Fig 013 Respiratory System

Respiratory System

The respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide.

Nasal Cavity - moistening and filtering of air
Pharynx - part of throat behind the mouth and nasal cavity and above the esophagus and the larynx
Larynx - splits from the pharynx and leads into the trachea
- Vocal Cords - generate sound by vibrating
- Epiglottis - helps close the air conducting passage way during swallowing
Trachea - supported by C-shaped hyaline cartilage rings
- Respiratory epithelium
Primary (Main) Bronchi - branches into the left and right lungs and is supported by hyaline cartilage
- Respiratory epithelium
Lungs
- Bronchioles
  - Simple ciliated columnar (or cuboidal) epithelium with Club cells
- Terminal Bronchioles
  - Simple ciliated columnar (or cuboidal) epithelium with Club cells

Conducting passages convey air into the respiratory passages.

Trachea - fibromuscular tube supported by hyaline cartilage
- Respiratory epithelium
Primary Bronchi - branches into the left and right lungs
- Respiratory epithelium
Secondary Bronchi - multiple branches from the primary bronchi within the lungs
- Simple ciliated columnar (or cuboidal) epithelium with Club cells
Bronchioles - multiple branches from secondary bronchioles within the lungs
- Primary Bronchioles
- Terminal Bronchioles

Respiratory passages are involved in the exchange of oxygen and carbon dioxide within the lungs.

Respiratory Bronchiole - gives rise to two or three alveolar ducts
- Simple ciliated columnar (or cuboidal) epithelium with Club cells
Alveolar Ducts - through fares lined by alveoli and terminate into alveolar sacs
- Simple squamous epithelium
Alveolar Sacs - round spaces with openings into alveoli
Alveoli - pockets that open into alveolar sacs
- Type I pneumocytes - simple squamous cells responsible for gas exchange
- Type II pneumocytes - produce and secrete surfactant
- Alveolar macrophages - phagocytic cells observed in the alveolar spaces