Anatomy and physiology of the nervous system


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Anatomy and physiology of the nervous system

  2. 2. 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
  4. 4. 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.  
  5. 5. 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.
  6. 6. 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
  7. 7. Assessment of the Nervous System Assessing consciousness and cognitive. Mental status  It begins by observing the patients 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
  8. 8. 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 patients though spontaneous, natural, clear, relevant and coherent?
  9. 9. Assessment of the Nervous System Emotional status : Is the patients 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.
  10. 10. 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.
  11. 11. 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).
  12. 12. 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)
  13. 13. 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.
  14. 14. Assessment of the Nervous System
  15. 15. Assessment of the Nervous Systemb. 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.  
  16. 16. 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.
  17. 17. Assessment of the Nervous System Assessment of disorders behavior / throught disturbance.  Hallucination.  Illusion.  Delusional thinking.  Delirious.
  18. 18. 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 . 
  19. 19. 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.
  20. 20. CT SCANPreparation 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.
  21. 21. 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.
  22. 22. Magnetic Resonance Imaging
  23. 23. Magnetic Resonance Imaging It can provide information about the chemical changes within cells, allowing to monitor a tumors response to treatment. It is particular useful in the diagnosis of brain tumor, stroke and multiple sclerosis.
  24. 24. OTHER DIAGNOSTIC STUDIES Nerve conduction stuies. Cerebral angiography. Single photon emission computed tomography
  25. 25.  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.  Allmetal objects and credit cards must be removed including medication patches that have a metal backing and metallic lead wired.
  26. 26. OTHER DIAGNOSTIC STUDIES4. Positron Emission tomography5-Electron encephalo – graphy.
  27. 27. 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 .
  28. 28. 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. 
  29. 29. EEG
  30. 30. EEG
  31. 31. EEG