Anatomy and Physiology

Anatomy and Physiology

• Anatomy studies bodily structures, while physiology studies bodily functions.
• Gross anatomy is a macroscopic view, while microanatomy (histology and cytology) involves a microscopic perspective.
• Structure determines function; the way a body part is built influences what it can do.
• For example, lungs contain alveoli, allowing for gas exchange.
• Anatomical and physiological disciplines are complementary, as the structure of the body determines how it functions.

Sub-Disciplines of Anatomy

• Regional anatomy focuses on specific body regions (e.g., cephalic).
• Systemic anatomy examines the body based on organ systems (e.g., respiratory).
• Surface anatomy studies the body based on surface features and landmarks (e.g., nail anatomy).
• Cytology involves the microscopic study of individual cells (e.g., blood cells, smooth muscle).
• Histology examines tissues, which are collections of similar cells (e.g., epithelial, connective, neural, muscular).
• Skeletal muscle histology includes cross-sections and longitudinal sections.

Anatomical Position and Terms

• Anatomical position involves standing upright, facing forward, arms at sides with palms forward, legs together, and feet slightly apart.
• Many anatomical terms originate from Latin and Greek roots (e.g., peri- around, cardia- heart).

Levels of Structural Organization

• Structural organization progresses from atoms to molecules, cells, tissues, organs, organ systems, and ultimately, the organism.
• Atoms combine to form molecules (e.g., water).
• Molecules form cells, the fundamental functional units of living organisms.
• Cells forming groups of similar cells compose tissues.
• Tissues combine to form organs.
• Multiple organs working together constitute organ systems, leading to the entire organism.

Body Cavities

• Body cavities are membrane-lined internal spaces that protect internal organs, with major divisions including dorsal and ventral.
• The dorsal cavity includes the cranial cavity (housing the brain) and the vertebral canal (enclosing the spinal cord).
• The ventral cavity, separated by the diaphragm, includes thoracic (containing lungs and heart) and abdominopelvic cavities (housing digestive, reproductive, and other organs).
• Other cavities include the orbital and middle ear cavities, and synovial cavities (joint cavities).

Serous Membranes

• Serous membranes line closed ventral body cavities and cover organs.
• They are composed of parietal (lining cavity) and visceral (covering organ) portions.
• Serous fluid contained between these layers reduces friction, protects tissues, facilitates organ movement, and maintains moisture.
• Examples include pleura (lungs), pericardium (heart), and peritoneum (abdominal organs).

Axial and Appendicular Regions

• The axial region includes the head, neck, and trunk.
• The appendicular region includes the appendages (limbs).
• Anatomical terms (e.g., anterior, posterior, superior, inferior, medial, lateral, proximal, distal, superficial, deep, midsagittal, frontal, transverse) describe body positions and directions.