Question 1

Spinal Cord

Accepted Answer

Begins at the foramen magnum.
Ends at the conus medullaris. 
•A cone shaped structure 
•At L1 to L2 vertebra 
FUNCTIONS: Provides two-way communication to and from the brain
•Contains spinal reflex center

Question 2

Spinal Cord is protected by

Accepted Answer

•Bone 
•Meninges: Pia mater, Dura and arachnoid mater 
•CSF 
•Cushions of fat in the epidural space 
•Filum Terminale: fibrous extensions from conus medullaris covered by pia mater. Descends through the sacral canal and attaches within the coccyx at the level of first coccygeal segment

Question 3

Spinal Nerves

Accepted Answer

•31 pairs 
•Each pair of spinal nerves receives sensory information and issues motor signals to muscles and glands. 
•Exit the vertebral canal through the intervertebral foramina

Question 4

Cervical and Lumbar Enlargements

Accepted Answer

•The width of the spinal cord is greater.
•Due to the spinal nerves that emerge to supply the upper and lower limbs

Question 5

Cauda Equina

Accepted Answer

•The collection of nerve roots from L2 and 1st coccygeal nerve inferior to the conus medullaris 
•Resembles a horse’s tail 

SPINAL CORD IS A COMPONENT OF THE CNS WHILE THE SPINAL ARE PART OF THE PNS

Question 6

Spinal Nerves

Accepted Answer

•Anterior Rootlets: Small bundles of axons. Arise from te spinal cord and merge to form a single ventral root (motor) 
•Dorsal Rootlers: Small bundles of axons. Enters the spinal cord. Arise from a single dorsal root (sensory) 
•Dorsal Root Ganglion: an enlarged area of the dorsal root that contains cell bodies of sensory neurons. 
•Spinal Nerve Root: The union of the ventral and dorsal roots within the. Intervertebral foramen

Question 7

Nerve fibers

Accepted Answer

•Afferent Nerve Fibers: Carry sensory nerve impulses. PNS to CNS.
•Efferent Nerve Fibers: Carry motor nerve impulses . CNS to PNS 
•Mixed Nerves: Contain both sensory (afferent) and motor (efferent) fibers. most nerves are a mixture. 
•Pure sensory (Afferent) or motor (efferent) nerves are rare. 
•Dermatome: a specific region of the skin innervated by a single spinal nerve.

Question 8

Meninges of the spinal cord. Dura Mater

Accepted Answer

•A Single layer of tough collagenous membrane surrounded by epidural space. Space between the vertebrae and spinal furs mater.
•Not attached to the bony walls of the vertebral column.
•Denticulate Ligaments
•Extensions of pia mater  that secure spinal cord to dura mater.

Question 9

Arachnoid mater

Accepted Answer

•A thin membrane deep to the dura matter
Arachnoid trabeculae: a loose network of collagen and elastic fibers 
•Submarachnoid Space: Space between the arachnoid mater and piña mater. Filled with CSF

Question 10

Pia Mater

Accepted Answer

A network of collagen and elastic fibers adherent to the spinal cord. Blood vessels run along the surface of the pis matter within the subarachnoid space. 
•Filium termínale and denticulate ligaments anchor the cord.
•Spinal meninges are continuous with the cranial meninges.

Question 11

Spinal Cord Cross- Sectional Anatomy

Accepted Answer

Consist of areas of white mater that surround the inner region of gray matter shaped like a letter H

Question 12

Gray Mater

Accepted Answer

Mainly neuron cell bodies ñ, unmyelinated axons and few myelinated axons and synapses. 
Can be divided into:
-Anterior Ventral Gray Horns 
-Lateral Gray Horns 
-Posterior Dorsal Gray Horns 
-Gray Commissure

Question 13

White Mater

Accepted Answer

•Mainly myelinated axons 
• Teo lengthwise grooves divided cord into right and left halves
-Anterior (Ventral) Median Fissure 
-Posterior (Dorsal) Median Sulcus

