VEEFINAL

Questions and Answers

What type of immunity involves the body producing its own antibodies?

Adaptive Immunity

Innate Immunity

Active Immunity (correct)

Passive Immunity

Which immunoglobulin is the most abundant in the human body?

IgA

IgD

IgE

IgG (correct)

What is a primary characteristic of passive immunity?

It is solely acquired through vaccinations.

It provides immediate but long-lasting protection.

It requires the body to create its own antibodies.

It provides immediate but temporary protection. (correct)

What type of carcinoma originates from the epithelial cells?

Carcinoma Signup and view all the answers

Which type of carcinoma is the most common skin cancer?

Basal Cell Carcinoma Signup and view all the answers

Which function does IgG have in the immune system?

Crosses the placenta Signup and view all the answers

What characteristic defines Squamous Cell Carcinoma?

Arises from flat epithelial cells Signup and view all the answers

What type of response does active immunity best describe?

A long-lasting immune response created by the host's own immune system Signup and view all the answers

What is the primary function of platelets in the immune response?

They plug and protect against bleeding. Signup and view all the answers

Which cell type is primarily responsible for presenting antigens to T cells?

Dendritic Cells Signup and view all the answers

What role do endothelial cells play in immune response?

Controlling the entry of immune cells. Signup and view all the answers

What is the first step in the inflammatory process?

Recognition of harmful stimuli. Signup and view all the answers

Which of the following cells are classified as first responders in the inflammatory process?

Neutrophils Signup and view all the answers

What do complement proteins primarily do in the immune response?

Mark pathogens for destruction. Signup and view all the answers

What function do mast cells have in the inflammatory response?

Release histamine to increase blood vessel permeability. Signup and view all the answers

Which of these statements about fibroblasts is correct?

They play a key role in tissue repair and structure building. Signup and view all the answers

What ocular symptom is characterized by the drooping of one or both eyelids, especially noticeable during prolonged upward gaze?

Ptosis Signup and view all the answers

Which symptom involves difficulty swallowing and may lead to choking or aspiration?

Dysphagia Signup and view all the answers

What is a common respiratory symptom associated with weakness in respiratory muscles?

Dyspnea Signup and view all the answers

Which examination finding indicates that pupils remain normal in size in this disorder?

Normal Pupils Signup and view all the answers

What characteristic finding in nerve conduction studies (NCS) is suggestive of myasthenia gravis?

Decremental Response Signup and view all the answers

What test shows increased variability in the response time of muscle fibers, often indicative of myasthenia gravis?

Electromyography (EMG) Signup and view all the answers

Which diagnostic test shows a positive response in myasthenia gravis due to increased acetylcholine availability?

Response to Acetylcholinesterase Inhibitors Signup and view all the answers

What can chest imaging reveal that is associated with myasthenia gravis?

Thymic Abnormalities Signup and view all the answers

Which genes are commonly associated with an increased risk of breast cancer due to hereditary mutations?

BRCA1 and BRCA2 Signup and view all the answers

What is the CD4 count range indicating Stage 2 HIV infection?

200-499 cells/μL Signup and view all the answers

Which hormone levels decrease during menopause, contributing to symptoms like hot flashes?

Estrogen Signup and view all the answers

What is the immediate treatment approach for testicular torsion?

Emergency surgery (orchidopexy) Signup and view all the answers

In males, what is typically the first sign of puberty?

Testicular enlargement Signup and view all the answers

How does a varicocele differ from a spermatocele?

Varicocele involves enlarged veins, spermatocele involves fluid-filled sacs. Signup and view all the answers

What condition is associated with the enlargement of veins within the scrotum, often impacting fertility?

Varicocele Signup and view all the answers

Which hormones increase due to the lack of negative feedback during menopause?

FSH and LH Signup and view all the answers

What is a significant risk factor for seizure recurrence and the development of epilepsy in children?

Family history of epilepsy Signup and view all the answers

Which of the following findings is commonly associated with generalized tonic-clonic seizures?

Loss of bladder or bowel control Signup and view all the answers

What should be assessed after a seizure to confirm the post-ictal state?

Level of consciousness Signup and view all the answers

Which of the following is important in differentiating true epileptic seizures from seizure mimics?

Physical exam findings Signup and view all the answers

In patients already taking antiepileptic medications, what should be checked to confirm adherence?

Medication levels Signup and view all the answers

What laboratory tests should be performed to rule out potential metabolic or toxic causes of seizures?

