Refers to the structure involved in the exchange of gases between the blood and the lungs and other organ systems.

1. Provide oxygen to the cell of the body. 2. Remove excess carbon dioxide

- they get Oxygen by diffusion from the fluid surrounding them and eliminate Carbon dioxide in the same way.

LARGE ANIMALS have two way systems

- that carry to and from the tissue cells quantity of oxygen and carbon dioxide

- a gas exchanger that loads the blood with 02 and removes excess CO2.

RESPIRATORY APPARATUS

is located within the skull, above the mouth and extending from the nostrils to the pharynx. It is divided into two halves by a structure called the nasal septum

Located behind the nasal cavity and mouth, extending down to the larynx and esophagus. It acts as a common pathway for both air (to the lungs) and food (to the stomach).

is the uppermost part of the pharynx. It is located behind the nasal cavity and extends from the internal nares (the openings at the back of the nose) to the soft palate.

lies just below the nasopharynx and extends from the soft palate to the hyoid bone which is located near the base of the tongue.

, commonly known as the windpipe, is a tubular structure that connects the larynx to the bronchi. It runs down the neck and into the thoracic cavity.

are found within the lungs, stemming from the tertiary bronchi. They progressively branch into smaller and smaller airways

are tiny, balloon-like structures located at the end of the respiratory bronchioles in the lungs. They are the primary site of gas exchange between the air and the bloodstream.

3 types of respiratory center;

Capable of initiating and maintaining sequence of the respiratory cycle. These centers are responsible for controlling breathing by regulating the rate and depth of respiration.

helps limit the duration of inhalation, which indirectly affects how quick the respiration.

promotes longer and deeper breaths by sending signals to the breathing muscles. It helps make get enough air, especially in situations where deep, controlled breathing is needed

Types of respiration

the normal quiet respiration

. - Difficulty in breathing

- Cessation or stopping of respiration

- Increase rate/depth of breathing or both

- Rapid, shallow breathing

the contraction of the diaphragm increases the longitudinal diameter of chest, also contraction of the external intercostal muscles that elevates the ribs resulting to increased diameter of the thorax.

The amount of air that moves into the lungs

The amount of air that moves into the lungs with each inspiration or the amount that moves out with each expiration is called

Types of LUNG VOLUME

This is the additional volume of air that can be inhaled after a normal inhalation.

This is the additional volume of air that can be exhaled after a normal exhalation

This is the amount of air that remains in the lungs after a maximal exhalation

When breathe in, air fills the alveoli, which have a high concentration of oxygen. The oxygen then moves from the alveoli (where there's more oxygen) into the bloodstream (where there's less oxygen) through the thin walls of the alveoli.

When a bird inhales, air enters through the nostrils and travels down the trachea. From the trachea, the air moves into the caudal air sacs -----------_---__------++------__ During the first exhalation, the air in the posterior air sacs is pushed into the lungs. In the lungs, oxygen is absorbed into the bloodstream, while carbon dioxide from the blood is transferred to the air in the lungs for removal.

air that is now depleted of oxygen and contains carbon dioxide moves from the lungs into the cranial air sacs (the air sacs located in front of the lungs)

air in the cranial air sacs is expelled out of the body through the trachea. This air has a higher concentration of carbon dioxide and is now ready to be removed from the bird's body.