excretion

Question 1

describe ultrafiltration

Answer 1

-in Malpighian corpuscle, renal arterie which bring blood to kidney splits into arterioles that enter a nephron then into capillaries which form glomerulus surrounded by bowman’s capsule
-afferent arteriole leading into the glomerulus is wider than efferent arteriole bringing blood out, creating a high hydrostatic pressure which forces plasma, disincluding blood cells, platelets, and large plasma protein and fat molecules with plasma
-basement membrane wraps around glomerulus which has tiny pores allowing water and small molecules to pass through
-filtrate collects in the bowman’s capsule in the Malpighian corpuscle

Question 2

selective reabsorption

Answer 2

-starts at proximal convoluted tube which absorbs over 80 percent of filtrate to ensure all useful materials is returned to the blood, all glucose, amino acids and 85 percent of mineral ions by active transport, small protein molecules 80 percent of water by water are reabsorbed by osmosis
-proximal convoluted tubule cells have many mitochondria to provide atp for active transport and microvilli to increase SA:V for faster absorption
-water in LoH, DCT, CD, salts in DCT
-water, salts and metabolic waste product passes out of collecting duct into renal pelvis to be excreted out

Question 3

osmoregulation

Answer 3

large intake of water, water potential of plasma increase, stimulates the hypothalamus causing less ADH to be secreted by pituitary glands, kidney tubules reabsorb less water, water potential of plasma returns to normal

Question 4

describe kidney dialysis

Answer 4

-patient’s blood is drawn from artery and enter dialysis machine
-dialysis fluid contains the same concentration of essential substances as the blood, no metabolic waste products
-concentration gradient set up between dialysis fluid and blood, small molecules and metabolic waste products diffuse out of the tubing while larger molecules remain in the tubing
-filtered blood is returned to the vein of the patients arm