Lecture 3 Flashcards
What are the four goals of the kidneys
balance water/solutes, excreate metabolic waste, conserve nutrients, regulate acid/base
How do the kidneys impact our endocrine function?
It regulates our blood pressure by releasing renin
It is a part of erythrocyte (RBC) production through the secretion of erythropoietin (more when O2 is low)
Assists in the metabolism of calcium. The kidney plays a key role in this process by the fine regulation of calcium excretion. More than 95% of filtered calcium is reabsorbed along the renal tubules. Apart from activation of Vitamin D, the kidneys increase calcium and phosphorus reabsorption in the tubules under the influence of 1,25-dihydroxyvitamin D (1,25VD).
What is the trigone area in the bladder?
A triangle shaped area between the open of the two ureters that empty into the bladder and above the urethra.
How long is the female urethra?
3-4cm
How long is the male urethra?
18-20cm
What is the gate in the urethra for urine to escape from
A smooth muscle called the internal urinary sphincter at the junction of the urethra and the bladder
How much urine can your bladder hold before it has the urge to void?
230-300ml causes the bladder to stretch and activate the parasympathetic fibers of the ANS Micturition Reflex
Another word for void
micturition
Difference between to cortex and medulla of the kidney
The cortex is the meaty outer part and the medulla is a pyramid. There are renal columns between the pyramids that release into the renal pelvis
What are the three functions of the nephron
glomerular filtration, tubular reabsorption, tubular secretion
Describe the anatomy of the nephron
Capillary branches off into renal corpuscle where the capillaries turn into a ball of yarn (glomerulus) which releases excess waste products, ions, and amino acids (aka: filtrate) from blood into capsule. RBCs and proteins too big and stay in blood then exit through the peritubular capillaries (vasa recta). Filtrate then goes into elaborately twisting 3cm long renal tube 3 parts 1st proximal convoluted tubule (PCT) then drops into dramatic hairpin turn called nephron loop (loop of Henle) then distal convoluted tube (DCT) than empties out into a collecting duct each part filters out certain things
- Describe proximal convoluted tubule (PCT)
Walls made of cuboidal epithelial cells with big mitochondria that fund active transport of sodium ions and other good filtrate back into blood
- Describe distal convoluted tube (DCT)
Loop of Henle dips into medulla and comes back into cortex. Biggest job is to release water on the way down and create a salt concentration on the way up in constant cycle that keeps water drawn out. Then urea enters collecting duct and is recycled by going through medulla again to make even more salty.
Describe tubular transport
The last minute throw away of excess hydrogen, potassium, acids and bases from blood using active transport
Describe glomerular filtrate rate
Kidneys can only process so much filtration at once. When the blood pressure increases and ball of yarn (glomerulus) experiences increased pressure it activates stimuli that shrinks glomerulus and closes the fire hose a bit.
Why does caffeine and alcohol make you pee more
It inhibits ADH which makes the loop of Henle not reabsorb as much water so it stays in medulla and you pee it out
which sphincter do you control to pee
external urethral sphincters’ made of skeletal muscle
What is the structural and functional unit of the kidney?
Structural lobe, functional nephron
How many nephrons in the kidney
1.2 million
Quickly name the path through the nephron
- corpuscle 2. proximal convoluted tubule 3. loop of henle 4. distal convultuled tuble 5. collecting duct
Three parts of the renal corpuscle
bowman’s capsule, glomerulus, mesangial cells
What is the function of the intercalated cell in the DCT?
Secrete H+, reabsorb K+ and HCO3
What is the function of the principal cell in the DCT?
Secrete K+, reabsorb sodium and water
Which part of the nephron eliminates drugs?
proximal tubule
What part of nephron determines urine concentration?
Loop of henle