Spinal Cord Anatomy and Receptors Flashcards Preview

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Flashcards in Spinal Cord Anatomy and Receptors Deck (27)
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1
Q

Where and why does the cervical enlargement occur?

A

C5-T1, corresponding to nerve roots from the brachial plexus, which innervate the upper limbs.

2
Q

Where and why does the lumbosacral enlargement occur?

A

L1-S3- corresponding to nerve roots from the lumbosacral plexus, which innervate the lower limbs.

3
Q

What is the caudal extent of the spinal cord?

A

In newborns: L3

In adults: L1/L2

4
Q

How many spinal nerves are there in an adult, on average.

A

31 pairs.

5
Q

Dermatome versus peripheral nerve field:

A

Dermatome refers to the cutaneous area innervates by fibers from a single dorsal root. Whereas peripheral nerve field, refers to sensory field that may use more than 1 dermatome.
Exceptions: no overlap seen in C2, and trigeminal nerves V1, V2 and V3.

6
Q

What are some common dermatomal references? (6)

A
C2 - back of head
C6- thumb and index finger
T4- nipples
T10- umbilicus
L3- Kneecap
S1- lateral foot
7
Q

T/F: The white matter and gray matter distribution in the brain and spinal cord are the same throughout.

A

False.
In the spinal cord, white matter is in the outer edges, gray matter in the inside versus the brain, gray matter is in the outside, white matter is in the inside.

8
Q

Where do vertebral arteries and nerves travel through?

A

Vertebral arteries travel through the transverse foramen, nerves exit the intervertebral space.

9
Q

Where does the dorsal root enter the spinal cord?

A

Posterior lateral sulcus.

10
Q

What is located in the anterior median fissure?

A

The anterior spinal artery.

1 unpaired arterial spinal artery sits in the anterior median fissure, while there are 2 posterior, very wiggly.

Both come off the vertebral artery.

11
Q

What important structure is in the anterior lateral sulcus?

A

Ventral/anterior horn exits.

12
Q

Where in the spinal cord does the dorsal column pathway travel through?

A

Posterior funiculus

13
Q

What pathway travels through the lateral funiculus?

A

The corticospinal tract descends through the lateral funiculus, until synapsing on anterior/ventral horn cells.

14
Q

What does the dorsolateral fasciculus contains?

A

AKA: zone of lissauer
Finely myelinated and unmyelinated axons originating in the substantial gelatinosa and involved in sensory modulation.

loc: between posterior and lateral funiculus

15
Q

What important fibers cross at the anterior commissure?

A

Many fibers can cross, but in particular, spinothalamic tract cross here after DRG synapses at nucleus proprius and ascend to the thalamus.

16
Q

What does the base of the alar plate become?

A

Dorsal horn, involved mostly in sensory/afferent.

17
Q

What does the base of the basal plate become?

A

Ventral horn, involved mostly in motor/efferent.

18
Q

What information does the substantial gelatinosa relay?

A

small compact cells that modify sensory input by synapsing on the nucleus proprius, and ascending/descending in Lissauer’s tract.
Homologous to the spinal trigeminal nucleus
At all cord levels

19
Q

What information does the nucleus proprius relay?

A
"proper sensory nucleus"
Receives many sensory inputs. 
Contains many interneurons
Contains "tract cells" that project contralatterally (through ant commissure) as the spinothalamic tract
At all cord levels 

STT = pain and temp body except head

20
Q

What information does the nucleus dorsalis is relay?

A

AKA: Clark’s nucleus
Receives muscle spindle information
Homologous to the lateral/accessory cuneate nucleus in the medulla.
Projects ipsilateral to the cerebellum as the DORSAL spinocerebellar tract.

21
Q

Where is Clark’s nucleus found?

A

AKA: Nucleus dorsalis. Found only at C8-L3

Projects ipsilateral to the cerebellum as the DSCT.

22
Q

Intermediolateral nucleus:

A

Origin of PREganglionic cholinergic sympathetic efferents
Loc: T1-L3
GVE

23
Q

Intermediomedial nucleus:

A

Receives visceral afferents
Projects to the IML
Found at all levels

24
Q

What does muscle spindles detect?

A

Muscle length/stretch. Important proprioception.

25
Q

What does golgi tendon organs detect?

A

Muscle tension. Internal tension/isometric contraction.

26
Q

DRG- lateral division

A

thin, lightly myelinated fibers

pain, temp, light touch, visceral afferents

27
Q

DRG- medial division

A

thick, heavily myelinated

2 point touch, limb position, muscle stretch, sends collaterals to medulla