Basic labs including electrolytes and glucose Signup and view all the answers

Which finding during a physical exam might suggest a structural brain lesion as the cause of the seizure?

Focal neurological deficits Signup and view all the answers

Which type of seizure can involve evidence of tongue biting or oral injuries?

Convulsive seizures Signup and view all the answers

What does preload measure in the heart?

The volume of blood filling the ventricles Signup and view all the answers

How does increased preload affect stroke volume?

It increases stroke volume Signup and view all the answers

What is the primary factor influencing afterload?

Arterial pressure Signup and view all the answers

What physiological analogy is used to describe preload?

Filling a water balloon Signup and view all the answers

What is the consequence of high afterload on heart function?

Slower and less efficient blood ejection Signup and view all the answers

What effect does increased venous return have on preload?

It increases preload Signup and view all the answers

What term describes the maximum amount of blood in the ventricle before it contracts?

End-diastolic volume Signup and view all the answers

How can lower afterload impact heart function?

Increases heart efficiency Signup and view all the answers

Which behavior is commonly associated with chronic stress that can contribute to hypertension?

Overeating and poor dietary choices Signup and view all the answers

How does elevated LDL cholesterol specifically contribute to hypertension?

By promoting atherosclerosis Signup and view all the answers

What is a critical component of managing diabetes to prevent high blood pressure?

Controlling blood sugar through diet and exercise Signup and view all the answers

What physiological effect can excessive caffeine intake have on blood pressure?

It can temporarily raise blood pressure Signup and view all the answers

Which type of cell acts as the first responder in the inflammatory process?

Neutrophils Signup and view all the answers

What is the main role of macrophages in the immune response?

Engulf debris and activate other immune cells Signup and view all the answers

Which cells are primarily responsible for the long-term memory in adaptive immunity?

Lymphocytes Signup and view all the answers

What function do mast cells serve during inflammation?

Massive release of histamine causing swelling and redness Signup and view all the answers

What is the primary function of the blood-brain barrier in the central nervous system?

To protect the CNS from harmful substances Signup and view all the answers

Which immune cell is primarily responsible for initiating the inflammatory response in MS by releasing gamma interferon?

Th1 Cells Signup and view all the answers

Which cells produce autoantibodies against the components of the myelin sheath in MS?

Plasma Cells Signup and view all the answers

What role do cytokines play in the pathology of Multiple Sclerosis?

Contribute to inflammation within the CNS Signup and view all the answers

What is the outcome of the immune attack on the myelin sheath in Multiple Sclerosis?

Formation of inflammatory plaques Signup and view all the answers

Which T cell subset is involved in activating B cells to produce autoantibodies in MS?

Th2 Cells Signup and view all the answers

What happens to the blood-brain barrier during the pathology of multiple sclerosis?

It becomes more permeable, allowing immune cells to infiltrate Signup and view all the answers

What type of lesions are formed as a result of demyelination in Multiple Sclerosis?

Inflammatory plaques Signup and view all the answers

What is the primary role of an electroencephalogram (EEG)?

To assess electrical activity in the brain during seizures Signup and view all the answers

What immediate action should be taken for airway management during a seizure?

Protect the patient’s airway from obstruction Signup and view all the answers

Where is anti-diuretic hormone (ADH) synthesized?

Hypothalamus Signup and view all the answers

What is a function of anti-diuretic hormone (ADH)?

Increases water reabsorption in the kidneys Signup and view all the answers

What is typically the first step in managing a seizure?

Ensure airway protection Signup and view all the answers

Which medication is often used for the termination of acute seizures?

Lorazepam Signup and view all the answers

What does ADH do primarily in the kidneys?

Enhances water permeability in collecting ducts Signup and view all the answers

What is important for the chronic management of seizures?

Referring to a neurologist Signup and view all the answers

What is the primary purpose of an ultrasound of the neck?

To visualize the lump and its relation to surrounding structures Signup and view all the answers

Which procedure is specifically used to obtain cells from a lump for cytological examination?

Fine Needle Aspiration (FNA) Biopsy Signup and view all the answers

Which imaging modality is best for assessing the extent of a lump's invasion into adjacent structures?

CT or MRI scan Signup and view all the answers

Which test is primarily utilized to evaluate thyroid hormone levels when a thyroid-related lump is suspected?

Thyroid Function Tests Signup and view all the answers

What is a common reason for performing a chest X-ray in the context of evaluating a neck lump?

