Final Review Deck - Lecture IV - Kidney Function Flashcards
What are the six functions of the kidneys?
- regulate the plasma volume, ecf volume, and blood pressure
- regulate blood osmolarity
- maintain ion balance of plasma
- regulate pH
- excrete wastes
- hormone secretion (renin, calcitriol, erythropoietin)
What does renin do?
it converts angiotensinogen to angiotensin I which goes to the adrenal cortex and releases aldosterone
How do the kidneys regulate plasma volume, ECF volume and blood pressure?
-because fluid leaks out of the capillaries and exchanges with the interstitial fluid until it is in equilibrium
-starlings law greater plasma volume greater EDV and greater CO and greater bp
How do kidneys regulate blood osmolarity?
-regulate water content of the plasma or the blood and bunch of fluid leaks out of the capillary from the kidney into kidney tubules and reclaim 99% or more depending on how much water and solute you are consuming
-need to transport solutes and calcium to main excitability of neurons and concentrations
-potassium needs to be kept low and excreted
How do the kidneys maintain pH?
-keep the proton concentration in a range from 7.4 +/- 0.1
How do the kidneys excrete wastes?
kidneys have to get rid of waste like nitrogen waste due to diet having amino groups on amino acids and nucleic acids and is converted to ammonia NH3 which can pick up a proton and become NH4+ which is converted to urea and excreted from the body
How are kidneys involved in the function of hormones?
-secretes calcitriol to increase the amount of calcium in the body
-erythropoietin is released which stimulates rbc production in red bone marrow
-also secrete renin in RAA system
Where are the kidneys located?
protrude into the abdomen and they are located behind the peritroneum which is a multicellular membrane that lines the abdomen and covers all of the abdominal organs and the kidney is an example of a major organ behind the peritoneum which covers the kidney
The renal arteries are behind the renal veins and what is their shape and diameter size?
short and large in diameter
How much blood flow do the kidneys get?
disproportionate; 20% of the CO
What is the product of the kidney?
the urine and it comes to the bladder through the ureter
When the bladder fills up what causes the expulsion of urine?
a spinal reflex and it leaves through the urethra which is shorter in women and longer in men because it wraps around the prostate and goes to the penis
What are three parts of the kideny?
outer part is cortex inner part is medulla and urine goes into the renal pelvis to the ureter
What are the two types of nephrons?
cortical and juxtamedullary nephron which is adjacent to the medulla and has a long loop of henle that dips int the medulla - there 80% cortical nephrons and 20% juxtamedullary nephrons
What does the collecting duct feed into and how many nephrons can it collect fluid from?
-feeds into the renal pelvis
-many different nephrons
What are the afferent and efferent arterioles and what do they feed blood into?
so both of these 2 vessels are arterials one is called the afferent arteriole because it is carrying towards something and they are carrying blood toward the glomerular capillaries and the other one is efferent arteriole carrying blood away from the glomerular capillary so the blood flow away and it then splits into capillaries and these are known as peritubular capillaries and they wrap all around a tubule and they wrap around the loop of henle
What is the shape of peritubular capillaries and what do they parallel?
long straight also known as vasa recta and they parallel the loop of henle
What are two other examples of portal veins in the body?
-There is a small portal vein (hypothalamic hypotheseal portal vein) below the median eminence of teh hypothalamus or just below the hypothalamus on the Brian so below the hypothalamus is this little protrusion in the midline called the medial eminence - there is a set of capillaries there that take hypothalamic releasing hormone from hypothalamic neurons and funnel them via the small portal vein to the capillaries of the anterior pituitary where the control anterior pituitary hormone release
-there is also the large vein between the intestine and liver which is the hepatic portal vein which carries nutrient rich blood from the intestine and carries it to the liver to make protein in the liver and gluose converted into glycogen stored in the liver and lipids and made lipoproteins in the liver
What completely surrounds the glomerulus?
bowman’s capsule
How does fluid travel in the kidney?
-fluid goes through glomerulus and is filtered through the proximal tubule down into the loop of henle descending limb which then goes up the ascending limb into the distal tubule this is also known as the distal convoluted tubule and the proximal convoluted tubule and the distal tubule will dump its contents into the collecting duct
