AOS3 unit2 Flashcards
(21 cards)
What is homeostasis?
The maintenance of a relatively stable internal environment within limits despite changes in the external environment.
Why is homeostasis important for cells?
It provides a stable environment so that cellular processes can function efficiently within optimal conditions
What is negative feedback?
A homeostatic mechanism where a response counteracts a change in internal conditions to return the body to its set point.
What systems work together to achieve homeostasis?
The nervous and endocrine systems.
What are the steps in the stimulus-response model?
Stimulus → Receptor → Control Center → Effector → Response.
How does the stimulus-response model support homeostasis?
It detects and responds to changes in internal conditions to restore stability.
What is thermoregulation?
The maintenance of a stable internal body temperature.
What is the difference between endotherms and ectotherms?
Endotherms regulate temperature internally; ectotherms rely on the environment.
Why is thermoregulation vital?
Low temperatures slow chemical reactions; high temperatures denature proteins.
Give an example of an endothermic and ectothermic animal.
Endothermic: Echidna. Ectothermic: Marine iguana.
What hormone lowers blood glucose levels?
Insulin.
What hormone raises blood glucose levels?
Glucagon.
What is hyperglycaemia?
High blood glucose levels.
What is hypoglycaemia?
Low blood glucose levels.
What causes type 1 diabetes?
The pancreas fails to produce enough insulin.
What organ plays a key role in water balance?
The kidney.
What part of the kidney is the functional unit for filtration?
The nephron.
How does the body respond to dehydration?
Hypothalamus triggers thirst; kidneys reabsorb more water, producing concentrated urine.
What is hypethyroidism?
A condition where there is an overproduction of thyroid hormones, disrupting homeostatic control.
What are the effects of hyperthyroidism?
Increased metabolism, weight loss, and heat sensitivity.
what is hypoglycemia
occurs when the blood sugar of a persom is too low. this usally occurs in type 1 diabetes patients when they take a med to lower their blood sugar
