vasocontriction and vascodilation

Question 1

the role of hypothalamus

Answer 1

responds to action potentials from the receptors, by sending out action potentials to the effectors

Question 2

where are the effectors located

Answer 2

skin
muscle
blood vessel
liver

Question 3

receptors in skin

Answer 3

monitor external environment
peripheral receptors
e.g. thermoreceptor

Question 4

sweating

Answer 4

when body is too hot, more sweat is secreted from sweat glands (effector)
swear evaporates carry hear away
skin cooled

Question 5

erector pili muscle

Answer 5

contract to make the hair stand up or relax to make them lie flat

Question 6

capillaries in skin

Answer 6

many found
arterioles supply these capillaries can constrict/relax, affect how much blood flows through capillaries

Question 7

thermoregulation to reduce body temperature

Answer 7

thermoreceptors in dermis detect increase in peripheral temp
initiate an action potential that travels along a sensory neuron to hypothalamus

hypothalamus sends an action potential back to the skin via motor neuron

action potential causes glands to secrete sweat into sweat duct and onto skin surface

sweat is warmed and evaporates, carrying heat away from the surface

Question 8

vasodilation

Answer 8

the arterioles that supply the capillaries dilate, cause more blood to flow through capillaries at skin’s surface
more heat lost from skins surface by radiation ,temp is lowered

Question 9

thermoregulation to increase body temp

Answer 9

Thermoreceptors in the dermis detect a drop in peripheral temperature.

initiate an action potential which travels along a sensory neurone to the hypothalamus.

hypothalamus detects that drop in core temp, sends action potential along motor neurone

action potential causes erector pili muscles to contract, erecting hairs

hair trap layer of air next to skin. act as insulator to limit loss of heat to environment

action potential causes muscular contraction in blood vessel walls

Question 10

vasoconstriction

Answer 10

occurs in arterioles supplying capillaries at skin surface
redirecting blood through deeper vessels
less blood flows through capillaries
less heart is lost to environment

Question 11

how do skeletal muscles and liver respond to maintain body temp

Answer 11

Skeletal muscles contract (shivering) to release heat.

Liver can increase or decrease its rate of respiration to increase or decrease the energy from food that is converted to heat.

Question 12

Panting

Answer 12

increase evaporation of water from the surface of the lungs and airways