Question | Answer |
Read vander p2-4 for functions of kidney | |
Cortex of the Kidney | Granular outer region that contains the glomeruli and tubules. |
Medulla of the Kidney | Darker inner region that contains:
1.NO glomeruli.
2.Parallel arrangement of tubules.
3.small Blood vessels. |
Medullary pyramids | the collecting ducts from a large portion of the medulla. Goes from cortex to minor calyces. |
How are nephrons catagorized? | by the location of the renal corpuscle in the cortex:
1.Superficial nephron (Only extend into outer medulla).
2.Mid-cortical nephron.
3.juxtamedullary nephron (extend down into inner medulla). |
Capillary endothelium in the glomerulus allow passage of everything except? | 1.Blood cells.
2.Platelets.
3.Large plasma proteins (ex: albumin) |
Juxtaglomerular apparatus | 1.Extraglomerular matrix: cont w/ smooth muscle cells of afferent and efferent arterioles.
2.Macula densa: specialized epithlium of thick ascending limb where it contacts glomerulus.
3.Granular (juxtaglom) cells: in wall of afferent arteriole. |
What is the function of the Granular (juxtaglomerular) cells | Production, storage, & regulation of renin. |
Are the resistances in the afferent and efferent arterioles High or Low? | HIGH |
What does the efferent arteriole turn into? | it travels deep into the medulla and turns into the hair pin loop called the VASA RECTA |
Is the pressure in the peritubular capillary high or low? | LOW.
**good for providing O2 and nutrients and removing waste. |
Renal Corpuscle consists of | 1.Glomerulus.
2.Bowman's capsule.
3.Bownan's space (this is where fluid filters). |
3 layers of the Filtration barrier | 1.Capillary endothelium.
2.Glomerular basement membrane.
3.Layer of epithelial podocytes.
**allows fluid movement, restricts protein movement. |
Filtration slits | Formed between in the spaces b/w pedicles of podocytes.
**Covered in neg charged glycoproteins so filtration favors + charged solutes. |
What do mesangial cells secrete and what happens when they contract | 1.Secrete extracellular matrix.
2.DECREASE surface area when they contract. |
What do macula densa cells detect? | Salt.
**Contribute to GFR and renin secretion. |
JGA contributes to control of | 1.RBF & GFR.
2.Na+ balance.
3.Systemic BP. |
Innervation of the Kidney | Mostly SNS
**no significant PNS |
Filtration | Fluid goes from glomerulus into Bowman's Capsule. |
Secretion | Moves from pericapillary, across basolateral then apical membranes to lumen of tubule |
Reabsorption | Moves from the tubule lumen, across apical then basolateral membranes back into pericapillary. |
What does freely filtered mean? | Substance presents in the filtrate at the same concentration as found in the plasma.
**Protein binding will decrease filtration. |
Glomerular filtrate | Fluid that has left the BL and entered bowman's capsule protein free. |
Glomerular filtration rate (GFR) | VOLUME of filtrate per TIME.
1.L/day:180.
2.ml/min:125. |
When do you put a patient on dialysis? | when GFR drops below 12ml/min |
Main functions of Proximal tubule | 1.Reabsorbs 2/3 of filtered water, Na, Cl.
2.Reabsorbs all of the organic substances (glucose, aa's).
3.Secretes waste and drugs (penicillin, morphine, urate) |
Main Function of Loop of henle(thin descending & ascending, thick ascending) | Allow Na+ and Water movement in order to creat a hyposmotic solution entering the distal convoluted tubule. |
main function of Distal & Connecting tubules | Reabsorb additional salt and water. |
what are the cortical collecting tubules & ducts regulated by? their effects? | 1.Aldosterone: Inc Na+ reabsorption & Inc K+ secretion.
2.ADH: Inc water reabsorption. |
With aldosterone present, do you have more or less Na+ present in urine? | LESS |
With ADH, is urine more concentrated or dilute? | Concentrated (due to water reabsroption) |
Organs influencing Hormonal control over the Kidney | 1.Adrenal cortex: aldosterone & cortisol.
2.Adrenal medulla: Epi & NE.
3.Pituitary (AVP/ADH).
4.Heart (ANP). |
What effect does Cortisol have on the kidneys? | Inc GFR b/c it Inc glomerular BF. |
What does SNS control in the kidenys? | 1.RBF.
2.GFR.
3.Renin release. |