Changes

[[Image:Bronchiole Histology.jpg|right|thumb|350px|©Nottingham 2008]]

[[Image:Bronchiole Histology.jpg|right|thumb|350px|©Nottingham 2008]]

*The histology of the '''Bronchi''' is almost identical to that of the trachea - the lumen of the bronchus is lined by a pseudostratified epithelium, including goblet cells and serous cells.

*The histology of the '''Bronchi''' is almost identical to that of the [[Trachea - Anatomy & Physiology|trachea]] - the lumen of the bronchus is lined by a pseudostratified epithelium, including goblet cells and serous cells.

Beneath the narrow layer of connective tissue under the epithelium lie well-developed spiral bands of smooth muscle.

Beneath the narrow layer of connective tissue under the epithelium lie well-developed spiral bands of [[Muscles - Anatomy & Physiology#Smooth Muscle|smooth muscle]].

*The '''Bronchioles''' have no cartilage rings but have well developed muscular walls to enclose the lumen. The epithelium is reduced to cuboidal, and in the normal animal it contains no mucus secreting glands. There are many lymphoid nodules beneath the epithelial layer.

*The '''Bronchioles''' have no [[Bones and Cartilage - Anatomy & Physiology#Types of Cartilage|cartilage]] rings but have well developed [[Muscles - Anatomy & Physiology|muscular]] walls to enclose the lumen. The epithelium is reduced to cuboidal, and in the normal animal it contains no mucus secreting glands. There are many [[Lymph Nodes - Anatomy & Physiology|lymphoid]] nodules beneath the epithelial layer.

*'''Respiratory Bronchioles''' have few alveoli scattered along the length, at the entrance of which is ''simple squamous'' epithelium, and bronchial smooth muscle bundles.

*'''Respiratory Bronchioles''' have few alveoli scattered along the length, at the entrance of which is ''simple squamous'' epithelium, and bronchial [[Muscles - Anatomy & Physiology#Smooth Muscle|smooth muscle]] bundles.

==Species Differences==

==Species Differences==