renal anatomy 2 Flashcards
What are the two types of nephrons and their properties
Cortica nephrons: lie mainly in crotex - 85% of nephrons - nephron loop dips into medulla
Juxtamedullary nephron - extends deep into medulla- renal corpussle close to medulla - concentrated urine
What is the basic structure of a nephron
Glomerular capsual - proximal convoluted duct- nephron loop - distal convoluted tubule - collecting duct
What is the function and acessory stucture with a nephron
Selective filtration of blood + reabsobtion of requires fitrate + waste removal + expulsion
Pritubular capilarys
glomerulus capillaries
What are podocytes and their specificatios
Specilised epithelium with branches wrapped around golmerular capillaries
Brances form pedicles forming filtration slits as they intertwine with one annother
- Filtrate passes through slits into capsular space
What are the functions of the capillarys associated with the nephron
Golmerulus capillaries - fenestrated capilarys fed + drained by arteriols which tightly regulated blood pressure
peritubular capillaries - specilised reabsoption wrapped around renal tubules
- fed filtered blood from efferent arteriol
- reabsobtion filtrate from nephron
- additional filtration of unfiltered solutes passed to nephron
vasa recta - extentions which follow nephron loop into medulla in juxtamedullary nephrons
What is the glomerular capsual
Two layers + space:
outer perietal layer - simple squamous cells
inner visceral parietal layer of podocytes
Between two layers - capsular space
What is the renal corpuscle
Glomerulus enclosed by the golmerular capsual -
filtration site where nephron + capillarys meet
- filtration barrier
What is the filtration barrier
Blood urine barrier
Lies between blood and capsular space
- enables passage of small molecules + water, prevents large molecules + RBC
- fenestrated endothelium of golmerular capillarys
- fused basement membrane - fused from both cells basement membrane
- filtration slits between pedicles of the podocytes
How to determine what is remaining in the urine
urine = Filtrate - reabsoption + secretions
What is the function of the proxmal convoluted tubule + anatomy
Bulk reabsoption - surrounded by peritubular capillaries
ring of simple cuobidal epithelium
- apical dense brush border
- infolded basolateral membrane
- leaky tight junctions, paracellular transport
- high mitochondral content, transcellular tansport
What is the function and anatomy of the nephron loop
Loop into the medulla (small cortical, lots juxtamedullary) - longer = more concentrated
Thick decending limb - Ep same as PCT
thin decending limb - simple squamous
thin acending limb - simple squamous
Thick assending limb Ep same as DCT
thick or thin changes periability
What is the function and anatomy of the distal conveluted tubule
Cuboidal epithelium (thiner than PCT)
- no brush boarder, few mitochondra
- Hormonal controled specific reabsoption
What is the function of the collecting duct
fine tuned reabsoption regulated by hormones
Many nephrons drain to collection duct whcih emptys to the renal papilla
cuboidal cells 2 types
princaple cells - reabsoption (few mitochondria + mitochondria, less than DCT)
Intercalated cells - acid/base balance
