A&P Term 3 Lab #8: Urinary System Flashcards
Urinary system
a group of organs that consist of the kidneys and the urinary tract, performs many functions critical to maintaining homeostasis
the urinary tract consists of…
the ureters, urinary bladder, and urethra
functions of the kidney
- filter the blood to remove metabolic waste
- regulate the body’s fluid, electrolyte, and acid-base balance
- help the liver detoxify compounds, make glucose during starvation, and produce erythropoietin
metabolic wastes
chemicals produced by the body that cannot be used for any purpose
erythropoietin
hormone that regulates blood cell formation
hormone that regulates blood cell formation
erythropoietin
the kidneys are _____ peritoneal
retroperitoneal
where are the kidneys located?
against the posterior body wall, posterior to the peritoneal membranes
the kidneys are encased with ___ layers of connective tissue. Name them.
3 layers
- Renal fascia (superficial)
- Adipose capsule (middle)
- Renal capsule (deep)
Renal fascia (material and function)
-most superficial layer of the kidney
-dense irregular collagenous connective tissue
-anchors the kidneys to the posterior abdominal walls and peritoneum
Adipose capsule (material and function)
-middle layer of the kidney
-thick adipose tissue
-wedges the kidneys in place
renal capsule (material and function)
-deep layer of the kidney
-thin dense irregular collagenous connective tissue
-encases the kidneys
the kidneys are shaped like a…
bean
renal hilum
medial indentation in kidneys where blood vessels/ureter enter and exit
3 regions of the kidney
- renal cortex (superficial)
- renal medulla (middle)
- renal pelvis (deep)
what color is the renal cortex? why?
dark brown bc of blood vessels that serve the nephrons
nephrons (function + location)
tiny blood-filtering structures of the kidney, located in the renal cortex
the renal medulla consists of triangular ___ ___
renal pyramids
renal pyramids are separated by ___, which are…
renal columns, inward extensions of the renal cortex
renal papilla
end/tip of a renal pyramid
what is the tip of a renal pyramid called?
renal papilla
what gives the renal pyramids a striated appearance?
the looping tubules of nephrons and structures that drain them
fluid from the renal papilla drain into ___ ____, which are … that eventually drain into ___ ___
minor calyces (tubes) that eventually drain into the major calyces
the major calyces drain into the _____ _____, which serves as a …
renal pelvis, basin for collecting urine
large renal arteries deliver approx. ______ ml blood/min to the kidney to be filtered
1,200ml
renal arteries branch into smaller arteries as they pass from ____ to _____ kidney structures
deep to superficial
(meaning they are larger within and become smaller as they move out of the kidney)
Renal artery flow
- segmental arteries (in renal pelvis, large)
–> - interlobular arteries (between renal/medullary pyramids in renal medulla)
–> - arcuate arteries (curve around top of pyramids)
–> - more interlobular arteries (aka cortical radiate arteries) in renal cortex
–> - tiny afferent arterioles
–> - supply the glomerulus (capillaries)
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capillaries of the glomerulus drain into a second arteriole called the _____ ____, which branches into a second capillary bed called the ____ ______
efferent arteriole, peritubular capillaries
peritubular capillaries (function and location)
surround tubules of nephron, provide them with O2 and nutrients and return substances absorbed by the tubules back into the blood
Renal vein flow
- peritubular capillaries
–> - small interlobular vein aka cortical radiate vein
–> - arcuate vein
–> - interlobular vein
–> - large renal vein
each kidney is composed of more than a million tiny units called ____
nephrons
2 parts of a nephron
- renal corpuscle
- renal tubule
2 parts of a renal corpuscle
- glomerulus (ball of looping capillaries)
- glomerular capsule
glomerulus
ball of looping capillaries, fenestrated (have large pores) so that large amounts of fluid can enter and exit
fenestrated
meaning the structure has large slits/pores
glomerular capsule layers (+ what they’re made of)
- outer parietal layer (simple squamous epithelium)
- inner visceral layer (consists of podocyte cells that surround the capillaries of the glomerulus)
podocytes of visceral layer of the glomerular capsule has extensions called ____, which…
foot processes, interlock to form narrow filtration slits
function of the filtration membrane of nephron
prevents large substances in the blood (aka blood cells and proteins) from exiting the glomerular capillaries
what does the nephron filtration membrane consist of?
