11.2 Lab + Lecture Notes Flashcards
Glomeruli
= circular, largely basophilic structures
- always found within the cortex
- use them to segment slide into cortex, medulla, sinus regions
what does Unperfused tissue mean
= vascular space filled with blood
Transitional epithelium will be seen where in kidney
- major + minor calyces
- ureter = thickest
what are Medullary Rays
- comprised of collecting ducts that travel radially towards the medullary pyramid
- define center of the cortical lobules
What are ducts of Bellini
= largest collecting duct as it exits medullary pyramid
- recognize it primarily by its location
- only nephric tubule near there is the thin tubule
- only capillary near that will be the vasa recta
PTCP
= systemic capillary bed supplying the cortex
Vasa Recta
= systemic capillary bed supplying the medulla
What are three things in the kidney you can label primarily by location
- thin tubules
- vasa recta
- ducts of Bellini
To identify a collecting duct in cortex
- use location + morphology
- look for medullary rays
- contains 2 types of cells
1) principle cells
2) Intercalated cells (5-10%) - contain higher density of mitochondria than principle cells
Compare the morphology of the PCT to the DT
- highly eosinophilic
- basal enfoldings
- cells should be larger (fewer nuclei within a given profile
- prominent brush border (microvilli) + glycocalyx
- since it is larger there will be more profiles ~ 7:1 ratio
Compare the morphology of the thick descending tubule to the think ascending tubule
- thick descending (like PCT)
- thick ascending (like DT)
- can’t use frequency of occurrence in the medulla though because it is closer to 1:1 ratio
What are the 4 cell types within the renal corpuscle and where will you find each
1) Epithelial Cells of parietal layer of bowman’s capsule = simple squamous epithelium (outside of bag)
2) Podocyte = visceral layer of Bowman’s capsule - poke into the urinary space, have relatively condensed nucleus
3) Capillary endothelial cell = squamous cell inside of glomerulus, poke inward towards capillary lumen
4) intraglomerular mesangial cell = round/cuboidal cell, euchromatic nucleus
What elements comprise the juxtaglomerular apparatus
1) Macula Densa
2) JG cells
3) Extraglomerular mesangial cells
What is the urinary pole of renal corpuscle
= where urinary space drains into a PCT
What are the components of the urinary system
1) Kidneys
- produce urine as filtrate of the blood
2) ureters
- tube the connects each kidney to the bladder
3) bladder
- stores urine until voiding
4) uretra
- tube the connects bladder to external environment
Describe the anatomy of the kidney
- each kidney is composed of lobes (with medulla at center surrounded by cortex)
- renal artery/vein give blood to/from the kidney
- urine is conveyed from minor calyx –> major calyx –> leaves kidney via ureter
- medulla = completely surrounded by minor calyx
- hilar = generic term describing region of indentation in kidney bean space
What is the location of the kidney
= retroperitoneal organ
- have dense CT compartment surrounding whole organ (adipose tissue in this CT)
- adrenal gland sits above it
Describe the FXN of the kidney
= filter blood - steps:
1) everything we could possible want removed is removed
- function of glomerular filtration barrier
- produces ultrafiltrate
2) somethings are selectively reabsorbed into circulation
- function of nephron + collecting ducts
- substance as it is being modified = filtrate
3) urine = end product
Describe the function of a nephron
= take everything out of blood + selectively reabsorb A) PCT - takes glucose (+ other lg. molecules) back - puts it into CT --> then back to blood B) descending parts = just water C) ascending parts = just salt D) collecting ducts = differential water resorption - hormonally dependent
What are the 4 basic morphologies of the kidney based on their function - include the relevant parts of the nephron and any functional ultrastructures that are important
1) Active resorption of water salts, especially small molecules
- PCT, PST, Thick descending
- basal striations, microvilli
2) Passive resorption of water
- thin loops
- squamous shaped cells?
3) Active salt transport + control of interstitial osmolarity
- Thick ascending, DST, DCT (DTs)
- basal striations
4) Active modification
- hormonally controlled
- collecting ducts/tubules
- cuboidal cells
Describe how 3 separate embryonic tissues contribute to the functional units of the adult kidney
1) mesonephros
- collecting tubule, collecting duct, calycies, ureter
- development of the collecting duct = the first tubular structure derived from CT
2) Metanephros
- loop of Henle & nephron (from metanephric tissue cap
- 2nd tubular epithelial structure being derived from CT
3) Endothelium
- glomerulus (descending artery)
- lined by visceral epithelium
- parietal layer of renal corpuscle (bowman’s capsule) –> between 2 epithelia = double thick BM = site of blood filtration
When does the induction of the nephron occur
= at week 23
- presence of nephric tubule (collecting tubule)
- -> induces formation of nephron out of mesenchymal tissue
Describe the kidney lobule organizational development
= overal = metanephric derived-tissue –> is centered around mesonephric derived tissue
1) In cortex
A) mesonephric derived center = collecting ducts (in medullary rays - cortical structure containing colelcting ducts that organize the cortex into lobules)
B) Metanephric derived exterior = renal corpuscles, PCTs, DTs
2) In medulla
A) mesonephric derived center = descending collecting ducts
B) metanephric derived exterior = thick descending limb; thin limb; thick ascending limb
Describe the kidney’s blood supply
- segmental artery = useful for surgeons because allow controlled blood supply to 1+ desired lobes of kidney only
- kidney weighs 5% of body weight –> but receives 25% of cardiac output
- kidney receives 1L/min of blood
- only produces 1 ml/min of urine
