Causes of Disease 1 Flashcards
How do bacteria cause disease?
Bacteria release toxins or physically damage tissues through their presence and reproduction, triggering an immune response.
How do viruses cause disease?
Viruses invade host cells, take over cellular machinery to replicate, and often kill or damage the host cell in the process.
What are key signs of inflammation?
Redness, heat, swelling, tenderness/pain.
What is the appropriate immune response to infection?
The body recognizes pathogens, activates white blood cells (like macrophages and neutrophils), releases inflammatory chemicals, and attacks invaders to clear the infection.
Name three types of pathological immune reactions.
1) Chronic inflammation, 2) Autoimmune reactions, 3) Hypersensitivity reactions (not deeply covered here but commonly includes allergies and overactive immune responses).
What is acute inflammation?
A short-term, appropriate immune response to injury or infection, meant to resolve and heal tissues.
What is chronic inflammation?
Long-term inflammation caused by repeated or unresolved injury, leading to damage of healthy tissue.
How do you differentiate between acute and chronic inflammation?
Chronic inflammation is prolonged, may damage healthy tissues, and often leads to tissue remodelling and sclerosis.
What are the pathological changes caused by chronic inflammation?
Continuous white blood cell activity, enzyme release that damages healthy tissue, and eventual tissue replacement with collagen (remodelling and sclerosis).
What is remodelling in chronic inflammation?
Replacement of normal tissue with post-inflammatory tissue like collagen.
What is sclerosis?
Abnormal hardening of tissue due to chronic inflammation and remodelling.
What is hypoxia?
Insufficient oxygen in body tissues, which may result from ischemia or other causes.
What is ischemia?
Decreased blood flow to tissues, limiting oxygen and glucose supply needed for cellular respiration.
How do ischemia and hypoxia cause disease?
By reducing energy production in cells, leading to dysfunction and eventually necrosis (cell death).
What are two ways the body creates acidosis?
1) Lactic acid build-up from anaerobic respiration during hypoxia.
2) Ketoacidosis from excessive fat metabolism when glucose is low.
What is the effect of lactic acid on the body?
Causes aching/burning in muscles and cellular damage due to acid build-up.
What happens during ketoacidosis?
Excess ketones (acids) lower blood pH, affecting consciousness, motor control, and overall cellular function.
What is necrosis?
Death of cells within a tissue due to prolonged lack of oxygen and nutrients.
What does necrotic tissue look like, and how is it treated?
It appears black and must be removed, as it is dead and cannot heal.
