Urinary System Flashcards
What are the structures of the urinary system?
2 kidneys
2 ureters
1 urinary bladder
1 urethra
What are the functions of the urinary system?
regulates:
- blood volume
- blood pressure
- pH
- ion concentrations
eliminates waste
- ex: urea, uric acid, hormones, drugs
What is the functional unit of the kidney called?
nephron
What does it mean for the kidneys to be retroperitoneal?
they lay behind to peritoneum
Which kidney is lower?
right is lower than left
What are the 3 layer of CT that support and protect the kidneys called?
fibrous capsule
perirenal fat capsule
renal fascia
What is the medial indentation of the kidney called?
The renal hilus or just hilum
What is the hilum entry points for?
- renal artery (superior)
- renal vein (inferior)
- ureter
- nerves
What is the difference between the renal cortex and renal medulla?
cortex: outer (superficial) part of kidney
medulla: inner (deep) part of kidney
What is the apex of the renal pyramid called?
renal papilla
What separates the renal pyramids and contains blood vessels?
renal columns
Where are renal corpuscles located? What do they do?
- located in the renal cortex of the kidney
- their function is to filter blood which is the first step in urine formation
What is the glomerulus? Where is it located?
a capillary bed located in the renal corpuscle
What is the Bowman’s capsule? Where is it located?
- collects filtrates from the glomerulus
- has 2 layers
- outer/parietal: simple squamous epithelium
- inner/visceral: podocytes (modified simple squamous epithelium) wrap around glomerular capillaries/endothelium
What is the filtration membrane of the renal corpuscles?
consists of:
- glomerular endothelium (capillaries), simple squamous epithelium with pore (fenestrations)
- basement membranes
- podocytes (of bowman’s capsule), simple epithelium projections cling to glomerulus
What makes up renal corpuscles? Where are they located?
located in the cortex of the kidney
- glomerulus
- bowman’s capsule
What are the 4 renal tubes? Where are they located?
- proximal convoluted tubule: in cortex, closest to renal corpuscle
- loop of henle: in medulla, ascending and descending limbs
- distal convoluting tubule: in cortex
- collecting ducts: in cortex and medulla, connects nephron to ureter
What are the 2 types of nephrons? What percentage of each?
- cortical: 85%
- juxtamedullary: 15%
Which type of nephron is closer to the surface in the cortex?
cortical
Which nephron type has shorter vs longer henle loops? What does this change?
cortical nephrons have short henle loops in the outer medulla, while juxtamedullar nephrons have longer henle loops penetrating deep into the medulla which allow concentration of urine depending on need
What does the juxtaglomerular complex do?
regulates filtrate formation
Describe the tubular portion of the juxtaglomerular complex
called the macula densa, made up of modified (tall and narrow) ascending limb cells
Describe the arteriolar portion of the juxtaglomerular complex
juxtaglomerular (granular) cells make up afferent and efferent arteriolar portion. They monitor blood pressure
Describe the histology of the ureter
- mucosa: transitional epithelium
- no submucosa: (lamina propria of mucosa is connected directly to muscularis externa)
- muscularis externa: 3 smooth muscle layers
- serosa/adventitia: retroperitoneal
Describe the histology of the urinary bladder
- mucosa: transitional epithelium with rugae
- no submucosa: (lamina propria of mucosa is connected directly to muscularis externa)
- muscularis externa: ~3 layers of smooth muscle form detrusor muscle
- serosa/adventitia:
- adventitia: inferior, anterior, and posterior
- serosa: superior
What is the difference between serosa and adventitia?
serosa has a layer of areolar CT and epithelium while adventitia only has areolar CT
What is a trigone?
- triangle of 2 ureters (posterior) and urethra openings
- mucosa of trigone lacks rugae (smooth) - allows openings to remain in fixed position
Describe the histology of the urethra
- mucosa: transitional to stratified squamous epithelium
- muscularis externa: smooth muscle
What are the 2 sphincters of the urethra?
- both surround proximal end of urethra
a) internal urethra sphincter (smooth muscle): thickening of detrusor muscle at base of bladder
b) external urethra sphincter (skeletal muscle): in urogenital diaphragm
