lab 15 Flashcards
function of the kidneys
- Excretion and the maintenance of a constant internal environment.
- Eliminates nitrogenous waste (urine), water, and salt. -Conserves necessary substance such as protein and glucose.
urinary bladder
temporary storage of urine
3 layers that surround the kidney
1-renal capsule
2-middle adipose capsule
3-renal fascia
-these 3 layers help protect the kidney from trauma and anchor it firmly in place.
nephron
- tubular structures that perform all phases of of urine formation(glomerular filtration, tubular reabsorption, tubular secretion).
- consists of a renal corpuscle and a renal tubule
- 2 types: cortical and juxtamedullary
collecting duct
receives urine from many nephrons
route of urine from glomerulus –> urethra
Glomerulus-> Bowman’s capsule-> Proximal convoluted tubule-> descending limb->loop of Henle -> ascending limb -> distal convoluted tubule -> collecting duct -> renal pyramid -> renal papilla -> minor calyx -> major calyx -> renal pelvis -> ureter -> urinary bladder -> urethra.
glomerulus
where filtrate is first formed
glomerular filtration
The passive process in which materials are separated based on their size in relation to the pores of the filtration membrane. They are forced through the membrane by glomerular hyrdrostatic pressure (sort of like glomerular blood pressure). E.g. water can pass through the filtration membrane, but blood cells are retained in blood.
tubular reabsorption
process which substances the body needs, such as glucose and water, reenter the blood from the filtrate. Begins in proximal convoluted tubule.
tubular secretion
process by which substances enter the filtrate from the blood in the peritubular capillaries. Allows waste and other materials, that were not passed into the filtrate during glomerular filtration, to leave the body in the urine.
pH of blood
must maintain a constant level of about 7.4 at all times
Antidiuretic hormone (ADH)
- helps prevent wide swing in water balance to prevent dehydration or water overload.
- i.e. Add water (dilute) ADH production decreases and you pee a lot. Salty blood (dehydration) increases ADH production and stimulates kidneys to reabsorb water.
- produced by hypothalamus, secreted by posterior pituitary gland
Diabetes insipidus
- a condition in which ADH secretion is deficient, and large amounts of urine are produced accompanied by extreme thirst.
- produced by adrenal gland cortex
Aldosterone
Helps maintain the sodium and potassium concentration of ECF by stimulating re-absorption of sodium ions and water, and promoted potassium excretion.
normal pH range of Urine
4.8 (a diet high in protein and whole wheat) - 7.5 (a vegetarian diet)
specific gravity
- the relative amounts of solutes (particles) to solvent in a solution.
- water SG= 1.0
- usual SG 1.005-1.030 (higher the #, the greater density of the urine)
