Sensory Physiology (TEST 2)

Question 1

Sensory (afferent) neurons?

Answer 1

carry information from sensory receptors to CNS

Question 2

Efferent Neurons?

Answer 2

carry information from the CNS to various parts of the body (eg. motor neurons)

Question 3

Interneurons?

Answer 3

Neurons that lie entirely within the CNS

Question 4

What senses are included in special senses?

Answer 4

vision, hearing, taste, smell, equilibrium

Question 5

What senses are included in somatic senses?

Answer 5

touch, temperature, pain, itch, proprioception

Question 6

What are the common elements of all sensory pathways?

Answer 6

1. Stimulus
2. receptor
3. Afferent Signal
4. CNS Integration

Question 7

What are the 4 main types of receptors?

Answer 7

1. Chemoreceptors
2. mechanoreceptors
3. thermoreceptors
4. photoreceptors

Question 8

Define Convergence?

Answer 8

multiple presynaptic neurons provide signals to a smaller number of post synaptic neurons

Question 9

What are first-order neurons?

Answer 9

• first order neurons are connected to the sensory receptor and are located within the peripheral nervous system
• these neurons are going to bring information into the CNS.

Question 10

What are second-order neurons?

Answer 10

• Will generally bring information into the thalamus, but sometimes directly to the cortex and typically these second order neurons will synapse third order neurons that bring information to the cortex for conscious perception

Question 11

What signals must the CNS recognize?

Answer 11

1. nature/modality of the signal
2. Location of signal
3. Intensity of Signal
4. Duration of Signal

Question 12

What are tertiary sensory neurons?

Answer 12

• they synapse with all secondary neurons in the thalamus, and they travel to the somatosensory region of the cerebral cortex

Question 13

What are the 2 pathways included in nociceptors pathways ?

Answer 13

1. Reflex protective responses

2. Ascending Pathways to cerebral cortex

Question 14

The external ear consists of what?

Answer 14

consists of the pinna and the ear canal.

Question 15

What is the middle ear structure?

Answer 15

Air filled cavity connecting pharynx to the eustachian tube

Question 16

What are the 3 middle ear bones?

Answer 16

1. malleus
2. Incus
3. Stapes

Question 17

The inner ear consists of 2 major sensory structures what are these?

Answer 17

1. vestibular apparatus

2. cochlea

Question 18

What are the steps in sound transduction?

Answer 18

1. Sound waves
2. mechanical vibrations
3. movement opens/closes ion channels on hair cell membrane
4. Electrical signal is created
5. electrical signals results in release of neurotransmitters
6. Neurotransmitters bind to primary auditory neurons

Question 19

Rods

Answer 19

• function well in low light (night vision)

Question 20

Cones

Answer 20

High acuity & colour vision