BIOL 302 – Respiratory System
Provides oxygen, removes carbon dioxide – gas exchange
Intimate relationship with circulatory system.
Get gases inside body to get to sites of exchange.
How we smell, pH regulation, how we talk/communication.
o Upper tract: nasal/oral cavity, larynx, trachea, primary (main) bronchi
o Lower tract (lungs): bronchi, bronchioles, respiratory bronchioles, alveolar
Lungs: Asymmetric – three lobes on right side (upper, lower, medial); two on left
o Pharynx - nasal + oral cavity
o Lined respiratory epithelium - simple stratified squamous near front of
o Entrance and filtration of air. Secrete mucous to trap dust. Moisturizes air
and warms it to facilitate gas exchange.
Respiratory Epithelium: ciliated (to move mucous) pseudostratified epithelium +
goblet cells (to trap particles)
Larynx: Easy to recognize - shaped like a cross. Responsible for speech -
vibrating tissues (folds in larynx). Two different epithelium, can see junction
between them - esophagus (stratified squamous) and trachae (ciliated
Single tracheae 2 primary bronchi 5 secondary bronchi tertiary bronchi
o Larynx (cross-like structure) opens into trachea.
o Mucosa consists of psuedostratified epithelium, lamina propria;
submucosa with glands and blood vessels; c-shaped hyaline cartilage
o Upper part of tissue is in neck - dense irregular connective tissue
o Trachea branches left and right into 2 primary bronchus.
o Upper part - nice psuedostratified epithelium, as you go deeper if becomes