Anatomy of the Spinal Cord and Meninges

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Questions and Answers

What is the primary function of cerebrospinal fluid (CSF)?

To enhance blood supply to the spinal cord

To transport neurotransmitters throughout the body

To act as a protective cushion and aid nutrient exchange (correct)

To provide structural support to neurons

Which structure directly protects the spinal cord?

The neurotransmitters

The vertebral arteries

The axon terminals

The meninges (correct)

In what part of the neuron does synaptic transmission occur?

At the axon

At the cell body

At the synapse (correct)

At the dendrites

Which of the following neurotransmitters is known as an inhibitory neurotransmitter?

y-aminobutyric acid (GABA) Signup and view all the answers

Where is cerebrospinal fluid produced?

In the ventricles Signup and view all the answers

What type of neuron carries impulses away from the central nervous system?

Motor neurons Signup and view all the answers

Which of the following correctly describes the relationship between the meninges layers?

The arachnoid membrane contains cerebrospinal fluid Signup and view all the answers

What does the term 'anastomosis' refer to in the context of blood supply to the brain?

Connection between blood vessels Signup and view all the answers

What is a transient ischemic attack often considered to be?

A warning sign of an impending stroke Signup and view all the answers

Which of the following describes ischemic strokes?

Caused by a clot blocking blood supply to the brain Signup and view all the answers

Which risk factor is associated with both ischemic and hemorrhagic strokes?

Advanced age Signup and view all the answers

What is the initial function likely to return after a cerebrovascular accident?

Facial function Signup and view all the answers

Which diagnostic tool is NOT typically used for confirming a stroke?

Electrocardiogram (ECG) Signup and view all the answers

Which of the following symptom types is NOT commonly associated with a stroke?

Excessive sweating Signup and view all the answers

What primary action should be considered following a transient ischemic attack?

Assess for possible signs of a stroke Signup and view all the answers

Which condition is most closely associated with hemorrhagic strokes?

High blood pressure (HTN) Signup and view all the answers

What is the primary cause of encephalitis?

Viral agent Signup and view all the answers

Which of the following signs indicates meningeal irritation?

Inability to straighten the leg when flexed Signup and view all the answers

What characterizes the CSF analysis in meningitis?

Cloudy, increased protein, decreased glucose Signup and view all the answers

Where is the highest transmission risk for meningitis likely to occur?

College dormitories Signup and view all the answers

Which intervention is essential for a client diagnosed with bacterial meningitis?

Maintain respiratory isolation Signup and view all the answers

What is a common psychosocial support measure for clients and families dealing with meningitis?

Educate about the condition and treatment options Signup and view all the answers

Which physical assessment finding suggests increased intracranial pressure (ICP)?

Decreased level of consciousness Signup and view all the answers

What is a recommended position for a patient with suspected meningitis?

Elevated head of bed at 30 degrees Signup and view all the answers

What is a primary nursing intervention for a client who has had a stroke during the postacute phase?

Perform passive range-of-motion exercises Signup and view all the answers

In which position should a stroke client be placed when resting on the affected side?

On the unaffected side for 20 minutes Signup and view all the answers

What type of fluids is recommended for stroke clients who have swallowing difficulties?

Flavored, cool or warm, thickened fluids Signup and view all the answers

Which of the following indicates unilateral neglect in a stroke client?

Lack of awareness of the paralyzed side Signup and view all the answers

How should food be placed when a stroke client is eating?

On the unaffected side towards the back Signup and view all the answers

What is a typical sign of homonymous hemianopsia in a stroke client?

Blindness in half of the visual field in both eyes Signup and view all the answers

What should be done to check the skin condition of a client who is wearing antiembolism stockings?

Remove daily to check the skin Signup and view all the answers

When caring for a stroke client who has diplopia, what is a recommended intervention?

Place a patch over the affected eye Signup and view all the answers

What does decerebrate posturing indicate?

A brainstem lesion Signup and view all the answers

Which of the following responses is associated with sympathetic nervous system activation?

Dilated pupils Signup and view all the answers

What Glasgow Coma Scale score indicates the presence of a coma?

8 or less Signup and view all the answers

Which assessment finding can indicate increased intracranial pressure (ICP)?

Rapid pulse rate exceeding 100 bpm Signup and view all the answers

What autonomic response is typically observed with parasympathetic activation?

Dilated blood vessels Signup and view all the answers

A Glasgow Coma Scale score between 3 to 4 is associated with what prognosis?

High mortality rates and poor prognosis Signup and view all the answers

Which of the following indicates a change in level of consciousness?

Responses ranging from active alertness to somnolence Signup and view all the answers

Which condition could cause a temperature elevation in a neurological patient?

