Urinary-Mace Flashcards
Functions of Urinary System:
- Protein metabolism= ___% secreted via urea
- Nucleotide _______
- muscle breakdown–> of _______
- 50%
- metabolism
- creatine phosphate
Functions of Urinary System (list 5 main fx)
- Excretion of Wastes
–BUN – blood urea nitrogen (6-20mg/100ml)
–Reflection of kidney health - Regulates:
a. Blood volume–> alters fluid loss
b. Blood composition –> inorganic ion balance/pH balance - Secretion hormones and enzymes
–Releases EPO in response to low O2
–Calcitriol and renin - Detoxifies free radicals/drugs: Penicillin, histamine, phenobarbital
- Gluconeogenesis (**during starvation)
(ERSDG)
Renal corpuscle consists of which 3 things:
- Glomerulus
- Visceral capsule layer, the glomerular space
- Parietal capsule layer= bowman’s capsule
Describe the Nephron structure
afferent arteriole & efferent 6arteriole–> vascular pole–> Glomerulus–> tubular pole–> PCT–> descending limb (of the nephron loop) –> ascending limb (of nephron loop) —> DCT–> collecting duct
Which cell types make up the collecting duct?
intercalated cells and principal cells**
Describe the relationship b/w nephron structures and location (ie in the cortex or medulla)
A/E arterioles and renal corpuscle are located in the cortex–>PCT is located in the cortex–> Descending limb and ascending limb are located in the **medulla—> DCT is in the cortex –> collecting duct is in the medulla
Describe the flow in the nephron
- afferent arteriole–> Glomerulus in renal corpuscle 2. Efferent arteriole 3. peritubular capillaries
Note: blood supply goes in the OPPOSITE direction of the filtrate in the vasa recta (this is a countercurrent= helps concentrate the urine)
JG apparatus consists of:
- macula densa cells of DCT
- Granular cells of afferent arteriole
Describe blood flow in the renal corpuscle VS filtrate flow
- afferent arteriole–> Glomerulus in renal corpuscle 2. Efferent arteriole 3. peritubular capillaries
Flow of Filtrate: 1. Vascular pole–> around renal corpuscle (inside the glomerular capsule) —> and out the tubular pole to the PCT
List 1 cell type within the Macula densa
extraglomerular mesangial cells
Renal corpuscle: is the location of _______
filtration
Renal cortex is made of: (list 3 structures)
-glomerulus, PCT, and DCT
Describe the blood flow of the Kidney
- Renal a
- Segmental a
- interlobar a’s
- Arcuate a
- interlobar a
- afferent arteriole
- glomerulus
- Efferent arteriole
- Peritubular capillaries (assoc. with convoluted tubules) AND the Vasa Recta (assoc. with the nephron loop)
- Interlobar V
- Arcuate V
- Interlobar vein
- Renal vein
Describe the structures that transport Filtrate vs Urine
-note: once filtrate enters the PCT it becomes ________
- *One filtrate enters the PCT= it becomes TUBULAR fluid
1. Filtrate in the capsular space
2. (becomes Tubular fluid) PCT–>3. Descending limb of nephron loop
4. Ascending limb of nephron loop
5. DCT
6. Collecting tubules
7. Collecting duct
- **becomes urine in the Papillary duct
- minor calyx
- Major calyx
- renal pelvis
- Ureter
- Urinary bladder
- urethra
**once it’s urine IT DOESN’T change! Once you hit the papillary duct it’s urine
Glomerular filtration=
The movement of substances from the blood within the glomerulus
into the capsular space
(note: only 1 direction of movement)
Tubular reabsorption=
The movement of substances from the tubular fluid back into the blood
(ie with the PCT, Ascending/descending limbs and DCT and collecting duct there are 2 directions of movement)
Tubular secretion=
The movement of substances from the blood into the tubular fluid
Urine Formation:
-consists of 4 major processes–>
- Filtration= Separation of particles and fluid according to size using hydrostatic pressure (BP)-> create a filtrate
- Reabsorption= Substances/particles move from filtrate into Bloodstream
–requires transport proteins in membrane of kidney tubule - Secretion= Substances move from Bloodstream into filtrate
- Water conservation= Water reabsorption, locally and systemically
regulated-> by concentration gradient and aquaporins.
