Introduction to Anatomy

Introduction to Anatomy

• Anatomy is the study of the structure of organisms and their parts.
• It encompasses the macroscopic (visible to the naked eye) and microscopic (requires a microscope) structures.
• The study of anatomy enables understanding how different organs and systems work together.
• It is a fundamental basis for understanding physiology (the function of organisms).

Branches of Anatomy

• Gross Anatomy: Examines large structures, visible without magnification. Includes:
  • Regional anatomy: Studies parts of the body in specific regions.
  • Systemic anatomy: Studies body systems, like the nervous or cardiovascular systems.
  • Surface anatomy: Studies external features and their relation to deeper structures.
• Microscopic Anatomy: Examines structures needing magnification. Includes:
  • Cytology: Studies the structure of individual cells.
  • Histology: Studies the structure of tissues, which are composed of cells.

Anatomical Terminology

• Precise language employed to describe body structures avoids ambiguity.
• Directional terms define the position of one structure relative to another.
• Regional terms delineate specific body regions.
• Planes and sections refer to ways the body is cut to reveal internal structures.

Anatomical Planes

• Sagittal plane: Divides the body into left and right portions.
  • Mid-sagittal plane: Divides the body into equal left and right halves.
• Frontal (coronal) plane: Divides the body into anterior (front) and posterior (back) portions.
• Transverse (horizontal) plane: Divides the body into superior (upper) and inferior (lower) portions.
• Oblique plane: Passes through the body at an angle.

Directional Terms

• Superior (cranial): Towards the head.
• Inferior (caudal): Towards the feet.
• Anterior (ventral): Towards the front.
• Posterior (dorsal): Towards the back.
• Medial: Towards the midline of the body.
• Lateral: Away from the midline of the body.
• Proximal: Closer to the point of attachment or origin.
• Distal: Farther from the point of attachment or origin.
• Superficial: Closer to the surface of the body.
• Deep: Further from the surface of the body.

Body Cavities

• Dorsal body cavity: Contains the cranial cavity (brain) and the vertebral canal (spinal cord).
• Ventral body cavity: Larger cavity, divided by the diaphragm. Contains the thoracic cavity (lungs, heart, and associated structures) and the abdominopelvic cavity (stomach, intestines, reproductive organs, and urinary organs).
• The diaphragm is a major anatomical landmark separating the thoracic and abdominopelvic cavities.

Body Regions

• Head
• Neck
• Trunk: Thorax, abdomen, pelvis
• Upper limbs (arm, forearm, wrist, hand)
• Lower limbs (thigh, leg, ankle, foot)

Basic Body Systems

• Integumentary system: Covers the body's surface.
• Skeletal system: Provides support and structure.
• Muscular system: Enables movement.
• Nervous system: Coordinates body functions.
• Endocrine system: Regulates body functions through hormones.
• Cardiovascular system: Circulates blood.
• Lymphatic/Immune system: Defends against disease.
• Respiratory system: Enables gas exchange.
• Digestive system: Processes food.
• Urinary system: Removes waste products.
• Reproductive system: Enables procreation.

Anatomical Position

• The standard position for describing anatomical locations.
• Standing upright, arms at the sides, palms forward, feet together.