Body Systems and Disease

Grade 10 · Health · Study Guide

An advanced examination of how the major body systems function, interact, and break down in the presence of disease.

The human body is composed of organ systems that work in highly coordinated ways to maintain homeostasis — a stable internal environment. When one system is disrupted by disease, the effects often cascade across multiple systems, demonstrating their interdependence.

The cardiovascular system pumps blood carrying oxygen and nutrients throughout the body. Diseases like atherosclerosis (plaque buildup in arteries) can lead to hypertension, heart attack, or stroke. Risk factors include high cholesterol, smoking, physical inactivity, and genetic predisposition.

The respiratory system exchanges oxygen and carbon dioxide in the lungs. Diseases such as asthma (chronic airway inflammation), COPD (chronic obstructive pulmonary disease), and pneumonia impair gas exchange and can strain the cardiovascular system due to reduced oxygen delivery.

The immune system defends against pathogens. Autoimmune diseases occur when it mistakenly attacks the body's own tissues — examples include Type 1 diabetes (attack on pancreatic beta cells), multiple sclerosis (attack on myelin sheaths), and rheumatoid arthritis (attack on joint linings).

The endocrine system regulates hormones. Type 2 diabetes results from insulin resistance, where cells fail to respond properly to insulin, leading to chronically elevated blood glucose and damage to kidneys, nerves, and blood vessels.

Cancer represents uncontrolled cell division caused by mutations in genes regulating the cell cycle (oncogenes and tumor suppressor genes). Carcinogens, viruses, and inherited mutations can all trigger these changes.

Understanding how systems fail helps us recognize symptoms, seek timely treatment, and make preventive lifestyle choices.

Key terms

Homeostasis
The body's ability to maintain a stable internal environment despite external changes.
Atherosclerosis
A disease in which plaque (fat, cholesterol, and other substances) builds up inside arteries, narrowing them and restricting blood flow.
Autoimmune Disease
A condition in which the immune system mistakenly attacks the body's own healthy cells and tissues.
Insulin Resistance
A condition in which cells do not respond effectively to insulin, causing the pancreas to produce more insulin and blood glucose to remain elevated.
Oncogene
A mutated gene that promotes uncontrolled cell growth, contributing to the development of cancer.
Pathogen
A microorganism (bacterium, virus, fungus, or parasite) that causes disease in a host.

Flashcards

Homeostasis
Maintenance of a stable internal environment; disrupted by disease.
Atherosclerosis
Arterial plaque buildup that restricts blood flow, increasing risk of heart attack and stroke.
Type 1 Diabetes
Autoimmune destruction of insulin-producing beta cells in the pancreas.
Type 2 Diabetes
Insulin resistance causing chronically high blood glucose; linked to lifestyle and genetics.
Autoimmune Disease
Immune system attacks the body's own tissues (e.g., MS, rheumatoid arthritis, lupus).
Cancer
Uncontrolled cell division caused by mutations in oncogenes or tumor suppressor genes.
COPD
Chronic obstructive pulmonary disease; irreversible lung damage typically caused by smoking.
Tumor Suppressor Gene
A gene that normally prevents uncontrolled cell growth; mutations can lead to cancer.

Questions

  1. Which condition results from the immune system attacking the body's own pancreatic beta cells?

    1. Type 2 diabetes
    2. Atherosclerosis
    3. Type 1 diabetes
    4. Asthma
    Show answer

    Answer: Type 1 diabetes

    Type 1 diabetes is an autoimmune disease in which the immune system destroys insulin-producing beta cells in the pancreas, requiring lifelong insulin therapy.

  2. Atherosclerosis only affects the heart and has no impact on the brain.

    Show answer

    Answer: False

    Atherosclerosis affects arteries throughout the body; plaque in cerebral arteries can cause strokes, making it a systemic cardiovascular disease.

  3. The body's ability to maintain a stable internal environment is called ________.

    Show answer

    Answer: homeostasis

    Homeostasis refers to the dynamic balance of internal conditions (temperature, pH, glucose levels, etc.) that the body continuously regulates.

  4. What characterizes cancer at the cellular level?

    1. Uncontrolled cell division due to genetic mutations
    2. Excessive immune response to pathogens
    3. Decreased production of red blood cells
    4. Inflammation of nerve tissue
    Show answer

    Answer: Uncontrolled cell division due to genetic mutations

    Cancer is defined by uncontrolled cell proliferation resulting from mutations in genes that regulate the cell cycle, including oncogenes and tumor suppressor genes.

  5. COPD is a reversible lung disease that can be fully cured with medication.

    Show answer

    Answer: False

    COPD is a chronic, progressive, and largely irreversible lung disease. Management can slow progression and reduce symptoms, but there is no cure.

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