Nervous/Sensory System

Question 1

CNS

Answer 1

Central Nervous System

Question 2

Peripheral nervous system

Answer 2

• To carry information from sensory organs and internal organs to CNS
• To carry information between CNS and other parts of the body, excluding the brain and spinal cord

Question 3

Somatic nervous system

Answer 3

• Controls voluntary movement via skeletal muscles

Question 4

Autonomic Nervous System

Answer 4

• Regulates involuntary movement of muscles of internal organs and glands (automatic functions)
• Heart rate, blood pressure, respiration, arousal, digestion
• Reflexes

Question 5

Sense organs

Answer 5

• Eyes: sense of sight
• Nose: sense of smell
• Tongue: sense of taste
• Ears: sense of hearing and balance
• Skin: sense of touch

Question 6

Layers of skin

Answer 6

• Epidermis
• Dermis
• Hypodermis

Question 7

What is the hypodermis also called?

Answer 7

Subcutaneous tissue

Question 8

Epidermis

Answer 8

• Outer/top layer
• Thinnest layer of skin
• Composed of a stratified layer of flattened cells
• Lacks blood cells
• Can be found in plants
• Provides water proof barrier
• Makes skin tone with melanin

Question 9

Dermis

Answer 9

• Middle layer
• Thickest layer of skin
• Composed of dense irregular connective tissue
• Is vascular (has blood vessels)
• Is not found in plants
• Supports elasticity, sweat glands and oil
• Supplies nutrients to epidermis

Question 10

Hypodermis

Answer 10

• Insulates body
• Contains energy
• Links to muscles

Question 11

Structure of an eye

Answer 11

• Sclera
• Pupil
• Iris
• Cornea
• Lens
• Retina
• Optic nerve

Question 12

Sclera

Answer 12

• White part
• Fibrous tissue
• Protects eyeball
• Maintains shape of eyeball

Question 13

Pupil

Answer 13

• Black centre of the eye
• Changes size to let light into the eye

Question 14

Iris

Answer 14

• Coloured tissue that makes eye colour
• Muscles in the iris control the opening size of the pupil

Question 15

Cornea

Answer 15

• Transparent cover over the pupil and iris
• Focuses entry of light into the eye

Question 16

Lens

Answer 16

• Behind the pupil
• Focuses light onto the retina at the back of the eye to obtain clear images of objects at various distances

Question 17

Retina

Answer 17

• A layer of photoreceptor cells and glial cells
• Cone cells - Helpful for seeing vivid colours in brightness
• Rod cells - Helpful for seeing in dark conditions
• Converts light that enters the eye into electrical signals that the optic nerve sent to the brain to create the images you see

Question 18

Parts of the ear

Answer 18

• Outer ear
• Middle ear
• Inner ear

Question 19

Optic nerve

Answer 19

• Transfers all information obtained by the eye to the brain

Question 20

Outer ear

Answer 20

• Collects sound waves and channels them into the external auditory meatus (ear canal) where sound will be amplified
• Pinna/auricle - external part of the ear
• External auditory canal - tube that connects the outer ear to middle and inner ear

Question 21

Middle ear

Answer 21

• Ossicles - small bones that transmit sound waves to the inner ear: Malleus, Incus, Stapes
• Eustachian tube - connected to nose, stabilises middle ear pressure which is important for sound wave transmission

Question 22

Inner ear

Answer 22

• Cochlea - detects sound low in frequency
• Vestibule - contains receptors to maintain balance during rotational movements
• Semicircular canals - 3 fluid-filled tubes that help you maintain balance during rotational movements

Question 23

How sound travels through the ear

Answer 23

• Sound waves enter the outer ear (pinna/auricle)
• Sound waves hit eardrum after travelling through the ear canal causing vibrations
• Sound moves through the middle ear and sound waves are amplified
• Sounds moves though the inner ear (cochlea) where vibrations are transformed into electrical signals by hair cells
• Signal/sound is interpreted by brain

Question 24

Taste

Answer 24

• Taste is detected with receptor cells known as taste buds
• Different taste buds detect different taste sensations
• Taste buds are evenly distributed across the tongue

Question 25

Smell

Answer 25

• Detected by olfactory receptor
• Humans detect smell from molecules, if an object has no molecules we cannot smell it
• If the human or animal lacks the specific receptor for a molecule, it cannot be smelled by that person

Question 26

Taste buds

Answer 26

Taste buds and olfactory receptors are both found on the tongue which causes taste of food to occasionally linger in your nose

Question 27

Tactile receptors

Answer 27

• Sensory neuron in the skin
• Transmits light-touch or low frequency vibrations from the peripheral nervous system to the CNV
• Possesses specialised endings that respond to mechanical stimuli

Question 28

Thermoreceptors

Answer 28

• A sensory end organ
• Detects heat and cold in the surrounding environment
• Certain body parts’ skin has more thermoreceptors which makes those places more sensitive to heat
• Separated into warm and cold, cold thermoreceptors are more common

Question 29

What is pain?

Answer 29

A warning mechanism to influence an organism to withdraw from harmful behaviour and activity

Question 30

How is pain detected and felt?

Answer 30

• Nociception: When information that tissue damage has or may occur is relayed to the brain
• Pain can be detected by tactile receptors but mostly by specialised nociceptors

Question 31

How is pain a protective mechanism?

Answer 31

• It allows the organism to be aware of the location of damaged tissue to prevent it from gaining further damage
• If pain could not be detected, a small injury could result in something much more severe due to the organism’s hypothetical ignorance of the damaged tissue