anatomy urinary final 2 Flashcards
What are the five known functions of intraglomerular mesangial cells
structural support of glomerular capillaries
regulation of the glomerular filtration rate
mesangial matrix formation
Phagocytosis
monitoring of capillary lumen glucose concentration.
produces a messangial matrix which contains fibronectin, type 4 collagen, prelecan and laminin
mesangial cells
Glomerular capillaries are fenestrated by
a two-layered filtration membrane called:
Fenestrated capillaries / Endothelial cells
podocytes
What cells cells control capillary blood flow
Mesangial cells
What kind of epithilium does the Proximal convoluted tubule have?
Whats the purpose
Simple cuboidal epithelium with microvilli
Reabsorb organic nutrients, water, ions and plasma proteins
what is the Loop of Henle
What kind of epithelium does it have?
Descending and ascending limbs, each containing a thick and thin segment
Thin = simple squamous epithelium, thick = cuboidal
Descending = permeable to water, reabsorbs Na and Cl
Ascending = impermeable, but actively moves ions
what is the purpose of Distal convoluted tubule
what kind of epithilium does it have
Important for:
Secretion of ions, acids, drugs, toxins
Reabsorption of Na and Ca
Reabsorption of water
- Epithelium is simple cuboidal WITHOUT microvilli
What are the two cell types of collecting duct that work together to control the acid-base balance of the blood
Principal cells – reabsorb water and secrete K
Intercalated cells
Alpha IC secrete H and reabsorb HCO3
Beta IC secrete HCO3 and reabsorb H
What are the two cell types of collecting duct that work together to control the acid-base balance of the blood
Principal cells – reabsorb water and secrete K
What are the two types of Intercalated cells?
What do they absorb and secrete?
Alpha IC(Intercalated cells) secrete H and reabsorb HCO3
Beta IC secrete HCO3 and reabsorb H
what ducts do nephrons pass through to reach the minor calyx
Several individual nephrons empty into a collecting duct
Several collecting ducts empty into a papillary duct
Papillary ducts converge as a minor calyx
What are the three stages of urine formation?
Filtration
reabsorption
secretion
describe filtration
Filtration – solutes pass through filtration membrane of renal corpuscle
describe reabsorption
Reabsorption – removal of water and solutes from that filtrate
describe secretion
Secretion – a backup process for filtration in which materials move from peritubular fluids into the collecting tubule, an important route for the removal of many drugs
What is transport maximum? (T^m)
What does it secrete and/or absorb?
Transport Maximum (Tm) = saturation level of the transport system (carrier proteins)
Secretion seldom saturates in healthy people
Reabsorption can saturate, especially after a meal, so glucose and amino acids can show up in urine
What is the adverage amount of filtration produced each minute? (GFR)
Amount of filtrate produce each minute = average of 125 mL/minute
Glomeruli produce about ___ liters of filtrate each day, but most (__%) is reabsorbed
180 liters
99%
GFR is controlled by:
Autoregulation
Hormonal control
Autonomic regulation
What are the functions of the renal tubule?
reabsorb organic nutrients
reabsorb 90% of water
secretes remaining waste
What are the Three types of organic waste:
Urea = generated through breakdown of amino acids
Creatinine = breakdown product of creatine phosphate during skeletal muscle contraction
Uric acid = waste formed through recycling of nitrogen bases from RNA
how is Urea formed?
Urea = generated through breakdown of amino acids
how is creatinine formed?
Creatinine = breakdown product of creatine phosphate during skeletal muscle contraction
How is uric acid formed?
Uric acid = waste formed through recycling of nitrogen bases from RNA
