Topic 4: PNS Road Maps Flashcards

1
Q

In the lumbosacral region, the nerve roots descend almost vertically below the cord to form the

A

Cauda Equina

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2
Q

The area from which a pair of dorsal and ventral roots arise is defined as

A

A segment of the SC

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3
Q

How many roots does each segment of the spinal cord connect to

A

4 roots

Each root consists of bundled nerve fibers.

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4
Q

The anterior and posterior roots join together at the intervertebral foramen, to form a

A

Spinal nerve

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5
Q

The ventral (anterior) root contains axons that carry _________ signals from the spinal cord to muscles and viscera.

The cell bodies of these axons lie in the SC.

A

Efferent

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6
Q

The dorsal root contains ________ signals. A dorsal root ganglion contains cell bodies of 1st order neurons. Unipolar.

A

Afferent

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7
Q

On emerging from the intervertebral foramen, a spinal nerve divides immediately into anterior and posterior ramus with medial and lateral branches each containing what fibres

A

Motor and Sensory fibres

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8
Q

Supplies the posterior body trunk and back of the head

A

Dorsal Rami

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9
Q

Supplies the lateral and anterior trunk and upper and lower extremities

A

Ventral Rami

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10
Q

Both dorsal and ventral rami contain autonomic fibers. Both dorsal and ventral rami are mixed nerves because

A

They are branches of the spinal nerve, not the root.

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11
Q

Axons in the ventral rami that serve the upper and lower extremities mix and mingle with each other to form nerve networks called

A

Plexuses

Peripheral nerves

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12
Q

Peripheral nerves i.e. Those serving the upper and lower extremities, usually contain fibres from more than one spinal nerve. Why is this advantageous?

A

Because a muscle getting innervation from multiple spinal nerves can retain some function if one spinal nerve is damaged at the spinal cord location

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13
Q

True or False?

Only ventral rami form plexus’?

A

True

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14
Q

The level of SC injury is indicated by the highest level that remains intact.

Give an example:

A

A C3 lesion means that the dermatomes and myotomes associated with C1 to C3 are fully functioning. All those below C3 are affected.

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15
Q

The brachial plexus supplies the upper limb and supporting musculature of the scapula. The brachial plexus is formed by the ventral rami _________ (which spinal segments)

A

C5 - T1

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16
Q

The plexusbhas different regions. What are they?

A

Roots, Trunks, Divisions, Cords —> post plexus nerves ex. Radial Nerve

17
Q

Innervates the muscles in the flexor compartment of the upper arm. (Biceps Brachii, brachilis, coracobrachialis)

A

Musculocutaneous

18
Q

Innervates most intrinsic muscles of the hand - except the Thenar Eminence

A

Ulnar Nerve

19
Q

Innervates most of the flexors muscles in the forearm and thenar muscles

A

Median Nerves

20
Q

Innervation to the deltoid and Teres minor

A

Axillary Nerve

21
Q

Innervates the extensor muscles of the elbow, wrist, and fingers & anotomical snuff box

A

Radial Nerve

22
Q

Long Thoracic Nerve

A

Serratus Anterior

23
Q

Thoracodorsal Nerve

A

Latissimus Dorsi

24
Q

Area of skin supplied by sensory nerve fibres originating from a single dorsal nerve root of a single spinal nerve

25
What is a receptive field?
Responsibility of 1 unipolar neuron
26
Dermatomes are named according to the
Spinal nerve which supplies them
27
Lateral shoulder and arm
C5
28
Thumb, index finger (radial border of hand)
C6
29
Middle Finger
C7
30
Digiti minimi (ulnar border of hand)
C8
31
Medial elbow
T1
32
Intercostal nn. form segmental strips on thorax
T2-T12
33
Goes across the nipples
T4
34
Across the umbilicus
T10
35
Across upper edge of pubic bone
T12