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20 Cards in this Set
- Front
- Back
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Functions of Kidney (5)
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1)Osmotic Regulation
2) Excretion of nitrogenous wastes 3) Filtration (lots of blood goes through kidney) 4) Regulation of Blood Pressure 5) Regulation of RBC Production - the hormone erythropoietin accelerates the maturation of the final precursor of RBC |
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Medullary Rays of Kidney
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located between the pyramids/medulla, they are collecting tubules & collecting ducts
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Calyx
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is the last place urine is stored in the kidney before it is sent out to the ureter, urinary bladder, and urethra.
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Parietal Epithelium of Bowman's Capsule
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Simple Squamous
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How to cause pressure in Bowman's capsule
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By closing the afferent (going to) arteriole
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Fenestrations
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greatest barrier for blood to get to bowman's space. even restricts proteins. do not allow platelets to get through.
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Proximal Convoluted Tubule
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Lots of reabsorption of glucose, amino acids, vitamins, proteins, and water. Its cells are large with eosinophilic (pink) cytoplasm. There is a fuzzy lumen due to microvilli and CT surrounds it.
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Distal Convoluted Tubule
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Compared to PCT, has a clearer lumen, more cells, not as much staining (cytoplasm is not eosinophilic), smaller.
There is active secretion of potassium and hydrogen (acid base) and reabsorption of sodium. |
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Henle's Loop Track
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Involved in the recirculation of NaCl b/c of its loop shape, thicker cells on one side and thinner on the other.
NaCl goes from thick segment (ascending loop), diffuses through CT, enters thin segment (descending loop) into lumen. Thin segment becomes more concentrated meaning hypertonic. Then going towards thick, it becomes isotonic again (it's isotonic at PCT before it gets to thin) |
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Henle's Loop Functions
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establish a salt gradient throughout the CT of kidney
The collecting duct cares about the salt concentration, it allows the duct to function Allows humans to retain lots of water. |
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Osmoreceptor and its hormone
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The osmoreceptor in the pituitary gland can swell and shrink in response to the water amount in the body. It then sends a consequent signal to a neuron, which releases Vasopressin, an anti-diuretic hormone (ADH), depending on the information
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Scenario 1: You drink 10 gallons of water
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Then osmoreceptors will shut down in the absence of ADH, and most of the water will be excreted. There are secretory vesicles stored inside the cells, which are outside of the lumen of the collecting duct (in the membrane). With lots of ADH, rater will be removed via osmosis from these channels.
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Scenario 2: You exercise for 12 hours in the hot sun with no water
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Then lots of ADH is secreted, water is reabsorbed through the channels which causes more water channels to form in the membrane. This is the function of the collecting duct - it responds to ADH.
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Juxtaglomerular Apparatus
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Composed of the edge of Bowman's Capsule, the afferent and efferent arteriole, and the distal convoluted tubule.
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Macula Densa
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On the side of the distal convoluted tubule that touches the bowman's capsule, there will be a cluster of nuclei, whereas on its other side, they will be more spread out. This spot of densely packed nuclei is called the macula densa. The macula densa cells are chemoreceptors for sodium in the filtrate.
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Juxtaglomerular Cells
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(will not identify these in lab) They are modified smooth muscle cells found in the wall of the afferent arteriole.
They are used to measure blood pressure (baroreceptors) b/c measuring pressure via the smooth muscle cells is the best way to go b/c smooth muscle can be stretched. |
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As blood pressure decreases...
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...less sodium is detected by macula dense. They cannot release renin but cause juxtaglomerular cells to release renin via communication via receptors
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Renin
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Is released by blood pressure into the blood.
Renin causes angiotensinogen (produced by liver) to turn into angiotensin I. Angiotensin I is converted into angiotensin II via a lung enzyme. |
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Angiotensin II (Method 1)
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Shorter and more potent than Angiotensin I, therefore serves as a better agent to bring blood pressure back up.
1) Causes the Zona glomerulosa of adrenal cortex to release aldosterone 2) which causes increased reabsorption of sodium in the distal convoluted tubule 3) which causes increase in water reabsorption 4) which causes increase in blood volume 5) which causes increased blood pressure |
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Angiotensin II (Method 2)
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Causes arteriolar constriction to increase, which causes increase in blood pressure
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