Section 6 - Coordination & Response

Question 1

What do receptors do?

Answer 1

Detect external stimuli
(eyes, nose, tongue)

Question 2

What are effectors?

Answer 2

Bring a response to the stimuli
(muscle cells + cells found in glands)

Question 3

Receptors and effectors

Answer 3

• They comunicate via the nervouse system or the hormonal system, sometimes both
• The route taken of this information is called reflex arc.

Question 4

What is the CNS?

Answer 4

• Consits of the brain and spinal cord
• It coordinates the response to stimuli

Question 5

Neurones

Answer 5

• Three main type: sensory, relay and motor.
• Transmit information using high speed electrical impulses

Question 6

Synapses

Answer 6

• connection between two neurones
• Nerve signals transferred by neurotransmiters which diffuse.

Question 7

Relfex arc

Answer 7

1. When stimulus is detected by receptors a sensory neuroneis sent to the CNS
2. In the CNS the sensory neurone passes the message along to the relay neurone
3. Relay neurons relay the message to motor neurone
4. Motor neurone then travels to the effector

Question 8

Simplified relfex arc

Answer 8

1. Stimulus
2. Receptor
3. Sensory neurone
4. CNS
5. Relay neurone
6. Motor neurone
7. Effector
8. Response

Question 9

Parts of the eye

Answer 9

• Sclera
• Cornea
• Iris
• Lens
• Optic nerves
• Fovea
• Pupil
• Conjunctiva
• Ciliary muscle
• Suspensory ligaments

Question 10

sclera

Answer 10

tough layer that protects the eye

Question 11

iris

Answer 11

control diameter of pupil

Question 11

cornea

Answer 11

refracts light into the eye

Question 12

lens

Answer 12

focus light into the retina

Question 13

Optic nerves

Answer 13

carries impulses to brain

Question 14

accommodation def

Answer 14

eye focuses light on the retina by changing the shape of lens

Question 15

Look distance

Answer 15

• Ciliary muscles relax allows suspensory ligaments to pull tight
• Makes lens go thin
• Refracts light by smaller amount

Question 16

Look near

Answer 16

• Ciliary muslce contract, allows suspensory ligaments slacken
• Lens become fat
• Increases the amount by which refracts light

Question 17

Hormones

Answer 17

• Adrenaline
• Insulin
• Testosterone
• Progesterone
• Oestrogen

Question 18

Adrenaline

Answer 18

• Source: Adrenal glands
• Role: Prepares body for action
• Effect: Increases heart rate, blood flow + blood sugar level

Question 19

Insulin

Answer 19

• Source: Pancreas
• Role: Helps control blood sugar level
• Effect: Stimulates liver to convert glucose into glycogen

Question 20

Testosterone

Answer 20

• Source: Testes
• Role: Main male sex hormone
• Effect: Promotes male secondary sexual characteristics

Question 21

Progesterone

Answer 21

• Source: Ovaries
• Role: Supports pregnancy
• Effect: Maintains lining of the uterus

Question 22

Oestrogen

Answer 22

• Source: Ovaries
• Role: Main female sex hormone
• Effect: Controls menstrual cycle + promotes female secondary sexual characteristics

Question 23

Homeostasis def

Answer 23

balancing body functions to maintain a ‘constant internal enviroment’

Question 24

What happens when its cold?

Answer 24

• little sweat is produced
• Blood vessels near the surface of the skin constrict (vasocontriction). Less blood flows near surface
• Shivering increases rate of respiration which transfers more energy
• Hair stand up to create a insulating layer of air

Question 25

What happens when your hot?

Answer 25

• Sweat produced that when evaporated transfers energy to enviroment cooling you down
• Blood vessels close to the surface of skin dilate (vasodilation). Transfers more energy into surroundings
• Hair lie’s flat