Part 10: Urinary system Flashcards
urinary system main function
Ensure optimal properties of the blood (homeostasis) by removing metabolic wastes generated by body cells (constant monitoring by the kidneys)
“Water treatment plant” of our body
kidneys
kidneys other functions
Regulates blood ionic composition
Regulates blood pH
Regulates blood volume & blood pressure
Produces hormones (calcitriol, erythropoietin)
Helps liver detoxify poisons & regulate glucose levels
Conserves valuable nutrients & eliminates the wastes (i.e., urea)
label composition of urinary system
(top to bottom)
kidney
ureter
urinary bladder
urethra
Location of the kidneys
Develop & remain outside the peritoneal cavity (not part of GI system, retroperitoneal, posterior abdominal wall)
position of left/right kidney
Left kidney: T12 – L2/Right kidney: L1 – L3 (lower than left kidney
Adrenal gland located on ______ of each kidney
superior-medial surface
label
- Spleen
- IVC
- Abdominal aorta
- Adrenal gland
- Left kidney
label
- Spleen
- IVC
- Abdominal aorta
- Left kidney
kidney is well cushioned by ____
fat
kidney is surrounded by a lot of CT: ____
Perirenal fat (around kidney)
Renal fascia (around fat)
Pararenal (retroperitoneal) fat (beside the kidneys, behind the parietal peritoneum)
label
- Liver
- IVC
- Abdominal aorta
- Right kidney
- Left kidney
- Pancreas
kidney is covered by ___
fibrous capsule
purple: fibrous capsule
yellow: minor calyx
blue: major calyx
green: renal pelvis -> the area at the center of the kidney
orange: ureter
red: cortex
pink: medulla
grey: renal pyramid-> triangular sections of tissue that constitute the medulla
brown: renal papilla -> the point of each pyramid projects into a calyx
black: renal lobe-> portion of a kidney consisting of a renal pyramid and the renal cortex above it
white: renal column -> medullary extension of the renal cortex in between the renal pyramid; anchors cortex
light blue: hilum
label blood circulation (mistake with interlobar/bobular veins - ignore)
red: interlobar arteries
blue: interlobular veins
pink: arcuate veins
black: arcuate arteries
green: segmental artery
orange: renal artery
grey: renal vein
label
red: interlobular artery
yellow: arcuate artery
green: arcuate vein
blue: interlobular vein
pink: renal papilla
black: minor calyx
brown: interlobar artery
grey: interlobar vein
the basic functional unit of the kidney + made of two parts
nephron
renal corpuscle + renal tubule
Blood is filtered in the _____ (first part); ___ retained by filter; ______ pass through; _____ reabsorbed in _____
renal corpuscle
blood cells & large proteins
Low molecular weight proteins, ions, metabolites, dissolved wastes
Water, ions, & useful substances
the renal tubule
label nephron
red: renal corpuscle
blue: proximal convoluted tubule
green: loop of henle -needed for recovery of water & Nacl
purple: descending limb
brown: ascending limb
pink: distal convoluted tubule
yellow: collecting tubule
part of nephron needed to produce filtrate
-renal corpuscle
part of nephron needed to perform reabsorption
proximal convoluted tubule
loop of henle
distal convoluted tubule
part of nephron needed to produce urine
collecting tubule + collecting ducts
types of nephrons
-blue:cortical nephron; responsible for most absorptions & secretion
-red: juxtamedullary nephron; necessary conditions for concentrated urine
salt gradient: salt conc increases as we enter into ______
medulla
capillaries in cortex: _____ arterioles form capillary beds around tubules in ______for _____
efferent
cortex
water, organics & salt re-absorption
efferent arterioles ____ glomerulus
leaves
afferent arterioles ____ glomerulus
enters
label renal corpuscle
red: Afferent arteriole
blue: Efferent arteriole
green: Glomerulus
orange: Bowman’s (glomerular) capsule
yellow: Mesangial cells
purple: podocyte - finely fenestrated
Vasa recta (______) retrieve water in _____(1) by maintaining _______ by salt exiting into _____
capillary beds in the medulla
descending limb
concentration of medulla
medulla in ascending limb
Mesangial cells are important for physical support of ______ in _____ .Adjusted ______in response to ______ (help maintain optimal filtration rate). Secretions important for _____ in the glomerulus. Important for ______
capillaries
glomerulus
contractions
blood pressure changes
immune defense & repair
phagocytosis
things filtered through glomerulus
small proteins, metabolites, ions, water, toxins
things not filtered through glomerulus
RBC, WBC, platelets, large proteins
Proximal/distal convoluted tubule epithelium
simple cuboidal cell
loop of henle function?