Damage to the temperature-regulating area of the brain Signup and view all the answers

Study Notes

Spinal Cord

Extends from the first cervical to the second lumbar vertebra
Protected by the meninges, cerebrospinal fluid (CSF), and adipose tissue

Nerve Tracts

White matter contains nerve tracts
Ascending tracts are the sensory pathway
Descending tracts are the motor pathway

Meninges

Dura mater is a tough and fibrous membrane
Arachnoid membrane is delicate and contains CSF
Pia mater is a vascular membrane
Subarachnoid space is formed by the arachnoid membrane and pia mater

Cerebrospinal Fluid (CSF)

Secreted in the ventricles
Circulates in the subarachnoid space and through the ventricles to the subarachnoid space of the meninges
Reabsorbed in subarachnoid space
Acts as a protective cushion and aids in the exchange of nutrients and wastes
Normal pressure is 6 to 25 cmH2O
Normal volume is 125 to 150 mL
About 500 mL/day is produced

Ventricles

There are four ventricles
Ventricles communicate between the subarachnoid spaces
They produce and circulate CSF

Blood Supply

Brain is supplied by the right and left internal carotid arteries and right and left vertebral arteries
Arteries supply the brain via an anastomosis at the base of the brain called the circle of Willis

Neurotransmitters

Acetylcholine
Epinephrine
Norepinephrine
Dopamine
Serotonin
y-aminobutyric acid (GABA)

Neurons

The neuron consists of the cell body, axon, and dendrites
The cell body contains the nucleus
Sensory neurons carry impulses from the peripheral nervous system to the central nervous system (CNS).
Motor neurons carry impulses away from the CNS.
Synapse is the chemical transmission of impulses from one neuron to another.

Axons and Dendrites

The axon conducts impulses from the cell body
The dendrites receive stimuli from the body and transmit them to the axon
Neurons are protected and insulated by Schwann cells.
The Schwann cell sheath is called neurolemma.

Neurological Assessment

Extensor (decerebrate posturing): Client stiffly extends one or both arms and possibly the legs. Extensor posturing indicates a brainstem lesion.
Flaccid posturing: Client displays no motor response in any extremity.
Assessment of reflexes
Assessment of meningeal irritation
Assessment of the autonomic system
- Sympathetic functions, adrenergic responses:
  - Increased pulse and blood pressure
  - Dilated pupils
  - Decreased peristalsis
  - Increased perspiration
- Parasympathetic function, cholinergic responses:
  - Decreased pulse and blood pressure
  - Constricted pupils
  - Increased salivation
  - Increased peristalsis
  - Dilated blood vessels
  - Bladder contraction
Assessment of sensory function: Touch, pressure, pain

Glasgow Coma Scale

Used to assess a client’s neurological condition.
Scored from 3 to 15 points.
Score lower than 8 indicates coma.

Altered Level of Consciousness

Monitor and evaluate vital sign changes indicating changes in condition:
- Pulse: A pulse rate change to 100 bpm can indicate increased intracranial pressure (ICP). A fast rate (>100 bpm) can indicate infection, thrombus formation, or dehydration.
- BP: Rising BP or widening pulse pressure can indicate increased ICP.
- Temperature: Report any abnormalities; temperature elevation can indicate worsening condition, damage to temperature-regulating area of brain, or infection.
- Level-of-consciousness changes: They may range from active to somnolent.

Cerebrovascular Accident (Stroke)

Transient ischemic attack (TIA) may be a warning sign of an impending stroke.
Permanent disability cannot be determined until cerebral edema subsides.
Order in which function may return is facial, swallowing, lower limbs, speech, and arms.
Sudden loss of brain function resulting from a disruption in the blood supply to a part of the brain.
Classified as thrombotic or hemorrhagic.

Hemorrhagic: Caused by a slow or fast hemorrhage into the brain tissue; often related to HTN.
Ischemic: Caused by a clot that has broken away from a vessel and lodged in one of the arteries of the brain, blocking the blood supply; often related to atherosclerosis.

Causes of Stroke

Thrombosis: Clot forms inside blood vessels
Embolism: Clot breaks away from a vessel and travels to the brain.
Thrombotic and embolic strokes are classified as ischemic strokes.
Hemorrhage: Rupture of a vessel causes bleeding in the brain.

