Lecture 5, General Sensory Information

Question 1

What are types of special senses?

Answer 1

• visions
• hearing
• smell
• taste
• equilibrium

Question 2

Where do exteroreceptive sensations originate from?

Answer 2

• surface of the body

Question 3

What type of sensations refer to the physical state of the body?

Answer 3

-proprioceptive sensations

Question 4

What type of sensations can be categorized as proprioceptive?

Answer 4

• body position
• muscle and tendon sensation
• pressure
• equilibrium

Question 5

What type of sense is stimulated by mechanical displacement of body tissue, that includes tactile and position?

Answer 5

-mechanoreceptive somatic senses

Question 6

What is the primary sensory neuron ascending pathway?

Answer 6

1. Starts at external receptors
2. Travels through dorsal root of spinal cord
3. Synapse with secondary neurons

Question 7

What is the pathway of secondary sensory neurons (ascending)?

Answer 7

1. these form tracts in the spinal cord and brain stem
2. Normally terminate in thalamus
3. Also synapse with the tertiary neurons

Question 8

What is a tertiary sensory neuron ascending pathway?

Answer 8

1. Travels from the thalamus to primary sensory cortex

2. Then travel through the internal capsule

Question 9

Which ascending pathways are used for conscious perception?

Answer 9

1. Spinothalamic system

2. Medial Lemniscal system

Question 10

Which ascending pathways are used for unconscious perception?

Answer 10

1. Spinocerebellar
2. Spino-olivary
3. Spinotectal
4. Spinoreticular

Question 11

The ascending pathways consist of three-neuron pathways to get from the external receptor to the primary sensory cortex. How much truth is there to this statement?

Answer 11

Not much as a majority of interneurons and other components are being excluded for simplicity

Question 12

What type of information is carried in the lateral spinothalamic tract?

Answer 12

1. Pain

2. Temperature

Question 13

How many spinal cord segments do primary fibers of the lateral spinothalamic tract ascend or descend before synapsing with secondary fibers?

Answer 13

1-2 fibers

Question 14

What regions do the secondary axons of the lateral spinothalamic tract decussate through?

Answer 14

Anterior gray and white commissures

Question 15

In what region of the spinal cord does the lateral spinothalamic tract travel?

Answer 15

Lateral column of the spinal cord, formed by secondary axons

Question 16

What information does the trigeminothalamic tract carry?

Answer 16

Pain and temperature from face and teeth

Question 17

True/False
Secondary fiber collaterals of the lateral spinothalamic tract project to reticular formation stimulate wakefulness and consciousness.

Answer 17

True

Question 18

Where do the secondary and tertiary fibers of the lateral spinothalamic tract synapse?

Answer 18

The ventral posterolateral (VPL) nucleus of thalamus

Question 19

Where do the tertiary fibers of the the lateral spinothalamic tract synapse?

Answer 19

1. Postcentral gyrus

- this corresponds to somatic sensory areas 1,2,3

Question 20

What type of information is carried by the anterior spinothalamic tract?

Answer 20

1. Light touch (crude)
2. Pressure
3. Tickle
4. Itch

Question 21

How many spaces can a primary neuron skip before connecting with seccondary neurons of the anterior spinothalamic tracts?

Answer 21

Skip 8-10 spinal cord segments

Question 22

Where do fibers of the anterior spinothalamic tract decussate at?

Answer 22

Anterior gray or white commissures

Question 23

Where do the secondary and tertiary fibers synapse, of the anterior spinothalamic tract?

Answer 23

Ventral posterolateral nucleus of the thalamus

Question 24

Where do the tertiary fibers of the anterior spinothalamic tract ascend to synapse at?

Answer 24

Ascend through the internal capsule to the primary sensory cortex.

Question 25

What information does the medial lemniscus system carry?

Answer 25

Sensation for two-point sensation (fine-touch) pressure and vibration

Question 26

What is the pathway of primary neurons of the medial lemniscus system to the synapse with secondary neurons?

Answer 26

Primary ascend the length of spinal cord. | -synapse in the medulla at the fasciculus gracilis and fasciculus cuneatus

Question 27

What region of sensation do the fibers of the fasciculus gracilis and nucleus gracilis relay?

Answer 27

This synapse relays information inferior to the midthoracic level

Question 28

Fibers of the medial lemniscus system that has the synapse of fasciculus cuneatus and nucleus cuneatus convey sensation from what region of the body?

Answer 28

Superior to the midthoracic level | - proprioceptive sensation of arms to cerebellum

Question 29

Where is the synapse of the secondary and tertiary neurons of the medial lemniscus system?

Answer 29

Ventral posterolateral region of the thalamus

Question 30

The primary somatosensory area is formed by what areas?

Answer 30

1. Brodmann's area 1, 2, 3

Question 31

Brodmann's areas 5 and 7 make up what region?

Answer 31

Somatosensory association area.

Question 32

What information is received in the somatosensory area I?

Answer 32

Information from: - thigh - thorax - neck - shoulder - hand, fingers - tongue - intra abdominal region

Question 33

What information is collected from somatosensory area II?

Answer 33

- leg - arm - face

Question 34

Where does the somatosensory area II receive information from?

Answer 34

- brain stem, which transmits signals upwards from both sides of body, - also receives information from somatosensory area I.

Question 35

The superficial layers of the somatosensory cortex, layers I and II receive signals from where?

Answer 35

Input signal from lower brain centers

Question 36

Layers II and III of somatosensory cortex receive what type of information?

Answer 36

Send information across corpus callosum to other hemisphere

Question 37

Where do layers V and VI send information?

Answer 37

Layer V: information to basal nuclei, brain stem, and spinal cord Layer VI: information to thalamus

Question 38

Add in where layer IV sends information to!

Answer 38

Huh?

Question 39

What type of information is collected by somatic senses from all over the body?

Answer 39

- received by mechanoreceptors - thermoreceptors - pain - -these are from external sources