excretory system

Question 1

kidneys

Answer 1

• excretes waste
• maintains homeostasis or body fluid volume and solute composition
• regulates blood pressure

Question 2

macula densa

Answer 2

monitors filtrate pressure in kidney tubules

Question 3

if low blood pressure –>

Answer 3

1. adrenal cortex is signaled to synthesize aldosterone
2. more water is reabsorbed from the kidney back into blood
3. blood pressure increases/normalizes

Question 4

nephron

Answer 4

functional unit of the kidney

Question 5

glomerulus

Answer 5

a capillary network that interacts with the Bowman’s capsule

Question 6

afferent arteriole

Answer 6

brings blood into glomerulus

filtered blood

Question 7

efferent arteriole

Answer 7

out of glomerulus

unfiltered blood

Question 8

Bowman’s capsule

Answer 8

a structure that surrounds the glomerulus

• materials are forced out of blood and into the tubule

Question 9

podocytes

Answer 9

cells in Bowman’s capsule that filters blood

Question 10

proximal convoluted tubule

Answer 10

• a portion between Bowman’s capsule and the loop of Henle
• substances are reabsorbed from the filtrate back into the blood
• most reabsorption occurs
• lots of mitochondria present

Question 11

Loop of Henle

Answer 11

consists of descending and ascending loops

Question 12

descending loop

Answer 12

• permeable to only water
• water leaves the kidney tubules, which increases the solute concentration in the tube

Question 13

ascending loop

Answer 13

• impermeable to water
• NaCl gets removed, which decreases the solute concentration in the tube

Question 14

distal convoluted tubule

Answer 14

more reabsorption of glucose, ions, and water

Question 15

collecting duct

Answer 15

• collects remaining filtrate
• hormones can act on it to affect secretion and reabsorption

Question 16

aldosterone

Answer 16

increases Na+ reabsorption from the kidney tubules into the bloodstream –> water follows Na+ out of the kidney and back into the blood –> water retention in blood is increased

Question 17

ADH

Answer 17

• increases collecting duct permeability to water –> water is reabsorbed out of kidney tubule and back into the bloodstream –> urine becomes more concentrated while blood pressure increases
• alcohol and coffee block synthesis of ADH, leading to more dilute urine flow

Question 18

marine fish

Answer 18

• body cells are hypotonic to environment
• this means water loss occurs
• they constantly drink water and rarely urinate to offset water loss

Question 19

freshwater fish

Answer 19

• body cells are hypertonic to environment
• this means water enters
• rarely drink water
• constantly urinate to stop body fluid from being diluted

Question 20

filtration

Answer 20

large particles (blood cells and albumin) remain in circulatory system; only small particles go through and form the filtrate, which is pushed into Bowman’s capsule

Question 21

reabsorption

Answer 21

glucose is completely reabsorbed; after passing through the components of the nephron, molecules and ions are pulled back into blood from kidney

Question 22

secretion

Answer 22

substances are removed and secreted from the blood through peritubular capillaries into the nephron

Question 23

excretion

Answer 23

urine physically leaves the body