Risk Factors for Stroke

HTN
Advanced age
Previous TIAs
Cardiac disease: atherosclerosis, valve disease, history of dysrhythmias
Diabetes
Oral contraceptives and HRT
Smoking
Alcohol (more than 2 drinks per day)

Diagnosis of Stroke

Diagnosis made by observation of clinical signs and is confirmed by:
- Cranial CT scan
- MRI
- Doppler flow studies
- Ultrasound imaging

Nursing Assessment for Stroke

Change in level of consciousness
Paresthesia, paralysis
Aphasia, agraphia
Memory loss
Vision impairment
Bladder and bowel dysfunction
Behavioral changes
Assessment of client’s functional abilities:
- Mobility
- Activities of daily living (ADLs)
- Elimination
- Communication

Nursing Interventions for Stroke

Administer intravenous fluids as prescribed
Maintain fluid and electrolyte balance
Prepare to administer anticoagulants, antiplatelets, diuretics, antihypertensives, and antiseizure medications as prescribed depending on the type of stroke diagnosed.

Postacute Phase of Stroke

Continue with interventions from the acute phase.
Position the client 2 hours on the unaffected side and 20 minutes on the affected side; the prone position may also be prescribed.
Provide skin, mouth, and eye care.
Perform passive range-of-motion exercises to prevent contractures.
Place antiembolism stockings on the client; remove daily to check skin.
Monitor the gag reflex and ability to swallow.
Provide sips of fluids and slowly advance diet to foods that are easy to chew and swallow.
When the client is eating, position the client sitting in a chair or sitting up in bed, with the head and neck positioned slightly forward and flexed.
Place food in the back of the mouth on the unaffected side to prevent trapping of food in the affected cheek.
Provide soft and semisoft foods and flavored, cool or warm, thickened fluids rather than thin liquids, because the stroke client can tolerate these types of food better.

Chronic Phase of Stroke

Neglect Syndrome:
- Client is unaware of the existence of the paralyzed side (unilateral neglect), which places the client at risk for injury.
- Teach the client to touch and use both sides of the body.
Hemianopsia:
- Client has blindness in half of the visual field.
- Homonymous hemianopsia is blindness in the same visual field of both eyes.
- Encourage the client to turn the head to scan the complete range of vision; otherwise, the client does not see half of the visual field.
Approach the client from the unaffected side.
Place the client’s personal objects within the visual field.
Provide eye care for visual deficits.
Place a patch over the affected eye if the client has diplopia.
Increase mobility as tolerated.
Monitor respiratory status and institute measures to prevent aspiration.
Provide respiratory treatments.
Prepare to initiate respiratory support.
Assess for complications of immobility.
Address advance directives as appropriate.
Provide the client and family with psychosocial support.

Encephalitis & Meningitis

Encephalitis: Inflammation of the brain parenchyma and often of the meninges. It affects the cerebrum, brainstem, and cerebellum. Most often caused by a viral agent.
Meningitis: Inflammation of the arachnoid and pia mater of the brain and spinal cord. Caused by bacterial and viral organisms, although fungal and protozoan meningitis also occur.

Diagnosis of Meningitis

CSF is analyzed to determine the diagnosis and type of meningitis.
In meningitis, CSF is cloudy, with increased protein, increased white blood cells, and decreased glucose counts.

Transmission of Meningitis

Transmission occurs in areas of high population density, crowded living areas such as college dormitories, and prisons.
Transmission of meningitis is by direct contact, including droplet spread.

Assessment of Meningitis

Mild lethargy
Photophobia
Deterioration in the level of consciousness
Signs of meningeal irritation, such as nuchal rigidity and a positive Kernig’s sign and Brudzinski’s sign
Red, macular rash with meningococcal meningitis
Abdominal and chest pain with viral meningitis

Kernig's Sign

Loss of the ability of a supine client to straighten the leg completely when it is fully flexed at the knee and hip; indicates meningeal irritation

Brudzinski's Sign

Involuntary flexion of the hip and knee when the neck is passively flexed; indicates meningeal irritation

Interventions for Encephalitis and Meningitis

Monitor vital signs and neurological signs.
Assess for signs of increased ICP.
Initiate seizure precautions.
Monitor for seizure activity.
Monitor for signs of meningeal irritation.
Perform cranial nerve assessment.
Assess peripheral vascular status (septic emboli may block circulation).
Maintain isolation precautions as necessary (bacterial meningitis).
Maintain urine and stool precautions (viral meningitis).
Maintain respiratory isolation for the client with pneumococcal meningitis.
Elevate the head of the bed 30 degrees, and avoid neck flexion and extreme hip flexion.
Prevent stimulation and restrict visitors.

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Description

This quiz covers the anatomy of the spinal cord, including its protective structures such as the meninges and cerebrospinal fluid. It also explores the functions of nerve tracts and the ventricular system. Test your knowledge of this critical aspect of human anatomy.