Histology

Description of Asthma Histologically

Asthma is the inflammation of an airway.

Asthma is a chronic inflammatory disease. Asthma is caused by the inflammation of the bronchi, which carry air in and out of the lungs. Asthma presents itself as airway hyperresponsiveness, which means the airway is overly responsive to a stimulus. Asthma is characterized by many histological responses in large airways including epithelial detachment, mucous plugging, eosinophilic inflammation, bronchial smooth muscle hypertrophy, and more.

Normal Respiratory Tract Cells

The airway and respiratory system includes many types of cells including Pseudostratified Columnar Ciliated Epithelial Cells, Goblet Cells, Simple Squamous Epithelium, Smooth Muscle Cells, and more cells that help the respiratory tract function properly.

Pseudostratified Columnar Ciliated Epithelial Cells

Lines the Respiratory Tract

Moisten & Protect the Airways

Goblet Cells

Secretes Mucus

Simple Squamous Epithelium

Lines the Alveoli in the Respiratory Tract

(alveoli allows for gas exchange)

Smooth Muscle Cells

Allows the airway to Contract

Asthmatic Respiratory Tract Cells

The histology of an asthmatic airway can include detached epitheliums, hyperplasia or hypertrophy of smooth muscle, thickening of the subepithelial layer, infiltration of inflammatory cells (typically eosinophils), goblet cell metaplasia, and more.

> Smooth Muscle Hypertrophy: characterized by increased size of smooth muscle cells and thickening of the smooth muscle layer around airways

> Goblet Cell Metaplasia: results in mucus hypersecretion