Coordination and response

Question 1

Define homeostasis

Answer 1

maintenance of a stable internal environment in the body

Question 2

define hormones

Answer 2

A chemical messenger which is made by an endocrine gland. Released in blood and affects target organs

Question 3

what is negative feedback

Answer 3

a corrective mechanism which responds to a change in conditions from ideal or set point and returns conditions back to set point

Question 4

define adrenaline

Answer 4

a hormone produced by the adrenal glands in response to fear or stress. Increase heart rate and boosts the delivery of blood to the muscles, fight or flight response.

Question 5

define ADH

Answer 5

hormone produced by the pituitary gland that increases the re absorption of water in the collecting duct of the kidney

Question 6

define auxin

Answer 6

plant hormone that control cell elongation and plant growth

Question 7

define CNS

Answer 7

the brain and spinal cord which coordinates the response of effectors

Question 8

define effectors

Answer 8

muscles or glands which bring about responses

Question 9

define FSH

Answer 9

a hormone produced by the pituitary gland that stimulates the growth of follicles in the ovary and stimulates the release of oestrogen

Question 10

define geotropism

Answer 10

a plants directional growth in response to gravity controlled by auxin

Question 11

define insulin

Answer 11

hormone secreted by the pancreas when blood glucose concentration is too high, reducing blood glucose concentration by increasing the uptake of glucose from the blood into liver

Question 12

define LH

Answer 12

hormone secreted by the pituitary gland that stimulate ovulation and the realease of progesterone

Question 13

what does sensory neurone do

Answer 13

Impulses from receptors pass along sensory neurones until they reach the brain and spinal cord

Question 14

what does relay neurone do

Answer 14

impulses pass to relay neurons in the CNS

Question 15

what does the motor neurone do

Answer 15

Impulse passes to effectors along motor neurone which causes the effector to contract

Question 16

define neurotransmitters

Answer 16

chemicals that are released at synapses

Question 17

define oestrogen

Answer 17

a female sex hormone release by the ovaries and stimulate the growth of the uterus lining whilst inhibiting the release of FSH

Question 18

define phototropism

Answer 18

a plants directional growth in response to light

Question 19

define progesterone

Answer 19

a hormone produced in the ovaries, specifically by the corpus luteum and the placenta that maintains the interim lining and inhibits the release of FSH and LH

Question 20

define receptors

Answer 20

cells that detect a stimulus

Question 21

what is the reflex arc

Answer 21

a rapid and automatic response to a stimulus

Question 22

What is the pathway of neurones

Answer 22

stimulus, receptor, sensory neurone, relay neurone, motor neurone, effector, response

Question 23

what is a stimulus

Answer 23

a change in an organism internal or external environment that can be detected by receptors

Question 24

what does sweat do

Answer 24

evaporation of water in sweat removes heat energy from the skin, cooling the body down by removing that heat

Question 25

what is the junction between two nerve cells

Answer 25

synapse, neurotransmitters released to diffuse across

Question 26

define testosterone

Answer 26

the main male reproductive hormone, produced by the testes, stimulating sperm production and secondary sexual characteristics

Question 27

define vasoconstriction

Answer 27

constriction of blood vessels near the surface of the skin to reduce blood flow near the surface of the skin and therefore reducing the amount of heat that is radiated from the skin

Question 28

define vasodilation

Answer 28

the dilation of blood vessels near the surface of the skin and increasing the amount of blood flowing near the surface of the skin and so increasing the amount of heat that is radiated from the skin

Question 29

where are receptor cells located

Answer 29

everywhere

Question 30

compare a reflex action to a voluntary action

Answer 30

reflex is faster and doesn’t use the brain. Automatic

Question 31

what happens in eye in dark light

Answer 31

radial muscles in iris contracts. circular relax. iris causes pupil to dilate to let more light in

Question 32

what happens in eye in bright light

Answer 32

radial muscles in iris relax. circular contract. iris causes pupil to get smaller to let less light in

Question 33

what happens in eye when focussing on far away object

Answer 33

suspensory ligaments contract ciliary muscle relax lens become long and thin light focused on retina

Question 34

what happens in eye when focussing on near object

Answer 34

suspensory ligaments slack ciliary muscle contract lens become thick

Question 35

what type of lens do long and short sighted people require

Answer 35

long: convex lens short: concave lens

Question 36

what are the two photoreceptors in retina and what do they do

Answer 36

rods: measure light intensity and send messages along sensory neurone cones: measure colour and send messages along sensory neurone

Question 37

what does the axon do

Answer 37

electrical impulse travels down it

Question 38

what does the myelin sheath do

Answer 38

insulates the axon

Question 39

what is the myelin sheath made out of

Answer 39

fatty substance

Question 40

what neurones have a myelin sheath

Answer 40

sensory and motor

Question 41

what neurones have cell body at end

Answer 41

relay and motor

Question 42

define thyroxine

Answer 42

growth hormone produced in thyroid gland

Question 43

define insulin

Answer 43

reduces blood glucose after a meal. produced in pancreas

Question 44

define glucagon

Answer 44

increases blood glucose after a meal. produced in pancreas.