Why? What is accomplished-> trying to make sure osmolarity of blood is correct and BP is correct
Filtration membrane contains:
- Endothelium of fenestrated capillary
- Basement membrane of capillary
- Filtration slits of visceral layer
Capillary lumen is surrounded by the visceral layer of glomerular capillary which contains a _______
podocyte–> pedicels located inside podocyte–> pedicel contraction= alters size of holes and alters size of filtration slits to determine how much plasma can go out of the glom capillary into the capsular space
Substances Filtered by Filtration Membrane:
- Filtration membrane:
- -Endothelium blocks–>_______
- -Basement membrane blocks–>______
- formed elements
- large proteins
Substances Filtered by Filtration Membrane:
- Filtration membrane:
- -Filtration slits of visceral layer block _____
small proteins
Filtrate coming OUT of the glomerulus into capsular space contains:
**water, glucose, amino acids,
ions, urea, hormones, vitamins B and C, ketones
(WAGI HUVK)
Determining Net Filtration Pressure in the Renal Corpuscle: -Glomerular hydrostatic pressure (HPg )= -Blood colloid osmotic pressure (OPg )= -Capsular hydrostatic pressure (HPc )= -Net filtration pressure (NFP)=
- 60mm Hg out
- 32mm Hg in
- 18mm Hg in
NET= 10mm Hg out
Net filtration pressure in renal corpuscle: The same as
Capillary exchange,
Except drainage done by?
afferent and efferent arteriole
Which of the following correctly describes the process of glomerular filtration?
A. Blood cells and plasma proteins are pushed out of the glomerulus into the glomerular capsule
B. Water, nitrogenous wastes, nutrients and ions are pushed out of the glomerulus into the glomerular capsule
C. Water and dissolved substances move out of the glomerulus by osmosis into the glomerular capsule
D. Water and formed elements are pushed out of the glomerulus into the glomerular capsule.
B. Water, nitrogenous wastes, nutrients and ions are pushed out of the glomerulus into the glomerular capsule
Which of the following would reduce the glomerular filtration rate?
A. Vasoconstriction of the efferent arteriole
B. A drop in oncotic pressure
C. Vasodilation of the afferent arteriole
D. Vasoconstriction of the afferent arteriole
E. An increase in osmotic pressure in the glomerular capsule
A. Vasoconstrict the efferent arteriole–> increases GFR
B. Drop in oncotic pressure (oncotic=colloid osmotic pressure)-– this would decrease amount of filtrate going into glomerulus–> actually **increasing GFR
C. Vasodilation of afferent–> Increases GFR
D. True decreases GFR
E. Increase GFR
D. is correct
Renal Autoregulation:
Glomerulus itself has a local autoregulatory mechanism= renal autoregulation due to _____
MAP=b/w 80-180 mmHg–> MAP is considered “normal” in this range. MAP will be maintained by the glomerulus itself
MAP BELOW 80 mmHg will lead to..
Insufficient
urine production
MAP above 180 will lead to..
Excessive
urine production
Normal MAP b/w 80-180 mmHg will lead to..
Normal urine production
maintained by renal autoregulation= GFR remains unchanged
Control of GFR via autoregulation:
Renal autoregulation in response to changes in ________
systemic BP
Decrease in systemic BP–> (describe what happens w/ GFR)
-**afferent arteriole vasodilates
-Widened arteriole lumen
-allows more blood into
glomerulus to offset a
decrease in systemic blood pressure
INCREASE in systemic BP–> (describe what happens w/ GFR)
- afferent arteriole vasoconstricts
- Narrowed arteriole lumen
- allows less blood into glomerulus to offset increased systemic blood pressure
Male GFR=
Female GFR=
**Male GFR = 120ml/min
Female GFR = 95ml/min
Decrease GFR via sympathetic stimulation:
-Vasoconstriction of afferent and efferent arterioles results in:
decreased blood flow to glomerulus–>
- Decrease in GFR
- Decrease in urine production
- Retain fluid
- Maintain Blood volume
Decrease GFR via sympathetic stimulation:
-Contraction of Mesangial cells results in:
decreased filtration at the glomerulus (decreased filtration SA) –>
- Decrease in GFR
- Decrease in urine production
- Retain fluid
- Maintain Blood volume