Chapter 13 - The Spinal Cord And Spinal Nerves

Front 1

- the spinal cord occurs within the vertebral foramina of the vertebrae that together form the vertebral cavity.

Back 1

Vertebral column

Front 2

Meninges (singular meninx)
Dura mater:

Back 2

Meninges (singular meninx)
1. Dura mater:
a. It is the outer most of the three meninges.
b. It is composed of dense irregular C.T.
c. It covers the brain and extends to the 2nd sacral vertebra.
d. Epidural space- a space between the dura mater and wall of the vertebral canal. It contains a cushion of fat and C.T.

Front 3

- a space between the dura mater and wall of the vertebral canal. It contains a cushion of fat and C.T.

Back 3

Epidural space

Front 4

Meninges (singular meninx)
Arachnoid mater:

Back 4

a. It is the middle meninx and is avascular.
b. It has a spider-web-like arrangement of collagen and elastic fibers.
c. Subdural space

Front 5

- is between the dura mater and arachnoid mater. It contains interstitial fluid.

Back 5

Subdural space

Front 6

Meninges
Pia mater:

Back 6

a. It is the thin transparent innermost layer and it attaches to the spinal cord and brain surface.
b. It contains blood vessels that service the spinal cord and is composed of C.T.
c. Subarachnoid space
d. Denticulate ligaments

Front 7

- is between the arachnoid mater and pia mater and it contains cerebrospinal fluid (CSF). A needle is inserted into this space in a spinal tap between vertebrae L3 and L4, or L4 and L5.

Back 7

Subarachnoid space

Front 8

- are extensions of the pia mater that suspend the spinal cord within the outer meningeal coverings (dural sheath)

Back 8

Denticulate ligaments

Front 9

The spinal cord in the adult extends from the ____________ ___________ down to the superior border of the ____ ______________ vertebra

Back 9

medulla oblongata
2nd lumbar vertebra

Front 10

- gives rise to nerves servicing the upper limbs.

Back 10

Cervical enlargement

Front 11

- gives rise to the nerves servicing the lower limbs.

Back 11

Lumbar enlargement

Front 12

- is the end of the spinal cord where it tapers.

Back 12

Conus medullaris

Front 13

e- is an inferior extension of the pia mater and anchors the spinal cord to the coccyx.

Back 13

Filum terminal

Front 14

- roots of spinal nerves within the spinal canal that extend downward from where the spinal cord ends (looks like a horse’s tail).

Back 14

Cauda equine

Front 15

- connect spinal cord with most of the body. Two roots connect each nerve to the spinal cord:

Back 15

Spinal nerves

Front 16

- contains sensory neuron fibers conducting impulses into the spinal cord. Its ganglion (dorsal root ganglion) contains cell bodies of these neurons.

Back 16

Posterior (dorsal) root

Front 17

- contains motor neuron axons conducting impulses from the cord to the rest of the body

Back 17

Anterior (ventral) root

Front 18

-is in the shape of an “H”.

Back 18

Gray matter

Front 19

-forms the crossbar.

Back 19

Gray commissure

Front 20

- contain cell bodies of motor neurons to skeletal muscles (somatic) and cell bodies of motor nuclei.

Back 20

Anterior gray horns

Front 21

- contain somatic and autonomic sensory nuclei.

Back 21

Posterior gray horns

Front 22

- contain cell bodies of autonomic motor neurons.

Back 22

Lateral gray horns

Front 23

- runs through gray matter and contains CSF.

Back 23

Central canal

Front 24

- is divided up into anterior, posterior, and lateral white columns.

Back 24

White matter

Front 25

connects white matter of right and left sides.

Back 25

Anterior white commissure

Front 26

- surrounds individual axons.

Back 26

Endoneurium

Front 27

- surrounds bundles (fascicles) of axons.

Back 27

Perineurium

Front 28

- the outer covering around the entire nerve.

Back 28

Epineurium

Front 29

- spinal nerves are called mixed nerves because they contain both sensory and motor neurons. After passing through the intervertebral foramen, each spinal nerve branches into:

Back 29

Components and branching

Front 30

- services the deep muscles and skin of the dorsum of the trunk.

Back 30

Posterior ramus

Front 31

- services upper and lower limbs also skin of the lateral and ventral parts of the trunk

Back 31

Anterior ramus

Front 32

- supplies vertebrae as well as blood vessels of spinal cord and meninges.

Back 32

Meningeal branch

Front 33

- a group of ventral branches (anterior rami) of adjacent nerves, which form a network.

Back 33

Plexus

Front 34

- supplies nerves to the skin and muscles of the head, neck, superior shoulders, and the diaphragm.

Back 34

Cervical plexus

Front 35

- supplies the shoulders and upper limb (arms and hands).

Back 35

Brachial plexus

Front 36

- supplies the anterolateral abdominal walls, external genitals, and part of the lower limb.

Back 36

Lumbar plexus

Front 37

- supplies the buttocks, perineum and remainder of the lower limbs.

