Term
| what is the gross anatomical and physiological makeup of a renal lobule? |
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Definition
Gross - a medullary ray
phys - the area drained by a collecting duct |
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Term
| What is the difference between juxtamedullary and cortical nephrons? |
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Definition
Juxtamedullary = long loop, vasa recta
cortical = short loop, lots of peritubular capillary |
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Term
| What sorts of cells create the filter of the glomerulus? |
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Definition
| The podocytes, with their pedicles |
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Term
| Name the layers that filtrate has to pass through to go from glomerulus to proximal convoluted tubule |
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Definition
| 1) glomerular endothelium 2) basement membrane 3) filtration slits of podocytes |
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Term
| what is the type of collagen that the GBM is made of? What is its net charge (combined with other GBM substances) |
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Definition
| type IV collagen -> negative charge |
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Term
| what type of epithelia are in the kidneys? |
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Definition
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Term
| What is the support cell of the glomerulus? |
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Definition
| the mesangium - phagocytosis, growth factor, physical support |
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Term
| What are the specializations of the proximal conv. tubule cells? |
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Definition
| Apical absorptive (long microvilli, glycocalyx w/ digestive enzymes), active transport (lots of mitochondria, basal foldings, tight junctions) |
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Term
| What is histological difference between proximal/distal conv. tubule cells? |
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Definition
apical nuc -> distal
shorter microvilli -> distal
no glycocalyx -> distal |
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Term
| What are the histological features of collecting duct cells? |
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Definition
Intercalated - dark (lots of mitochondria), secretes H+, reabsorb HCO3-
Principle cells - lighter, aquaporins (ADH) and Na+ channels (aldosterone) |
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Term
| What is the location of the dural venous sinuses relative to the meninges? |
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Definition
| They are located in the middle of the meningeal (central) layer of the dura mater. |
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Term
| What is the nerve supply to the dura mater? |
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Definition
Supratentorial -> CN V
Infratentorial -> Upper cervicals |
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Term
| What is the source of bleed for a subdural hemotoma? |
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Definition
| bridging veins (between brain and dural v. sinsuses) are torn at plane of dural border cells |
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Term
| what are arachnoid villi? |
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Definition
Projections from arachnoid barrier cell layer (contain trabecuale too!) -> dural v. sinuses
Transmits CSF -> DVS's |
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Term
| What is source of bleed of subarachnoid hemotoma? |
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Definition
| arteries in sub arachnoid space |
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Term
| how do toxins drain from the brain? |
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Definition
| the CSF especially (takes place of lymph) |
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Term
where is the choroid plexus located?
What else secretes CSF? |
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Definition
1.All 4 ventricles (only roofs of 3+4)
2. Ependyma |
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Term
| What is the characteristic of the endothelium in most of the brain? What sort of structures form exceptions to this characteristic? |
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Definition
Most - tight junctions, no/little pinocytosis
Body-monitoring nuclei (circumventricular: around 3+4 ventricles) = fenestrated, pinocytosis |
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Term
| What are the arteries that supply the spinal chord? |
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Definition
| The anterior (single) and posterior (paired), and the artery of adamkiewicz |
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Term
| How many posterior communicating arteries are there? Anterior ""? |
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Definition
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Term
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Definition
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Term
| What is the site of action of ADH? Aldosterone? |
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Definition
ADH -> CD
Aldosterone -> CD, DCT |
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Term
| Where in the kidney would there be most damage if there was a toxic substance secreted in the urine? |
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Definition
| tubular cells in the (deep) medulla - because there would be highest [solute] |
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Term
| What layers are present in the ureters and bladder? |
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Definition
| Epithelium, L.P. with lot of collaginous CT, 2-3 layers of muscle (more distally). Adventitia (well vascularized, innervated, continuous with pelvic fascia.) |
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Term
| What type of cells/where are the JG cells? |
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Definition
| These are specialized renin-filled myoepithelioid cells in the afferent arteriole. |
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Term
| What are macula densa cells? |
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Definition
| These are cells that maintain contact with the JG cells (no basement membrane). They are part of the very proximal distal convoluted tubule, and are tall and crowded. |
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Term
| What are the cells between the macula densa and the glomerulus? |
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Definition
| the extraglomerular mesangial cells |
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Term
| What is the net effect on blood pressure during partial kidney loss? |
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Definition
Increase -
1) less Na+ excretion -> greater extracellular fluid volume
2) greater renin secretion (mechanism unknown - but renin secretion does increase in partial kidney loss) |
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Term
| What is uremia? Sympotms? |
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Definition
| Uremia is kidney failure, characterized systemic buildup of substances (eg urea) the kidney was supposed to excrete. Symptoms include edema (Na retention, low plasma [protein] 2ndary to proteinuria), itching, anemia (low [EPO]), fatigue (2ndary to anemia), dyspnea (2ndary to pulmonary edema), myalgia ("") (muscle pain), nocturia, protein in urine |
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Term
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Definition
| A protein found in the diaphragms between podocyte pedicles |
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Term
| can proteins be filtered across the glomerulus/bowman's capsule barrier? |
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Definition
Yes - but only if they're quite small, like myoglobin
typically, the net filtration is zero, because of the constant pinocytotic activity of the proximal tubule. |
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Term
| which three forces determine the starling forces that affect glomerular filtration? |
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Definition
| colloid osmotic pressure of plasma, capillary hydrostatic pressure, bowman's space hydrostatic pressure |
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Term
| why is the renal medulla nearly hypoxic? |
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Definition
| All blood supply to the renal medulla is indirect, passing through glomerulus first (vasa recta). |
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Term
| what are the greatest sites of vascular resistance (and thus regulation) in the kidney? |
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Definition
| the afferent and efferent arterioles |
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Term
| why is it that the peritubular capillaries are mostly absorptive, while the glomerular capillaries are mostly secretive? |
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Definition
| The efferent arteriole is high resistance, so there is a large pressure drop over its length, so that for the peritubular capillaries, the net starling forces (sum of hydrostatic + colloid osmotic pressures) favor absorption |
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Term
| is the glomerulus a high-resistance vascular system? |
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Definition
| No! Very little observable pressure drop over the glomerulus (also, remember that only ~1% of incoming plasma is being filtered, so there is no pressure difference across glomerulus due to change in capillary wall tension) |
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