Anatomy and physiology of the nervous system

ANATOMY AND PHYSIOLOGY OF THE NERVOUS SYSTEM

DR.FATMA ABBAS SALEM ( PHD IN MED.SURG.NG.)

ANATOMY AND PHYSIOLOGY OF THE NERVOUS SYSTEM

Nervous system

Central nervous peripheral nervous autonomlc nervous

system system system

  brain spinal cord cranial spinal sympathetic

parasympathetic nerves nerves 12pairs 31pairs     Cerebrum cerebellum brain stem All lobes 1-frontal 2-parital 3-temporal 4-occipital b- diencephalon 1-thalamus 2-hypothalamus

ANATOMY AND PHYSIOLOGY OF THE NERVOUS SYSTEM

GENERAL FUNCTION OF THE NERVOUS SYSTEM

control & coordinates all parts of the body receives stimuli from the body’s interior and

from the external environment through the system.

determines the body’s responses to these impulse – messages-through the motor system.

Contains the human higher functions e.g memory ,reasoning.

Assessment of the Nervous System

Identification data. Neurologic history (health)

Present condition, is the important aspect. Presence of pain and impairment (Assessment of pain). Seizures which manifest as an alteration in sensation,

behavior, movement, perception or consciousness it may be short as in blank stare that lasts only a second or of longer aeration as a tonic – clonic ground mal seizure that can last several minutes.

Dizziness and vertigo: Dizziness is an abnormal sensation of imbalance or movement but vertigo declined as an illusion of movement, usually rotation

Visual disturbances. Muscle weakness. Abnormal sensation.

Assessment of the Nervous System Past history.

Trauma (at birth of through life)Pervious neurologic problems e.g. Convulsions, headache etc.

Family History: Hereditary Neurologic disorder.

Examination: A neurologic assessment is divided into

five components: consciousness and cognition , Cranial nerves, Motor system,

Sensory system Reflexes

Assessment of the Nervous System

Assessing consciousness and cognitive. Mental status

It begins by observing the patient's appearance and behavior, noting dress, grooming, and personal hygiene. Posture gestures, movements and facial expressions often provide important information about the patient.

Assessing orientation to time, place, person.

Assessment of immediate (recent) and remote memory

Assessment of the Nervous System

Intellectual function: A person with an average IQ can repeat

seven digits without faltering and recite five digits backward. The examiner might ask the pt. to count backward from 100 or then 7 from that and so forth called serial 7s.

Thought content During the interview, are the patient's

though spontaneous, natural, clear, relevant and coherent?

Assessment of the Nervous System

Emotional status : Is the patient's effect (external manifestation of

mood) natural and even or irritable and angry, anxious, apathetic or flat or euphoric?

Does the patent unpredictably swing from joy to sadness during the interview?

 Language ability The person can understand and communicate in

spoken and written language. Impact on lifestyle The nurse assesses the impact any impairment

has on the patient’s lifestyle , the patient’s role in society including family and community role.

Assessment of the Nervous System

level of consciousness To be assessed the examiner observes for

alertness and ability to follow commands. a)Alert; disoriented ; drowsy ,stupor,

comatose . b) The examiner observes for eye opening,

verbal response and motor response to stimuli according to glascoma scale.

Assessment of the Nervous System2. examining the cranial nerves : is assessed

when level of consciousness is decreased.3. examining the motor function: a. motor ability including assessment of

muscle size and tone(spasticity. rigidity ,flaccidity)

b. muscle strength c. Balance and coordination- by having the patient perform rapid, alternating

movements and point to point testing.- Gait & balance (cerebellar function).

Assessment of the Nervous System Examining the sensory systemIt involves tests for tactile sensation

superficial pain, temperature, vibration and position sense (proprioception).

Also disturbances in pain perception (paresthesia, anesthesia, hyposthesia, hyperesthesia)

Assessment of the Nervous System Examining the reflexes Reflexes are involuntary contractions of

muscles or muscle groups in response to a stimulus.

