Spinal cord

Question 1

____ ls the central bony pillar of the body. It supports the skull, pectoral girdle, upper limbs,
and thoracic cage and, by way of the pelvic girdle,
transmits body weight to the lower limbs. Within its cavity lie the spinal cord, spinal nerve roots, and the covering meninges, to which gives great protection.

Answer 1

The vertebral column

Question 2

The vertebral column is composed of
____ vertebrae, ___cervical, ___thoracic, ___lumbar, ___ sacral (fused to form the sacrum), and _____ coccygeal (the lower ___ are commonly fused).

Answer 2

33 vertebrae-7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused to form the sacrum), and 4 coccygeal (the lower 3 are commonly fused)

Question 3

The vertebral column is segmented and made up of vertebrae, joints, and pads of fibrocartilage called_______, it is a flexible structure. It forms about a quarter of the length of the column. They are thickest in the cervical and lumbar regions, where the movements of the vertebral column are greatest. They serve as shock absorbers when the load on the vertebral column is suddenly increased.

Answer 3

intervertebral discs

Question 4

The vertebral arch consists of;
* a pair of _____, sides of the arch, and
*a pair of _____, which complete the arch posteriorly

Answer 4

*Cylindrical pedicles
*Flattened laminae

Question 5

The vertebral arch gives rise to seven processes: What are these 7 process?

Answer 5

one spinous, two transverse, and four articular

Question 6

The _______ are vertically arranged and consist of two superior and two inferior processes. The two superior articular processes of one vertebral arch articulate with the two inferior articular processes of the arch above, forming two synovial joints.

Answer 6

articular processes

Question 7

The ______ are notched on their upper and lower borders, forming the superior and inferior vertebral notches. On each side, the superior notch of one vertebra and the inferior notch of an adjacent vertebra together form an intervertebral foramen that serves to transmit the spinal nerves and blood vessels.

Answer 7

pedicles

Question 8

True/ False
The anterior and posterior nerve roots of a spinal nerve unite within these foramina with their coverings of the dura to form the segmental spinal nerves

Answer 8

True

Question 9

_______ is below the axis, the vertebrae articulate with each other through cartilaginous joints between their bodies and by synovial joints between their articular processes

Answer 9

Vertebral Column Joints

Question 10

_____ is sandwiched between the vertebral bodies is an intervertebral disc of fibrocartilage

Answer 10

Intervertebral body joints

Question 11

The ______ is wide and is strongly attached to the front and sides of the vertebral bodies and the intervertebral discs

Answer 11

anterior ligament

Question 12

The ______ is weak and narrow and is attached to the posterior borders of the discs

Answer 12

posterior ligament

Question 13

The _______ runs between the tips of adjacent spines

Answer 13

supraspinous ligament

Question 14

The _________ connects adjacent spines

Answer 14

Interspinous ligament

Question 15

The ________ run between adjacent transverse processes

Answer 15

Intertransverse ligaments

Question 16

The _______ connects the laminae of adjacent vertebrae

Answer 16

Ligamentum flavum

Question 17

In the cervical region, the supraspinous and interspinous ligaments are greatly thickened to form the ______

Answer 17

Strong ligamentum nuchae

Question 18

_______ is roughly cylindrical, begins superiorly at the foramen magnum, where it is continuous with the medulla oblongata and terminates inferiorly in the adult at the level of the first lumbar vertebra

Answer 18

Spinal cord

Question 19

(Spinal cord) In the young child, relatively longer and usually ends at the upper border of the ______.

Answer 19

third lumbar vertebra

Question 20

(Spinal cord) it occupies the upper two-thirds of the vertebral canal of the vertebral column surrounded by the three meninges:
*The _____
*The _____
*The _____

Answer 20

the dura mater,
the arachnoid mater, and
the pia mater

Question 21

(Spinal cord) Further protection is provided by the cerebrospinal fluid (CSF), which surrounds the spinal cord in the subarachnoid space. Fusiformly enlarged:
*in the cervical region, where it gives origin to the ______, and
*in the lower thoracic and lumbar regions, where it gives origin to the ______
**The enlargements are referred to as the _______

Answer 21

*brachial plexus
*lumbosacral plexus
Cervical and lumbar enlargements

Question 22

____ pairs of spinal nerves are attached by the anterior (motor) roots and the posterior (sensory) roots

Answer 22

31 pairs

Question 23

Each posterior nerve root possesses a _____, the cells of which gave rise to peripheral and central nerve fibers.

