An overview of the study of animal physiology, including the basic principles and concepts related to the functions and processes of animals at the cellular, tissue, and organ levels.
Introduction to Animal Physiology
The study of how animal bodies work, from cells to whole organisms.
| Concept | Description | Example |
|---|---|---|
| Homeostasis | Maintenance of stable internal conditions despite external changes. | Regulation of body temperature in mammals. |
| Feedback Loops | Mechanisms that adjust physiological variables; can be negative (stabilizing) or positive (amplifying). | Insulin‑glucose regulation (negative feedback). |
| Metabolism | All chemical reactions that provide energy and build cellular components. | Aerobic respiration of glucose in muscle cells. |
| Allometry | Relationship between body size and physiological traits. | Larger animals have slower heart rates per gram of tissue. |
| Adaptation | Physiological traits that improve survival in a specific environment. | Counter‑current heat exchange in bird legs. |
| System | Primary Functions | Key Physiological Processes |
|---|---|---|
| Nervous | Rapid communication, integration of sensory information, coordination of behavior. | Action potentials, synaptic transmission. |
| Endocrine | Hormone production, long‑term regulation of metabolism, growth, reproduction. | Hormone synthesis, receptor binding. |
| Circulatory | Transport of gases, nutrients, wastes; temperature regulation. | Cardiac output, blood pressure control. |
| Respiratory | Gas exchange (O₂ uptake, CO₂ removal). | Ventilation, diffusion across alveolar membranes. |
| Digestive | Breakdown of food, absorption of nutrients, waste elimination. | Enzymatic hydrolysis, peristalsis. |
| Excretory (Urinary) | Removal of metabolic waste, osmoregulation, acid‑base balance. | Glomerular filtration, tubular reabsorption. |
| Musculoskeletal | Movement, support, protection of internal organs. | Muscle contraction, bone remodeling. |
| Immune | Defense against pathogens, tissue repair. | Innate and adaptive immune responses. |
| Reproductive | Production of gametes, nurturing offspring (in viviparous species). | Hormonal control of gametogenesis, gestation. |
Cell Membrane Transport
Signal Transduction
Energy Production
Protein Synthesis & Turnover
| Step | Mechanism | Outcome | |------