Urinary 1 Flashcards
Mastery
Kidneys - Functions include:
- Excretion…
- H2O …
- Blood pressure…
- Acid-base…
- Blood Cell…
- Vitamin …
Urinary System - Consists of
K…
Blood supply
* …% of total flow
…. vessels
* U
* U
* U
Kidneys - Functions include:
- Excretion of wastes
- H2O balance * Plasma volume
- Blood pressure control * Renin
- Acid-base balance
- Blood Cell production * erythropoietin
- Vitamin D activation
Urinary System - Consists of
Kidneys
Blood supply
* 20% of total flow
Transport vessels
* Ureters
* Urinary bladder
* Urethra
Kidney
- Parts
Podocytes
shape? filtration? renal failure? allows?
Kidney - CCMP
- Renal Calyces
- Renal Cortex outer
- Renal Medulla *Inner
- Renal Pelvis
Podocytes
Can change shape
Control filtration
Renal failure
Large slits
Allows proteins and RBC’s in
Nephron
… unit of kidney
~ # / kidney
Two types
….
* length?
* …%
- length
- ~…%
- Osmotic gradient
Nephrons
shape? supply?
Functional unit of kidney
~ 1million / kidney
Cortical
* Shorter
* ~85%
Juxtamedullary
* Longer
* ~15%
* Osmotic gradient
Nephrons
Tubule
Blood supply
Nephron
- … component
- … Artery
- … Arteriole
- ….. * Ball-like tuft of capillaries
- …. Arteriole
- ….. capillaries
- …. vein
Tubule
- …. capsule
- …. tubule
- …. of Henle
- ….
- ….
- …. tubule
- …. duct
Nephron
- Vascular component
- Renal Artery
- Afferent Arteriole
- Glomerulus * Ball-like tuft of capillaries
- Efferent Arteriole
- Peritubular capillaries
- Renal vein
Tubule
- Bowman’s capsule
- Proximal tubule
- Loop of Henle
- Ascending
- descending
- Distal tubule
- Collecting duct
Basic Renal Processes - Urine results from these three
processes.
-
Basic Renal Processes - Urine results from these three
processes.
GRS
- Glomerular filtration
- Fluid into tubule. FLUID into bowman’s capsule, put only small stuff gets through
- Tubular reabsorption
- From tubule into blood . the body takes back useful substances like water, glucose, and electrolytes into the bloodstream
- Tubular secretion
- From blood into the tubule. waste from blood. BIg that can’t get into capsule
Substance can be
Filtered and secreted
* Some only secreted
Filtered and reabsorbed - glucose, 100% reabsorbed
Filtered and partially reabsorbed - Na+
Substance can be
Filtered and secreted
* Some only secreted
Filtered and reabsorbed
Filtered and partially reabsorbed
Sites of Action
Filtration
….
Loop of Henle
….
Reabsorption and Secretion
….
….
* …. controlled
….
Filtration - Bowman’s capsule
Loop of Henle
Creates osmotic gradient
* reabsorption
Reabsorption and Secretion
Proximal tubule
Distal tubule
* Hormone controlled
Collecting ducts
TEST
substances
Glomerular filtration
All but….
Reabsorption
Secretion
Glomerular filtration
All but RBC’s and proteins
* Too big
Reabsorption
WCC PNG
Na+, Cl-, Ca2+, PO4, water, glucose
Secretion
KHLO
K+, H+, large organics
Glomerulus
Tuft of capillaries
Hole? permeable? Surrounded by?
Glomerular Filtration - Across three layers of the glomerular membrane
Glomerular capillary wall
Basement membrane
* …. layer
⬧ made of…
Inner layer of Bowman’s capsule
* Consists of….
Glomerular Filtration
~…. / day (~…. mL/min)
Moves electrolytes, water, glucose into tubules
…. are too large to be filtered
Urine
<…% of filtrate
Fenestrated * More permeable
Surrounded by Bowman’s capsule
Basement membrane
* Acellular gelatinous layer
⬧ collagen and glycoproteins
Inner layer of Bowman’s capsule
* Consists of podocytes that encircle the
glomerulus tuft
Glomerular Filtration
~160-180 L / day (~125 mL/min)
Moves electrolytes, water, glucose into tubules
RBC’s and most proteins are too large to be filtered
Urine
<1% of filtrate. 99% reabsorbed
Three main physical forces involved
Glomerular capillary blood pressure
….
