Neuro Exam 2 Somatosensation/spinal Cord

Front 1

Where does the Spinal Cord start and end? What stucture is at the end of the spinal cord and where does that end?

Back 1

Starts at the foramen magnum and ends at L2 where the cauda equina continues to S2.

Front 2

Where are the 2 enlargments of the spinal cord and why are they enlarged?

Back 2

Cervical enlargement for nerves to enter/exit for the arms. Lumbosacral enlarment for the nerves to enter/exit for the legs.

Front 3

Name the different parts of the spine and how many vertebrae accompany each.

Back 3

Cervical- C1-C8
Thoracic- T1-T12
Lumbar- L1-L5
Sacral- S1-S5
Coccygeal(Co)
Gives rise to 31 pairs of nerves

Front 4

What is a dermatone map?

Back 4

A dermatone map indicates the sensory distribution of each spinal nerve

Front 5

What types of matter does column and horn refer to?

Back 5

column- white matter
Horn- gray matter

Front 6

What types of cells correspond to Dorsal column, ventral column, and lateral column?

Back 6

Dorsal: cell processes of sensory neurons
Ventral column: motor neurons
Lateral columns: Sympathetic neurons of the ANS

Front 7

What types of cells correspond to dorsal horn, anterior horn, and lateral horn?

Back 7

dorsal horn- Ascending sensory pathway. Contains interneurons, projection neurons, dendrites, and cell bodies.
Anterior Horn- Contain cell bodies of skeletal motor neurons
Lateral Horn- sympathetic system between T1-L3. Parasympathetic between S2-S4

Front 8

What is the function of the dorsal root?

Back 8

An afferent sensory axon. Cell body contained in the dorsal root ganglia. Project into the posterior horn of the SC where it may synapse w/ interneurons, ascend, or descend

Front 9

The combination of which 2 roots for the spinal nerves?

Back 9

dorsal and central roots

Front 10

What are the function of the ventral roots?

Back 10

Efferent motor nerves. Cell bodies are in the grey matter of the anterior(somatic neurons) and lateral(autonomic neurons) horns.

Front 11

What is endoneurium, perineurium, and epineurium?

Back 11

endoneurium is a delicate structure surrounding each nerve and schwann cell.
Perineurium surrounds each fascicle.
Epineurium surrounds groups of nerve fascicles and is continuous with the dura mater surrounding the CNS.

Front 12

What are the 2 ascending pathways? Where do they terminate? Where do they cross over? What types of information do they transmit?

Back 12

Lateral Spinothalamic tract carries info regarding pain and temperature and crosses over almost immediately after entering the SC.
The dorsal column carries info about touch, pressure, and conscious proprioception. Crosses over in the medulla.
Both terminate in the thalamus.
Alight touch sensation is a combination between the two.

Front 13

What are the 3 main tracts involved in unconscious sensation? What do they do and went do they cross over?

Back 13

Spinocerebellar- Unconcious propriception(multi tasking without thinking). Fibers are ipsilateral.
Spinoreticular- Carries pain info to the reticular formation, crosses over almost immediately.
Spinomesencephalic tract- Carries pain info to the superior colliculus(involved w/ getting eyes/head to look at stimulus). Crosses over almost immediately.

Front 14

Where do the descending pathways cross?

Back 14

Medulla

Front 15

Which motor neurons extend to the skeletal muscle?

Back 15

Lower motor neurons.

Front 16

What symptoms/signs accompany a hemi-sectional spinal cord lesion?

Back 16

ipsilateral paralysis, consious proprioception, and sensory loss.
Loss of pain/temperature contralaterally

Front 17

What symptoms/signs accompany a posterior column spinal cord lesion?

Back 17

loss of stereognosis(sensory) and concious proprioception ipsilaterally

Front 18

What symptoms/signs accompany an anterior spinal cord lesion?

Back 18

paralysis both sides
loss of pain and temp both sides

Front 19

What symptoms/signs accompany a central lesion at the level of the cervical cord ?

Back 19

bi lateral loss of pain/temperature at the level of the lesion.

Front 20

Where is the lesion if there is a loss of all sensory modalities in an entire extremity?

Back 20

probably above the spinal cord.

Front 21

What are the 5 reflex components?

Back 21

Sensory receptor
Sensory Neurons
Interneurons (monsynaptic reflexs don't have interneurons)
Motor neurons
Effector Organ

Front 22

What are 4 types of reflexes? Do you know what they do?

Back 22

Stretch reflex-excitatory
Golgi Tendon Reflex- inhibitory
Withdrawal reflex- excitatory interneurons for flexors. Inhibitory to stop extensor muscles.
Crossed Extensor muscles-excitatory to extend opposite leg of withdrawal.

Front 23

What are some examples of specialized senses?

Back 23

hearing, sight, taste, smell, balance etc..

Front 24

What is the difference between somatic and visceral senses?

Back 24

Visceral senses have infor about the internal organs.
Somatic senses are info about the body and environment(touch, pressure, temp pain etc.)

Front 25

What is a nociceptor?

Back 25

a pain receptor

Front 26

Where are the cell bodies of the somatosensory receptors?

Back 26

Dorsal root ganglion.

Front 27

What are some examples of sensory information not perceived?

Back 27

Some info about position and movement sent directly to the cerebellum.
receptors monitoring BP, oxygen, pH etc. do so unconsciously. (homeostatsis)
Cortex supression.
Neuromodulators can decrease frequency of action potentials.
Adaptation.

Front 28

What is hyperalgesia?

Back 28

normally mildly uncomfortable stimuli is perceived as very painful

Front 29

What is Allodynia?

Back 29

unpainful stimuli perceived as painful(swallowing)

Front 30

What is Ataxia?

Back 30

incoordination not due to weakness. People can sometimes compensate using vision.

Front 31

What is the Romberg Test?

Back 31

Used to determine between Sensory ataxia and cerebellar ataxia. Pt. closes eyes.
Sensory ataxia- pt becomes shaky when eyes close.
Cerebellar ataxia- always shaky.