-1432312372_1. Ch 1 Intro

Foundations of Anatomy and Physiology

  • Anatomy is the study of body form and structure.
  • Physiology examines how the body functions.
  • Anatomical structures are specially adapted and shaped to perform their specific physiological function; this principle is defined as form follows function.
  • Form and function are intrinsically interrelated and cannot be fully understood in isolation.

Anatomists vs Physiologists

  • Small Intestine Interrelationship Example:

    • Anatomists study the structural form of the small intestine:
    • Relationship of the small intestine to other organs in the digestive tract (esophagus, stomach, large intestine).
    • Description of the multiple tissue layers composing the intestinal wall.
    • Identification of specific tissue structures and individual cells, such as epithelial cells lining intestinal villi.
    • Physiologists focus on the functional mechanisms of the small intestine:
    • Examination of how smooth muscle layers perform peristalsis through coordinated waves of contraction, bolus positioning, and muscle relaxation to propel food forward.
    • Elucidation of biochemical mechanisms by which digestive enzymes break down macronutrients (carbohydrates, proteins, fat globules, and bile salts).
    • Characterization of transport mechanisms by which absorbed nutrients (monosaccharides, amino acids, monoglycerides) cross intestinal epithelial cells into blood and lymphatic capillaries.

  • Subdisciplines of Anatomy:

    • Microscopic Anatomy: Examines anatomical structures that cannot be observed with the unaided eye.
    • Cytology: Study of body cells and their internal structures.
    • Histology: Study of tissues and cellular organization.
    • Gross Anatomy (Macroscopic Anatomy): Examines structures visible to the unaided eye.
    • Systemic Anatomy: Studies the structure of each individual body system (e.g., respiratory system, digestive system).
    • Regional Anatomy: Examines all structures situated within a specific body region (e.g., head, neck, or thorax).
    • Surface Anatomy: Focuses on superficial anatomic markings and internal body structures as they relate to overlying skin landmarks.
    • Comparative Anatomy: Examines anatomical similarities and differences across different animal species.
    • Embryology: Studies structural changes occurring from conception to birth.
    • Diagnostic and Research Subdisciplines:
    • Pathologic Anatomy: Examines macroscopic and microscopic anatomical changes resulting from disease.
    • Radiographic Anatomy: Investigates internal body structures visualized through specialized medical imaging and scanning procedures.

Characteristics of Living Organisms

  • Living organisms share six fundamental characteristics:
    • Organization: All living organisms exhibit complex, highly ordered structural arrangements maintained by cellular energy.
    • Metabolism: The sum of all chemical reactions occurring within the body.
    • Anabolism: Metabolic pathways where small, simple molecules are joined together to form larger, complex molecules.
    • Catabolism: Metabolic pathways where large, complex molecules are broken down into smaller, simpler ones.
    • Growth and Development: Organisms assimilate materials from their external environment to increase in structural size (growth) and undergo