Respiration Overview

Respiration

• Respiration is a sequence of events resulting in gas exchange between the body's cells and the environment.
• Includes ventilation, external respiration, and internal respiration.

Outline of Respiration

• Gas exchange surface
• Human respiratory system
• Ventilation
• Gas exchange and transport
• Respiration and health

Gas Exchange Surfaces

• Respiration involves gas exchange between the body's cells and the environment.
• Ventilation is part of the process.
• External respiration is a part of the gas exchange process.
• Internal respiration is a part of the gas exchange process.

Human Respiratory System

• Air is filtered, warmed, and humidified as it travels through the nose, pharynx, trachea, and bronchi to the lungs.
• By the time air reaches the lungs, it's at body temperature and saturated with water.

Ventilation

• Humans breathe using a tidal mechanism.
• Expanding the thoracic cavity increases the lung volume, creating negative pressure and drawing air into the lungs.
• Muscle contractions lower the diaphragm and raise the ribs, expanding the thoracic cavity.
• Increased hydrogen ion and carbon dioxide concentrations in the blood trigger an increase in breathing rate.

Inspiration vs. Expiration

• Inspiration: Rib cage moves up and out, diaphragm contracts and moves down, pressure in lungs decreases, and air rushes in.
• Expiration: Rib cage moves down and in, diaphragm relaxes and moves up, pressure in lungs increases, and air is pushed out.

Gas Exchange and Transport

• Most oxygen entering the pulmonary capillaries combines with hemoglobin to form oxyhemoglobin.
• Some carbon dioxide combines with hemoglobin to form carbaminohemoglobin.
• Most carbon dioxide is transported in the form of bicarbonate ions.

Respiration and Health

• Upper Respiratory Tract Infections:

  • Strep Throat (Streptococcus pyogenes)
  • Sinusitis (infection of sinuses)
  • Tonsillitis (infection of tonsils)
  • Laryngitis (infection of larynx)

• Common Bronchial and Pulmonary Diseases:

  • Pulmonary Tuberculosis (tubercles encapsulate bacteria, reducing lung elasticity).
  • Emphysema (alveoli burst and fuse, reducing gas exchange surface area).
  • Asthma (airways inflamed, bronchioles constrict due to muscle spasms).
  • Bronchitis (airways inflamed due to infection or irritants, coughing brings up mucus and pus).
  • Pneumonia (alveoli fill with fluid, hindering gas exchange).
  • Pulmonary Fibrosis (fibrous connective tissue builds up, reducing elasticity).
  • Lung Cancer (cells lining the airways thicken).