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.