CSDS 172: Exam #2 (part 1)

How many pairs of spinal nerves are there?

31 pairs

Spinal Nerves cervical

8 pairs

Spinal nerves thoracic

12 pairs

Spinal nerves lumber

5 pair

Spinal nerves sacral

5 pair

Spinal nerves coccygeal

1 pair

What is the overall function of the spinal nerves

described as mixed nerves, and carry both sensory and motor fibers, afferent or efferent fibers.

Define the two ventral roots of the spinal cord

contain motor nerve cells whose axons leave the cord through the anterior roots to activate visceral and skeletal muscles and glands. These nerve fibers are called efferent fibers or or motor fibers.

Define the two dorsal roots of the spinal cord

contain nerve cells that receive sensory information from the body through the dorsal root fibers. These nerve fibers are called afferent fibers or sensory fibers.

How many pairs of cranial nerves are there?

12 pairs

Cranial Nerve I: Olfactory nerve

Smell

Cranial Nerve II: Optic nerve

Vision

Cranial Nerve III: Oculomotor nerve

innervation of muscles to move eyeball, pupil, and upper lid

Cranial Nerve IV: Trochlear nerve

Innervation of the superior oblique muscles of the eye for eye movement

Cranial Nerve V: Trigeminal nerve

chewing and sensation to face, teeth, and anterior tongue

Cranial nerve VI: abducens nerve

Innervation of lateral rectus muscles for abduction of the eye

Cranial nerve VII: facial nerve

movement of all facial muscles, except for those mastication, taste, and salivary glands

Cranial nerve VIII: acoustic-vestibular nerve

hearing and vestibular sense of motion (equilibrium)

Cranial Nerve IX: glossopharyngeal nerve

taste, swallowing, elevation of the pharynx and larynx, parotid salivary gland, sensation to posterior tongue, upper pharynx

Cranial nerve X: vagus nerve

taste, swallowing, elevation of palate, phonation, parasympathetic

Cranial nerve XI: spinal accessory nerve

innervation to two major neck muscles to turn the head and shrug the shoulders

Cranial Nerve XII: hypoglossal

innervation of the tongue for movement of the tongue

Cranial Nerves for speech and hearing

Cranial Nerve V: trigeminal nerve

Cranial Nerve VII: facial nerve

Cranial Nerve VIII: acoustic-vestibular nerve

Cranial Nerve IX: Glossopharyngeal nerve

Cranial Nerve X: vagus nerve

Cranial Nerve XI: spinal accessory nerve

Cranial Nerve XII: hypoglossal nerve

Cranial nerves for speech and hearing: Cranial nerve V, trigeminal nerve function

primarily responsible for mastication and for sensation to the face, teeth, gums, and anterior two thirds of the tongue

Cranial nerves for speech and hearing: Cranial nerve VII, facial nerve function

primarily responsible for all movements of facial expression, also assists in lifting the larynx up and back through the belly of the digastric muscle

Cranial nerves for speech and hearing: Cranial nerve VIII, acoustic-vestibular nerve function

takes afferent information from the inner ear to the central nervous system. It is responsible for sound sensitivity

Cranial nerves for speech and hearing: Cranial nerve IX, glossopharyngeal nerve function

efferent to the stylogpharyngeaus muscle only, which functions to dilate the pahrynx laterally and contributes to the elevation of the pharynx and larynx. Thus, it helps to clear the pharynx and larynx for swallowing

Cranial nerves for speech and hearing: Cranial nerve XI, spinal accessory nerve function

functions primarily as a motor innervation to the sternocleidomastoid muscles that help turn, tilt, and thrust forward the head or raise the sternum and clavicle if the head is in a fixed position

Cranial nerves for speech and hearing: Cranial nerve XII, hypoglossal nerve

innervates the muscles responsible for tongue movement

1. The four intrinsic muscles of the tongue control shortening, concaving, narrowing, elongating, and flattening

2. The extrinsic muscles of the tongue account for tongue protrusion (genioglossus) draw the tongue upward and backward (styloglossus), and retract and depress the tongue (hyoglossus)

Describe the overall function of the autonomic nervous system

to maintain the stability of the body’s internal environments or homeostasis.

ANS in regard to speech production and perception

If an individual becomes excited, there will be changes in breathing patterns (respiratory cycles), voice patterns (frequency and intensity), and articulatory patterns (intelligibility) commensurate with the stress or urgency being felt.

When one returns to a normal condition, the breathing rates, voice shifts and articulatory precision will then be altered accordingly.

The voice, in particular, has been referred to as the major conveyor of emotions and appears to be specifically altered by the ANS.

Describe the function of the sympathetic system

Referred to as “fight-or-flight” - helps prepare the body for emergency situations - is responsible for such preparatory measures as:

accelerating the heart rate

causing constriction of the peripheral blood vessels

raising the blood pressure

redistributing the blood so that it leaves the skin and intestines to be used by the brain, heart, and skeletal muscle

serves to raise the eyelids and to dilate the pupils

Describe the function of the parasympathetic system

Opposite to Sympathetic: calming effect on bodily functions - it serves to conserve and restore energy by slowing down the heart rate, increasing intestinal peristalsis, and opening the sphincters

What are the three meningeal membranes in the brain and spinal cord?