Answer 23

posterior root ganglion

Question 24

On the cross section, the gray matter ls seen as an H-shaped pillar with ______, or _____, united by a thin ____ containing the small central canal. A small _______ is present in the thoracic and upper lumbar segments of the cord.

Answer 24

*anterior and posterior gray columns
*horns
*gray commissure
*lateral gray column or horn

Question 25

Gray Matter Structure consists of a mixture of nerve cells and their processes, neuroglia, and blood vessels. The nerve cells are ____, and the neuroglia form an intricate network around the nerve cell bodies and their neurites

Answer 25

multipolar

Question 26

ANTERIOR GRAY COLUMN NERVE CELL GROUPS Most nerve cells are large and multipolar , and their axons pass out in the anterior roots of the spinal nerves as a efferent, which Innervate _____. The smaller nerve cells are also multipolar, and the axons of many of these pass out In the anterior roots of the spinal nerves as ______ which innervate the lntrafusal muscle fibers of neuromuscular spindles.

Answer 26

*skeletal muscles *y efferent

Question 27

ANTERIOR GRAY COLUMN NERVE CELL GROUPS -The medial group is present in most segments of the spinal cord and is responsible for innervating the _______

Answer 27

muscles of the neck and trunk

Question 28

____ is the smallest; present in some cervical and lumbosacral segments.

Answer 28

The Central Group

Question 29

(Central group) In the cervical part of the cord, some of these nerve cells (segments C3—C5) specifically innervate the _____ and are collectively referred to as the _____

Answer 29

diaphragm - phrenic nucleus

Question 30

In the upper five or six cervical segments, some of the nerve cells innervate the ________ and are referred to as the _____ (form the spinal part of the accessory nerve) lumbosacral nucleus

Answer 30

sternocleidomastoid and trapezius muscles - accessory nucleus

Question 31

____ is present in the cervical and lumbosacral segments of the cord and is responsible for innervating the skeletal muscles of the limbs

Answer 31

The Lateral Group

Question 32

_______ is situated at the apex of the posterior gray column throughout the length of the spinal cord. It is largely composed of ______ and receives afferent fibers concerned with ____, ____, and ___ from the posterior root. It receives input from descending fibers from supraspinal levels

Answer 32

substantia gelatinosa *Golgi type II neurons *pain, temperature, and touch

Question 33

The _____ is a group of large nerve cells situated anterior to the substantia gelatinosa throughout the spinal cord. This nucleus constitutes the main bulk of cells present in the posterior gray column and receives fibers from the posterior white column that are associated with the _____, _____, and ____.

Answer 33

nucleus proprius *senses of position and movement (proprioception), two-point discrimination, and vibration

Question 34

The _______ is a group of nerve cells situated at the base of the posterior gray column and extending from the ______ caudally to the _____. Most of the cells are comparatively large and are associated with_____ (neuromuscular spindles and tendon spindles).

Answer 34

nucleus dorsalis (Clarke column) *eighth cervical segment - third or fourth lumbar segment * proprioceptive endings

Question 35

*The lntermediolateral group of cells forms the small lateral gray column, which extends from the ________ of the spinal cord. The cells are relatively small and give rise to preganglionic sympathetic fibers. A similar group of cells found in the second, third, and fourth sacral segments of the spinal cord give rise to _______.

Answer 35

LATERAL GRAY COLUMN NERVE CELL GROUPS *first thoracic to the second or third lumbar segment *preganglionic parasympathetic fibers

Question 36

GRAY COMMISSURE AND CENTRAL CANAL *In transverse sections of the spinal cord, the anterior and posterior gray columns on each side are connected by a _______; the gray matter resembles the letter H. *The ______ is situated In the center of the gray commissure. *The part of the gray commissure that is situated posterior to the central canal is the posterior gray commissure; the anterior part is the anterior gray commissure.

Answer 36

transverse gray commissure *central canal

Question 37

*The _____ is present throughout the spinal cord. Superiorly, it is continuous of the caudal half of the medulla oblongata; above this, it opens into the cavity of the ______. *Inferiorly ln the conus medullaris, it expands Into the fusiform _____ and terminates below within the root of the filum terminal. *It Is filled with CSF and Is lined with ciliated columnar epithelium, the ____.

Answer 37

central canal - fourth ventricle *terminale ventricle *ependyma

Question 38

The ______ may be divided into anterior, lateral, and posterior white columns or funiculi. The anterior column on each side lies between the midline and the point of emergence of the anterior nerve roots; the lateral column Lies between the emergence of the anterior nerve roots and the entry of the posterior nerve roots; the posterior column lies between the entry of the posterior nerve roots and the midline.

