PP C

Degenerative Disease

• Definition:

  • Degenerative disease results from continuous degenerative cell changes, affecting tissues/organs.

  • These diseases progressively worsen over time due to factors such as normal bodily wear or lifestyle choices (e.g., diet, exercise).

Example: Atherosclerosis

• Description:

  • Atherosclerosis is the hardening and narrowing of arteries due to plaque buildup.

  • It silently blocks blood flow and can lead to serious conditions like heart attacks, strokes, and peripheral vascular disease (collectively known as cardiovascular disease).

Atherosclerosis Details

• Normal vs. Narrowed Artery:

  • Normal artery: unblocked, healthy blood flow.

  • Narrowed artery: plaque includes lipids, calcium, cellular debris, altering blood flow significantly.

Multifactorial Disease

• Definition:

  • Multifactorial diseases arise from gene defects influenced by environmental factors (e.g., tobacco, alcohol, diet, parental age).

  • Clinical manifestations can include congenital defects like cleft lip/palate and club foot.

  • Some multifactorial diseases may not manifest until later, such as hypertension, diabetes, and cancers.

• Examples:

  • Diabetes involves both genetic predisposition and dietary factors.

Medical Genetics

Chromosome Basics

• Chromosome Structure:

  • Chromosomes contain DNA, which contains genetic information for cell function and development.

  • A normal karyotype has 46 chromosomes (22 pairs of autosomes and one pair of sex chromosomes, XX or XY).

  • Aneuploidy (abnormal chromosome number) can lead to conditions like Down syndrome (Trisomy 21).

Chromosomal Disorders

• Types of Disorders:

  • Dominant Disorder:

    • Caused by a single defective gene (e.g., some hereditary diseases).

    • Each child has a 50% chance of inheriting the disorder from an affected parent.

  • Recessive Disorder:

    • Requires two defective genes (one from each parent) to express the condition (e.g., sickle cell anemia).

    • Each child has a 25% chance of manifesting the condition.

X-Linked Disorders

• Inheritance:

  • Generally passed from affected mothers to sons, but fathers do not transmit the disorder to sons.

  • Daughters of carriers have a 50% chance of being carriers themselves.

• Examples include hemophilia A and red-green color blindness.

Inflammation

Overview

• Definition:

  • Inflammation is the body's response to harmful stimuli (pathogens, irritants) involving the immune system and blood vessels.

• Goals of Inflammation:

  1. Increase blood flow to injury site.

  2. Alter healing product composition.

  3. Remove injured tissues and prepare for healing.

Signs and Symptoms

• Classical Signs:

  • Heat (increased blood flow)

  • Redness (vasodilation)

  • Swelling (fluid accumulation)

  • Pain (compression & chemical mediators)

  • Loss of function.

• Acute vs. Chronic Inflammation:

  • Acute Inflammation: Initial response lasting days/weeks (e.g., acute cholecystitis, pancreatitis).

  • Chronic Inflammation: Lasts several weeks; associated with ongoing tissue damage and healing (e.g., chronic cholecystitis).

Autoimmune Diseases

• Definition:

  • The immune system attacks the body's own tissues without foreign invaders.

• Examples:

  • Hashimoto's thyroiditis, rheumatoid arthritis, lupus, celiac disease, type 1 diabetes, and multiple sclerosis.

Nutritional Diseases

• Definition:

  • Diseases related to nutrient deficiencies/excesses, obesity, and chronic diseases (e.g., cardiovascular disease, diabetes).

• Indicators of Malnutrition:

  • Stunting: Low height for age.

  • Wasting: Low weight for height.

  • Underweight: Low weight for age.

• Common Conditions:

  • Marasmus (severe malnutrition), kwashiorkor (protein malnutrition).

• Consequences:

  • Chronic undernutrition leads to severe health problems, especially in impoverished populations.

Vitamins and Minerals

• Vitamins:

  • Organic molecules needed for metabolism (e.g., B vitamins, vitamin C, vitamins A, D, E, K).

• Minerals:

  • Inorganic molecules required for normal body function.