Reflexes are classified as deep tendon, superficial or pathologic

Deep tendon reflexes, examining the following. Biceps reflex. Triceps reflex Brachio radialis reflex Patellar reflex Achilles reflex Clonus.

Assessment of the Nervous System

Assessment of the Nervous System

b. Superficial reflex, including corneal, gag and plantar reflexes and upper or lower abdominal .

c. Pathologic Reflex, are seen in the presence of neurologic disease.

A wall known pathologic reflex indicative of central nervous system disease affecting the corticospinal tract is the Babinski reflex, in which a person who has central nervous system disease of the motor system, the toes fan out and draw back.

Assessment of the Nervous System

Assessment of signs of meningeal irritation Neck stiffness. Retracted head. Arched back Photophobia. Unusual sensitivity of skin and muscles. Pain if the leg is extended with the thigh

flexed. With an attempts to flex the head involuntary

flexion of hip occurs associated with pain.

Assessment of the Nervous System Assessment of disorders behavior /

throught disturbance. Hallucination. Illusion. Delusional thinking. Delirious.

Assessment of the Nervous System Assess for associated observation.

Respiratory pattern (hyperventilation). Pupillary signs. Ocular movements.

Motor response: monoplegia, hemiplegia

Assess vital signs. Assess associated symptoms e.g.

nausea , vomiting . 

Diagnostic evaluation

Imaging procedure. Skull x-ray. Computed Tomography scanning uses a

narrow x-ray beam to scan body parts in successive layers.The images provide cross-sectional views of the brain, distinguishing differences in tissue densities of the skull, cortex sub cortical structures and ventricles.

Abnormalities of tissue density indicate possible tumor mass brain infection, ventricular displacement.

CT SCAN Preparation includes teaching the patient, about the

need to lie quietly throughout the procedure. A review of relaxation techniques may be helpful for

patients with claustrophobia. Sedation can be used if agitation, restlessness or confusion interferes with a successful study.

Ongoing patient monitoring during sedation is necessary.

If a contrast agent is used, the patient must be assessed before the CT scan for an iodine shellfish allergy, because the contrast agent used may be iodine based. Renal function must be evaluated. A suitable I.V. line for contrast injection and a period of fasting usually 4 hrs are required prior to the study.

Magnetic Resonance Imaging

uses a powerful magnetic field to obtain images of different areas of the body. The magnetic field causes the hydrogen nuclei (protons) within the body to align like small magnets in a magnetic field. In combination with radiofrequency pulses, the protons emit signals which are converted to images.

Magnetic Resonance Imaging

Magnetic Resonance Imaging It can provide information about

the chemical changes within cells, allowing to monitor a tumor's response to treatment. It is particular useful in the diagnosis of brain tumor, stroke and multiple sclerosis.

OTHER DIAGNOSTIC STUDIES

Nerve conduction stuies. Cerebral angiography.

Single photon emission computed tomography

Nursing interventions. Patient preparation includes teaching and obtaining

an adequate history. Ferromagnetic substances in the body may become dislodged by the magnet. The patient is questioned about any implants of any metal objects (eg. Aneurysm clips, orthopedic hardware, pacemakers, artificial heart values, intrauterine devices ).

These object could malfunction, be dislodged, or heat up as they absorb energy.

All metal objects and credit cards must be removed including medication patches that have a metal backing and metallic lead wired.

OTHER DIAGNOSTIC STUDIES

4. Positron Emission tomography5- Electron encephalo – graphy.

ANALYSIS

CSF Lumber puncture (Spin tap) is carried

out by inserting a needle into the lumber subarachnoid space to withdraw CSF.Purpose:

To obtain CSF for examination To measure and reduce CSF pressure To determine the presence or absence of

blood in the CSF and WBC for infection .

CSF

To administer medication intrathecally (into the spinal canal)

Site: The needle is usually inserted into

the subarchnoid space between the third and fourth or fourth and fifth lumbar vertebrae.

EEG

EEG

EEG