To evaluate lungs and mediastinum for related abnormalities Signup and view all the answers

What does bronchoscopy allow clinicians to directly visualize?

The trachea and bronchi Signup and view all the answers

Insulin resistance primarily affects which group of cells in the body?

Cells in muscle, fat, and liver Signup and view all the answers

Which of the following is NOT a purpose of conducting a CT or MRI scan?

To visualize thyroid hormone levels Signup and view all the answers

What unhealthy behavior can chronic stress lead to that contributes to hypertension?

Increased consumption of sugary drinks Signup and view all the answers

Which type of cholesterol is particularly known for contributing to atherosclerosis?

LDL cholesterol Signup and view all the answers

What is an effective method for managing diabetes to help prevent hypertension?

Controlling blood sugar levels Signup and view all the answers

How does excessive caffeine intake affect blood pressure?

It can temporarily raise blood pressure Signup and view all the answers

What is the relationship between preload and stroke volume?

Higher preload results in an increased stroke volume. Signup and view all the answers

Which cell type is primarily responsible for phagocytosis during an inflammatory response?

Neutrophils Signup and view all the answers

Which factor is NOT a determinant of afterload in the heart?

Venous return Signup and view all the answers

What role do macrophages play in the immune response?

Engulf debris and activate immune cells Signup and view all the answers

Why is increased afterload potentially detrimental to heart performance?

It requires the heart to generate more force to eject blood. Signup and view all the answers

What is the primary function of eosinophils within the immune system?

Combat parasites and contribute to allergies Signup and view all the answers

In what scenario is preload considered maximized?

When there is a significant increase in venous return. Signup and view all the answers

What physiological concept explains the relationship between myocardial stretch and contractile strength?

Frank-Starling Law Signup and view all the answers

Which cell type is involved in the vascular response during inflammation by releasing signals?

Platelets Signup and view all the answers

How does compliance of the ventricles influence preload?

Higher compliance facilitates greater preload. Signup and view all the answers

The analogy of a water balloon is used to describe which cardiac concept?

Preload Signup and view all the answers

What happens to heart function when afterload is decreased?

The efficiency of blood ejection improves. Signup and view all the answers

What is the primary difference between active and passive immunity?

Active immunity requires direct exposure to pathogens. Signup and view all the answers

Which immunoglobulin is specifically noted for its ability to cross the placenta?

IgG Signup and view all the answers

Which type of carcinoma is associated with the most common presentation as a pearly nodule?

Basal Cell Carcinoma Signup and view all the answers

What characteristic primarily differentiates carcinomas from other types of tumors?

They derive from epithelial cells. Signup and view all the answers

What immediate effect can passive immunity provide to an individual?

Immediate protection without antibody generation. Signup and view all the answers

How does the role of IgG in the immune system primarily differ from that of IgM?

IgM is the first antibody produced during an immune response. Signup and view all the answers

What defines the key difference between basal cell carcinoma and squamous cell carcinoma?

Squamous cell carcinoma has higher rates of metastasis. Signup and view all the answers

Which immunoglobulin is primarily involved in opsonization, making pathogens easier for phagocytes to recognize?

IgG Signup and view all the answers

What initiates the cascade of neuronal dysfunction in Alzheimer's disease?

Accumulation of neuritic plaques Signup and view all the answers

How do neurofibrillary tangles primarily affect neurons in Alzheimer's disease?

They accumulate inside neurons, leading to their dysfunction. Signup and view all the answers

Which mnemonic effectively summarizes the damage caused by amyloid and tau in Alzheimer's disease?

Amyloid disrupts outside, Tau tangles inside. Signup and view all the answers

What is the primary hypothesis explaining the onset of Alzheimer's disease?

Amyloid hypothesis emphasizing the role of beta-amyloid accumulation Signup and view all the answers

What is one of the earliest signs of multiple sclerosis related to visual function?

Optic neuritis causing unilateral visual impairment Signup and view all the answers

Which symptom is commonly associated with multiple sclerosis and results from lesions affecting eye movement?

Double vision or diplopia Signup and view all the answers

What brain changes are characteristic of Alzheimer's disease?

Presence of neuritic plaques and neurofibrillary tangles Signup and view all the answers

Which factor may predispose individuals to an earlier onset of Alzheimer's disease?

Genetic mutations that increase beta-amyloid production Signup and view all the answers

What leads to the initiation of an action potential in a neuron?