Answer 38

white matter

Question 39

*On entering the spinal cord, the sensory nerve fibers of different sizes and functions are sorted out and segregated into nerve bundles or ____ in the white matter. *Some of the nerve fibers serve to link different segments of the spinal cord, while others ascend from the spinal cord to higher centers and thus connect the spinal cord with the brain these bundles of are referred to as the _______ and it conduct two types of afferent information: **_______ originates from outside the body, such as pain, temperature, and touch **________ originates from inside the body, for example, from muscles and joints

Answer 39

*tracts *ascending tract **exteroceptive information **proprioceptive information

Question 40

_____ gives rise to an axon that decussates (crosses to the opposite side) and ascends to a higher level of the CNS, where it synapses with the third-order neuron

Answer 40

The Second-Order Neuron

Question 41

_____ is usually in the thalamus and gives rise to a projection fiber that passes to a sensory region of the cerebral cortex. *The three-neuron chain is the most common arrangement, but some afferent pathways use more or fewer neurons. *Many of the neurons in the ascending pathways branch and give a major input into the reticular formation, which, in turn, activates the cerebral cortex, maintaining ____

Answer 41

The Third-Order Neuron - wakefulness

Question 42

Pain and thermal receptors in the skin and other tissues are _____ the pain impulses are transmitted to the spinal cord in fast-conducting _____ and slow-conducting _____ *The______ alert the individual to initial sharp pain. *The______ are responsible for prolonged burning, aching pain. The sensations of heat and cold also travel from this fibers.

Answer 42

free nerve endings *Delta A-type fibers - C-type fibers * fast-conducting fibers * slow-conducting fibers

Question 43

Pain and temperature Receptor: First-order neuron: Second-order neuron: Third-order neuron:

Answer 43

Receptor: Free nerve ending First-order neuron: Posterior root ganglion Second-order neuron: Substantia gelatinosa Third-order neuron: Ventral posterolateral nucleus of the thalamus

Question 44

Light touch and pressure Receptor: First-order neuron: Second-order neuron: Third-order neuron:

Answer 44

Receptor: Free nerve endings First-order neuron: Posterior root ganglion Second-order neuron: Substantia gelatinosa Third-order neuron: Ventral posterolateral nucleus of the thalamus

Question 45

Discriminative touch, vibratory sense, conscious muscle joint sense Receptor: First-order neuron: Second-order neuron: Third-order neuron:

Answer 45

Receptor: Meissner corpuscles, Pacinian corpuscles, Muscle spindles, Tendon organs First-order neuron: Posterior root ganglion Second-order neuron: Nuclei gracilis and cuneatus Third-order neuron: Ventral posterolateral nucleus of the thalamus

Question 46

A-alpha Size: Information normally carried:

Answer 46

Size: Large (Insulated) Information normally carried: Proprioception - muscle tense

Question 47

A-beta Size: Information normally carried:

Answer 47

Size: Medium (Insulated) Information normally carried: Fast tissue damage

Question 48

C fibers Size: Information normally carried:

Answer 48

Size: Small (Uninsulated) Information normally carried: Slow tissue damage

Question 49

Its axons entering the spinal cord from the posterior root ganglion proceed to the tip of the posterior gray column and divide into ascending and descending branches. *These branches travel for a distance of one or two segments of the spinal cord and form the ___ *These fibers of the first-order neuron terminate by synapsing with cells in the posterior gray column, including cells in the ____

Answer 49

Lateral Spinothalamic Tract - posterolateral tract of Lissauer *substantia gelatinosa

Question 50

_____ a peptide, is thought to be the neurotransmitter at these synapses. Axons of the second-order neurons now cross obliquely to the opposite side in the anterior gray and white commissures within one spinal segment other cord, ascending in the contralateral white column as the_______

Answer 50

Substance P * lateral spinothalamic tract

Question 51

As the lateral spinothalamic tract ascends through the spinal cord, new fibers are added to the anteromedial aspect of the tract. thus, in the _____ of the cord, the sacral fibers are ___ and the ____ are ___. The fibers carrying pain are situated slightly anterior to those conducting temperature

Answer 51

upper cervical segments - lateral and the cervical segments are medial

Question 52

As the lateral spinothalamic tract ascends through the medulla oblongata, it is now accompanied by the anterior spinothalamic tract and the spinotectal tract; together they form the ______

Answer 52

spinal lemniscus