed the first recorded dissection of a human body
• Leonardo da Vinci:
  • Integrated art and science to illustrate the human form
  • Pioneered the depiction of cross-sectional anatomy
• Andreas Vesalius: considered the Father of Modern Anatomy
  • Published "De Humani Corporis Fabrica Libri Septem", the first illustrated anatomy textbook

Approaches to Studying Anatomy

• Regional Anatomy (Topographical Anatomy):
  • Focuses on specific body regions
  • Examines the arrangement and relationships of structures within a region
• Surface Anatomy:
  • Visualizes structures based on their surface appearance
  • Used to identify palpable structures and abnormalities
• Systemic Anatomy:
  • Studies organ systems that work together to perform complex functions

Divisions of Anatomy

• Gross Anatomy:
  • Examines structures visible to the naked eye
  • Examples: Muscles, bones, organs
• Microscopic Anatomy:
  • Studies structures too small to be seen without a microscope
  • Divided into:
    • Cytology: Study of cells
    • Histology: Study of tissues
• Embryology:
  • Studies the development of an organism from fertilization to birth

Levels of Anatomic Organization

• Cells are the basic units of life
• Cells work together to form tissues
• Tissues work together to form organs
• Organs work together to form organ systems
• Organ systems work together to form an organism

Different Body Systems

• Integumentary System (Dermatology):
  • Includes skin (largest organ), hair, and nails
  • Functions: Protection, temperature regulation, excretion, sensation
• Skeletal System (Osteology and Arthrology):
  • Includes bones, cartilage, ligaments, and joints
  • Functions: Support, movement, protection, mineral storage, hematopoiesis (red blood cell production)
• Muscular System (Myology)
  • Includes skeletal, smooth, and cardiac muscles
  • Functions: Movement, support, heat production
• Cardiovascular System (Cardiology and Angiology):
  • Includes heart and blood vessels
  • Blood functions: Transports nutrients, waste, and gases
• Respiratory System (Pulmonology):
  • Includes nasal passages, pharynx, larynx, trachea, bronchi, and lungs
  • Functions: Gas exchange
• Digestive/Alimentary System (Gastroenterology):
  • Includes oral cavity, esophagus, stomach, small intestines, large intestines, rectum, liver, pancreas
  • Functions: Food breakdown, absorption of nutrients, water, minerals, vitamins, elimination of waste
• Urinary System:
  • Includes kidneys, ureters, bladder, urethra
  • Functions: Excretion of nitrogenous waste, maintaining water and salt balance, blood pH regulation

Anatomical Terminology

• Anatomic Position:
  • Standing erect with palms facing forward, feet slightly apart
• Planes and Sections:
  • Sagittal Plane: Divides the body into left and right portions
  • Transverse Plane: Divides the body into superior and inferior portions
  • Coronal Plane: Divides the body into anterior and posterior portions
• Terms of Relationship and Comparison:
  • Superior: Above
  • Inferior: Below
  • Anterior: Front
  • Posterior: Back
  • Medial: Toward the midline
  • Lateral: Away from the midline
  • Proximal: Closer to the origin of a structure
  • Distal: Farther from the origin of a structure
  • Superficial: Closer to the surface
  • Deep: Farther from the surface
• Terms of Laterality:
  • Ipsilateral: On the same side of the body
  • Contralateral: On the opposite side of the body
• Body Cavities:
  • Dorsal Cavity: Includes the cranial cavity (brain) and vertebral canal (spinal cord)
  • Ventral Cavity:
    • Thoracic Cavity: Contains the heart, lungs, and major blood vessels
    • Abdominal Cavity: Contains the stomach, intestines, liver, spleen, kidneys, and other organs
  • Pelvic Cavity: Contains the bladder, reproductive organs, and rectum
• Body Regions:
  • Head: Includes the skull and face
  • Neck: Connects the head to the torso
  • Thorax: The chest region
  • Abdomen: The area between the thorax and the pelvis
  • Pelvis: The area between the abdomen and the lower limbs
  • Upper Limb: Includes the shoulder, arm, forearm, wrist, and hand
  • Lower Limb: Includes the hip, thigh, leg, ankle, and foot

Terminology Related to Movement

• Flexion: Decreases the angle between bones at a joint
• Extension: Increases the angle between bones at a joint
• Dorsiflexion: Flexion at the ankle joint (lifting the toes)
• Plantarflexion: Moving the sole of the foot inferiorly (standing on toes)
• Abduction: Movement away from the midline
• Adduction: Movement towards the midline
• Inversion: Turning the sole of the foot medially (inward)
• Eversion: Turning the sole of the foot laterally (outward)
• Rotation: Movement around a long axis
  • Medial (Internal) Rotation: Anterior surface faces medially
  • Lateral (External) Rotation: Anterior surface faces laterally
• Circumduction: A sequence of movements combining flexion, extension, abduction, adduction, and rotation
• Pronation: Turning the forearm medially (palms down)
• Supination: Turning the forearm laterally (palms up)
• Protraction: Moving a body part forward
• Retraction: Moving a body part backward