The influx of sodium ions after reaching the threshold Signup and view all the answers

What is the typical resting membrane potential of a neuron?

-70 mV Signup and view all the answers

Which mechanism primarily maintains the resting state of a neuron?

Sodium-potassium pump activity Signup and view all the answers

What occurs during the depolarization phase of an action potential?

A large influx of sodium ions causes the membrane potential to become positive Signup and view all the answers

What is the significance of the threshold level in neuronal firing?

It triggers a rapid change in voltage, resulting in an action potential. Signup and view all the answers

What happens to sodium channels after the peak of an action potential?

They close to stop the influx of sodium ions. Signup and view all the answers

How does the neuron restore its resting state after an action potential?

By allowing potassium ions to leave the cell Signup and view all the answers

During repolarization, which ion primarily contributes to returning the neuron's membrane potential to its resting state?

Potassium ions Signup and view all the answers

Study Notes

Key Immune Cells and Their Roles

Platelets: Function to plug wounds and protect the body from blood loss.
Dendritic Cells: Present antigens to T cells to initiate the immune response.
Endothelial Cells: Form the lining of blood vessels and regulate the entry of immune cells.
Fibroblasts: Responsible for tissue repair and construction of new structural fibers.

Purpose of Inflammatory Process

Defense Mechanism: Protects against harmful stimuli such as pathogens and damaged cells.
Key Objectives: Eliminate the cause of injury, clear out dead cells, and facilitate tissue repair.
Recognition of Stimuli:
- Macrophages and dendritic cells detect harmful agents via pattern recognition receptors (PRRs).
- The complement system activates to mark pathogens for destruction by immune cells.

Recruitment of Immune Cells

Neutrophils: Quickly recruited to sites of injury or infection as the first line of defense.
Macrophages: Arrive after neutrophils to sustain the inflammatory response.
Mast Cells: Release mediators like histamine to enhance blood vessel permeability and facilitate immune cell movement.

Immunity Types

Active Immunity: Body produces its own antibodies and memory cells; long-lasting protection occurs through illness recovery or vaccination.
Passive Immunity: Receives antibodies from another source; provides immediate but temporary protection, such as maternal antibodies or antivenom.

Immunoglobulin Importance

IgG: The most abundant immunoglobulin, crucial for long-term immunity. Involved in neutralizing pathogens, opsonizing microbes, and activating the complement system. Unique for crossing the placenta to offer passive immunity to the fetus.

Carcinoma Definition

Carcinoma: A type of cancer originating from epithelial cells lining body surfaces and organs. Uncontrolled growth leads to invasion of surrounding tissues.
Types:
- Basal Cell Carcinoma: Most common skin cancer, starting from basal cells; appears as a pearly nodule.
- Squamous Cell Carcinoma: Arises from squamous cells, found on skin and lining of various organs.

Neurological Symptoms and Signs

Ocular Symptoms:
- Ptosis: Eyelid drooping noticeable over time.
- Diplopia: Double vision that worsens with visual tasks.
Bulbar Symptoms:
- Dysarthria: Slurred speech due to muscle weakness.
- Dysphagia: Difficulty swallowing, risking choking.
Respiratory Symptoms:
- Dyspnea: Breathing difficulties due to respiratory muscle weakness.

Examination Findings

Pupillary Status: Normal pupil size in conditions like myasthenia gravis.
Autonomic Functions: Typically remain unaffected.
Deep Tendon Reflexes: Preserved even with significant muscle weakness.

Diagnostic Approaches

Nerve Conduction Studies: Reveal a decremental response with repeated stimulation in conditions like myasthenia gravis.
Electromyography: Shows increased jitter, indicating variability in muscle reaction times.
Response to Acetylcholinesterase Inhibitors: A positive response supports the diagnosis of myasthenia gravis.
Chest Imaging: Can show thymoma or hyperplasia linked to myasthenia gravis.

Seizure Evaluation

Family History: Increases risk of seizure recurrence; detail eyewitness accounts of the event is crucial.
Physical Examination: Look for incontinence, oral trauma, and confusion post-seizure; assess for neurological deficits.

Differential Diagnosis

Seizure Mimics: Distinguish seizures from conditions like syncope and migraines through detailed history and examination.

Diagnostic Evaluation for Seizures

Medication Levels: Check for adherence and therapeutic range of antiepileptic drugs.
Laboratory Tests: Basic labs like electrolytes and glucose to rule out metabolic causes.

