Nervous System

What are the functions of the nervous system

It’s the bodies communication netowrk, responsible for coordinating actions, transmitting signals, and processing sensory information.

What are the 2 main components

Centran nervous system (CNS) and Peripheral nervous system (PNS)

Where is the brain located

In cranium and protected by skull

How many layers is the brain covered by and what are they called

3 layers called meninges

What does the space between the meningeal layer contain

Cerebrospinal fluid (CSF)

What does CSF do

Cusions and nourrishes the brain and spinal cordW

What are the major regions of the brain

Brainstem, cerebellum, cerebrum

What is the spinal cord

A cylindrical mass of nerve tissue protected by the vertebrae.

Where is the spinal cord lcoated

Extends from medulla (part of brainstem) to 1st or 2nd lumbar vertebrae.

What does the spinal cord contain

Contains sensory and motor pathways

What does the spinal cord do

Regular reflex pathways

What is it protected by

Meninges

How many segments is it divided into and what are they called

5

Cervical, thoracic, lumbar, sacral and coccygeal

What parts of the body does the cervical spine control

Head, neck and arms

What parts of the body does the thoracic spine control

Chest and abdominal muscle

What parts of the body does the lumbar spine control

Leg muscles

What parts of the body does the sacral spine control

Bowel, bladder and sexual functions

What is the peripheral nervous system

Nervous system outside brain and spinal cord

What does it connect

Connects CNS to sensory organs, like eyes and ears, other organs of the body, muscles, blood vessels and glands

What does the peripheral nerves include

12 cranial nerves, spinal nerves and autonomic nerves that are concerned specifically with the regulation of involuntary actions within the body.

Name all cranial nerves

Olfactory (I),

Optic (II),

Oculomotor (III),

Trochlear (IV),

Trigeminal (V),

Abducens (VI),

Facial (VII),

Vestibulocochlear (VIII),

Glossopharyngeal (IX),

Vagus (X),

Accessory (XI),

Hypoglossal (XII)

What does the Olfactory cranial nerve control

smell

What does the optic cranial nerve control

Transmits usual info to the brain

What does the oculomotor cranial nerve control

Eye movement, pupil constriction, eyelid elevation

What does the trochlear cranial nerve control

Moves the eye downward and inward

What does the trigeminal cranial nerve control

Facial sensation and chewing musclesA

What does the abducens cranial nerve control

Abducts eye

What does the facial cranial nerve control

Facial expressions, taste from the anterior 2/3 of the tongue

What does the vestibulocochlear cranial nerve control

Hearing and balance

What does the glossopharyngeal cranial nerve control

Taste from posterior 1/3 of tongue, gag reflex

What does the vagus cranial nerve control

Voice, swallowing and gag reflex

What does the accessory cranial nerve control

Head, neck and shoulder movement

What does the hypoglossal cranial nerve control

Movement of tongue

Name the parts

Frontal lobe function

Thinking, decision-making and planning

Occipital lobe function

Processing visual info from eyes

Temporal lobe function

Hearing → Processing hearing into speech and words

Frontal lobe function

Parietal lobe function

Taste, temperature and touch

Cerebellum function

Balance and motor-coordination

Pons function

Key role in sleep and dreaming

Medulla Oblongata function

Regulating life sustaining factors

How to examine olfactory nerve

Patient closes eyes and plug one nostril. Place something to smell underneath both nostrils, one at a time.

How to examine optic nerve

1. Confrontation visual field

Patient stands infornt of you arms length away, covers 1 length and looks straight at you using upper and lower visual field, have patient tell you how many fingers you’re holding

2. Visual activity (snellen chart)

Patient 20ft away from chart. Patient covers R eye and reads lowest line they can. Repeat with both eyes.

How to examine oculomotor nerve

• Dim lights, patient look at distant object (pupils dilate)

• Shine light from the side in each eye, pupil should constrict

• Observe eyelids for ptosis (drooping)

  • Use 6 cardinal fields of gaze

Ptosis

Drooping

How to examine trochelear nerve

• Patient follows the pen light by moving 12-14in. from the patient’s face in 6 cardinal fields of gaze (start in midline)

• Watch for nystagmus

• Patient stares at pen, slowly move closer to nose.

• They should constrict and cross

Nystagmus

Involuntary movement of eye

How to examine trigeminal nerve

• Touch forehead, cheecks and chin with light touch and/or something sharp and dull

• Patient bites, feels masseter (should feel firm)

• Patient open mouth against resistance (hand under chin)

How to examine abducens nerve

• Use 6 cardinal fields of gaze

• Eyes abduct (move laterally)

  • Bring pen light closer and move side to side

How to examine facial nerve

Patient raises eyebrows, smile, frown, puff out cheeks

How to examine vestibulocochlear nerve

• Occlude 1 ear and whisper 2 words, patient repeats back

• Repeat for both ears

  • Rinne and weber tests

How to examine glossopharyngeal nerve

Pt says ahh, uvula will move up

Also gag reflex

How to examine vagus nerve

Patient can swallow with ease and has no hoarseness when talking

Gag reflex can also be done

How to examine accessory nerve

Patient moves head side to side and up and down

Shrugs shoulders against resistance

How to examine hypoglossal nerve

Pt sticks out tongue and moves it side to side

What are deep tendon reflexes (DTR)

Rapid, involuntary muscle contractions triggered by tapping a tendon

Why do we assess DTR

Helps us to evaluate the lower motor neurons/fibers at specific levels in the body

Why is it used in neuro and labour and delivery?

DTR play a crucial role in managing preeclampsia, a serious complication of pregnancy characterized by high blood presymptoms. Hyperrflexia, or abnormally active reflexes, is a key sign of preeclampsia and can indicate the need for magnesium sulface, a medication used to prevent seizures.

What is the process to evaluate DTR

1. Stimulus

2. Sensory input

3. Reflex arc

4. Motor output

5. Response

Stimulus

Tapping a tendon with a relfex hammer stretches the muscle connected to that tendon

Sensory input

This stretch activates sensory receptors within the muscle, which sends a signal along a sensory neuron to the spinal cord

Reflex arc

The sensory neuron synapses back to the muscle causing it to contract

Motor output

The motor neuron sends a signal back to the muscle causing it to contract

Response

This muscle contraction results in a quick twitch or jerk

DTR reflexes grading 4+

Very brisk, hyperactive, with clonus

DTR reflexes grading 3+

Brisker than avg, slightly hyperreflexic

DTR reflexes grading 2+

Avg, expected response, normal

DTR reflexes grading 1+

Somewhat diminished, low normal

DTR reflexes grading 0

No response, absent

What tendons are commonly evaluated

Biceps, triceps, brachioadialis, patellar, and achilles

What nerve does the biceps reflex trigger

C5 (root nerve in the 5th Cervical Spine vertebrae)

How to check biceps reflex

Flex arm at elbow, put thumb over biceps tendon, strike hammere with the pointy end through your finger

What should happen for biceps reflex

Watch for elbow flexion or a contraction of the biceps tendon under your finger

What nerve does the brachioradialis reflex trigger

C6 (root nerve in the 6th Cervical Spine vertebrae)

How to check brachioradialis reflex

Hand partly pronated, strike the radois with the flat edge of the reflex hammer

What should happen for brachioradialis reflex

Watch for flexion and supination of the forearm

What nerve does the triceps reflex trigger

C7 (root nerve in the 7th Cervical Spine vertebrae)

How to check triceps reflex

Flex the arm at the elbow, strike the triceps tendon above the elbow

What should happen for triceps reflex

Watch for elbow extenion or evidence of muscle contraction of the triceps