Urinary Flashcards
What aspects of homeostasis does the urinary tract regulate?
Water balance Electrolytes PH Blood pressure RBC production Vit D activation
What are the 4 organs of the urinary system?
Kidneys, ureters, urinary bladder, urethra
Where are the kidney located?
Size of bar of soap
Below 12th rib
Right kidney slightly lower
What are the layers surrounding the kidney, from inside to outside?
Fibrous renal capsule
Perirenal fat (adipose capsule)- surrounds and protects
Renal fascia- helps maintain position
What are the three regions of the kidney from outside to inside?
Renal cortex
Renal medulla
Renal pelvis (drain in centre)
What are three main components within the kidney?
Medullary pyramids (triangular, in medulla, connected to CALYCES)
Renal columns- extension of cortex between pyramids
CALYCES (major and minor) - funnels that move urine towards ureter
What are the main arteries and venuoles in the kidney?
Renal artery- Large branch of abdominal aorta- brings blood into kidney
Interlobular arteries- between pyramids of medulla
Afferent arterioles- feeding into nephrons
What is the purpose of the urinary tract?
Eliminate waste products- nitrogenous waste, toxins, drugs
Regulate HOMEOSTASIS
What are the two main structures of a nephron?
Glomerulus- knot of capillaries in bowmans capsule
Renal tubule- filter system reabsorbing or secreting things
What are the characteristics of the glomerulus and what does it do?
thin, single layer of epithelial cells
Many fenestrations (to increase filtration)
Large AFFERENT
Narrow EFFERENT
What is the purpose of the renal tubule and what are its 3 regions?
Hollow tube- SIMPLE CUBOIDAL and SIMPLE SQUAMOUS
Site of filtration, reabsorption, and secretion
1- proximal convoluted tubule
2- loop of henle
3- distal convoluted tubule
Then collecting duct, where waste ends up (URINE)
Where does the collecting duct drain?
Into renal PAPILLA of pyramid
Where does most reabstorbtion of nutrients in the nephron take place? How?
Proximal convoluted tubule
Interconnected with PERITUBULAR CAPILLARIES
What are the main functions of the kidney?
Filter blood and form urine
Where does most reabstorbtion of nutrients in the nephron take place? How?
Proximal convoluted tubule
Interconnected with PERITUBULAR CAPILLARIES
What are the main functions of the kidney?
Filter blood and form urine
What are the 3 process of urine formation?
Filtration
Reabsorption
Secretion
What is the process of filtration?
Passive process depending on blood pressure
Blood flows through GLOMERULAR capillaries
Water and smaller solutes are filtered out of blood through tiny fenestrations INTO BOWMANS CAPSULE (this is GLOMERULAR filtrate, precursor to urine)
Blood cells and proteins are too large to go through fenestrations and remain in blood capillaries
What is found in filtrate?
Water, salts, bicarbonate, ions, glucose, amino acids, nitrogenous wasters (urea), vitamins, drugs
Need to REABSORB: water, salts, electrolytes, glucose, amino acids, some drugs
Is reabsortbtion in the nephron passive or active?
Passive- osmosis
Active- certain salts, etc
What are some things that ARENT reabsorbed into blood?
Urea (amino acid byproduct), uric acid (nucleic acid byproduct), creatinine (from muscles)
Excess water
What are the two sphincters in the urethra?
Internal urethral sphincter- involuntary
External urethral sphincter- voluntary
When 200 ml passes internal sphincter micturtion reflex happens
What are come characteristics of the urinary bladder?
Closed mostly of smooth muscle
Can distend
500ml reservoir for urine
