The Respiratory System Functions & Anatomy Equine Science Ms. Weller

What is the Respiratory System? Organs that deliver oxygen to the circulatory system for transport to the cells in the animal’s body http://www.localriding.com/horses-respiratory-system.html

Functions Provides oxygen to tissues and cells Removes carbon dioxide from the body Controls body temperature Eliminates water (as vapor) Aids in voice production

Anatomy Nostrils Nasal Cavity Pharynx Larynx Trachea Bronchi (Bronchial Tubes) Lungs Bronchioles Alveoli

Nostrils External openings of the respiratory tract Lead into nasal cavity Shape and size varies amongst species

Nasal Cavity Air is warmed and moistened Dust particles filtered out Site of smelling (olfactory receptors located in turbinate bones) Separated from the mouth by a hard and soft palate

Pharynx Passages of nostrils and mouth join here (air and food cross paths) Epiglottis: keeps food from going to the lungs (valve-like) Short, funnel-shaped tube Filled with mucus membrane and ciliated cells to remove more impurities

Larynx Vocal chords Composed of cartilage structures Vibrate when air passes over Produces the neighing, whinnying or nickering sound Composed of cartilage structures Located in the middle of the neck Controls breathing Prevents inhalation of foreign objects into the lungs

Trachea Windpipe (single tube) Wall lined with series of c-shaped rings of cartilage (rigid) Help to maintain the shape of the passage during breathing Enters chest cavity Contributes to the cleansing function of the respiratory system

Bronchi The branches the trachea divides into to connect to the lungs Contribute to the cleansing function of the respiratory system Branch into bronchioles inside the lungs

Lungs Elastic, spongy material Cone shaped May be incompletely divided into several lobes Located in thoracic cavity Greatly expand when filled with air

Bronchioles Smaller branches of the bronchi The first few contribute to the cleansing function of the respiratory system Terminate in the alveoli

Alveoli Tiny air sacs that are the end of bronchioles Have very thin walls Surrounded by tiny blood capillaries Exchange of gases occurs here through diffusion

Diaphragm Body partition of muscle and connective tissue Separates the thoracic cavity from the abdominal cavity

Terms Respiration: the act of breathing Inspiration: inhalation brought about by a contraction of the diaphragm and an outward rotation of the ribs Expiration: expulsion of air effected by a relaxation of muscles and a contraction of rib and abdominal muscles

Stats Average lung capacity = 1.5 cubic feet of air Normal breathing rate (at rest) = 8-16 times per minute Inhales approximately 250 cubic inches of air at each respiration