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L8 Columnar Tissue and Lung Disease

Types of Tissue in the Body

  • There are 4 main types of tissue:

    • Epithelial

    • Muscle

    • Connective

    • Nervous

  • Three key types of epithelial tissue:

    • Squamous epithelial

    • Columnar epithelial

    • Endothelial (lines blood vessels and internal structures)

Squamous Epithelial Tissue

  • Composed of squamous epithelial cells.

  • Characterized by a single layer, thin, and smooth.

  • Ideal for rapid diffusion due to its thin nature.

Gas Exchange Process

  • Alveoli are the sites of gas exchange in the lungs.

  • Lined with squamous epithelial cells, providing a very short diffusion pathway.

  • Oxygen diffuses from air into blood while carbon dioxide diffuses from blood into air.

Chronic Obstructive Pulmonary Disorder (COPD)

  • COPD is a group of lung diseases causing damage to gas exchange tissues, slowing gas exchange, and leading to breathing difficulties.

  • The condition can arise from various causes and manifests with distinct symptoms.

COPD: Chronic Bronchitis

  • Airways become inflamed and squamous epithelial tissue thickens.

  • Increased mucus production leads to airway blockage.

COPD: Emphysema

  • Primarily caused by smoking, which damages alveoli.

  • Results in enlarged air spaces, decreased surface area, and impaired diffusion.

  • Loss of elasticity in alveoli hinders effective exhalation.

Columnar Epithelial Tissue

  • Made from columnar-shaped cells, including ciliated and unciliated (goblet) cells.

  • Lines the respiratory and intestinal tracts.

Protecting the Lungs

  • Columnar epithelial tissue forms a protective layer in the trachea and bronchi.

  • Goblet cells produce mucus to trap pathogens and debris.

  • Cilia create waves to move mucus and trapped materials out of the respiratory system.

Effects of Smoking

  • Smoking is a significant cause of COPD and contributes to cardiovascular issues.

  • Important to research the components of smoke that damage respiratory and cardiovascular structures.

Damage from Smoking Components

  • Carbon Monoxide: Damages the inner lining of arteries.

  • Nicotine: Triggers white blood cells to release inflammation-causing chemicals in the bronchioles.

Exam Questions

  • Complete and self-assess exam questions as homework.