Internal Regulation: Homeostasis, thermoregulation, hunger, and thirst

Question 1

Ectotherm

Answer 1

body temp = environmental temp
standard metabolic rate

Question 2

Endotherm

Answer 2

Internal mechanism = constant core temp
Basal metabolic rate

Question 3

Homeotherm Body Temperature

Answer 3

Constant, if any changes proteins can be broken down which becomes harmful to the body; this is also to stay prepared for flight or fight

Question 4

Autonomic nervous system mechanisms to heat

Answer 4

activate SNS = sweat
inhibit SNS = blood to skin and adrenal hormones
inhibit thyroid = decrease metabolic rate
Behavioral change = open body, panting, inhibit food seeking

Question 5

Autonomic nervous system mechanisms to cold

Answer 5

Activate SNS = vasoconstriction (bypass skin)
Activate motor neurons = shivering, unconscious movements
Activate thyroid = increase metabolic rate
Behavioral change = closed body, increased movement, initiate food seeking

Question 6

Types of thirst

Answer 6

hypovolemic and osmotic

Question 7

Osmotic Thirst

Answer 7

OVLT:
Receptor - ADH - reabsorption
blood osmolarity increases; osmoreceptors release antidiuretic hormone (ADH) or vasopressin; ADH binds to receptors on collecting ducts, H2O reabsorbed

Question 8

Glucagon

Answer 8

converts glycogen to glucose, when glucose is low, alpha cells

Question 9

Insulin

Answer 9

glucose is high, beta cells

Question 10

Ghrelin

Answer 10

appetite stimulant

Question 11

Peptide YY

Answer 11

appetite suppressant

Question 12

Cholecystokinin (CCK)

Answer 12

stomach stretch signal, binds vagus nerve

Question 13

Leptin

Answer 13

Long term satiety signal, secreted by adipose cells
more fat cells = more leptin
less fat cells = less leptin
lower levels = hunger increases
higher levels do not necessarily decrease hunger; it decreases sensitivity