Lab 9: Urinary System Flashcards
The urinary system is the principal component for what?
Water and electrolyte homeostasis in body.
What does maintenance of homeostasis require?
Any input into a system must be balanced out by an equivalent output.
Function of urinary system?
Eliminating water, electrolytes, toxic wastes/nitrogenous compounds - urea and creatinine. = Urine. Also, hormone production.
Functional unit of kidney?
Nephron.
Function of nephrons?
1) Filtration of small molecules from plasma to form filtrate.
2) Selective reabsorption of most water and other molecules from filtrate, leaving excess and waste to be excreted.
3) Secretion of some excretory products from blood to filtrate.
How does the urinary system link with the circulatory system?
1) Renin-angiotensin-aldosterone mechanism which maintains blood pressure
2) Secreting erythropoietin which stimulates erythrocyte production, maintaining oxygen carrying capacity of blood.
What is the hilus?
Concavity on medial side of kidney, where renal artery, renal vein, and ureter joins kidney.
What is the cortex?
Outer layer of kidney tissue.
What is the medulla?
Central part of kidney tissue.
What is the papilla?
Cone shaped projection of medulla, where apex is directed toward hilus.
What is the sinus?
Cavity in hilus.
What is the pelvis?
Expanded portion of ureter located within renal sinus.
What type of epithelium does the bladder have?
Transitional epithelium, which is thicker & impermeable to toxic urine.
3 loosely arranged layers of bladder wall?
Smooth muscle: longitudinal inner and outermost, circular outer.
How does urinary system maintain acid-base balance?
By excreting alkaline or acid (uric acid) in urine when needed.
How does urinary system regulate blood pressure?
Excreting more/less water when blood pressure increased/decreased. Renin-angiotensin-aldosterone regulation to constrict vessels or conserve sodium to increase blood pressure.
How does urinary system maintain homeostasis in hormone production?
Produces erythropoietin (maintain level of erythrocytes) & calcitriol (active vitamin D to promote intestines to absorb more calcium or promote bones to move calcium to blood).
How does urinary system maintain homeostasis by waste removal?
Filtrate is filtered from glomerulus to capsule or proximal convoluted tubule or is secreted by peritubular capillaries. Some reabsorbed but not all.
Do you need to know the diseases?
D:
