genitourinary Flashcards
- What are the main functions of the kidney?
Excretion of metabolic products such as urea, uric acid, creatinine
Excretion of foreign substances Homeostasis of bodily fluids, electrolytes and acid-base balance Regulates blood pressure Secretes hormones such as erythropoeitin and renin
- Where does the urine once formed, travel through in the kidney?
Minor calyx to the Major calyx and then through the ureter
- What are the functions of the peritubular capillaries?
Provide oxygen and nutrients to the nephron to allow them to perform their functions
Help in reabsorption of different substances along the nephron and then take it away to the circulatory system Help in secretion of different substances into the tubular fluid
- What is the function of the detrusor muscle?
- What does stretching of the trigone to its limit lead to?
Detrusor muscle - Contracts to build pressure in the urinary bladder to support urination
Signals sent to the brain about the need for urination
- Is it the internal or external sphincter that gives involuntary control to prevent urination?
Internal sphincter - must be relaxed for urination to proceed
External sphincter gives voluntary control to prevent urination
- What are the 2 different cell type classes in the distal convoluted tubule and the collecting duct and describe their mitochondria density?
Principal cells - Low density of mitochondria, the main Na+ reabsorbing cells and the site of action of aldosterone K+ sparing diuretics
Intercalated cells - High density of mitochondria, regulation of acid-base homeostasis
- What are the anatomical differences between the juxtamedullary and superficial nephrons?
The glomerulus of the superficial nephron is in the upper cortex, whereas the juxtamedullary nephron has its glomerulus closer to the medullary border
The Loop of Henle in the superficial nephron only extends to the outer medulla, whereas the juxtamedullary nephron has its one extending into the inner medulla
- Why does the cortex have a granular appearance, whereas the medulla has a striated appearance?
Loop of Henle extending through the medulla gives it its striated appearance
- What are the main functions of this juxtaglomerular apparatus?
- What forms the juxtaglomerular apparatus?
GFR regulation through tubular-glomerular feedback mechanism
Renin secretion for regulating blood pressure
macula densa on distal convoluted tubule
juxtaglomerular cells
extraglomerular mesangial cells
- What are the 4 main renal proccesses?
Glomerular filtration
Reabsorption Secretion Excretion
- Describe the permeability of the filtration barrier
Highly permeable to fluids and small solutes
Impermeable to cells and proteins
- What is the name of the spaces between capillary endothelium and how big are they?
- What substances can pass through these spaces?
Fenestrae
70nm in diameter
Water, ions and small proteins
- What substances can pass through the slit diaphragm of the glomerular basement membrane?
- What are podocytes?
Water and small solutes only
Highly specialised cells of the kidney glomerulus that wrap around capillaries and that neighbour cells of the Bowman's capsule
- How do you calculate the net ultrafiltration pressure?
Puf = HPgc - HPbw - πgc
Puf - Net ultrafiltration pressure HPgc - hydrostatic pressure in glomerular capillaries HPbw - hydrostatic presure in bowman's capsule πgc - Oncotic pressure of plasma proteins in glomerular capillaries
- What is meant by the glomerular filtration rate and how do you calculate it?
Amount of fluid filtered from the glomeruli into the Bowman’s capsule per unit time (ml/min)
GFR = Puf x Kf Kf - ultrafiltration coefficient (membrane and surface area available for filtration