Adjusts salt content of filtrate, medulla stays “salty”, tries to retrieve as much water as possible in the vasa recta
thin limb of loop of henle is ____+ function
descending limb
Reabsorption of water (aquaporins on basal & apical surfaces – permeable to water)
thick limb of loop of henle is ____+ function
ascending limb
Reabsorption of Na+ & Cl- (impermeable to water)
Distal convoluted tubule function
Variable reabsorption of ions & electrolytes
Allows excretion of acids, toxins, & urea (to maintain high salt gradient in medulla)
distal convoluted tubule: Na+ absorption is regulated ______
by aldosterone (hormone from adrenal glands)
Macula densa in _______ regulates ______
distal convoluted tubule
blood flow to keep filtrate constant despite individual’s blood pressure
The juxtaglomerular apparatus consists of three types of cells
the macula densa
juxtaglomerular cells, (also known as granular cells) which secrete renin
extraglomerular mesangial cells
JGA function + feedback mechanism
Regulation of blood pressure, blood flow, & filtrate formation
Feedback mechanism: regulates blood flow & keeps rate of filtration constant
the macula densa function
Monitor electrolyte concentration
juxtaglomerular cells, (also known as ____cells) function
granular
Secrete the hormone renin (increase BP in glomerulus - increases filtration rate)
Constricts smooth muscle cells in the efferent & afferent arterioles
label JGA
top to bottom
Extraglomerular mesangial cells
Macula densa
Juxtaglomerular cells
Collecting tubules & ducts function
Variable reabsorption of water & ions
Papillary duct function
Delivery of urine to calyces
Antidiuretic hormone (ADH released by _____) released when _____: makes collecting ducts ______
posterior pituitary
dehydrated
more permeable to water (concentrates the filtrate by activating aquaporins)
absence of ADH = _____
large volume, dilute urine
presence of ADH = _____
small volume, conc. urine
ureter does what?
transports urine
urethra does what?
eliminates urine
urinary bladder does what?
stores urin
epithelium of urinary bladder + descr.
transitional (urinary) epithelium
Multiple layers of cells
Outermost cells large & dome-shaped
Changes appearance with stretching
uteters position
retroperitoneal
Ureteric openings connect ___ to ____ where?
ureter
bladder
posterior to bladder
ureter epithelium?
‘Stretchy’ transitional epithelium
Impermeable
ureter has ___ for peristalsis of urine
smooth muscle
ureteric constriction (def.)
blockage in ureter
Sites of ureteric constriction
- Ureteropelvic junction – stone leaving the kidney (T10-L1)
- Stone crossing of the common iliac vessels (T11-L2)
- Ureterovesical junction – stone entering the urinary bladder (L1-L2)
label referred pain
1) liver, gallbladder and duodenum
2) stomach
3) spleen
4) small intestine
5) sigmoid colon
6) kidney and ureter
Label urinary bladder
left (top to bottom)
rugae (folds- transitional epithelium- to expand)
ureteric opening
internal urethral sphincter
prostate gland
right (top to bottom)
ureter
detrusor muscle (smooth muscle)
trigone: triangle defined by ureteric opening + internal urethral sphincter
urethra
external urethral sphincter (skeletal muscle)
label lumen of urinary bladder
red: transitional epithelium
yellow: lamina propria
blue: submucosa
green: serosa (parietal peritoneum)
purple: detrusor muscle
Sympathetic innervation of urinary system:
Stimulate contraction of internal urethral sphincter
Inhibit detrusor contraction
Parasympathetic innervation of urinary system:
Relaxation of internal urethral sphincter
Stimulate detrusor contraction
Somatic innervation of urinary system:
Control of the external urethral sphincter (skeletal muscle)
urethra : differences between sexes
male : 3 parts-> prostatic urethra, membranous urethra, penile (spongy) urethra = 18-20 cm long
female: Short (3-5 cm long) & straight
