Chapter 28 Flashcards
gluconeogenesis
the production of glucose from non-carbohydrate carbon substrates
Basic function of the urinary system
Remove toxins, metabolic waste and excess ions from the blood
structures of the urinary system
Kidneys
Ureters
Bladder
Urethra
what is each kidney supported by
3 Layers of supportive tissue
how many times a day do the kidneys filter the body’s entire plasma?
60 times
what supplies nerves to the Kidneys
sympathetic fibers from the renal plexus
3 layers of supportive tissues of the kidneys
Renal Fascia
Perirenal fat capsule
Fibrous Capsule
the structural and functional unit of the kidney
nephron
2 types of Nephrons
cortical - 85%
Juxtamedullary - 15%
Nephron Pathway
Glomerulus Bowman Capsule Proximal Convoluted Tubule Loop Of Henle Distal Convoluted Tubule Collecting Ducts
3 capillary beds of the nephron
Glomerulus
Peritubular Capillaries
Vasa Recta
what forms the filtration silts that allow filtrate to pass into the capsular spaces
The podocytes
2 types of cells of the collecting duct
Intercalated cells
Principal cells
what type of tissue is the urinary bladder lined with?
transitional epithelial mucosa
2 sphincters of the Urethra
Involuntary Internal Sphincter
Voluntary External Urethral Sphincter
Glomerular Filtration Rate (GFR)
Volume of filtrate formed per minute by the kidneys
what does renin convert angiotensinogen to?
angiotensin I
effect of Angiotensin II on BP
increases BP
function of aldosterone
reabsorb sodium
where does 65% of water and sodium re-absorption happen
Proximal Convoluted Tubule
3 steps of Urination
Glomerular filtration
Tubular reabsorption
Tubular secretion
urine characteristic of a UTI
Cloudy urine
what sits on top of the kidneys that is not part of the urinary system?
the adrenal glands
function of the ureters - R
to tranport urine from the kidneys to the urinary bladder
What transports urine outside of the body?
the urethra
characteristics of the renal fascia
the anchoring outer layer of dense fibrous connective tissue
chacteristics of the Perirenal Fat Capsule
“fatty cushion”
chacteristics of the Fibrous Capsule
surrounds and protects the kidney itself
2 layers of the glomerular capsule:
parietal
visceral
layer of the glomerular capsule consists of branching epithelial podocytes that cover the capillaries
The visceral layer
part of the nephron pathway that receives all the filtrate from all the nephrons
collecting duct
normal NFP
10mm Hg
function of the intercalated cells
maintain the body’s acid-base balance
function of prinicpal cells
help maintain the body’s water and salt balance
what are diuretics?
substances that increase urine output
what do the kidneys remove from the blood?
toxins
metabolic wastes
excess ions
what do the kidneys regulate?
blood volume
chemical composition
pH
what does the kidney produce via gluconeogenesis during prolonged pasting?
glucose
the endocrine functions of the kidney
- produce renin and erythropoietin
- activate vitamin D
which kidney is lower?
the right kidney
where do the ureters, blood vessels, lymphatics, and nerves enter and exit?
medial hilum
another word for the glomerular capsule
Bowman capsule
what forms the filtration slits?
the foot-like extensions of the podocytes
another word for urination
micturition
what makes urination possible?
contraction of detrusor muscle
opening of the internal urethral sphincter
opening of the external urethral sphincter
average amount of urine produced in a day?
1.5L
the major excretory organ of the urinary system
kidneys
temporary storage for reservoir for urine
bladder
organ that transports urine from the kidneys to the bladder
ureters
organ that transports urine outside of the body
urethra
4 main functions of the kidney
a) remove toxins and metabolic wastes
b) regulate bloodvolume and pH
c) produceglucose via gluconeogenesis
d) produce hormones (renin, erythropoietin, vitamin D)
kidneys are located…
retroperitoneally in the superior lumbar region
what makes the right kidney lower than the left?
the liver
what separates medullary or renal pyramids?
renal columns
which part of the renal pyramids does urine drip out of?
papillae
what form major calyces?
minor calyces
where does urine from the papillae drip into?
minor calyces
what form the renal pelvis
major calyces
2 main parts of nephrons
a tuft of capillaries (glomerulus)
tubule
what does the first part of the tubule form?
the glomerular or bowman capsule
what does the outer visceral layer of the glomerular consist of?
branching epithelial podocytes that cover the outside of the glomerular capillaries
mechanorecptors that react to changes in the blood pressure
Granular or juxtaglomerular or JG cells
what hormone do the granules of JG cells contain?
renin
the portion of the kidney that extends between the renal pyramids
renal columns
correct order of filtrate flow
glomerular capsule PCT Loop of Henle DCT Collecting duct
which structure of the nephron reabsorbs the most substances?
proximal convoluted tubule
which part of the nephron employs a countercurrent mechanism?
loop of henle
normal pH range for urine
4.5-8
what does urine consist of?
95% water
5% solutes
the volume of plasma cleared of a particular substance in a given time
Renal Clearance (RC)
function of the vasa recta
they function in the formation of concentrated urine
2 controls of GFR
intrinsic controls
extrinsic controls
GFR controls that only takes over under extreme stress
extrinsic controls
what drives Glomerular filtration?
net filtration pressure
cells that secrete renin
granular cells
what cells act as chemoreceptors?
macula dense cells
how much blood do renal arteries deliver to the kidneys each minute?
1/4 or 1200ml
type of urination in infants
reflexive urination
the site of most obligatory reabsorption
PCT
what performs the second step of obligatory reabsorption?
loop of Henle
site of bladder infection
trigone
smooth triangular area outlined by the openings for the ureters and urethra
trigone
how many liters of filtrate do the kidneys produce per day?
180L
what converts angiotensin I to angiotensin II?
angiotensin converting enzyme (ACE)
how does angiotension II increase BP?
it stimulates the hypothalamus which releases aldosterone
another name for a bladder infection
cystitis
what part of the kindey contains hormones?
DCT
which hormones control the DCT?
parathyroid
ADH
Aldosterone
ANP
What part of the nephron employs a counter mechanism?
loop of Henle
how should urine smell?
aromatic
what does the filtration membrane between the blood and the capsular space contain?
the fenestrated endothelium
gel-like basement membrane
visceral membrane
which cells degrade macromolecules that make it through the filtration membrane?
glomerular mesangial cells
what appears when the bladder is empty and the lining collapses?
rugae
where is the detrusor muscle located?
the thick wall of the bladder
how is urine pushed towards the bladder?
peristalsis
2 routes of tubular reabsorption
transcellular route
paracellular route
location of the vasa recta
run parallel to the loops of Henle
normal GFR
120-125 ml/min
which limb of the loop of henle reabsorbs Na, Cl, and K?
Ascending limb
which limb of the loop of henle reabsorbs water?
the descending limb
where does the transcellular route go through?
through tubule cells
where does the paracellular route go through?
through leaky tight junctions
what releases renin from the granular cells?
reduced stretch of the cells and hypotension
how many nephrons does each kidney have?
about 1 million
how is backflow of urine in the ureters prevented?
as bladder pressure increases, distal ends of the ureters close, oreventing backflow of urine
the opening in the bladder for the ureters and the urethra
trigone
the main for behind glomerular filtration
Glomerular Hydrostatic Pressure
the opposing forces to Glomerular Hydrostatic Pressure
Colloid Osmotic Pressure and Capsular Hydrostatic Pressure
cells interconnected with gap junctions between macular densa and granular cells
Extraglomerular Mesangial Cells