Breast Cancer Risk

Genetic Factors: Hereditary mutations in BRCA1 and BRCA2 genes increase breast cancer risk, though few breast cancers are hereditary.

HIV Staging

Stage 1: CD4 count over 500 cells/μL; no symptoms.
Stage 2: CD4 count 200-499 cells/μL; still no AIDS-defining illnesses.
Stage 3 (AIDS): CD4 count below 200 cells/μL; presence of AIDS-defining illnesses.

Menopause Hormonal Changes

Estrogen: Decreases, causing symptoms like hot flashes and reduced bone density.
Progesterone: Also declines, ending menstrual cycles.
FSH and LH: Increase due to decreased feedback from ovarian hormones.

Testicular Torsion Treatment

Emergency Surgery (Orchiopexy): Untwist the spermatic cord and secure the testicle to prevent recurrence; timely treatment needed (within 6 hours) to avoid damage.

Puberty Signs

Males: Testicular enlargement marks the first sign of puberty.
Females: Breast development (thelarche) is typically the first sign.

Varicocele, Spermatocele, Hydrocele

Varicocele: Enlargement of scrotal veins, often on the left side; may affect fertility.

Preload

Volume of blood filling the heart's ventricles before contraction.
Reflects the initial stretch of cardiac muscle fibers at the end of diastole.
Directly related to left ventricular end-diastolic volume (EDV).
Higher preload results in a stronger contraction, influencing stroke volume and cardiac output.
Factors influencing preload include venous return and ventricular compliance.

Afterload

Resistance the heart must overcome to eject blood during contraction.
Refers to the force needed to open the aortic valve and push blood into the aorta.
Influenced by arterial pressure and vascular resistance; higher afterload means more work for the heart.
Analogy: Pushing open a heavy door; similar to how high afterload affects heart function.

Stress and Hypertension

Chronic stress can lead to hypertension through unhealthy behaviors like poor diet and inactivity.
Stress management techniques can help reduce blood pressure.

High Cholesterol Levels

Elevated LDL cholesterol contributes to atherosclerosis and increased blood pressure.
Management includes diet changes, exercise, and medications.

Diabetes Management

Poorly managed diabetes heightens the risk of hypertension.
Control blood sugar levels through diet, exercise, and medications to prevent high blood pressure.

Excessive Caffeine Intake

High caffeine consumption can temporarily elevate blood pressure.
Reducing caffeine intake can benefit those sensitive to its effects.

Cells Involved with Inflammation

Neutrophils: First responders; perform phagocytosis.
Macrophages: Clean up debris and activate immune cells.
Lymphocytes: Include T cells and B cells; target specific invaders and produce antibodies.
Mast Cells: Release histamine, causing swelling and redness.
Eosinophils: Fight parasites and contribute to allergies.
Basophils: Similar to mast cells; involved in allergic responses.
Platelets: Form clots and release signals to boost inflammation.

Multiple Sclerosis (MS)

A chronic autoimmune disease affecting the central nervous system (CNS).
Immune system attacks the myelin sheath around nerve fibers, leading to neurological symptoms.

Key Pathological Processes of MS

Breakdown of the Blood-Brain Barrier (BBB) allows immune cell infiltration.
Th1 Cells: Activate macrophages to release inflammatory cytokines.
Autoantibody Production: Involves Astrocytes and B cells producing antibodies against myelin components.
Demyelination and Plaque Formation: Formation of inflammatory lesions (plaques) within the CNS.

Anti-Diuretic Hormone (ADH)

Also known as vasopressin; regulates water balance in the body.
Synthesized in the hypothalamus; stored and released by the posterior pituitary gland.
Acts on kidneys, increasing water reabsorption in collecting ducts.

Evaluating a "Lump on the Trachea"

Physical Examination: Assess size, consistency, mobility, and associated symptoms.
Ultrasound of the Neck: Visualize the lump and differentiate between solid and cystic masses.
Fine Needle Aspiration (FNA) Biopsy: Obtain cells for cytological examination, especially for thyroid nodules.
CT or MRI Scan: Detailed imaging of the trachea and surrounding structures.
Chest X-ray: Evaluate lungs and mediastinum for related abnormalities.
Thyroid Function Tests: Assess thyroid hormone levels if the lump is thyroid-related.
Bronchoscopy: Direct visualization of the trachea and bronchi when indicated.

