The Back Vertebral Canal and Spinal Nerves

Question 1

innervate the Deep Epaxial Muscles (Intrinsic
Muscles) that lie dorsal to the transverse process of the
vertebrae. Actions: Extend the vertebrae column

Answer 1

Posterior Ramus

Question 2

Innervate the Hypaxial muscles (Muscles
located ventral to the transverse processes and include muscles
of the abdominal and thoracic wall). Also the Intermediate
Group (Serratus Posterior Superior and Serratus Posterior
Inferior).
Action: Flex the vertebral column

Answer 2

Anterior Ramus

Question 3

innervates via C3,C4,C5 the Levator
scapulae, and via C4,C5 the Rhomboid major and Rhomboid
minor muscles.

Answer 3

Dorsal scapular nerve

Question 4

innervates the Trapezius

Answer 4

Accessory nerve(Cranial nerve XI (11)

Question 5

innervates the Latisimus Dorsi
muscle.

Answer 5

Thoracodorsal nerve via C6-C8

Question 6

The length of the spinal cord varies according to
age. In the first trimester, the spinal cord
extends to the end of the spinal column, but as
the fetus ages, the vertebral column lengthens
more than the spinal cord. At birth, the spinal
cord ends at approximately L3 and in the adult,
the cord ends at approximately L1 with 30% of
people having a cord that ends at T12 and 10%
at L3

Answer 6

Spinal Tap

Question 7

Reasons for a lumbar puncture

Answer 7

1. Collect cerebrospinal fluid for laboratory analysis
2. Measure the pressure of your cerebrospinal fluid
3. Inject spinal anesthetics, chemotherapy drugs or
   other medications
4. Inject dye (myelography) or radioactive
   substances (cisternography) into cerebrospinal fluid
   to make diagnostic images of the fluid’s flow

Question 8

What Information gathered from a lumbar puncture can help diagnose

Answer 8

1. Serious bacterial, fungal and viral infections, including meningitis, encephalitis and syphilis
2. Bleeding around the brain (subarachnoid hemorrhage)
3. Certain cancers involving the brain or spinal cord
4. Certain inflammatory conditions of the nervous system, such as Multiple Sclerosis and Guillain-Barre syndrome

Question 9

Demyelinative diseases

Answer 9

Demyelinative diseases of the central nervous system are characterized by loss of myelin with variable loss of axons. In contrast, infarcts, contusions, encephalitis, and other conditions destroy myelin and axons equally. The main demyelinative disease of the CNS is multiple sclerosis (MS) and its variants. Its counterpart in the peripheral nervous system is inflammatory demyelinative polyradiculoneuropathy (Guillain-Barré syndrome-GBS) and its chronic variants. MS and GBS are autoimmune inflammatory diseases. There are also virus-induced demyelinative diseases, such as progressive multifocal leukoencephalopathy. Demyelinative diseases should be distinguished from leukodystrophies, which are inherited metabolic disorders of myelin lipids and proteins.

Question 10

A process leading to scars in the central nervous system that involves the production of a dense fibrous network of neuroglia (supporting cells) in areas of damage. it is a prominent feature of many diseases of the central nervous system, including multiple sclerosis and stroke. After a stroke, neurons die and disappear with replacement gliosis.

Answer 10

Gliosis

Question 11

The CSF of people with MS usually contains:

Answer 11

Elevated levels of IgG antibodies, as well as
A specific group of proteins called oligoclonal bands.
Occasionally there are also certain proteins that are the breakdown products of myelin

Question 12

Other tests that your doctor might recommend to rule out or confirm a diagnosis of MS include:

Answer 12

1. blood tests
2. MRI (magnetic resonance imaging) test
3. Evoked potential test

Question 13

measure the electrical activity of the brain in response to stimulation of specific sensory nerve pathways. They are able to detect the slowing of electrical conduction caused by damage (demyelination) along these pathways even when the change is too subtle to be noticed by the person or to show up on neurologic examination. Because the diagnosis of MS requires evidence of demyelination in two distinct areas of the central nervous system, EP testing can help confirm the diagnosis by enabling the physician to identify a second demyelinating event that caused no clinical symptoms or was not otherwise apparent.In order to measure evoked potentials, wires are placed on the scalp overlying the areas of the brain being stimulated. The examiner then provides specific types of sensory input (e.g., sound, light or sensation), and records the responses of the person’s brain. Evoked potential testing is harmless, generally painless, and is a very sensitive technique for detecting lesions (damaged areas).

Answer 13

Evoked potential (EP) tests