Lungs

The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

Erythema Multiforme, Circular Lesions - Hands

Erythema multiforme lesions are circular and may appear in concentric rings (often called target lesions). Target lesions may also be associated with other medical conditions such as herpes infection, streptococcal infection, tuberculosis (TB), or as a reaction to chemicals or medications.

Erythema Multiforme, Target Lesions on the Palm

Erythema multiforme lesions are often referred to as target lesions because of the concentric rings the lesions produce. The "target" appearance is well demonstrated in this photograph.

Erythema Multiforme on the Leg

The red spots on this person's back appear where blisters (bullae) caused by Erythema multiforme have ruptured and the overlying skin removed (denuded). The resulting lesions are yellow-crusted ulcers (erosions). Erythema multiforme may be associated with herpes simplex infection, mycoplasma pneumonia, or other medical conditions such as streptococcal infection, tuberculosis (TB), or may result from exposure to chemicals or medications.

Exfoliation Following Erythroderma

This picture shows diffuse redness (erythema) and scaling on the arm.

Respiratory System

Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.