Sensory Pathways

Question 1

Fast pain fibers make up the ____ tract while the slow pain fibers make up the _____ tract.

Answer 1

1. NEO-spinothalamic

2. PALEO-spinothalmic

Question 2

Cold Nerve endings are mainly transmitted through what fiber type?

Answer 2

A-delta

Question 3

Ascending pathways for CONSCIOUS Perception

Answer 3

1. Spino-THALAMIC system

2. Medial Lemniscal system

Question 4

Which layers of the Somatosensory Cortex receive input from LOWER brain centers?

Answer 4

I & II

Superficial Layers

Question 5

Characterized headaches are caused by what?

Answer 5

• Meningitis
• Migraines
• Removal of Spinal fluid

Question 6

Widespread bilateral excision of Somatosensory Area 1 causes loss of ability to do what?

Answer 6

• Localize sensations
• Judge pressure
• Judge weights
• Judge shapes or forms
• Judge texture

Question 7

Three types of receptors that incriminate THERMAL gradations

Answer 7

1. Cold
2. Warmth
3. Pain

Question 8

What sensory information is carried by the Anterior Spino-Thalamic Tract?

Answer 8

• Pressure
• Tickle
• Itch

Question 9

Headaches are a result of what?

Answer 9

Pain REFERRED to the Surface from DEEP Head structures

Question 10

What type of fibers are pain fibers?

Answer 10

C fibers

Question 11

Warm Nerve endings are mainly transmitted through what fiber type?

Answer 11

C fibers

Question 12

Characteristics of FAST Pain

Answer 12

• Felt w/in 0.1 sec after stimulus

- NOT felt in DEEPER tissues

Question 13

Referred pain for the Heart? Esophagus?

Answer 13

Heart:

• Shoulder
• Arm
• Forearm

Esophagus

• Upper Chest
• Shoulder

Question 14

Purpose for Lateral Inhibition

Answer 14

• Important in blocking the lateral spread of excitatory signals
• Increases the degree of contrast in the cerebral cortex

Question 15

Which layers of the Somatosensory Cortex are the deepest

Answer 15

V & VI

Question 16

What type of pain fibers are carried by Fast pain?

Answer 16

A-delta

Question 17

Where do Tertiary Neurons Terminate?

Answer 17

SOMATOSENSORY Cortex

Question 18

Somatosensory Area 2 receives signals from where?

Answer 18

• Brainstem
• Somatosensory Area 1
• Visual and Auditory

Question 19

The Tertiary fibers of the Lateral Spino-Thalamic tract synapse where?

Answer 19

POST-Central Gyrus

• Somatic sensory areas 3, 1, 2

Question 20

Layers of the Somatosensory Cortex

Answer 20

I -> VI

Question 21

Primary Sensory Neurons originate from where?

Answer 21

• Originate from PERIPHERAL receptors such as Merkel’s receptors

Question 22

What are most ascending pathways made up of?

Answer 22

3 orders of Neurons

Question 23

In the Dorsal Column pathway, the Axons from the UPPER limb travel in what portion of the 2 Dorsal columns

Answer 23

LATERAL

Fasciculus CUNEATUS

Question 24

Secondary Neurons Characteristics

Answer 24

• Travel through spinal cord in one of the myelinated columns
• make up tracts in spinal cord
• DECUSSATE (Crossover)

Question 25

Two point discrimination

Answer 25

The ability to Distinguish TWO SEPARATE points as close as 2mm apart

Question 26

Purpose of the ANALGESIA System.

Answer 26

To Ignore Pain

Question 27

Referred Pain

Answer 27

- Occurs when pain fibers stimulate fibers that conduct pain signal to the SKIN

Question 28

Primary Sensory Neurons Characteristics

Answer 28

- Enter spinal cord or brain via DORSAL roots of Spinal/Cranial nerves - Cell bodies of these Neurons are located in the Dorsal root ganglia

Question 29

Lateral Spinothalamic Tract carry what type of sensation?

Answer 29

PAIN and TEMP

Question 30

Which layers of the Somatosensory Cortex sends info through the Corpus Callosum to the OPPOSITE hemisphere?

Answer 30

II & III

Question 31

Pain travels through what pathway?

Answer 31

Anterolateral

Question 32

Where do Primary Sensory Neurons Synapse?

Answer 32

- In Spinal cord | - With Secondary Neurons

Question 33

Where do slow pain fibers terminate?

Answer 33

Layers II and III of dorsal horns

Question 34

Characteristics of SLOW Pain?

Answer 34

- Felt about 1sec after stimulus - Increases over several seconds - Aching, SLOW burning

Question 35

The Major Components of the Analgesia System

Answer 35

1. Peri-Quaductal Gray/ Periventricular regions 2. Raphe Magnus 3. Pain Inhibitory complex

Question 36

T/F: Visceral pain is only of the Chronic suffering pain.

Answer 36

True

Question 37

Where do Secondary Neurons Synapse?

Answer 37

THALAMUS w/ tertiary neurons

Question 38

Which layers of the Somatosensory Cortex receive incoming sensory signal ?

Answer 38

Layer IV

Question 39

What are the 3 order of Neurons?

Answer 39

- Primary SENSORY Neurons - Secondary Neurons - Tertiary Neurons

Question 40

Where do Nociceptors terminate?

Answer 40

In Lamina of the Dorsal Horns

Question 41

Where do Secondary Neurons Originate?

Answer 41

In the GRAY MATTER of the spinal cord

Question 42

The Ascending order of the pathway?

Answer 42

Start: Primary (Low) Middle: Secondary End: Tertiary (Highest)

Question 43

Nociceptors

Answer 43

- Pain receptors | - FREE Nerve endings

Question 44

Ascending pathways for UNCONSCIOUS Perception

Answer 44

1. Spino-CEREBELLAR 2. Spino-OLIVARY (Brainstem) 3. Spino-TECTAL (Mesencephalon) 4. Spino-RETICULAR (Ret. Formation)

Question 45

Dorsal Column-Medial Lemniscal Pathway

Answer 45

AKA Posterior Column system - Carries Sensations for 2-point sensation - Primary fibers ascend ENTIRE length of spinal cord and synapse w/ Secondary neurons in medulla

Question 46

In the Dorsal Column pathway, the Axons from the LOWER limb travel in what portion of the 2 Dorsal columns

Answer 46

MEDIAL | Fasciculus GRACILIS

Question 47

Tertiary Neurons Characteristics

Answer 47

-Travel from the Thalamus to Primary Sensory Cortex | - Travel through Internal capsule Myelinated pathway b/w Thalamus and some of the basal Nuclei