Anatomy and Physiology: Respiratory System

Respiratory System (Apparatus Respirators)

• Uses the nose, nasal cavity, pharynx, larynx, trachea, bronchi, and smaller passageways to bring air to the alveoli or sites of gaseous exchange within the lungs.

• Various structures associated with these passageways modify or regulate the flow of air, serve as olfactory receptors, facilitate water and heat exchange, and make phonation possible.

Parts of the Respiratory System

• For Air Conduction:

  • Nasal Cavity

  • Nasopharynx

  • Larynx

  • Trachea

  • Bronchi

  • Bronchioles

• For Gas Exchange:

  • Alveoli

Functions of the Respiratory System

• Includes inspiration and expiration

• Provides an exchange of respiratory gases (oxygen and carbon dioxide)

• Warms, cleans, and humidifies air

• Aids olfaction and phonation

Nasal Cavity

1. The entry point for air, lined with mucous membranes that help filter and humidify the air.

2. Contains nasal turbinates, bony structures covered with mucous membrances, which increase the surface area for air conditioning.

3. Goblet cells secrete mucus, while ciliated cells help move mucus and trapped particles toward the throat.

Pharynx (throat)

• Serves as a common passage for air and food

• Divided into 3 parts: Nasopharynx (connected to the nasal cavity), oropharynx (connected to the mouth), and the laryngopharaynx (connected to the larynx).

Larynx (voice box)

• Contains the vocal cords that produce sound during vocalization

• Composed of cartilaginous structures like thyroid cartilage, cricoid cartilage, and arytenoid cartilages.

• Epiglottis prevents food from entering the respiratory tract during swallowing.

Trachea (windpipe)

• Tubular structure made of c-shaped cartilage rings for support

• Conducts air from the larynx into the bronchi and lungs

• Tracheal smooth muscle allows for some degree of constriction or dilation to regulate airflow.

What are the two main parts that the trachea is divided into?

Trachea divides into two main bronchi, one entering each lung

• Bronchi

• Bronchioles

Bronchi

Bronchi further divide into smaller bronchioles, lacking cartilage and surrounded by smooth muscle

Bronchioles

Bronchioles continue branching into smaller passages, leading to terminal bronchioles and ultimately alveolar ducts.

Lungs

• Paired organs enclosed within the thoracic cavity by pleural membranes

• Each lung contains lobes separated by fissures

• Alveoli, located at the end of bronchioles, facilitate gas exchange between air and blood.

Pleura

• the pleura is a thin, double layered membrane surrounding each lung and lining the chest cavity

• Visceral

Ventilation

Gas Exchange

Transport of Gases

Respiratory Defense Mechanisms