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Joe Pistack MS/ED.  The brain, the spinal cord and the peripheral nervous system work together as a communication system.

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Presentation on theme: "Joe Pistack MS/ED.  The brain, the spinal cord and the peripheral nervous system work together as a communication system."— Presentation transcript:

1 Joe Pistack MS/ED

2  The brain, the spinal cord and the peripheral nervous system work together as a communication system.

3  In the absence of spinal cord function, there is no sensory activity present.  Person cannot feel any type of sensation.  Lack of voluntary motor activity, cannot move.

4  Continuation of the brain stem.  Tube like structure, located within the spinal cavity.  17 inches long and extends from the foramen magnum to the level of the first lumbar vertebrae.

5  Lumbar puncture- a hollow needle is inserted into the subarachnoid space between L3 and L4.  A sample of cerebrospinal fluid is withdrawn, sample is analyzed for elevated glucose, protein, bacteria and WBC’s.

6  Gray matter-of the spinal cord is located in the center and shaped like a butterfly.  Two projections of gray matter are the dorsal (posterior) horn and the ventral (anterior) horn.

7  Central canal- opening or hole that extends the entire length of the spinal cord.  Cerebrospinal fluid- flows from the ventricles in the brain through the central canal into the subarachnoid space.

8  White matter- composed primarily of myelinated axons.  Grouped together into nerve tracts.

9  Ascending Tracts-carry information from the periphery, up the spinal cord, and toward the brain. Ex.- spinothalamic tract carries sensory information for touch, pressure and pain.  Descending tracts-carries information from the brain, down the spinal cord, and toward the periphery.  Ex.-motor tracts

10  Decussation- the crossing over from one side to the other.  Most motor tracts decussate at the level of the brain stem.  Most sensory tracts decussate in the spinal cord and travel up the spinal cord to the brain.

11  Quadriplegia-paralysis of all four extremities caused by the severing of the spinal cord at the neck region.  Usually caused by an injury where the neck is compressed or bent excessively.  Paraplegia-paralysis of the lower extremities, person has use of upper extremities.

12  The spinal cord serves three main functions:  Sensory pathway  Motor pathway  Reflex center  Sensory pathway-spinal cord serves as a pathway for information traveling from the periphery to the brain.  EX.-pick your finger-information ascends the spinal cord to the brain where you experience the sensation.

13  Motor Pathway-spinal cord provides a pathway for information coming from the brain and going to the periphery.  Ex.-kicking a football-information needs to travel from the brain, down the spinal cord and to the muscles of the leg and foot.  Reflex center-the spinal acts as a major reflex center.  Ex. When you stick your finger, you automatically withdraw it from the object that you picked it with.

14  Reflex- involuntary response to a stimulus. Ex. Touch a hot surface, pull hand away.  Patellar or knee-jerk reflex-in response to a tap on your kneecap, your lower leg quickly and involuntarily pops up.

15  Reflex arc-nerve pathway involved in a reflex.  Four components of a reflex arc:  (1) Receptor-area is stimulated.  (2) Afferent or sensory neuron-nerve impulse is carried by the sensory neuron to the spinal cord.  (3) Efferent or motor neuron-nerve impulse is carried by a motor nerve to the muscle.  (4) Effector organ-the stimulated organ will move.

16  Reflexes help to regulate body function.  Some reflexes are used for diagnostic purposes.  Abnormal reflexes of the CNS may indicate lesions, tumors, or other neurological diseases such as MS

17  Pupillary reflex-regulates the amount of light that enters the eye.  Bright light directed into the eye, muscles that control pupillary size constrict.  Baroreceptor reflex-when blood pressure changes, these reflexes cause the heart and blood vessels to respond in a way that restores blood pressure to normal.

18  Babinski reflex- stroking the lateral sole of the foot in the direction of heel to toe with a hard blunt object.  In an adult, if the response is curling of the toes it is negative or normal.  An abnormal response is dorsiflexion of the big toe, with fanning or the spreading of the other toes. Could be a sign or a lesion or damage to the spinal cord.


20  Peripheral nervous system-consists of the nerves and ganglia located outside the CNS.  Nerves are classified as follows:  Sensory nerves-composed only of sensory neurons.  Motor nerves-composed only of motor neurons.  Mixed nerves-contains both sensory and motor neurons.

21  Classified in two ways:  Structurally-by parts.  Functionally-according to what they do.  Structurally-divides the nerves into the cranial and spinal nerves.  Twelve pair of cranial nerves, each has a specific number, designated by a roman numeral, and a name.

22  Carry sensory information for the special senses: smell, taste, vision and hearing.  Carry sensory information for the general senses: touch, pressure, pain, temperature and vibration.  Carry motor information that results in the contraction of the skeletal muscles.  Carry motor information that results in the secretion of glands and contraction of cardiac and smooth muscle.

23  I Olfactory  A sensory nerve that carries information from the nose to the brain.  Concerned with the sense of smell.  Damage to this nerve may result in loss of sense of smell.

