Hearing and Other Senses

Question 1

3 parts of hearing:

Answer 1

1. Outer - funnels sound into ear
2. Middle - registers and transmits the vibrations
3. Inner - cochlea, generates nerve impulses

Question 2

Cochlea function

Answer 2

Identifies amplitude and frequency of sound

Question 3

Neurons in the ear

Answer 3

• Basilar and vestibular membranes move when the pressure changes
• Hair cells move which sends messages to the brain (synapses onto cochlear neurons)

Question 4

Hearing theories

Answer 4

1. Place theory
2. Frequency theory
3. Combination

Question 5

Place theory

Answer 5

Different points along the cochlea are sensitive to different frequencies

Question 6

Frequency theory

Answer 6

Cochlear neurons fire at the frequency of the sound

Question 7

Combination theory

Answer 7

Frequency theory for low frequencies, partial frequency theory for intermediate, place theory for high frequencies

Question 8

Sounds in the brain

Answer 8

Messages from ear go to cochlear nucleus, thalamus and A1 (primary auditory cortex)

Question 9

Mechanical senses

Answer 9

Sensing physical changes of body parts (movement)

Question 10

Chemical senses

Answer 10

• Sensing chemicals (smell, taste)
• Receptors exposed to chemicals that are being sensed
• Receptors can be modified by chemicals
• Cells damaged and need to be replaced throughout lifetime

Question 11

Vestibular senses

Answer 11

Helps maintain balance and stabilize vision

Question 12

Touch pathway

Answer 12

Sensory nerves connect to spinal cord, pathway up through thalamus to primary somatosensory cortex

Question 13

Taste buds

Answer 13

• Chemicals on tongue detected by taste receptors inside taste buds
• 5 types: salty, sweet, bitter, sour, savoury

Question 14

Taste pathway

Answer 14

• Receptors on tongue activate sensory neurons
• Neurons enter medulla oblongata to thalamus to insula

Question 15

Smell

Answer 15

Odor receptors in nose direct to limbic system and thalamus to olfactory cortex