Pathogenesis of Type 2 Diabetes Mellitus (DM)

Insulin Resistance: Cells in muscle, fat, and liver become less responsive to insulin.

Preload and Afterload

Preload: The volume of blood in the heart's ventricles before contraction; reflects the "initial stretch" of cardiac muscle fibers.
Preload is directly tied to left ventricular end-diastolic volume (EDV), indicating the maximum blood volume before contraction.
Analogy: Preload compares to filling a water balloon; more blood causes greater stretch, leading to stronger contraction (Frank-Starling Law).
Influenced by factors such as venous return and ventricular compliance; higher preload results in a stronger contraction and increased stroke volume.
Afterload: The resistance the heart must overcome to eject blood during contraction.
Specifically refers to the force needed by the left ventricle to open the aortic valve and push blood into the aorta.
Factors affecting afterload include arterial pressure and vascular resistance; high afterload makes it harder for the heart to pump blood efficiently.
Analogy: Afterload is like pushing a heavy door; higher resistance requires more effort, leading to slower and less efficient ejection of blood.

Health Factors Impacting Hypertension

Chronic Stress: Can lead to hypertension through unhealthy behaviors; managing stress via relaxation techniques can help reduce blood pressure.
High Cholesterol Levels: Elevated LDL cholesterol contributes to atherosclerosis, increasing blood pressure; diet, exercise, and medications assist in control.
Diabetes Management: Poorly controlled diabetes heightens hypertension risk; maintaining blood sugar through diet and medication is vital.
Excessive Caffeine Intake: High caffeine can cause temporary spikes in blood pressure; reducing intake helps, especially for sensitive individuals.

Cells Involved in Inflammation

Neutrophils: First responders that engulf invaders (phagocytosis); remember as "neutralizes threats quickly."
Macrophages: Act as the cleanup crew, engulfing debris and activating immune cells; known as "big eaters."
Lymphocytes: Include T cells and B cells that attack specific invaders and produce antibodies; associated with "long-term memory."
Mast Cells: Release histamine causing inflammation (swelling/redness); identified with "massive histamine release."
Eosinophils: Combat parasites and contribute to allergies; associated with "ejects granules."
Basophils: Function similarly to mast cells in allergic reactions; linked to "baseline allergic response."
Platelets: Form blood clots and release signals to enhance inflammation.

Immunity Types

Active Immunity: Body generates its own antibodies and memory cells for long-lasting protection (e.g., post-illness recovery, vaccinations).
Passive Immunity: Antibodies received from another source offer immediate, but temporary, protection (e.g., maternal antibodies or antivenom).

Immunoglobulin

IgG: The most abundant immunoglobulin; crucial for long-term immunity, prevalent in blood and extracellular fluid.
Functions include neutralizing pathogens, opsonization for phagocytosis, and activating the complement system; can cross the placenta providing passive immunity.

Carcinoma

Carcinoma: A cancer type originating from epithelial cells lining body surfaces.
Types include:
- Basal Cell Carcinoma: Most common skin cancer, arises from basal cells; appears as a pearly papule/nodule.
- Squamous Cell Carcinoma: Develops from squamous cells on the skin's surface and internal linings.

Alzheimer's Disease Process

Beta-Amyloid: Plaque buildup starts the deterioration process; triggers tau protein changes, leading to neurofibrillary tangles.
Both plaques and tangles contribute to neuron dysfunction and progression of Alzheimer's symptoms.
Neuritic Plaques: Clusters of beta-amyloid between neurons.
Neurofibrillary Tangles: Twisted tau proteins within neurons.
Amyloid Hypothesis: Pertains to excess beta-amyloid causing inflammation and neuron damage; genetic mutations can lead to increased beta-amyloid production.

Multiple Sclerosis (MS) Symptoms

Visual Problems:
- Optic Neuritis: Early sign involving inflammation of the optic nerve, causing visual impairment and pain.
- Nystagmus: Uncontrolled eye movements affecting vision.
- Double Vision (Diplopia): Result of lesions on nerves controlling eye movements.

Neuron Action Potential

Resting State: Neuron's baseline condition, typically around -70 mV; maintained by the sodium-potassium pump.
Depolarization:
- Triggered by stimulus causing sodium channels to open.
- Sodium influx occurs when Na⁺ ions enter the neuron, potentially reaching the threshold (-55 mV) triggering an action potential.
Repolarization: Following peak positive charge (+30 mV), sodium channels close, stopping Na⁺ influx.

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