Detailed Introduction to the Feline Respiratory System

1 Overview

Structure of the Feline Respiratory System

Besides breathing, the feline respiratory tract has other important roles: humidifying and warming air before it enters the body, trapping and removing foreign matter, aiding smell, and producing sounds (meowing, purring). The system consists of the nasal cavity, the back of the mouth (nasopharynx), larynx, trachea, lower airways, and lungs.

The respiratory tract is a large, continuous system made of several structures. It starts at the nostrils, involves several structures in the head, continues down through the neck, and finally reaches the lungs in the chest.

1. The nose is in the center of the face.

2. The nasal passages lie between the nostrils and the back of the throat. There is a passage on each side of the nose, separated by a bony plate or nasal septum, ending at the nasopharynx.

3. Around the nasal cavity are the sinuses, air-filled spaces within the skull. The main sinuses lie below and above the eyes.

4. The pharynx is the structure at the back of the mouth and throat. It is the cavity behind the tongue and the nasal passage; both food and air pass through it to deeper structures. Part of the pharynx is the nasopharynx, which connects the back of the nasal cavity to the larynx.

5. The larynx lies behind the root of the tongue and soft palate, between the pharynx and trachea. During swallowing it covers the trachea so food does not enter it.

6. The trachea is a cylindrical tube running from the bottom of the larynx to the start of the lung airways. At its end in the chest it splits into two branches, one for each lung (left and right). In the chest it lies above the base of the heart, beside and below the esophagus.

7. Once the trachea splits into two branches, the airways are called bronchi. They spread into lung tissue and keep dividing into smaller and smaller hollow channels as they go deeper. The respiratory tract ends in tiny air sacs called alveoli.

8. On each side of the chest are two sets of lungs. They surround the heart and fill most of the chest, from the base of the neck to the diaphragm, the muscle that separates the chest from the abdomen.