Urinary System Flashcards
urinary organs (4)
urinary organs
- kidneys
- ureters
- urniary bladder
- urethra
functions of urinary system (5)
functions of urinary system
- water and electrolyte hemostasis
- filtration of blood
- reabsorption of water and solutes
- regulation of fluid balance
- electrolytes homeostasis and acid/base balance
- excretion of waste products and excess water
- renin ad EPO hormones
- regulation of blood pressure
- activation of vitamin D
Kidney
Kidney
- functional unit of a kidney is a nephron
- osmoregulate via filtration and selective reabsorption of water
- note diagram
Identify
Identify and explain
Kidney flow chart: elements
Nephron
Nephron= functional unit of the kidney
- composed of…
- glomerulus
- all tubule segments through the connecting segment
- not collecting ducts or tubules
Identify and explain
Renal corpuscles
- structure
- glomerulus
- bowman’s capsule= glomerular capsule
- 4 types of cells
- podocytes- visceral layer of capsule
- squamous cells- parietal layer of capsule
- endothelial cells- fenestrated glomerular capillaries
- mesangial cells- between fenestrated capillaries (phagocytic cells)
- vascular pole vs. urinary pole
vascular pole-
urinary pole-filtrate is collected and sent into proximal convoluted tubule
outside lumen= urinary space
podocytes- involved in filtration. small projections are called pedicels
Identify and explain
blood- urine barrier (3)
glomerular filtrate pathway
Renal tubules
renal tubules
- proximal tubule
- cuboidal tubular epithelial cells woth microvilli (brush border)
- thin henles loop
- distal convoluted tubule
Identify
renal tubules
Proximal tubules
- closest portion is proximal convoluted tubule (PCT) = only present in the cortex. Site of absorption
- strait portion is in medulla
- note cuboidal lining and microvilli
renal tubules
Note: no microvilli in distal tubules
Identify and discuss
Renal tubules
Nephron Loop
Loop of Henley
- U shape
- nephron loop parallel to vasa recta, facilitation ion and water exchange.
- to identify, the tube with blood in lumen is vasa recta (see orange part of the blue stained image)
Identify and discuss
Renal tubules
Distal convoluted tubules
- no brush borer
- basal striations
- target cells of aldosterone
- specialized cells of Macula Densa
- AKA juxtaglomerular apparatus: functions in regulation of blood pressure
Identify
Renal tubules
Part of the distal convoluted tubules
**when looking at image, jg is the juxtoglomerular cells, g is the glomerulus, md is macula densa
Identify and discuss
Collecting ducts
come after the distal convoluted tubules
- lined by cuboidal cells
- lumen contains urine
- terminal portion is papillary ducts which empty into renal crest or papilla
- Intercolated cells incolved in acid-base balance
***end of kidney is here
Post kidney urinary system (3)
Post kidney urinary system (3)
- Ureters
- Urinary Bladder
- Urethra
***Three tunics
- epithelial mucosa= transitional epithelium
- lamina propria and submucosa are same
- muscularis
Identify
Identify
Identify
Urethra: male (5) and female (1)
Urethra= last step
Male
- pelvic and penile segments
- begins transitional but turns stratified squamous
- sex glands and deferent ducts empty to urethra too
- vascualar stratum: corpus spongiosum
- tunica muscularis: mostly skeletal muscle
Female
- lined by transitional epithelium
Renal Development
She says details are not testable “i am not going to ask you, but it is very important to be aware of different stages of development of the kidney”
Three stages of development
- pronephros= begining of formation of glomerulus
- mesonephros= most parts regress but the duct is retained in males and becomes spididymis and ductus deferens
- metanephros= forms definative kidney
CLINICALLY RELEVANT because failures in stages of development can lead to problems
- ex. nephroblastoma= renal development got stuck at some point and the cells reproducing cause embryonal neoplasms
