Urology anatomy & physiology Flashcards
Where are the kidneys found?
Which ones lower than the other?
Retroperitoneal
T12 - L3
The right kidney is lower because of the presence of the liver above it.
What is on the top of each kidney?
Describe the structure.
Adrenal glands
Outer cortex and inner medulla
Cortex has 3 layers (GFR)
- glomerulosa
- fasciculata
- reticularis
Medulla: chromaffin cells
Which layers of the adrenal gland produces what?
CORTEX: outer layers
- glomerulosa produces mineralocorticoids: aldosterone
- fasciculata produces
glucocorticoids: cortisol - reticularis produces androgens: testosterone precursor, DHEA
MEDULLA: inner
- chromaffin cells produce adrenaline and noradrenaline
What is DHEA?
Dehydroepiandrosteron
Describe the blood supply to and from the kidneys?
Renal artery, which divides into segmental arteries
Renal vain
Describe the structure of the kidney?
Draw and label it.
(not including nephron)
Surrounded by renal capsule
Renal hilus: where the renal artery enters and the renal vein and ureter leaves the kidney
Outer layer: renal capsule
Inner pyramidal sections: renal medulla
Each pyramid of the medulla connects to minor calyx (a collecting tube)
The minor calyces join to form 3 major calyces.
Major calyces join to become the renal pelvis, which drains into the ureter
http://www.newhealthadvisor.com/Kidney-Structure-and-Function.html
What is a nephron?
Where are they?
What do they do?
Draw one!
A nephron is a functional unit where blood is filtered and urine is produced.
There are a million per kidney
There are two types, cortical and juxtamedullary (this tells you where each type is found)
They consist of:
- renal corpuscle (glomerulus + Bowman’s capsule)
- tubule (proximal, loop of Henle, distal)
- collecting duct
http: //www.austincc.edu/apreview/PhysText/Renal.html
What is a renal corpuscle?
Describe in detail.
The glomerulus + Bowman’s capsule
Glomerulus is a network of capillaries. Blood is brought to it by the afferent and Exits by the Efferent.
Bowman’s capsule is where blood contents diffuse across into the tubule network.
Podocytes are present to help with filtration
How do podocytes help with filtration?
Podocytes form filtration slits, which they can make bigger and smaller and thus let more or less through
What are:
- mesangial cells
- juxtaglomerular cells
Mesangial:
- cells between the capillaries
Juxtaglomerular cells:
- cells around the afferent arterioles which store renin
What is the macula densa?
Cells of the distal tubule which detect concentration of NaCl
If the concentration decreases the macula densa signal to…
- reduce resistance to blood flow in afferent arteries
- increase renin release from juxtaglomerular cells
Describe the RAAS pathway?
Drop in BP detected by carotid sinus baroreceptors
Macula densa detects drop in NaCl concentration, causing JXTG cells to release renin
Renin is an enzyme which converts angiotensinogen (from liver) to angiotensin 1
ACE (from lung + kidney) converts angiotensin 1 to angiotensin 2
Angiotensin 2 does lots of things that result in water and salt retention and raise in BP
What does angiotensin 2 do?
- Stimulates release of aldosterone which acts on distal tubule to reabsorb Na and H2O and excrete K, which increases blood volume
- Stimulates release of ADH, which causes reabsorption of water and vasoconstriction. It also causes thirst and hunger for salt.
- Arteriolar constriction, raising BP
What is vasopressin?
Where is it released?
Another name for ADH
Released from the posterior pituitary
What are the 6 functions of the kidneys?
- Production and concentration of urine
- Electrolyte regulation
- BP regulation
- EPO production
- Conversion of vitamin D to active form
- Acid-base regulation