Dura mater, arachnoid mater, pia mater

Dura mater in the brain

the outermost membrane covering

marked by complex folds that divide the contents of the cranial cavity into different cerebral subdivisions.

Arachnoid Mater in the brain

the second membrane covering and is located directly below the fluid under the dura mater

bridges over the sulci (folds) of the brain, and further projects into the venous sinuses to form arachnoid villi

Pia Mater in the brain

closest to the surface of the brain

covering the gyri (ridges) and going down into the sulci

Dura Mater in the spinal cord

a single-layer meningeal membrane that looks like a loose tube pierced by the spinal nerve roots, separates from the wall of the spinal canal by an extradural space.

Arachnoid mater in the spinal cord

begins at the foramen magnum and extends to the nerve fibers that extend beyond the spinal cord.

Pia Mater in the spinal cord

surrounds and tightly adheres to the spinal cord

What are the three major parts of the ventricular system of the brain?

Lateral ventricles

Third ventricle

Fourth ventricle

Lateral ventricles

paired, with one located in each hemisphere, shaped like a C, curve through the frontal, parietal, occipital, and temporal lobes, connects to the third ventricle via the interventricular foramen of Monro

Third Ventricle

small slit between the thalami, connects to the fourth ventricle via the cerebral aqueduct of Sylvius

Fourth Ventricle

between the brainstem (pons and medulla) and the cerebellum, continuous superiorly with the cerebral aqueduct and the central canal below

What are the four functions of cerebral spinal fluid?

Protection, Buoyancy, Excretion of waste products, Endocrine medium for the brain

Cerebral Spinal Fluid: Protection

The CSF protects the brain from damage by "buffering" the brain. The CSF acts to cushion a blow to the head and lessen the impact

Cerebral spinal fluid: Buoyancy

Because the brain is immersed in fluid, the net weight of the brain is reduced from about 1,400 gm to about 50 gm. Therefore, pressure at the base of the brain is reduced

Cerebral Spinal fluid: Excretion of waste products

The one-way flow from the CSF to the blood takes potentially harmful metabolites, drugs and other substances away from the brain

Cerebral Spinal Fluid: Endocrine medium for the brain

The CSF serves to transport hormones to other areas of the brain. Hormones released into the CSF can be carried to remote sites of the brain

Briefly describe the circulation pathway of the cerebral spinal fluid

the path of cerebrospinal fluid circulation flows from the lateral ventricles into the

(1) third ventricle, to the

(2) fourth ventricle, and into the

(3) subarachnoid space

It then travels to reach the (4) inferior surface of the cerebrum and then to move (5) superiorly over the lateral aspect of each hemisphere

Some of the fluid moves into the subarachnoid space around the spinal cord

Name the arteries involved in the circle of Willis

The internal carotid artery

Vertebral artery

Posterior communicating artery

Clinical significance: internal carotid artery

supplies the brain itself

the middle cerebral artery is the largest branch

blood enters the circle of willis from this artery

Clinical significance: vertebral artery

Blood supply between anterior and posterior circulation

passes through the transverse foramina in the upper six cervical vertebrae and enters the skull through the foramen magnum.

Clinician significance: Posterior communicating artery

runs posteriorly above the oculomotor nerve and joins the posterior cerebral artery,

joins the internal carotid arteries to the posterior circulation

Principles of neurologic organization that are essential to the understanding and diagnosis of communicative disorders

Contralateral Motor Control

Ipsilateral Motor Control

Bilateral Speech Motor Control

Unilateral Language Mechanisms

Scheme of Cortical Organization

Describe Contralateral Motor Control

this principle is that major movement patterns in human have contralateral neurologic control in the brain. This contralateral motor control is brought about by the crossing of the major voluntary motor pathway at the level of the brainstem.

Describe Ipsilateral Motor Control

knowledge of the principles of neurologic organization can be used to determine whether effects of lesions are ipsilateral or contralateral. In many spinal cord injuries, paralysis and sensory loss occurs below the point of injury

Describe Bilateral Speech Motor Control

The midline muscles of the body in the head, neck, and trunk tend to be represented bilaterally, and the nerve fibers supplying these regions descend from both cerebral hemispheres.This bilateral neural control provides smooth, symmetrical movement for some muscles used in speaking such as the lips, tongue, soft palate, jaw, abdominal muscles, and diaphragm. The principle of bilateral control of speech muscles suggests that serious involvement of the speech muscles usually results from diseases that affect bilateral neurological mechanisms.

Describe Unilateral Mechanisms

major language disturbance is a neurologic sign of left cerebral injury and further, the left hemisphere has special anatomical properties for language. An impressive aspect of cerebral asymmetry is that language mechanisms are unilaterally controlled in the brain as compared with the bilateral speech muscle mechanism. Over 99% of right-handed adults and most left handed adults across the globe have left hemisphere dominance for language. Thus, the mechanisms for language are primarily in the left hemisphere.

Descibe Scheme of Cortical Organization

The right and left hemispheres may be characterized as nonverbal and verbal; whereas the anterior and posterior portions of the cerebral cortex may be designated as motor sensory areas