Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
44 Cards in this Set
- Front
- Back
|
What structures are located in the cortex of the kidneys?
|
Renal corpuscles, convoluted and straight tubules, collecting tubules, vascular supply
|
|
|
What are medullary rays?
|
Aggregates of straight tubules and straight collecting tubules extending from cortex into the medulla
|
|
|
What are renal pyramids?
|
Conical structures formed from the tubules in the medulla; base toward the cortex, 6-12 per kidney
|
|
|
What does each lobe of the kidney consist of?
|
Renal pyramid, cortical region above it, 1/2 of each cortical column beside it; 6-12 lobes per kidney
|
|
|
In what order does filtrate flow through the structures of the kidney (9 structures)?
|
1. Glomerulus and Bowman's space
2. Proximal convoluted tubule 3. Proximal straight 4. Descending thin limb 5. Ascending thin limb 6. Thick ascending limb 7. Macula densa (adjacent to vascular pole) 8. Distal convoluted tubule 9. Collecting tubule |
|
|
What is the renal corpuscle?
|
Glomerulus + Bowman's capsule + efferent and afferent arterioles
|
|
|
Where do the renal corpuscles lie in cortical nephrons? In Juxtamedullary nephrons?
|
Cortical nephrons - outer part of cortex
Juxtamedullary - inner cortex |
|
|
How do the Loops of Henle compare between cortical and juxtamedullary nephrons?
|
Cortical - short loop, just enters medulla
Juxtamedullary - long loop, runs deep into medulla |
|
|
How do the functions of cortical and juxtameduallry nephrons differ?
|
Cortical - Filtration
Juxtamedullary - Concentrate urine by creating higher osmolarity in medulla |
|
|
What is the parietal layer of Bowman's capsule made of?
|
Squamous cells lining renal corpuscle
|
|
|
What is the visceral layer of Bowman's capsule made of?
|
Special epithelial cells called podocytes that surround glomerular capillaries
|
|
|
How does the glomerulus restrict that filtration of red blood cells?
|
Fenestrated endothelium around glomerular capillaries prevents RBC filtration
|
|
|
The glomerular basement membrane represents a fusion of which 2 cell layers?
|
Fusion of the endothelial basement membrane and the basement membrane of podocytes
|
|
|
What are the layers of the glomerular basement membrane?
|
Lamina lucida interna
Lamina densa Lamina lucida externa |
|
|
What is the role of the lamina lucida interna?
|
Contains polyanions that act to prevent the loss of negatively charged ions from the blood
|
|
|
What is the role of the lamina densa?
|
A type IV collagen meshwork that acts as a physical barrier, preventing loss of proteins >70kD
|
|
|
What is the role of the lamina lucida externa?
|
Prevents negatively charged molecules from leaving blood
|
|
|
How are podocytes structured to act as a filtration barrier?
|
Podocytes have filtration slits between pedicels that act as the final filtration barrier
|
|
|
What are the roles of mesangial cells?
|
1. Phagocytose trapped residues and aggregated proteins from basement membrane of glomerulus - keep free of debris
2. Structural support for podocytes 3. Extraglomerular mesangial cells provide structural support for vascular pole |
|
|
What are the roles of the proximal tubules?
|
Reabsorb 65% of primary filtrate, salts, amino acids, sugars, polypeptides, small proteins (endocytosis)
|
|
|
How is the structure of proximal tubule cells designed for best reabsorbing filtrate?
|
1. Brush border to increase surface area
2. Infolding of basal process 3. Basal striations of elongated mitochondria in basal processes |
|
|
What type of epithelial cells line the thin segments of the loop of Henle?
|
Simple squamous
|
|
|
What is the role of the loop of Henle in juxtamedullary nephrons?
|
Create and maintain osmolarity of medullary interstitium
|
|
|
What happens to the filtrate in the thin descending tubule?
|
Filtrate becomes hypertonic - water flows out freely
|
|
|
What happens to the filtrate in the thin and thick ascending limbs?
|
Filtrate becomes hypotonic; impermeable to water, but salts can move out
|
|
|
How does the movement of salts differ in the thin vs. thick ascending tubule?
|
Thin ascending tubule - passive diffusion of salts into medullary interstitium
Thick ascending tubule - active transport of salts |
|
|
What structures are included in the Juxtaglomerlar apparatus?
|
Efferent and afferent arterioles, macula densa, juxtaglomerular cells, and extraglomerular mesangial cells
|
|
|
Where is the macula densa and how are the cells different than the surrounding cells?
|
Macula densa located where the thick ascending tubule approaches the vascular pole
Cells are thicker, taller, have more prominent nuclei |
|
|
What are the roles of the macula densa?
|
Senses osmolarity of the filtrate, controls the release of renin from juxtaglomerular cells
|
|
|
What are the juxtaglomerular cells?
|
Smooth muscle cells of afferent arteriole, release renin
|
|
|
What are the roles of the Juxtaglomerular cells?
|
Regulate blood pressure and filtrate osmolarity by secreting renin
|
|
|
How is the distal convoluted tubule different from the proximal tubule?
|
DCT is...
1. Less tortuous 2. Lined by simple cuboidal epithelium, thinner walls 3. Bigger lumen 4. No brush border, less surface area |
|
|
What is the role of the distal convoluted tubule and what regulates this?
|
Sodium reabsorption; regulated by aldosterone (increases reabsorption)
|
|
|
What is renovascular hypertension?
|
If decreased flow to the kidney, J cells secrete excess renin --> increase ang II and aldosterone --> higher blood pressure
|
|
|
Where are the collecting ducts and collecting tubules located?
|
Collecting ducts - medulla
Collecting tubules - medullary rays |
|
|
What are the roles of the collecting ducts and tubules?
|
1. Contribute urea to create high osmolarity of inner medullary region
2. Control concentration of urine in response to ADH secretion |
|
|
What is diabetes insipidus?
|
Absence of ADH, leading to lots of hypotonic urine
|
|
|
Where does the peritubular capillary network come from and what are its roles?
|
Mostly comes from efferent arteriole of cortical nephrons
Important in reabsorption of water and ions |
|
|
Where does the vasa recta come from and what are its roles?
|
Comes from efferent arterioles of juxtaglomerular nephrons, descend alongside loop of Henle
Permeable to salts and water, maintain high osmolarity in medulla |
|
|
Through what structures does urine flow once it leaves the collecting tubules?
|
Ducts of Bellini (collecting ducts) --> minor calyx --> major calyx --> renal pelvis --> ureter --> urinary bladder
|
|
|
What type of epithelium lines the excretory passages?
|
Transitional epithelium, gets thicker as you go lower down the urinary tract
|
|
|
How is reflux of urine into the ureters from the bladder prevented?
|
When the bladder distends with urine, the openings of the ureters are compressed
|
|
|
What are the muscle layers of the ureters?
|
Inner longitudinal, outer circular, outer longitudinal in some areas
|
|
|
What are the wall layers of the bladder?
|
Transitional epithelium, lamina propria, longitudinal smooth muscle, circular smooth muscle
|
