Nervous Syst Disorders, Aging,Sp2025-TO POST-1 (1)
Page 1: Nervous System Disorders
Overview
PHLT 304: Focus on Aging & Neurodegenerative Diseases
Page 2: Nervous System Disorders
Introduction
Introduction to various nervous system disorders.
Page 3: Nervous System Structure and Function
Nervous System Divisions
Somatic Nervous System: Controls voluntary muscle actions and sensory input.
Autonomic Nervous System: Regulates glands and involuntary muscles (e.g., cardiac muscle).
Neuron Functionality
Sensory (afferent) neurons: Carry impulses from receptors to CNS.
Efferent neurons: Carry impulses from CNS to effectors (e.g., muscles or glands).
Impulses in individual neurons travel in one direction only.
Example Scenario
Touching a Hot Stove: A scenario illustrating sensory feedback and reflex actions.
Page 4: Neuron Structure
Types of Neurons
(A) Sensory Neuron: Receives input from sensory receptors.
(B) Motor Neuron: Transmits impulses to muscles or glands.
(C) Myelin Sheath: Electrical insulator for neurons.
Key Components
Dendrites: Extensions that transmit electrical impulses toward the cell body.
Axon: Extension that transmits impulses away from the cell body.
Page 5: Myelin Sheath in CNS
Functionality
Oligodendrocytes: Function to produce the myelin sheath segments that electrically insulate CNS neurons.
Page 6: Myelin Sheath in PNS
Formation and Function
In PNS, the myelin sheath is created by Schwann cell membrane layers, insulating neurons.
Nodes of Ranvier: Gaps between myelin segments that facilitate rapid impulse conduction.
Regeneration: In PNS, damaged nerves can regenerate through the myelin tunnels.
Page 7: Nerve Impulse Transmission
Action Potential
Action Potential: Mechanism for transmitting nerve impulses, only in one direction.
Neurons can transmit hundreds of action potentials per second.
The myelin sheath significantly accelerates action potential velocity.
Page 8: Brain Disorders Overview
Impacts of Brain Disorders
Brain disorders can affect both physical and mental functions.
Page 9: Parkinson's Disease and Alzheimer's Disease
Parkinson's Disease
Affects physical function in 50-80% of cases, often accompanied by dementia.
Alzheimer's Disease
Characterized by memory loss, cognitive decline, and impaired social skills; severe brain function loss in advanced stages.
Page 10: Multiple Sclerosis
Conditions and Symptoms
Overview: Autoimmune disorder affecting the CNS by destroying myelin-forming cells.
Symptoms: Muscle weakness, paralysis, and numbness.
Risk Factors: Epstein-Barr virus infection and Vitamin D deficiency.
No cure; unpredictable disease progression.
Page 11: Parkinson's Disease Details
Characteristics
Typically onset around age 60.
Symptoms include tremors, rigidity, and impaired movement.
Page 12: Further Impacts of Parkinson's Disease
Secondary Impacts
Can lead to difficulties in speech, behavior changes, sleep issues, and memory problems.
Second most common neurodegenerative disease after Alzheimer's.
Page 13: Epilepsy
Overview
A brain disorder characterized by seizures due to various causes including stroke, tumors, and infections.
Not contagious, with over 500 associated genes.
Page 14: Tetanus
Cause and Symptoms
Caused by exposure to Clostridium tetani; results in strong muscle contractions.
Global neonatal tetanus deaths have decreased significantly; vaccination and hygiene are critical.
Page 15: Bacterial Meningitis
Overview
Several types of bacteria can cause meningitis, often leading to serious complications like brain damage.
Symptoms include fever, headache, and neck stiffness.
Page 16: Rabies
Transmission and Effects
Caused by Lyssavirus; any mammal can be infected.
Infection occurs through bites, leading to severe CNS involvement and is fatal once symptoms appear.
Page 17: Aging and Neurodegenerative Diseases
Impact of Aging
Aging population growth affects healthcare and support systems.
Page 18: Global Demographics Changes
Current Statistics
Adults aged 65+ now outnumber children aged <5.
Emphasis on healthy aging for economic and social support.
Page 19: Subjective Cognitive Decline (SCD)
Cognitive Decline Statistics
1 in 9 people aged 45+ report worsening memory problems.
83% have at least one chronic condition; significant impact on daily activities.
Page 20: Caregiving
Caregiver Dynamics
Considerations for caregivers and their challenges.
Page 21: Neurodegenerative Diseases
Definition and Categories
Incurable conditions causing progressive nerve cell degeneration.
Categories include ataxias and dementias (like Alzheimer's).
Page 22: Ataxia
Characteristics
Ataxia entails poor muscle control affecting speech and coordination.
Causes include MS, strokes, and exposure to toxic substances.
Page 23: Dementia
Overview
Dementia is characterized by impaired ability to perform daily activities.
Various types include vascular dementia, Alzheimer's, and Lewy body dementia.
Page 24: Alzheimer's Disease
Prevalence and Impact
The most common cause of dementia; imposes severe social and financial burdens.
Page 25: Alzheimer's Disease Mechanisms
Neurobiological Changes
Current theories regarding how Alzheimer's alters brain function.
Page 26: Vascular Dementia
Characteristics and Risk Factors
Impaired blood flow causing cognitive issues; risk factors include various cardiovascular issues.
Page 27: Dementia-Like Symptoms
Factors Affecting Symptoms
Conditions such as fluid buildup, tumors, and nutritional deficiencies can mimic dementia.
Page 28: Alzheimer's Disease Risk Factors
Modifiable vs. Non-Modifiable Factors
Modifiable risks include hypertension and obesity, while age and gender are non-modifiable.
Page 29: Primary Prevention
Health Recommendations
Recommendations for maintaining cognitive health include physical activity, balanced diet, and blood pressure management.
Page 30: Secondary Prevention
Importance of Diagnosis and Awareness
Diagnosing and addressing treatable conditions; awareness and support for patients and caregivers are essential.
Page 31: Alzheimer's Disease Affected Population
Prevalence
Nearly 54% of individuals have been affected by Alzheimer's in some way.
Page 32: Long-Term Care Costs
Financial Considerations
Overview of average costs associated with long-term care services in the U.S.
Page 33: Addressing the Growing Dementia Issue
Key Messages
The global increase in dementia cases requires proactive prevention, personalized care, and planning for future care needs.
Page 34: Questions?
Final Thoughts
Invites questions and discussion about the material covered.