Kidneys Flashcards
What is the function of the kidneys?
remove waste products and filters blood
regulates electrolytes
regulates blood pressure
reabsorption of water, glucose and amino acids
What does the volume of fluid depend on?
balance of fluid intake and output, kidneys are a major part of this process
Where do we get the feeling of thirst?
receptor cells in hypothalamus activate when hypertonic conditions secrete hormones
receptor cell cease secretion when hypertonic condition is balanced
How does the body know when there is too much fluid in the body?
heart activates stretch receptors which signals reduction of anti-diuretic hormone and less fluid reabsorbed by kidneys, which leads to dilation
What happens when there is an increase in glomerular blood pressure?
increased filtration and less water being reabsorbed into plasma
What are the hormones that are produced by kidneys?**
erythropoietin, renin-aldosterone-angiotensin system, 1,25 dihydroxyvitamin D3 (100%)
What is the site of synthesis of erythropoietin in adults? (TQ)**
kidney
What is the site of synthesis of erythropoietin in fetuses? (TQ)**
liver
Is erythropoietin a neurotransmitter?**
no
What is the function of erythropoietin?**
stimulate development of RBCs in bone marrow
What is erythropoietin a treatment for?
anemia
What can cause high levels of erythropoietin?
performance enhancing drug, but can cause dehydration (increased in exercise)
can also increase thickness of blood (leading to heart attacks and strokes)
What does erythropoietin control the secretion of?**
STH endorphins substance P ADH oxytocin thyroxine
What is the function of renin-angiotensin-aldosterone system?**
regulates blood pressure and fluid balance, stimulates release of norepinephrine, increases vasoconstriction of blood vessels (increase blood pressure when pressure is too low)
What happens if there is a loss of blood volume or blood pressure?**
the baroreceptors in the carotid sinus sense the drop in the BP or blood volume
the macula densa cells signal the juxtaglomerular cells to release renin
What does the macula densa do?**
senses decrease in blood pressure, which causes decrease in glomerular filtration rate (GRF) and increases amount of water retension
WHAT DOES PLASMA RENIN ACTIVATE THE CONVERSION OF?
ANGIOTENSINOGEN FROM LIVER –> ANGIOTENSIN i AND IS CONVERTED TO –>ANGIOTENSIN II - BY ANGIOTENSIN CONVERTING ENZYME FOUND IN THE LUNGS
THUS, LUNG PROBLEMS CAN LEAD TO KIDNEY PROBLEMS AND VICE VERSA
What releases renin into circulation to decrease fluid flow?*
juxtaglomerular cells
What does angiotenin II do in the renin-angiotensin-aldosterone system?
causes blood vessels to constrict and stimulate the release of aldosterone from the adrenal cortex
What is the function of aldosterone in the renin-angiotensin-aldosterone system?**
increases reabsorption of sodium and water increasing blood pressure and fluid volume
What are the hormones of the kidneys?
anti-diruetic hormone, aldosterone, parathyroid hormone, atrial naturetic hormone
What is the function of the renin-angiotensin-aldosterone system?
brings blood pressure back to normal
