Urinary system Flashcards
What is the function of the urinary system?
- regulates plasma ion concentrations
- regulates blood volume and BP
- helps stabilize blood pH
- prevents the loss of valuable nutrients
- eliminates metabolic waste
- synthesizes calcitriol (active form of vitamin D) and erythropoietin (RBC production)
- aids the liver with some metabolic functions
What does the urinary system consist of?
- Kidneys
- urinary tract
What is the function of the kidneys?
- produce urine
- & associated nephrons
what is the function of the urinary tract?
- transports/stores urine
- consists of:
a. ureters
b. urinary bladder
c. urethra
what is the medical term for eliminating urine?
- micturition
- urination
what are the 3 layers of connective tissue that function to protect the kidneys?
- fibrous capsule
- perinephric fat (perirenal fat capsule)
- renal facia
How big is the typical kidney?
- 4 inches long
- 2.2 inches wide
-1.2 inches thick
What does a kidney lobe consist of:
- renal pyramid (overlaying)
- renal cortex &
- adjacent renal columns
what does the kidney consist of?
- renal cortex
- renal medulla
deep to the cortex:- renal pyramids
- renal papillae
- renal columns
where does blood in the renal arteries flow to?
- segmental arteries
- interlobular arteries
- arcuate arteries
- cortical radiate arteries
- afferent arteries
- glomerular capillaries
what does the renal pelvis consist of?
- Minor calyx
- major calyx
(also comprises most of the renal sinus)
what are nephrons?
- where filtration occurs in the kidney
- it creates a concentrated urine by creating an ultrafiltrate from blood
How does blood leave the kidneys?
- glomerular capillaries
- efferent arteriole
- peritubular capillaries
- cortical radiate veins
- arcuate veins
-interlobar veins - renal vein
NO SEGMENTAL veins
what does each nephron have?
- a renal capsule
- renal tubule
how does blood go in & out of the kidneys?
IN: OUT
1. renal artery 1. peritubular capillaries
2. segmental arteries 2. venules
3. interlobar arteries 3. cortical radiate veins
4. arcuate arteries 4. arcuate veins
5. cortical radiate arteries 5. interlobar veins
6. afferent arterioles 6. renal veins
7. glomerulus capillaries
in the nephron where blood is going through the efferent arteriole `
define autoregulation.
- what urine production is regulated by
- involves reflxive change in diameter of nephron arterioles
what does a renal capsule consist of?
- glomerular capillaries (glomerulus)
- glomerular capsule
- glomerular filtrate leaves the glomerular capillaries and enters the glomerular capsule - afferent arteriole and efferent arteriole form the vascular pole
What is the flow of the nephron & collecting system?
- renal tubule
- proximal convoluted tubule (PCT)
- nephron loop
- distal convoluted tubule (DCT)
- Filtrate from the DCT empties into the collecting system
- connecting tubules from several nephrons lead to a common collecting duct
- the collecting duct passes through the renal pyramids
How does the filtrate flow in the connecting duct?
- Papillary duct
- minor calyx
- major calyx
- filtrate is now called urine
How does urine leave the kidneys?
Via the urinary tract:
1. ureter
2. urinary bladder
3. urethra
what are the two types of nephrons?
- cortical nephrons
- juxtamedullary nephrons
what are features of cortical nephrons?
- 85 % of the nephrons are cortical
- most of the nephron is located in the cortex
- have a relatively short nephron loop
what are some features of juxtamedullary nephrons?
- 15% of nephrons are juxtamedullary
- capsule is located near the border of the cortex
- have a long nephron loop
what are the main fuctions of the nephron?
- reabsorbs useful organic material & ions from the filtrate
- reabsorbs more than 99 % if water from filtrate
- enhances the elimination of wastes by actively secreting them into the filtrate