-fenestrated glomerular endothelial cells
-podocytes
-shared basal lamina
what easily crosses the filtration membrane? where does it go?
water and small solutes (electrolytes, glucose, amino acids, urea), cross to enter the filtrate in the capsular space
capsular space
the space between the parietal and visceral layers of the glomerular capsule
the space between the parietal and visceral layers of the glomerular capsule is called the…
capsular space
fluid forced out of the glomerular capillaries and into the capsular space is called _____
filtrate
filtrate
fluid forced out of the glomerular capillaries and into the capsular space
The renal tubule is described as the ____ of the kidneys, and has ___ parts
“plumbing” of the kidneys, 3 parts
The renal tubule has ___ parts, name them.
3 parts
- Proximal tubule (aka proximal convoluted tubule)
- Descending and ascending limbs of the nephron loop
- Distal tubule (aka distal convoluted tubule)
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where are the renal tubules located in the kidney?
most of the renal tubule is confined to the renal cortex, but some of the nephron loops dip down into the renal medulla
several distal tubules drain into one of the two ____ ____. Name them.
collecting ducts
- cortical collecting duct
- medullary collecting ducts
cortical collecting ducts
collecting ducts in the renal cortex
medullary collecting ducts
collecting ducts in the renal medulla
near the renal papilla, the medullary collecting ducts enlarge to form _____ _____, which empty into the _____ _____
papillary ducts, minor calyces
macula densa cells
tall, closely packed cells located at the junction between the ascending limb of the nephron loop and the distal tubule
juxtaglomerular (JG) cells
specialized cells found on part of the afferent and efferent arterioles
mesangial cells
located in the glomerulus and in between the afferent and efferent arterioles
juxtaglomerular apparatus
-JG cells
-Macula densa cells
-Mesangial cells
what are the JG, macula densa, and mesangial cells together called?
juxtaglomerular apparatus
juxtaglomerular apparatus function
plays a role in controlling the flow of filtrate through the nephron and blood pressure within the glomerulus
Once the filtrate leaves the papillary ducts and enters the ____ ____, it is known as ____
minor calyces, urine
papillary ducts –> ____ _____ –> ____ ____–> ____ ____
minor calyces, major calyces, renal pelvis
from the renal pelvis, the urine enters the _____ _____
urinary tract
the first portion of the urinary tract is the…
ureters
ureters (material and function)
tubes lined with transitional epithelium and walls made of smooth muscle, which massage the urine via peristalsis
the ureters drain into the ______ wall of the urinary bladder at the _____ _____
posterioinferior wall, at the retail offices
urinary bladder is lined with…
transitional epithelium and smooth muscle, which is sometimes called detrusor muscle
urinary bladder rug
folds that allow the bladder to expand when it is filled with urine
trigone
triangular-shaped area on the smooth inferior portion of the urinary bladder wall
final organ of the urinary system
urethra
urethra has ___ rings of muscle. Name them.
2 rings
-internal urethral sphincter: involuntary smooth muscle
-external urethral sphincter: voluntary skeletal muscle
when the urethral sphincter relaxes, urine is ___ through the _______ ______ _____ by a process called _______
expelled through the external urethral orifice by micturition
female urethra length
4 cm
male urethra length
20 cm
male urethra has ___ divisions. Name them
- prostatic urethra
- membranous urethra
- spongy urethra
prostatic urethra
division of the urethra that passes through the prostate gland
membranous urethra
division of the urethra that passes through the pelvic diaphragm
spongy urethra
division of the urethra that passes through the pelvic diaphragm
urinary bladder sits ___ to the rectum
anterior
transitional epithelium
stratified epithelium w cells that differ in appearance on the apical and basal sides
apical edge: dome shaped / squamous
basal edge: cuboidal
ureter/urinary bladder histology layers
- Mucosa (innermost layer)
-transitional epithelium and a thin layer of loose connective tissue - Submucosa (middle layer)
-loose connective tissue and glands that secrete watery mucus
-the mucus plays a critical protective role by preventing chemicals in the urine from damaging and ulcerating the epithelium - Muscularis (outermost layer)
-dense irregular collagenous connective tissue
kidney histology regions and what they’re made of
renal cortex and renal medulla, made of simple epithelia
