excretion

Question 1

ultrafiltration process?

Answer 1

process by which small molecules are filtered out of the blood by the glomerulus into the Bowman’s capsule
1) afferent arteriole has a wider diameter than efferent arteriole, creating high blood pressure in the glomerulus to force water and small,soluble molecules out into the Bowman’s capsule (glomerular filtrate)

Question 2

selective reabsorption process?

Answer 2

1) process in which useful substances that the body needs are reabsorbed into the blood capillaries (ag,mw, aaa, sms)

Question 3

adaptations of the glomerulus?

Answer 3

1) network of blood capillaries —> provide large surface area for filtration process
2) blood capillary walls are one cell thick and have tiny pores —> allows small molecules or ions to pass through
3) blood capillaries covered by a thin,ppm —> only allows very small and soluble substances to pass through

Question 4

where and how does reabsorption occur?

Answer 4

1) proximal convoluted tubule (mwo, agaat, mmsdat)
2) loop and henle and distal convoluted tubule (swo, smsat)
3) collecting duct (swo)

Question 5

osmoregulation?

Answer 5

maintenance of body water potential by controlling water potential and solute concentration in the blood

Question 6

anti diuretic hormone functions?

Answer 6

1) increase water reabsorption in nephrons
2) acts on cells in the walls of distal convoluted tubule and collecting duct to make them more permeable to water

Question 7

where is ADH produced and secreted?

Answer 7

1) hypothalamus in the brain
2) pituitary gland into the bloodstream

Question 8

dehydration?

Answer 8

water potential of blood plasma falls below norm, stimulating the hypothalamus in the brain to produce more ADH and the pituitary gland to secrete more ADH into the bloodstream. Cells in the walls of DCT and collecting duct become more permeable to water, resulting in less water being reabsorbed into bloodstream and urine that is smaller in volume and more conc, allowing the water potential of blood plasma to rise back to normal

Question 9

too much water?

Answer 9

water potential of blood plasma rise above norm, stimulating the hypothalamus in the brain to produce less ADH and the pituitary gland to secrete less ADH into the bloodstream. Cells in the walls of DCT and collecting duct become less permeable to water, resulting in less water being reabsorbed into bloodstream and urine that is larger in volume and more dilute, allowing the water potential of blood plasma to fall back to normal

Question 10

kidney failure causes?

Answer 10

high blood pressure, alcohol abuse, diabetes

Question 11

kidney failure treatment?

Answer 11

1) live with one kidney
2) kidney transplant
3) kidney dialysis

Question 12

kidney dialysis procedure?

Answer 12

1) blood drawn from being and pumped through tubing in the machine (fistula strengthens vein and allows high blood flow and faster dialysis, connect artery to vein)
2) blood flows over artificial ppm of tubing bathed in dialysis fluid
3) small molecules diffuse down the conc gradient from the blood into dialysis fluid; large molecules remain in tubing
4) dialysis fluid is continuously changed; filtered blood returned to patient’s arm

Question 13

features of dialysis machine?

Answer 13

1) dialysis fluid has similar conc of essential substances as healthy blood —> ensures no net loss of substances + if patient’s blood lacks these substances, they will diffuse into the blood
2) direction of blood flow is opposite to flow of dialysis fluid —> maintain conc gradient for removal of waste products
3) tubing is long, narrow and coiled —> increased sa:v ratio, increased rate of exchange of substances between patient’s blood and dialysis fluid