Neuroanatomy - Processing Sensory Info & Intro to Special Senses

Question 1

Lists the 3 levels of processing sensory info

Answer 1

1. Receptor level
2. Circuit level
3. Perceptual level

Question 2

General potentials and receptors potentials are for what?

Answer 2

General potentials are for free dendrites or encapsulated receptors

Receptor potentials are for special senses

Question 3

What is adaptation?

Answer 3

Reduction of sensitivity in the presence of constant stimulus - that is not painful.

Question 4

Explain peripheral adaptation.

Answer 4

Peripheral adaptation is at the level of the receptors and reduces how much info is sent to CNS.

Question 5

Explain central adaptation.

Answer 5

Central adaptation is at the level of the neural pathway to brain and involves brain nuclei.

Question 6

Which receptors are fast adapting and what are they called?

Answer 6

Phasic receptors such as lamellar, tactile, special sense, which provides info on rate of change of stimulus.

Question 7

Which receptors have little to no adaptation for a sustained response and what are they called?

Answer 7

Tonic receptors such as nociceptors & proprioceptors informs about presence and strength of stimulus.

Question 8

In a chain of 3 neurons, what can the 1st order neuro do?

Answer 8

It can breach to lead to motor reflexes (ex. knee jerk) or branches synapse with 2nd order neuron to move up to thalamus or cerebellum.

Question 9

List the 3 pathways for somatosensory info to ascend spinal cord.

Answer 9

• Dorsal column-medial lemniscal pathways
• Spinothalamic pathways
• Spinocerebellar pathways

Question 10

Which out of the 3 ascending tracts for sensory info has the thalamus as the target, with a receptors that can be localized precisely, and there is decussation at the level of medulla?

Answer 10

Dorsal column-medial lemniscal pathways

Question 11

Which out of the 3 ascending tracts for sensory info has the thalamus as the target, has serval receptors that don’t localize source as precisely, and there is decussation at the level of spinal cord?

Answer 11

Spinothalamic pathways

Question 12

Which out of the 3 ascending tracts for sensory info has the cerebellum as the target, for coordination of skeletal muscle activity, is ipsilateral, and we are not aware?

Answer 12

Spinocerebellar pathways

Question 13

What is the difference between sensation and perception?

Answer 13

• Sensation: aware of changes in environments
• Perception: conscious interpretations of those changes for a correct response

Question 14

Lists the 6 properties of sensory perception.

Answer 14

• Perceptual detection
• Magnitude estimation
• Spatial discrimination
• Feature abstraction
• Quality discrimination
• Pattern recognition

Question 15

What is associated with a sharp pain?

Answer 15

You feel aware. It is carried by small myelinated A-delta fibers.

Question 16

What is associated with a burning pain?

Answer 16

You feel the aching and the inflammation. It is carried by slow small nonmyelinated C fibers

Question 17

Explain the neurotransmitters for pain.

Answer 17

Glutamate & substance P in which the 2nd order axon from both ascend via spinothalamic tract.

Question 18

List the two pain suppression endogenous opioids.

Answer 18

Endorphins and enkephalins (triggered by SNS)

Question 19

What is somatic pain (musculoskeletal pain)?

Answer 19

Aching, cramping, easily localized because bones and muscles are well innervated.

Question 20

What is visceral pain?

Answer 20

Pain associated with organs of thorax and abdominal cavity. Can lead to reffered pain.

Question 21

What is referred pain?

Answer 21

Pain arising from one part of body appears to come from somewhere else.
- Ex. heart attack

Question 22

What is phantom pain?

Answer 22

Type of hyperalgesia where the pain is ‘learned’ because of NMDA receptors (especially during amputations).

Question 23

What gives tongue the bumpy surface?

Answer 23

Papillae

Question 24

Describe the 3 types of papillae

Answer 24

• Fungiform: surface of tongue with 1-5 taste buds each
• Vallate: largest 8-12 vallate at the back
• Foliate: lateral, # decrease with age

Question 25

Gustatory hairs have receptors for food chemicals called __________.

Answer 25

Tastants

Question 26

What replaces taste cells during a turnover at 7-10 days?

Answer 26

Basal epithelial cells

Question 27

What are the 5 basic tastes modalities?

Answer 27

Sweet, sour, salty, bitter, umami

Question 28

Taste receptors are most sensitive for which modalities?

Answer 28

With different thresholds: bitter

Question 29

For sour taste, what can occur as threshold?

Answer 29

H+ can go in or black leaky K+ channels, leading to depolarization

Question 30

What is the G protein associated with sweet, bitter, and umani?

Answer 30

Gustducin

Question 31

List the 3 cranial nerves associated with the gustatory pathway.

Answer 31

Facial nerve (VII), Glossopharangeal (IX), and Vagus (X)

Question 32

What type of cells is the olfactory epithelium?

Answer 32

Pseudostratified columnar cells

Question 33

Are olfactory sensory neurons unipolar, bipolar, or multipolar?

Answer 33

Bipolar - sensory neurons

Question 34

Explain how odorant chemicals are captured.

Answer 34

The substance must be violate and dissolve in the mucus.
Non-motile cilia are covered by mucus.
The axons gather into small fascicles to form filaments of olfactory nerve, projecting trough cribriform plate to synapse in olfactory bulb.
Axons of mitral cells form olfactory tract.

Question 35

Describe the olfactory transduction and the effects of Na+ and Ca++ that enters.

Answer 35

• influx of Na+: depolarization
• influx of Ca++: adapt and decreasing response to a sustained stimulus (opens Cl- channels)

Question 36

What are the two destinations of the olfactory tracts?

Answer 36

Olfactory cortex & limbic system