Urinary System Flashcards
Which blood vessel feeds into the kidney?
Renal artery
The basic structural and functional unit of kidney is the _
Uniferous tubule
Blood arrives at the glomerulus by _ arteriole
Afferent
Blood leaves the glomerulus by _ arteriole
Efferent
Describe structure and function of cortical nephrons.
85% of nephrons. Located mostly in the cortex, have short loop. Fxn: reabsorption and secretion
Describe structure and function of juxtamedullary nephrons.
15% of nephrons. Long loops that extend deep into the medulla. Fxn: water conservation aka urine concentration
Describe the Renal Corpuscule.
Bowman’s capsule with the glomerulus inside. Has capillaries coming into and out.
The space inside the Renal corpuscule is called _
The Bowman’s / Urinary space
Describe the lining of the Bowman’s capsule
The visceral (inside), where the glomerulus makes contact is lined with Podocytes. The outer wall surrounding the Bowman’s space is lined with simple squamous epithelial cells and is called the Parietal layer.
Describe location and function of Podocytes.
Found on visceral epithelium of Bowman’s capsule, in contact with the glomerulus.
Fxn: forms slits for filtration.
Describe the location and function of Extraglomerular mesangial (Lacis) cells.
Located at the visceral pole.
Fxn: physical support, phagocyte and contractile bc they have receptors for vasoconstriction (Angiotensin II)
Describe the location and function of Intraglomerular mesangial cells.
Located within Renal corpuscule.
Fxn: physical support, phagocyte and contractile bc they have receptors for vasoconstriction (Angiotensin II).
Describe the proximal tubule.
Has 2 parts - convoluted and pars recta. Lined with simple cuboidal epithelium with microvilli. Make fxn is absorption of all organic nutrients (60% of Na, Cl, K, Ca, Mg, etc) and with these comes water.
Describe the Descending thin limb.
Very permeable to water, reasonably permeable to urea, Na, Cl etc.
Describe the Ascending thin limb.
Moderately permeable to water.
Describe the Distal convoluted tubule.
Impermeable to water and urea, but in response to Aldosterone, can absorbs Na (and Cl passively). This will INC BP! Has a section called theMacula Densa.
Describe location and function of Macula densa.
Located in Distal concoluted tubule.
Fxn: secreting ions, acids etc. Selective reabsorption of Na and Ca. And selective reabsorption of water. Chemoreceptors. Kind of like the quality assurance - checking if urine is right concentration.
Location and function of Juxtaglomerular cells.
Located in tunica media of afferent (sometimes efferent) glomerular arterioles. Modified smooth muscle cells, contain granules of renin. In close contact with macula densa. Fxn: secrete renin.
Location and function of Juxtaglomerular apparatus.
Made of Macula densa of distal tubule, juxtaglomerular cells of afferent glomerular arteriole and extraglomerular mesangial cells. Fxn: regulate BP
Describe the Collecting tubules.
Ultrafiltrate enters the CT, is modified and delivered to medullary papillae. They are impermeable to water, unless in the presence of ADH.
Describe the effects of ADH on collecting tubules and urine.
Yes ADH = Collecting tubule is permeable to water (and urea). Causes low volume and concentrated urine.
No ADH = CT is impermeable, high volume and diluted urine.
Describe the layers of the Ureter.
- Star shaped lumen!
- Tunica mucosa - Transitional/ urothelium
- Tunica Muscularis - inner longitudinal and outer circular
- Tunica Adventitia - CT, blood, lymph, nerves.
Locationg and function of Uroplankins (umbrella) cells.
Located in bladder. Give the epithelium flexibility, lets it expand after it is full. Forms and impermeable layer.