Plasma-colloid osmotic pressure
….
Bowman’s capsule hydrostatic pressure
* (Bowman’s capsule osmotic pressure)
….
NET FILTRATION OF…
Three main physical forces involved
Glomerular capillary blood pressure
encourage blood in, filtration
Plasma-colloid osmotic pressure
oppose filtration
Bowman’s capsule hydrostatic pressure
* (Bowman’s capsule osmotic pressure)
oppose filtration
NET FILTRATION OF 10
Volume of fluid? osmolarity?
Bowman’s Capsule
End of proximal
End of loop of Henle
end of collecting duct
Glomerular Filtration Rate (GFR)
Depends on
- ….pressure
- How much….
- How permeable the glomerular membrane is
* ….
* ….
GFR will change if the blood hydrostatic pressure changes
….Regulated
Tubuloglomerular feedback
* ….control
Hormones / Autonomic
* Change …..
Tubulo feedback?
lower GFR? higher GFR?
Glomerular Filtration Rate (GFR)
Depends on
- Net filtration pressure
- How much glomerular surface area is available
for penetration
- How permeable the glomerular membrane is
* Podocytes
* Slit size can change with infection
GFR will change if the blood hydrostatic pressure changes
Auto- Regulated
Tubuloglomerular feedback
* Local (paracrine) control
Hormones / Autonomic
* Change arteriole resistance
STRETCH RECEPTORS IN MACULA DENSA, SEND MESSAGE TO AFFERENT ARTERIOLE, SHUT DOWN FILTRATION, TOO MUCH FLUID.
Lower GFR if - Afferent arteriole constricts OR efferent
arteriole dilates
Higher GFR if - Afferent arteriole dilates OR efferent arteriole constricts
Extrinsic Control on GFR
Sympathetic control
-….
Input to afferent arterioles
* …..
Lower blood pressure means lower…
Other examples of when GFR can change:
Plasma-colloid osmotic pressure changes
* Eg.Severely burned patient …. GFR
⬧ Loss of proteins from blood to repair sites … osmotic pressure
- Dehydrating diarrhea …. GFR
⬧ Loss of fluids …. osmotic pressure
Bowman’s capsule hydrostatic pressure changes
* Obstructions such as kidney stone or enlarged prostate
* elevates capsular ….
* …. GFR
Sympathetic control
long-term regulation of arterial BP
Input to afferent arterioles
* Baroreceptor reflex
Lower blood pressure means lower GFR and retention of fluids
Plasma-colloid osmotic pressure changes
* Eg.Severely burned patient ↑ GFR
⬧ Loss of proteins from blood to repair sites lowers osmotic pressure
* Dehydrating diarrhea ↓ GFR
⬧ Loss of fluids increases osmotic pressure. GET rid of less.
Bowman’s capsule hydrostatic pressure changes
* Obstructions such as kidney stone or enlarged prostate
* elevates capsular hydrostatic pressure
* Decreases GFR
Measuring GFR
Use … to measure GFR
No…
So Excretion = …
Use inulin to measure GFR
No reabsorption or secretion
So Excretion = filtration
Na+ Reabsorption
…. process
Na+ - K+ ATPase pump
in …. membrane
is essential for … reabsorption
Affects ….of other substances
Na+/K+ pump creates Na+ gradients across
membranes
Facilitates Na+ ….
Na+ Reabsorption - 3 membranes for price of one
Active process
Na+ - K+ ATPase pump
in basolateral membrane
is essential for Na+ reabsorption
Affects reabsorption of other substances
Na+/K+ pump creates Na+ gradients across
membranes
Facilitates Na+ reabsorption
Movement
Trans-cellular transport
Active or passive
* Eg. …
Paracellular transport
…. only
Diffusion of….
Tubular Reabsorption
Passive reabsorption
…. is required
Down ….
Active reabsorption
Requires ….
Moves …
Trans-cellular transport
Active or passive
* Eg. Na+, glucose
Paracellular transport
Passive only
Diffusion of water, ions
Tubular Reabsorption
Passive reabsorption
No energy is required
Down electrochemical or osmotic gradients
Active reabsorption
Requires energy
Moves against electrochemical gradient
