Nares are the external structure of the bovine respiratory system. Located at the tip of the muzzle, the nares lead to the nasal cavity, which divides into two sides by the septum. 

Mucous Membranes and Cilia work to trap free particles in the nasal cavity. Turbinates are bony structures that increase the surface area, allowing the nasal cavity to humidify incoming air. Olfactory epithelium is also present. 

The pharynx is a muscular tube connecting to the esophagus and larynx. The nasopharynx connects to the nasal cavity, the oropharynx is the middle section behind the oral cavity and the laryngopharynx opens to the esophagus and larynx. The pharynx allows for speech and deglutition. 

The epiglottis is the entrance to the larynx and is made of elastic cartilage. The primary function is to protect the glottis during deglutition by folding over. It prevents liquids and solids from entering the airway. 

The glottis is located in the larynx and is responsible for phonation, protection of the lungs during deglutition and breathing. 

The hyoid apparatus is located in the anterior neck, below the mandible. It is unique in that it is not connected to any other structure in the body. It supports breathing and swallowing. 

Thyroid cartilage is vital to the structure of the larynx and has two lamina. 

Located in the ear, the vestibular system detects changes in head positions. 

Arytenoid cartilage also is located in the larynx and plays a vital role in phonation during speech. 

Similarly to the thyroid and arytenoid cartilage, the cricoid cartilage is vital to phonation and breathing and is located in the larynx. 

The trachea connects the larynx to the bronchi in the lungs. 

Tracheal Rings are cartilage structures that surround the trachea and provide support.  

Annular Ligaments are the connective tissues in the trachea. 

Trachealis Muscle is located at the back of the trachea and connects the c-shaped cartilage rings. 

The carina is located at the bottom of the trachea and is important for the bifurcation of the trachea into the two bronchi. 

The primary bronchi are responsible with providing the lungs with air from the trachea. They divide into the right and left lungs. 

The esophageal hiatus is an opening in the diaphram that allows the esophagus to pass through. 

Similarly to the esophageal hiatus, the aortic hiatus allows the aorta to pass though the diaphram. 

The vena caval foramen, also known as the caval hiatus, is another opening in the diaphram which allows the vena cava to pass though. 

Pleura is the thin membrane that surrounds the lungs and lines the inside of the thoratic cavity. It helps to reduce friction. 

The diaphragm is a large muscle located at the bottom of the thoracic cavity. Contraction of the diaphragm causes a vacuum during inhalation