Physiology: An Overview

Structure & Function of animals

"Form Fits Function"

Structural organization of animals

1. Cells
   • Form Fits Function!
     • Squamous and cuboidal epithelial cells
     • Sensory neurons & interneurons
2. Tissues
   1. Epithelial tissue
      • Layer(s) of connected cells
      • Control passage of chemicals, water, and cells
      • Epidermis & Internal linings of organs
   2. Connective tissue
      • Cells imbedded in matrix
      • 6 types: loose, dense, bone, fat, blood, cartilage
   3. Muscle tissue
      • Contractile proteins (actin & myosin)
      • 3 types: cardiac, smooth, skeletal
   4. Nervous tissue
      • Nerve cells (neurons)
      • Send, receive, integrate signals
3. Organs
   • Heart, lung, liver, kidney, skin
   • Which organ in your body is the largest?
4. Organ systems
   1. Digestive
   2. Circulatory
   3. Respiratory
   4. Immune
   5. Excretory
   6. Endocrine
   7. Reproductive
   8. Nervous
   9. Musculoskeletal

Physiological Principles

Exchange with the environment

"Rate of flow is proportional to surface area"

Examples & physiological adaptations

1. Respiration: alveoli (300 - 600 million): ~100 m2
2. Nutrient absorption: microvilli (>250 m2)
3. Circulation: capillaries (6300 m2)
4. Filtration of blood: nephrons (2 million) = ~0.3 m2

Homeostasis

• Negative feedback
• Positive feedback

Examples of homeostasis

1. Thermoregulation
2. Acid-base balance (pH)
3. Osmoregulation (salt/water balance)