Respiratory System Anatomy

Anatomy of the Respiratory System

• Respiratory tract comprises two main systems:
  • Conducting system: Includes nasal cavity, sinuses, larynx, trachea, bronchi, and bronchioles.
  • Exchange system: Primarily involves lungs and alveoli.

Nasal Cavity Structure

• Contains dorsal concha (turbinate) and ethmoidal conchae.
• Features narrow spaces known as meatuses.
• Longitudinal sections reveal distinct anatomical structures.

Histology of the Respiratory System

• Mucosa consists of pseudo-stratified ciliated epithelium with goblet cells, which produce mucus.
• Submucosa is composed of connective tissue that contains glands and blood vessels.

Physiology Functions

• Oxygenation of blood and tissues.
• Regulation of body temperature.
• Sense of smell (olfaction).
• Maintenance of acid-base balance.
• Influence on blood pressure.
• Detoxification processes in the respiratory system.

Bacterial Presence

• Hosts a normal population of bacteria that are typically harmless unless stressed by factors such as viruses.
• Example includes Mannheimia haemolytica, which causes "Shipping Fever" in cattle.

General Pathology Overview

• Escape of blood from cardiovascular system can occur as external or internal bleeding.
• Reactions in living tissue involve vascular changes and cellular responses to local injury.

Exudate Types and Characteristics

• Exudate: Fluid leaking from blood vessels, comprising cells, proteins, and solids.
  • Catarrhal exudate: Mainly mucus with few inflammatory cells; associated with mucous membrane inflammation.
  • Fibrinous exudate: Composed primarily of fibrin; indicates acute and severe inflammation, often adhering to surfaces.
  • Purulent exudate: Rich in pus from dead neutrophils, indicates infections; can form abscesses (localized) or cellulitis (diffuse).
  • Caseous exudate: Associated with chronic inflammation, containing cheesy necrotic material, predominantly macrophages, and giant cells.

Duration of Inflammation

• Inflammation can be classified by duration:
  • Peracute
  • Acute
  • Subacute
  • Chronic (including chronic-active).

Immune Cells

• Granulocytes:
  • Neutrophils: Key players in acute inflammation.
  • Eosinophils: Involved in allergic responses and parasitic infections.
• Agranulocytes:
  • Lymphocytes: Important for adaptive immunity.
  • Plasma cells: Produce antibodies.
  • Macrophages: Involved in phagocytosis and tissue repair.
  • Giant cells: Formed in response to chronic irritation, encapsulate foreign material.