24  II Optic nerve  sensory nerve that carries visual information from the eye to the brain, specifically the occipital lobe of the cerebrum.  Damage to this nerve causes diminished eye site or blindness.

25  III-Oculomotor  primarily a motor nerve that causes contraction of the extrinsic eye muscles, thereby moving the eyeball in the socket.  raises the eyelid and constricts the pupils of the eye.

26  III Oculomotor  Damage to this nerve interferes with raising the eyelid, results in ptosis (drooping of the eyelid).  Compression of this nerve interferes with the ability of the pupil to respond to light. (sluggish pupillary response) With severe compression, the pupil may become fixed and dilated.

27  IV- Trochlear  Primarily a motor nerve that innervates one of the extrinsic muscles of the eyeball, helps to move the eyeball.  Damage may cause double vision or inability to rotate the eye properly.

28  V-Trigeminal  mixed nerve with three branches supplying the facial region.  Two sensory branches carry information regarding touch, pressure and pain from the face, scalp, eye, and teeth to the brain.  Ophthalmic branch detects sensory information from the cornea.  If cornea is touched, motor fibers will respond by eliciting blinking or secretion of tears.

29  Both the trigeminal and facial nerves participate in the corneal reflex.  The motor branch innervates the muscles of mastication.  Nerve damage causes a loss of sensation and impaired movement of the mandible.

30  Trigeminal neuralgia or tic douloureux- inflammation of the trigeminal nerve.  Pain may be triggered by eating, shaving, or exposure to cold temperatures.

31  VI- Abducens  Primarily a motor nerve, controls eye movement by innervating only one of the extrinsic eye muscles.  Nerve damage prevents a lateral rotation of the eye At rest the eye drifts medially, toward the nose.

32  VII-Facial  A mixed nerve that performs mostly motor functions.  Called the nerve of facial expressions. Allows us to smile, frown, and make other faces.  Stimulates the secretion of saliva and tears.  Sensory function is taste.

33  If the facial nerve is damaged, facial expression is absent on the affected side.  This condition is Bell’s Palsy.  One side of the face sags while the other side looks normal.

34  Cosmetically, this condition is very distressing.  Condition responds well to steroid therapy.

35  VIII- Vestibulocochlear  A sensory nerve that carries information for hearing and balance from the inner ear to the brain.  The vestibular branch of this nerve is responsible for equilibrium, or balance and the cochlear branch is responsible for hearing.  Damage to this nerve may cause loss of hearing or balance or both.


37  IX Glossopharyngeal  A mixed nerve that carries taste sensations from the posterior tongue to the brain.  Motor fibers stimulate the secretion of salivary glands in the mouth.  Other motor fibers innervate the throat and aid in swallowing.

38  This nerve is associated with the gag reflex.  Loss of the gag reflex places you at risk for choking.  Sensory function is to regulate BP

39  X Vagus  A mixed nerve that innervates the tongue, pharynx, larynx, and many organs in the thoracic and abdominal cavities.  Nerve damage causes hoarseness or loss of voice, impaired swallowing, and diminished motility of the digestive tract.  Sensory fibers also participate in the regulation of BP.


41  XI Accessory  Primarily a motor nerve that supplies the sternocleidomastoid and the trapezius muscles.  Controls the movement of the head and the shoulder regions.  Nerve damage impairs the ability to shrug your shoulders.


43  XII hypoglossal  Primarily a motor nerve that controls movement of the tongue.  Affects speaking and swallowing activities.  Nerve damage causes the tongue to deviate toward the injured side.



46  Thirty-one pairs of spinal nerves emerge from the spinal cord.  Each pair is numbered according to the level of the spinal cord from which it arises.

47  The 31 pairs are grouped as follows:  8 pairs of cervical nerves.  12 pairs of thoracic nerves.  5 pairs of lumbar nerves.  5 pairs of sacral nerves.  1 pair of coccygeal nerves.

48  Cauda equina- “horse’s tail”- area where the lumbar and sacral nerves exit from the vertebral column.

49  Plexuses-points where nerve fibers converge together.  Three major nerve plexuses:  Cervical plexus  Brachial plexus  Lumbosacral plexus  Each plexus will sort out the fibers and send them to specific parts of the body.

50  Cervical plexus-(C1 to C4): fibers from the cervical plexus supply the muscles and skin of the neck. Stimulate the contraction of the diaphragm.  Brachial plexus-(C5 to C8, T1): supply muscles and skin of the shoulder, arm, forearm, wrist, and hand.  The axillary nerve can be damaged with crutch walking. Patient should be taught not to put weight on the plexus or it will cause crutch palsy.

51  Lumbosacral plexus- (T12, L1, to L5, S1 to S4): gives rise to the nerves that supply the muscles and skin of the lower abdominal wall, external genitalia, buttocks, and lower extremities.  Sciatic nerve-longest nerve in the body, arises from the lumbosacral plexus.  When the sciatic nerve is inflamed, it causes intense pain in the buttock and posterior thigh region.

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