Homeostasis Flashcards
What is homeostasis
The maintenance of a stable internal environment despite external changes.
Why is homeostasis essential?
It ensures the survival of cells and the organism by maintaining conditions for physiological processes.
What is negative feedback?
A mechanism where the response opposes the change to maintain stability (e.g., shivering to generate heat).
What are the components of a negative feedback system?
Sensor, Integrator, Effector.
Give an example of a physiological negative feedback loop.
Body temperature regulation: too hot → sweat; too cold → shiver.
What is positive feedback?
A mechanism where the response amplifies the change for a rapid effect (e.g., oxytocin during labor).
What is enantiostasis?
Maintaining homeostasis by compensating for changes in one variable with adjustments in another.
What is acclimatization in homeostasis?
Gradual adaptation to new environmental conditions, like developing a thicker fur coat in winter.
What are two common challenges in negative feedback systems?
Delays in response initiation and stopping, leading to overshooting the set-point.
How can negative feedback systems adapt to delays?
Through anticipation (e.g., skin detects temperature changes before affecting body temperature).
What are examples of set-point changes?
Fever (temporary), puberty (permanent), daily body temperature cycles (cyclical).
What is the smallest unit of life involved in homeostasis?
The cell.
Name the four types of tissue in animals.
Epithelial, connective, muscular, nervous.
How does epithelial tissue contribute to homeostasis?
It forms barriers and facilitates material exchange (e.g., skin, digestive tract).
What is the role of muscular tissue in homeostasis?
Movement and force generation, including involuntary actions like heartbeats.
What is intrinsic regulation?
Local regulation within a single organ or tissue (e.g., blood flow adjustments in active muscles).
What is extrinsic regulation?
Coordination of multiple organ systems for overall homeostasis (e.g., hormonal regulation during exercise).
What are the two main control systems for homeostasis?
Nervous system (fast) and endocrine system (slow, sustained).
How does the respiratory system support homeostasis?
By maintaining O₂ and CO₂ levels and regulating acidity.
What is the role of the circulatory system in homeostasis?
Transporting nutrients, oxygen, and waste products.
How does the excretory system maintain fluid balance?
By removing excess water, salts, and waste.
What is the function of the integumentary system in homeostasis?
Protection, temperature regulation, and preventing fluid loss.
Why is homeostasis considered an evolutionary advantage?
It allows organisms to survive and reproduce in a wide range of environments.
How do regulators, conformers, and avoiders differ?
Regulators: Maintain a constant internal state (e.g., humans).
Conformers: Match their internal state to the environment (e.g., marine snails).
Avoiders: Avoid environmental extremes (e.g., migrating birds).
