Costanzo Neurophysiology - Somatosensory System Flashcards Preview

Neuro > Costanzo Neurophysiology - Somatosensory System > Flashcards

Flashcards in Costanzo Neurophysiology - Somatosensory System Deck (33):
1

What does the somatosensory system include?

Sensations of touch, movement, temperature and pain

2

What are the pathways in the somatosensory system?

Dorsal column system
Anterolateral system

3

What signals does the dorsal column system process?

Sensations of fine touch, pressure, two point discrimination, vibration, and proprioception

4

What fibers make up the dorsal column system?

group II fibers

5

What is the course of the dorsal column system?

Primary afferent neurons have cell bodies in the dorsal root.

Axons ascend ipsilaterally to the nucleus gracilis and nucleus cuneatus of the medulla.

Second order neurons then cross the midline and ascend to the contralateral thalamus and synapse on third order neurons.

Third order neurons ascend to somatosensory cortex, and synapse on fourth order neurons?

This card is actually not that much of a fuck. This is why neuro is hard.

6

What does the anterolateral system processs?

Sensations of temperature, pain, and light touch

7

What fibers make up the anterolateral system? Where do they terminate?

Made up of group III and IV fibers

Enters spinal cord and terminates in the dorsal horn

8

What is the course of the anterolateral system?

Second order neurons cross the midline to the anterolateral quadrant of the spinal cord and ascend to contralateral thalamus.

Synapse on third order neurons at contralateral thalamus.

Third order neurons ascend to somatosensory cortex and synapse on fourth order neurons.

9

Describe the structure of a Pacinian corpuscle.

Onion-like structures in the subcutaneous skin, surrounding unmyelinated nerve endings.

10

What sensations do Pacinian corpuscles detect?

Vibration, tapping

11

What is the adaptation rate of Pacinian corpuscles?

rapid

12

Describe the structure of a Meissner's corpuscle?

Present in non-hairy skin

Pretty lame, Costanzo.

13

What sensations do Meissner's corpuscles detect?

velocity (?). Also, fuck you Costanzo.

14

What is the adaptation rate of Meissner's corpuscles?

Rapid

15

Describe the structure of a Ruffini's corpuscle.

Encapsulated

16

What sensations do Ruffini's corpuscles detect?

Pressure

17

What is the adaptation rate of Ruffini's corpuscles?

Slowly adapting

18

Describe the structure of a Merkel's disc.

Transducer is on epithelial cells

19

What sensations do Merkel's discs detect?

location

20

What is the adaptation rate of Merkel's discs?

slowly adapting

21

What does the thalamus do?

Arrange information from different parts of the body somatotopically

22

What happens with destruction of the thalamic nuclei?

Loss of sensation on the contralateral side of the body

23

What is another word for the somatosensory cortex?

Sensory homunculus

24

What are the major areas of the somatosensory areas of the cerebral cortex?

SI and SII

25

What is the arrangement of SI?

Somatotopic representation similar to that in the thalamus

26

What is another name for the 'map' of the body in the somatosensory cortex?

Sensory homunculus

27

What are the largest areas of the somatosensory cortex?

Areas that represent face, hands and fingers - precise localization is most important.

I know, you're wondering about the genitals. Fairly small area actually. Now you have a scientific justification for that "wrong hole" excuse! Yay science!

28

What is the neurological term for pain, and what does in entail in a general sense?

Term = nociception

Associated with detection and perception of noxious stimuli

29

What are the receptors for pain?

Free nerve endings in skin, muscle and viscera

30

What is an important neurotransmitter for pain?

Substance P

31

What class of drugs inhibit the release of substance P?

Opiods

32

How is fast pain carried?

Group III fibers

Rapid onset and offset, localized

33

How is slow pain carried?

Carried by C fibers

Characterized by achy, burning or throbbing that is poorly localized