Nervous System

Question 1

Labels of the eye

Answer 1

Cornea- very outside of the eye
Lens- middle circle(pupil)
Iris- muscle like flaps over the pupil
Fovea- back lines

Question 2

Explain a function of the retina

Answer 2

Absorbs light, contains rods and cones, colour vision

Question 3

2 ways the nervous system controls the action of the eye to enable effective sight

Answer 3

Controls dilation to adapt to different light levels, focus image onto the retina, change direction of Vision

Question 4

Explain an advantage of eye positioning in sheep

Answer 4

Wide angled peripheral vision, early detection of danger, evasive action

Question 5

Functions of each part of the eye

Answer 5

Iris- controls how much light enters the eye, controls pupil size
Lens- focused light
Retina- absorbs light, detects colour and movement
Cornea- protection, refraction

Question 6

Describe the role of the tapetum lucidum

Answer 6

Bounces light back, improving vision in nocturnal animals

Question 7

State the two parts of the central nervous system

Answer 7

Brain and spinal CORD

Question 8

Explain the function of the parasympathetic nervous system

Answer 8

Slows heartbeat/relax, constricts pupils, stimulates saliva, contracts bladder

Question 9

How a nerve impulse is transmitted between neurons

Answer 9

Stimulate action potential, synapse, eels ease of neurotransmitter, nerve ending

Question 10

Symptoms of listeriosis in ruminants

Answer 10

Loss of appetite, fever, facial paralysis, loss of balance

Question 11

Eyes of an owl adaptation

Answer 11

Binocular vision, see prey

Question 12

Photoreceptors in the eye

Answer 12

Rods and cones

Question 13

Adaptations to help animals see in the dark

Answer 13

Large pupils, more rods, specialised reflective layer at back of the eye

Question 14

Hormone released when an animal is stressed

Answer 14

Adrenaline

Question 15

How sense organs cause response to stimuli

Answer 15

Receptors detect stimuli, brain processes message, effector generates response, send impulses to CNS

Question 16

Vasoconstriction-

Answer 16

Happens when an animal gets cold, blood vessels constrict, less blood to the skin, reduced heat loss

Question 17

Vasodilation-

Answer 17

Happens when an animal gets hot, blood vessels dilate, increased blood flow, cools down

Question 18

Two types of neuron

Answer 18

Sensory, motor, relay /interneuron

Question 19

What is a neuron

Answer 19

information messengers. They use electrical impulses and chemical signals to transmit information between different areas of the brain, and between the brain and the rest of the nervous system.

Question 20

What is a glial cell

Answer 20

Clean up brain debris
Transports nutrients to neurons
Maintains neurons
Provide supporting functions to nervous system

Question 21

Parasympathetic-

Answer 21

Rest and digest, restores normal body’s functions, neurotransmitter is acetylcholine(Ach), consticts pupils, slows heartbeat, stimulates gastric juice secretion, contracts bladder

Question 22

Sympathetic-

Answer 22

Prepares for physical activity, neurotransmitter used noradrenaline (NA), dilates pupils, accelerates heartbeat, relaxes bladder, dilated bronchi, stimulates release of glucose

Question 23

Reflex arc-

Answer 23

Neutral pathway that controls a reflex, allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain

Question 24

Neuron cells structure

Answer 24

Dendrite- outer coating to the axon, protects and maintains
Cell body/soma- contains genetic info that controls neuron
Nucleus- encapsulates nucleus
Myelin sheath- receive communications from other neutral cells through their tree like projections
Node of ranvier- connects neuron to target cells
Schwann cells- helps to form myelin sheath, speeds up transmission of nerve impulses
Axon terminals- allows impulses to jump by ‘salaries conduction’

Question 25

Synapse

Answer 25

The junction between two neurons