Lecture 7

Question 1

How do our senses respond biologically to relevant stimuli?

Answer 1

They are specialized and have evolved to give us useful information

Question 2

What are sound waves

Answer 2

Periodic compressions, causing vibrations

Question 3

What is sound frequency

Answer 3

The number of compressions per time. Relates to perceived PITCH

Question 4

What is sound amplitude

Answer 4

Intensity of the sound wave, which relates to perceived loudness

Question 5

What is sound

Answer 5

A complex set of acoustic information is transferred

Question 6

How are sound waves detected

Answer 6

Pinna (outer ear) then travels to the Tympanic membrane (eardrum). The system converts sound waves into waves of greater pressure onto oval window of cochlea to move the viscos fluid within towards the hair cells which are displaced by vibrations, then goes to the auditory nerve (nerve bundle)

Question 7

What is the pinna

Answer 7

The outer ear

Question 8

What is a tympanic membrane

Answer 8

Eardrum - a thin membrane where information is carried via vibrations and then via the instruments of the middle ear

Question 9

What is the cochlea

Answer 9

3 fluid tunnels (snail shaped) and allows us to distinguish between frequencies. Has hair cells in it that are displaced when there are vibrations

Question 10

What are the auditory nerves

Answer 10

Nerve bundles

Question 11

Where is the sound info processed

Answer 11

After reaching the ear, it goes to the cochlear nucleus then over to the primary auditory cortex. There is a CROSSOVER between left ear and right hemisphere

Question 12

What makes us able to distinguish between different frequencies

Answer 12

Basilar membrane of cochlea and primary auditory cortex. High frequency sounds excite near the base, low frequency near the apex. 4% of people are tone deaf = amusia. Neighbouring cells respond to neighbouring frequencies

Question 13

If the primary auditory cortex is damaged will it cause deafness

Answer 13

Sound processing would be affected but not cause deafness

Question 14

If the middle ear is damaged, could it cause deafness?

Answer 14

It can cause conductive deafness if the bones in the middle of the ear are damaged. Or nerve deafness when cochlea, hair cells or auditory nerve is damaged

Question 15

How can we locate sounds

Answer 15

Both ears receive different information. There’s three differences: time of arrival, intensity, phase in sound waves

Question 16

Can we hear all loud sounds in our close srrounding

Answer 16

No. We have highly specialized hearing systems.

Question 17

What does a vestibular organ do

Answer 17

Detects position and movement of the head - crucial for balance

Question 18

How many canals does the vestibular organ have

Answer 18

3

Question 19

Describe the vestibular organ canals

Answer 19

Next to inner ear, filled with jelly-like substance, lined with hair cells

Question 20

How does vestibular sensation work

Answer 20

Head moves, then within the 3 semicircular canals the jelly-like substance moves. Calcium carbonate particles move against hair cells towards brainstem then cerebellum.

Question 21

Why are there 3 canals

Answer 21

They represent three dimensions and different movement directions

Question 22

Where are taste buds found

Answer 22

Grouped in papillae on the tongue

Question 23

What do fungiform papillae affect

Answer 23

Sensitivity to all tastes - many = high sensitivity

Question 24

How many receptor cells are there in one taste bud

Answer 24

50

Question 25

How do taste buds behave

Answer 25

Like neurons - release neurotransmitters to excite nearby neurons. But they are not neurons - they are modified skin cells and replaced after 10-14 days.

Question 26

What are the four primary tastes

Answer 26

Sweet, salty, sour and bitter

Question 27

Can the 4 primary tastes describe all tastes

Answer 27

No. - glutamate taste receptors, the monosodium glutamate in fast food

Question 28

How does the brain encode taste

Answer 28

1. Taste nerves. 2. Medulla (at nucleus of the tractus solitaris). Then either Insula (for taste) or somato-sensory cortex (for touch)

Question 29

Why are there other sensory organs

Answer 29

By tasting, humans obtain information on the chemical environment with physical contact and with a focus on food, but there is additional important information in the chemical environment.

Question 30

How do we detect smell

Answer 30

Olfactory receptor cells - in nasal cavity, hundreds of types for many different chemicals. Olfactory bulb - processes the information (in the limbic system)

Question 31

Discuss the vomeronasal sensation

Answer 31

Auxiliary olfactory - in nonhuman mammals. It detects odourless chemicals that affect behaviour sing receptors at the olfactory bulb

Question 32

Name two neurodegenerative diseases

Answer 32

Huntington's disease and Parkinson's disease

Question 33

Discuss Huntington's disease

Answer 33

Motor disorders - arm jerks, facial twitches. Psychological disorders - depression, anxiety, hallucinations. Gradual brain damage, firstly in the basal ganglia then cerebellum, cerebral cortex and more. Strong genetic influence

Question 34

Discuss Parkinson's diseas

Answer 34

Motor disorders - spontaneous, rigidity and slowness. Cognitive disorders - imagining movement and events. Gradual death of neurons in substantia nigra (mid-brain), decrease in dopamine activity, reduced stimulation of the motor cortex. Genetic & exposure to toxins

Question 35

How do we move

Answer 35

Skeletal muscles - control movement of body in relation to the environment. Smooth muscles control internal organs. Cardiac muscles controls heart muscles and fuse to make a pump. Movement results from muscle fiber contractions

Question 36

Name the 3 muscle types

Answer 36

Skeletal muscles. Smooth muscles. Cardiac muscles.

Question 37

What is neuromuscular junction

Answer 37

Synapse of muscle fiber & motor neuron axon. Each muscle fiber is innervated by one motor neuron axon

Question 38

How do skeletal muscles move

Answer 38

Acetylcholine released by axons = muscle contraction. Acetylocholine absence = muscle relaxation

Question 39

What is required in order for movement to other directions

Answer 39

Antagonistic muscles

Question 40

How does the brain control complex movements

Answer 40

Primary motor cortex - axons - brainstem&spinal cord - impulses that control muscles

Question 41

Discuss the primary motor cortex

Answer 41

It has a map of areas of the body movements - stimulation at each spot causes specific movement, active even when we think about movement

Question 42

What other brain areas are involved in movement

Answer 42

Cerebral cortex (movement preparation) - prefrontal cortex, supplementary motor cortex, posterior parietal cortex. Basal ganglia (initating actions). Cerebellum (timing/attention/balance)