Question 14

Gray Commissure

Accepted Answer

•Gray Mater 
•Contains axons that cross from one side of the cord to the other.
•Encloses central canal

Question 15

Posterior Gray Horns

Accepted Answer

Contains cell bodies of interneurons and axons of somatic and autonomic sensory neurons that enter the cord via dorsal roots

Question 16

Anterior Gray Horns

Accepted Answer

Contains cell bodies of somatic motor neurons whose axons exit the cord via ventral roots

Question 17

Lateral Gray Horns

Accepted Answer

•Contains cell bodies of autonomic motor neurons (cardiac ms, smooth ms and glands) 
•Only in Thoracic and lumbar regions (T1-L2)

Question 18

White Matter

Accepted Answer

•Consist mostly of ascending sensory and descending motor tracts.
•Tracts are located in three white columns (funiculi) 
Dorsal : (posterior) White column  (Funiculus) 
Lateral White Column (Funiculus) 
Ventral (Anterior) white column (funiculus)

Question 19

Each spinal tract is

Accepted Answer

Composed of bundles of axons with similar functions. Named based on tract’s origin and termination.

Question 20

Transverse Tracts

Accepted Answer

Comissural fibers. Cross from one side to the other (decussation). The anterior white columns are connected by the anterior white commissure

Question 21

Nerve Structure/ Connective Tissue Coverings

Accepted Answer

Epineurium-Tough fibrous sheath around a nerve.

Question 22

Perineurium

Accepted Answer

Coarse connective tissue that bundles fibers into
 fascicles

Question 23

Endoneurium

Accepted Answer

Loose connective tissue that encloses axons and
 their myelin sheaths

Question 24

Spinal Nerves

Accepted Answer

Just after passing through the IVF, a spinal nerve divides into a:
Dorsal Ramus
Ventral Ramus 
Rami Communicantes
Gray Rami Communicantes
All spinal nerves
White Rami Communicates
Spinal nerves T1 – L2
Meningeal Branch

Question 25

Spinal Nerves/ Dorsal Rami

Accepted Answer

Sensory from skin of back
Motor to deep muscles of the back
No innervation to extremities
No plexus formation

Question 26

Dorsal Rami

Accepted Answer

Carry sensory and motor fibers
Skin and muscles of the upper and lower extremities and anterior
     and lateral surfaces of the trunk 
Except for T2 – T12, all ventral rami don’t go directly to
     the body structures they supply
Instead, just lateral to the vertebral column they branch and join
    with axons from ventral rami of adjacent nerves to form complex
    of interwoven nerve networks called nerve plexuses which
    contain sensory and motor fibers

Question 27

Meningeal Branch

Accepted Answer

Reenters the vertebral canal to innervate the
 meninges, vertebrae and blood vessels

Question 28

Rami Communicantes

Accepted Answer

Contain axons associated with the autonomic
nervous system
Extend between the ventral rami and
 sympathetic trunk ganglion

Question 29

Nerve Plexuses

Accepted Answer

Contain sensory and motor fibers
Ventral rami  branch and anastomose
     repeatedly to form four nerve plexuses
Cervical Plexus
Brachial Plexus
Lumbar Plexus
Sacral Plexus

Question 30

Nerve Plexuses/ Cervical Plexus

Accepted Answer

Ventral rami of C1 to C5 
Supplies
Neck 
Parts of upper chest and shoulders
Phrenic Nerve (C3 – C5) 
Innervates the diaphragm
Damage to cord above C3 causes respiratory
 arrest

Question 31

Nerve Plexuses/ Brachial Plexus

Accepted Answer

Ventral rami of C5 to T1
Passes between the 1st rib and clavicle
Supplies 
Pectoral girdle/shoulder (anterior/posterior)
Upper extremities

Chapter 13- (A&P 1)