Lecture 37 - Renal Organization and Function Flashcards
Two major functions of the kidneys:
Excretion of metabolic waste products and regulation of the volume and composition of extracellular fluid
_________ transport urine from kidney to bladder while the _______ transfers urine from the bladder to outside of the body
Ureters, Urethra
The outermost layer of the kidney is the:
Cortex (C for Capsule)
The inner layer of the kidney is the:
Medulla (M for middle)
The structure which collects the urine in the kidney before the urine passes into the ureter is known as the
Renal pelvis
what is the renal hilus:
The indented area where the ureter, blood vessels, nerves, and lymphatics enter or leave the kidney
Which animal has lobed kidneys:
Cows - they are grossly lobed as well
Pigs - their kidneys are lobed but not externally apparent
What is it called when a stone is located in the urinary tract?
Urolithiasis
Medical term for urination:
Micturition
Name the epithelium lining of the bladder
Transitional epitheliumW
Does the bladder contain smooth or skeletal muscle?
Smooth
Does the external urethral sphincter contain smooth or skeletal muscle?
SkeletalW
What gives urine its yellow colour?
Urobilinogen - conjugated bilirubin is converted by colonic bacteria to urobilnogen and stercobilin. Some of the urobilinogen is reabsorbed into the blood and then removed by the kidney.
Besides blood in the urine, why else might it be reddish?
Dye from the diet. E.g. eating beets, blueberries, rhubarb
What is the functional unit of the kidney?
Nephron
What makes up the renal corpuscle?
The glomerular tuft and bowman’s capsule
Which area of the kidney contains corpuscles?
Cortex (C for capsule and for corpuscle)
What are the two major parts of the nephron?
- The renal corpuscle and 2. the tubules
What is the filtering unit of the kidney?
The glomerulus
Glomerulus:
A specialized bundle of capillaries that are uniquely situated between two resistance vessels and within a capsule
What is the name for the liquid pushed out of the glomerulus into the urinary/Bowman’s space of the Bowmans capsule?
Ultrafiltrate NOT URINE
What is unique about the blood supply of the nephrons?
This is the only place in the body where the portal system is an arteriole going to another arteriole (not a venule). Afferent arteriole –> efferent arteriole
The efferent arterioles of nephrons give rise to the ___________ capillaries
Peritubular
What are the three parts of the loop of henle
The thin descending limb, the thin ascending limb, and the thick ascending limb
After the thick ascending limb reaches the same level of its glomerulus of origin, what happens to it?
It proceeds as the distal tubule
What sets up the counter current exchange?
The opposite flow of the descending and ascending limb of the loop of henle which also allows different permeability (water vs sodium)
Describe the path of bloodflow from the start to the end of the nephron (name the vessels)
Afferent arteriole –> glomerulus –> efferent arteriole –> peritubular capillaries
What is the juxtaglomerular apparatus’s job?
To control the rate of golmerular blood flow and filtration depending on hydration, blood volume, ion concentration, by regulating the function of each nephron.
What are the three cells of the juxtaglomerular apparatus
- The macula densa
- The juxtaglomerular cells
- Extraglomerular mesangial cells
What do juxtaglomerular/granular cells do?
Secrete renin which has downstream effects on blood pressure through the RAA system
What do the macula densa cells do?
Cells of the distal tubule that sense salt levels and can impart paracrine effects on the surrounding cells such as the juxtaglomerular cells to alter blood pressure and other cells reabsorption levels in the rest of the nephron
What role do the extragolmerular mesangial cells play in the control of the nephron?
They have smooth muscle properties so can impact blood pressure through altering size of the arteriole lumen
What cells secrete renin?
Juxtaglomerular aka granular cells
Which cells belonging to the juxtaglomerular apparatus are belonging to the distal convoluted tubule?
Macula densa