"System" - what is it, definition of the term
The concept denotes an organized arrangement of interrelated components that operate collectively to process inputs, generate outputs, and regulate themselves through feedback, thereby achieving a specific function; in the context of rodents such as rats and mice, it describes the integrated physiological and behavioral networks that sustain homeostasis, coordinate sensory‑motor activity, and support adaptive responses.
Detailed information
Rats and mice possess intricate physiological networks that coordinate essential functions. The circulatory complex transports oxygenated blood from the heart to peripheral tissues, while returning deoxygenated fluid for re‑oxygenation. Cardiac output, vascular resistance, and capillary exchange rates define performance parameters, influencing metabolic capacity and thermoregulation.
The nervous arrangement comprises central and peripheral components. The brainstem regulates autonomic processes; the cerebellum controls motor precision; the cerebral cortex processes sensory input and cognitive tasks. Peripheral nerves transmit signals to muscles and organs, maintaining reflex arcs and voluntary movement.
Respiratory mechanisms involve alveolar ventilation, gas diffusion, and airway resistance. Tidal volume, respiratory rate, and oxygen extraction efficiency determine the animal’s capacity to meet energetic demands during activity or stress.
Digestive and excretory complexes manage nutrient assimilation and waste elimination. Stomach acidity, intestinal surface area, and enzymatic activity dictate digestion efficiency. Renal filtration rate, tubular reabsorption, and urine concentration mechanisms maintain fluid and electrolyte balance.
Key physiological parameters can be summarized:
- Heart rate: 300–500 beats min⁻¹ (mouse), 250–350 beats min⁻¹ (rat)
- Body temperature: 36.5–38 °C (both species)
- Blood glucose baseline: 5–7 mmol L⁻¹
- Urine output: 0.2–0.5 mL day⁻¹ g⁻¹ body weight
These networks interact continuously, ensuring homeostasis and enabling adaptation to environmental changes. Understanding each component’s structure and function provides a comprehensive view of the organism’s internal organization.