u2: osmoregulation (excretory system)

Question 1

functions of the excretory system

Answer 1

• excrete metabolic wastes
• maintain salt-water balance
• maintain acid-base balance
• secretion of hormones

Question 2

part of the excretory system

Answer 2

kidneys connect to bladder via ureters. urethra comes down from bladder

Question 3

osmoregulation

Answer 3

process of keeping water and solute concentration inside/outside of cells in balance

Question 4

how does blood get to and from the kidneys

Answer 4

• renal artery: delivers oxygenated blood to kidneys, splits into small capillaries called glomerulus
• renal vein: blood vessel that removes deoxygenated blood, water, and solutes back to body

Question 5

parts/layers within kidney

Answer 5

• outer layer: renal cortex
• inner layer: medulla
• renal pelvis: cavity connecting kidney to ureter where urine passes to bladder

Question 6

nephron

Answer 6

• microscopic structures w/ blood vessels associated
• filter out substances from blood to turn into urine

Question 7

bowman’s capsule

Answer 7

• at top of each nephron
• filtration structure
• in each capsule, splits into network of capillaries called glomerulus

Question 8

glomerulus

Answer 8

• filtration device
• water, small molecules, ions, and urea pass further in the nephron

Question 9

tubules and ducts

Answer 9

• filtrate (fluid) goes through tubules, which reabsorbs nutrients like glucose
• tubules empty into a collecting duct which reclaims as much water as possible
• filtrate left over in duct in urine

Question 10

how is urine formation like a see-saw?

Answer 10

• brain monitors blood content
• materials are secreted and absorbed until solute content in blood is at perfect level

Question 11

secretion

Answer 11

pushing materials from blood into tubules of nephron to become urine

Question 12

(re)absorption

Answer 12

pushing materials from tubules of nephron back into blood to reabsorb nutrients

Question 13

how does filtration occur

Answer 13

as body fluids move from the blood into the Bowman’s Capsule

Question 14

what is urine in animals?

Answer 14

• hypoosomotic to surrouding body fluids
• water moves from urine into body fluids

Question 15

define glomerulus and bowman’s capsule

Answer 15

• filtration
• blood pressure forces water/dissolved substances through pores of the glomerular walls

Question 16

proximal (convoluted) tubule

Answer 16

• reabsorb nutrients
• such as glucose, amino acids, sodium, potassium, calcium, and vitamins
• reabsorb water through osmosis

Question 17

descending loop of henle

Answer 17

water moves back to blood via osmosis

Question 18

ascending loop of henle

Answer 18

salt passes back to blood (Na+ and Cl- ions)

Question 19

distal (convoluted) tubule

Answer 19

• reabsorbs sodium, water (osmosis), nd negative ions
• secretes hydrogen and potassium

Question 20

collecting tube

Answer 20

reabsorb water (osmosis)

Question 21

what’s left in urine

Answer 21

• water
• urea (nitrogenous product of protein metabolism)
• Cl-
• Na+
• K+

Question 22

regulation of water-balance

Answer 22

• balance of salt-water determined by ADH (antidiruetic hormone)
• ADH secreted by pituitary gland

Question 23

what happens if body is dehydrated?

Answer 23

• ADH released to allow water to be taken in
• urine is darker bc of high solute concentration

Question 24

wht happens if ADH is decreased?

Answer 24

• occurs when body needs more solute
• less ADH = more urine is produced and excreted from body

Question 25

wht happens if ADH is decreased?

Answer 25

- occurs when body needs more water - ADH released into bloodstream to allow for greater reuptake of water in collecting tube

Question 26

what are alcohol and coffee called? wht do they do?

Answer 26

- diuretics (promote dehydration) - block release of ADH (which tells kidneys to hold water), which increases volume of urine released by body = dehydration