(2) Homeostasis

Question 1

Diffusion

Answer 1

molecules move passively from high to low concentration

Question 2

Osmosis

Answer 2

diffusion of water

Question 3

Freshwater

Answer 3

hypotonic = less solute/ more water outside cell, so water will diffuse INTO cell

Question 4

Saltwater

Answer 4

hypertonic = more solute/ less ater outside of cell, so water will diffuse OUT of cell

Question 5

Isotonic

Answer 5

balance/equilibrium

Question 6

Marine Environment (invertebrates)

Answer 6

Ex. cnidarians, crustaceans, echinoderms
-MOST invertebrates are in osmotic equilibrium with saltwater

Question 7

Freshwater Environment

Answer 7

water is flowing in and ions are flowing out = hypotonic
-crabs and fish need to maintain a higher ion concentration
-hypersomatic regulators

Question 8

Marine Environment (fish)

Answer 8

• water is flowing out and ions are flowing in = hypertonic
  -Hyposomatic regulators
  -must drink saltwater
  -excrete salt via salt glands

Question 9

Terrestrial Environment

Answer 9

lose water in respiration, evaporation, excretion
- ions ingested
-H2O ingested and produced by metabolism
-Protein -> ammonia to be excreted

Question 10

Invertebrates (Excretion)

Answer 10

Nephridium (kidney in greek) filters blood -> body waste
a). Protonephridium: flame cekk, flatworm
b). Metanephridium: more advanced design; molluscs, annelids
c). Antennal Gland: crustaceans
d). Malphigian Tubules: insects, spiders

Question 11

Vertebrates (Excretion)

Answer 11

kidney

Question 12

Mammalian Kidney Structure

Answer 12

(outer) Cortex -> hypotonic
(inner) Medulla -> hypertonic
- blood via renal artery and vein
- urine via ureter -> bladder->urethra

Question 13

Nephron

Answer 13

functional unit

Question 14

Functioning of Kidney

Answer 14

1. Glomerular filtration
2. Tubular reabsorption
3. Water excretion
4. Tubular secretion

Question 15

Glomerular Filtration

Answer 15

1. Blood pressure filters out the glomerulus, collected in Bowmans’s capsule
2. Filtrate included H2O, inorganic ions, glucose, amino acids, vitamins, urea, etc = small
3. Leaves behind rbc, plasma proteins = large

Question 16

Tubular Reabsorption

Answer 16

1. Diffusion and active transport of solutes back into interstitial fluid and blood capillaries from the primary filtrate
2. Water by osmosis follows these solutes out of primary filtrate to be retained by body
3. H2O, urea, and Na+ are left behind as the primary filtrate

Question 17

Aquaporins

Answer 17

water needs these protein channels in the cell membrane of PCT wall to pass through plasma amembrane

Question 18

Microvilli

Answer 18

epithelial cells of wall of PCT have increased surface area to aid movement of these solutes out of primary filtarte

Question 19

Water Excretion

Answer 19

1. Preliminary structural features
2. movement of H2O leaves primary filtrate by osmosis in descending LoH via aquaporins
3. Movement of NaCl

Question 20

Tubular Excretion

Answer 20

1. Inorganic ions are secreted actively or passively into urine
2. drugs, and other foreign materials also secreted
   3 Homeostatic regulation of blood pressure/osmotic concentration

Question 21

Vasopressin

Answer 21

hypothalamus of brain signals anterior pituitary to release antidiuretic (ADH)

Question 22

Vasoconstriction=

Answer 22

Renin activates angiotensis

Question 23

ADH=

Answer 23

more aquaporins = more water from urine

Question 24

Aldosterone=

Answer 24

more Na+ and H2O from urine - also thirst

Question 25

Natural Diuretics

Answer 25

caffeine, alcohol, celery, tomatoes, watermelon

Question 26

Urinary Bladder Structure

Answer 26

1. Bladder wall=smooth muscle
2. Internal urethral sphincter at bottom= smooth muscle
3. external urethral sphincter at very bottom= skeletal muscle

Question 27

Urinary Bladder Functioning

Answer 27

200-400ml produces pressure; stretch receptors initiate reflex arc
- bladder wall contracts
- internal and external urethral sphincter relaxs
- urination =micturate

Question 28

Incontinence

Answer 28

prior to two years of age, urination is involuntary. the sphincter is not fully developed, it must be learned.

Question 29

Ectotherms (Cold blooded)

Answer 29

heat is produced by metabolism, but it is lost as fast as it is produced, body temperature is determined by the environmental temperature

Question 30

Ectotherms Behavioral Adjustments

Answer 30

bask, seek shade

Question 31

Ectotherms Physiological Adjustments

Answer 31

vasodilatation and vasoconstriction to shunt blood closer to or farther from surface to aid warming and cooling

Question 32

Ectotherms Metabolic Adjustments

Answer 32

“temperature compensation”=enzyme variants designed to function better under warmer or cooler temperatures

Question 33

Endotherms (warm-blooded)

Answer 33

heat production is by metabolism and muscle contraction; van be regulated to some degree

Question 34

Radiation (endotherms)

Answer 34

by electromagnetic waves

Question 35

Conduction (endotherms)

Answer 35

by direct contact

Question 36

Convection (endotherms)

Answer 36

by moving air

Question 37

Evaporation (endotherms)

Answer 37

cooling as water evaporated from a surface

Question 38

Small Mammals Hot Environment Response

Answer 38

nocturnal, fossorial

Question 39

Large Mammals Hot Environment Response

Answer 39

1. Light fur reflects heat
2. Heat lost from the underside
3. Body heat stored during day and lost passively at night
4. Concentrated urine, dry feces
5. fat concentrated is one spot on back to avoid trapping heat

Question 40

Cold weather response- Increase Heat Production

Answer 40

hormones -> mitochondria produce heat vs more ATP

Question 41

Cold weather response - Decrease Heat Loss

Answer 41

1. Behavioral, ectotherms
2. Increase insulation (fur, feathers)
3. Countercurrent
4. Torpor: short-term (night) controlled lowering of body temp. decrease fuel needs