3.7 Homeostasis & Kidney Flashcards
(26 cards)
What is homeostasis?
Maintenance of a constant internal environment by negative feedback
Homeostasis prevents fluctuations beyond optimal range, allowing cells and metabolism to function efficiently.
How does the body maintain dynamic equilibrium?
Constant changes occur but are brought back to set point
This involves adjustments in response to changes like core body temperature and pH levels.
What are some changes that homeostasis regulates?
- Core body temperature
- pH levels
- Water potential of body fluids
What are the primary functions of the kidneys?
- Excretion and removal of nitrogenous waste
- Osmoregulation
What is urea?
A product formed from the deamination of excess amino acids in the liver
Urea is removed from the body by the kidneys.
What is osmoregulation?
The control of water potential of the body’s fluids
What happens to excess amino acids in the liver?
They are deaminated, with the amino group removed and converted to ammonia, then to urea.
What is the role of the renal capsule?
It surrounds the kidney
The renal capsule provides protection and structural support.
What is a nephron?
The functional unit of the kidney
What is the path of blood through the kidney?
Renal artery → nephron → renal vein
Blood enters the kidney through the renal artery, is filtered in the nephron, and returns to general circulation via the renal vein.
What is ultrafiltration?
The process by which blood is filtered in the nephron
What is selective reabsorption?
The process of reabsorbing essential substances back into the blood after ultrafiltration
What does the ureter do?
Carries urine from the kidneys to the bladder
What is the role of the bladder?
Stores urine until it is expelled from the body
Fill in the blank: The _______ carries urine out of the body.
urethra
What is the pelvis in relation to the kidney?
It empties urine into the ureter
What is negative feedback?
A change in a system produces a second change, which reverses the first change.
What is the role of a receptor in negative feedback?
Detects a deviation from the set point in the internal environment.
What does the coordinator do in negative feedback?
Receives instructions from the receptor and communicates with effectors.
What happens to the factor in negative feedback?
It returns back to normal (the set point) and is monitored by receptors.
What is the role of effectors in negative feedback?
They make responses that are corrective based on feedback from the coordinator.
What is excretion?
The removal of wastes produced by the body due to metabolism.
What wastes are removed by the lungs?
CO2 and water in expired air.
What wastes are removed by the kidneys?
Urea and creatinine in urine.
