R e v i e w G u i d e 1 : A n a t o m y , P h y s i o l o g y , H o m e o s t a s i s

Review Guide 1: Anatomy, Physiology, and Homeostasis

1. Relationship Between Anatomy and Physiology

• Anatomy: The study of the structure of body parts and their relationships to one another.
• Physiology: The study of the function of those body parts and how they work to carry out life-sustaining activities.
• Relationship: Structure dictates function. The specific anatomical features of an organ determine its physiological capabilities.
  • Example (Heart):
    • Anatomy: The heart has four chambers ($2$ atria, $2$ ventricles), a muscular wall (myocardium), and a system of valves. Its ventricles have thick, muscular walls, especially the left ventricle.
    • Physiology: The heart's anatomy allows it to function as a pump. The strong ventricular walls are necessary to generate pressure to propel blood through the circulatory system, while the valves ensure unidirectional blood flow, preventing backflow and maximizing pumping efficiency. If the anatomy changes (e.g., a weakened heart muscle or faulty valve), its ability to pump blood (physiology) is impaired.

2. Definitions of Stems

• Bi, di: Two (e.g., bilateral, disaccharide)
• Cyt(o)-: Cell (e.g., cytology, erythrocyte)
• Tri-: Three (e.g., triceps, triglyceride)
• Quat-: Four (e.g., quadriceps)
• Blast: Germ, bud, immature cell (e.g., osteoblast, fibroblast)
• Peri-: Around, surrounding (e.g., pericardium, periosteum)
• Ex, extra, exo: Out, outside, away from (e.g., exhale, extracellular, exocytosis)
• Intra, endo-: In, within (e.g., intracellular, endoskeleton)
• Epi-: Upon, above (e.g., epidermis, epithelial)
• Hyper-: Above, excessive (e.g., hyperthermia, hypertension)
• Hypo-: Below, deficient (e.g., hypothermia, hypotension)
• -itis: Inflammation (e.g., appendicitis, arthritis)
• My(o)-: Muscle (e.g., myocardium, myopathy)
• Osteo-: Bone (e.g., osteocyte, osteoporosis)

3. Six Levels of Structural Organization

• The human body is organized in a hierarchical manner, with increasingly complex levels built upon simpler ones:
  1. Chemical Level: The most fundamental level, involving atoms (e.g., Carbon ($C$), Hydrogen ($H$), Oxygen ($O$), Nitrogen ($N$)) and molecules (e.g., water ($H_2O$), proteins, carbohydrates, lipids, nucleic acids). These are the building blocks of life.
  2. Cellular Level: Cells are the basic structural and functional units of living organisms. Molecules combine in specific ways to form organelles, which are the functional components within cells (e.g., mitochondria, nucleus). A living cell is the smallest unit that can carry out all processes of life.
  3. Tissue Level: Tissues are groups of similar cells that work together to perform a specific function. There are four primary tissue types:
     • Epithelial Tissue: Covers body surfaces and lines cavities.
     • Connective Tissue: Supports, protects, and binds other tissues.
     • Muscle Tissue: Involved in movement.
     • Nervous Tissue: Facilitates communication.
  4. Organ Level: An organ is a structure composed of at least two, but usually four, different tissue types working together to perform complex functions. Examples include the heart, liver, stomach, and brain.
  5. Organ System Level: An organ system consists of multiple organs that cooperate closely to achieve a major physiological function. Examples include the cardiovascular system (heart, blood vessels, blood), digestive system (esophagus, stomach, intestines), and nervous system (brain, spinal cord, nerves).
  6. Organismal Level: The highest level of organization, representing the living human being. All the organ systems work together in an integrated fashion to maintain life.
• Relation: Each level builds upon the previous one. Atoms form molecules, molecules form organelles, organelles form cells, cells form tissues, tissues form organs, organs form organ systems, and organ systems form the complete organism. Disruption at any lower level can affect the function of higher levels.

4. Metabolism

• Definition: The sum of all chemical reactions that occur within an organism to maintain life. These reactions involve the breakdown of substances to produce energy and the synthesis of new substances to build and repair body components.
• One word: Chemical reactions (or