Back 37

Sacral plexus

Front 38

- is a certain area that provides sensory input to one pair of spinal nerves or cranial nerve

Back 38

Dermatome

Back 39

V (trigeminal nerve).

Front 40

Describe the clinical significance of dermatomes

Back 40

-The clinical significance is that if the skin of a certain dermatome is stimulated but not felt by the patient then the sensory neurons of that nerve are probably damaged. Also, if the spinal nerve to a dermatome also supplies a damaged organ, pain may be referred to that dermatome.

Front 41

are groups of axons that carry different types of information along certain routes.

Back 41

White matter tracts

Front 42

- these white matter tracts carry sensory information to the brain along ascending tracts, e.g. spinothalamic tracts and posterior column.

Back 42

Sensory tracts

Front 43

- these white matter tracts carry motor information from the brain to the periphery along descending tracts, e.g. direct pathways and indirect pathways.

Back 43

Motor tracts

Front 44

- are fast automatic responses to changes in the environment (E.g. to avoid danger). These are also used to diagnose disorders.

Back 44

Reflexes

Front 45

- integration occurs in spinal cord.

Back 45

Spinal reflex

Front 46

- this occurs in the brain stem.

Back 46

Cranial reflex

Front 47

- the effector is a skeletal muscle.

Back 47

Somatic reflex

Front 48

- the effector is smooth or cardiac muscle, or a gland.

Back 48

Autonomic (visceral) reflex

Front 49

- responds to a change (stimulus) in the internal or external environment by producing a graded potential.

Back 49

Sensory Receptor (often is a dendrite of a sensory neuron)

Front 50

- conducts impulses from a receptor to the spinal cord or brain stem.

Back 50

Sensory neuron

Front 51

- one or more association neurons that carry impulses to a motor neuron.

Back 51

Integrating center

Front 52

- conducts impulses to the part of the body that responds (effector).

Back 52

Motor neuron

Front 53

- the part of the body (E.g. muscle or gland) that responds to the stimulus.

Back 53

Effector

Front 54

- causes a muscle to contract in response to stretching. This helps control muscle length to prevent overstretching.

Back 54

Stretch reflex

Front 55

- causes a muscle to relax as tension on its tendon increases. This helps prevent tearing of a tendon by a muscle force that is too strong.

Back 55

Tendon reflex

Front 56

- causes flexor muscles to contract in response to a painful stimulus. This helps to withdraw part of the body from a painful stimulus to avoid damage.

Back 56

Flexor (withdrawal) reflex

Front 57

- causes extensor muscles on the side opposite of the painful stimulus to contract. This helps maintain balance if one foot is withdrawn from a painful stimulus.

Back 57

Crossed extensor reflex

Front 58

- can indicate nerve damage often due to chronic diabetes, eurosyphilis, or alcoholism.

Back 58

Absence of patellar or achilles reflex

Front 59

- paralysis of just one limb. caused by traumatic injuries

Back 59

Monoplegia

Front 60

- paralysis of both upper limbs or both lower limbs. caused by traumatic injuries

Back 60

Diplegia

Front 61

- paralysis of both lower limbs. caused by traumatic injuries

Back 61

Paraplegia

Front 62

- paralysis of upper and lower limbs and trunk on one side of the body. caused by traumatic injuries

Back 62

Hemiplegia

Front 63

- paralysis of all four limbs. caused by traumatic injuries

Back 63

Quadriplegia

Front 64

Shingles:
Symptoms

Back 64

pain, skin discoloration, line of skin blisters.

Front 65

Shingles:
Causes

Back 65

Neuritis caused by herpes zoster virus (Chickenpox virus).

Front 66

Poliomyelitis:
Symptoms

Back 66

fever, severe headaches, stiff neck and back, deep muscle pain and weakness, some somatic reflexes are lost, may produce paralysis.

Front 67

Poliomyelitis:
Causes

Back 67

the poliovirus which invades cell bodies of motor neurons in anterior gray horns of spinal cord and nuclei of cranial nerves.

Front 68

Injection of an anesthetic drug into the epidural space - the space between the dura mater and the vertebral column - in oder to cause a temporary loss of sensation - childbirth

Back 68

Epidural block

Front 69

unflammation of the meninges due to an infection usually caused by virus or bacteria.
Symptoms include fever, headache, stiff neck, vomiting, confusion, lethargy, and drowsiness
- bacterial can be fatal if not treated promptly

Back 69

Meningeitis

Front 70

inflammation of the spinal cord

Back 70

myelitis

Front 71

CT or X ray image of the spinal cord with contrast to diagnose tumors and herniated disks

Back 71

myelography

Front 72

loss of sensation to a region due to injection of a local anesthetic

Back 72

nerve block

Front 73

attacks of pain along the entire course or branch of a sensory nerve

Back 73

neuralgia

Front 74

inflammation of one or several nerves that may result from irritation to the nerve produced by direct blows, bone fx, contusions or penetrating injury, infection, vitamin deficiancy, poisons

Back 74

neuritis

Front 75

an abnormal sensation such as burning, prickling, ticking, or even tingling resulting from a disorder of a sensory nerve.

Back 75

paresthesia