Respiratory System

Upper Respiratory Tract

Consists of the nose, pharynx, larynx and trachea

Lower Respiratory Tract

Consists of the lungs, bronchi, bronchioles and alveoli

Upper Respiratory Tract

Consists of the nose, pharynx, larynx and trachea

Lower Respiratory Tract

Consists of the lungs, bronchi, bronchioles and alveoli

External Respiration

Gaseous exchange between the air and the blood. Happens in the alveoli in the lungs

Internal Respiration

Gaseous exchange between the lungs and the tissues. Happens in the tissues

Nares

The nostrils

Turbinates

Small structures inside the nose that cleanse and humidify air that passes through the nostrils into the lungs

Paranasal Sinuses

Hollow, air-filled spaces in the bones around the nose

Palate

The roof of the mouth, separating the cavities of the nose and the mouth in vertebrates

Nas/o, Rhin/o

Nose

Nose

2 chambers. Warm blooded animals have nasal turbinates. Lined with ciliated mucous membranes. Meatus. Alar fold

Alar Fold

A bulb located inside the nostrils

Pharyng/o

Pharynx

Pharynx

Three sections: nasopharynx, oropharynx, laryngopharynx. Shared with digestive system. Soft palate moves to close off nasopharynx

Palat/o

Palate

Laryng/o

Larynx

Larynx

“Voice box.” Regulates gases into respiratory tract. Prevents anything other than gases from entering. Suspended from skull by hyoid apparatus. Epiglottis

Epiglottis

A flap of cartilage in the throat that prevents food and drink from entering the lungs while swallowing:

Trache/o

Trachea

Trachea

Directs air from larynx to bronchi. Tube of C-shaped cartilaginous rings. Lined with ciliated mucous epithelium. Cilia sweeps particles and mucus upwards

Cough

Reflex causing sudden expulsion of air from the respiratory tract. Common clinical sign of disease. May be dry and hacking or moist and productive. Many causes including left sided heart failure, foreign bodies, neoplasia, lungworm infection or pneumonia

Bronchi/o

Bronchi

Bronchi

Trachea splits into right and left. They continue to get smaller to form bronchioles

Bronchiol/o

Bronchioles

-ole

Small, little

Bronchioles

Branches of bronchi

Alveol/o

Alveoli

Alveoli

External respiration takes place here. Capillaries carry O2 in. O2 diffuses into the blood. CO2 diffuses out of blood. Capillaries carry CO2 out

Pneum/o, Pneumon/o, Pneu, Pulm/o, Pulmon/o

Lungs

Lungs

Right and left. Divided into lobes. Encased in pleura. Lie on either side of the mediastinum. Canines and felines have 3 left lobes and 4 right lobes. Lobes: cranial or apical, middle or cardiac, caudal or diaphragmatic. 4th lobe is the accessory lobe

Pleur/o

Pleura

Pleura

Membranous sac that covers the lungs. Has two layers

Mediastinum

A membranous partition between two body cavities or two parts of an organ, especially that between the lungs.

Breathing

The rhythmical process of moving air into and out of the lungs to facilitate gas exchange with the internal environment

Inhalation

The action of breathing in

Exhalation

The flow of the breath out of an organism

-pnea, Ox/i, Ox/o, Ox/y, Capn/o

Breathing

Total Volume (TV)

The maximum amount of air that can be held in the lungs when an animal breathes in as much as possible

Respiratory Rate

The number of breaths an animal takes per minute

Thoracic Cavity

A hollow space in the chest that houses vital organs and structures

Pleural Cavities

Vacuum with small amount of fluid for lubrication

Diaphragm

Dome-shaped. Separates thorax and abdomen. Contraction increases thorax volume

External Intercostal Muscles

A set of muscles that help change the volume of the thoracic cavity during breathing

Internal Intercostal Muscles

A group of muscles that run between the ribs and are responsible for helping with breathing

Pneumotaxic

A neural network in the brainstem that controls breathing rate and pattern

Apneustic

A rare condition in which breathing is arrested during a tonic inspiration

Inspiratory

Relating to the act of breathing in

Frontal Sinuses

A hollow, funnel-shaped space in the frontal bone of the skull that helps keep the nose from drying out

Maxillary Sinuses

A pair of large, pyramid-shaped cavities in the cheekbones

Sphenoid Sinus

A hollow space located in the skull behind the nose and between the eyes

Palatine Sinus

An extension of the maxillary sinus

Lacrimal Sinus

Bilobed, tear-shaped hollow space with the primary function of secreting the aqueous portion of the tear film, thereby maintaining the ocular surface

Stridor

A high-pitched, abnormal breathing sound that occurs when the upper airway is narrowed or obstructed

Avian

No diaphragm. Air sacs in all major bones. Lungs do not expand during inspiration

Syrinx

A rare, fluid-filled neuroglial cavity within the spinal cord, in the brain stem, or in the nerves of the elbow

Choana

The opening between the nasal cavity and the nasopharynx

Reptiles

Can hold breath for long periods of time. Tolerate high levels of CO2. No diaphragm

Ectothermic

An organism that relies on external sources to regulate its body temperature

Apnea

A potentially serious sleep disorder in which breathing repeatedly stops and starts

Dyspnea

An uncomfortable feeling of difficulty breathing

Bradypnea

Abnormally slow breathing rate

Tachypnea

Abnormally rapid breathing

Hypoxia

A condition that occurs when the body or a part of the body doesn't receive enough oxygen, which can lead to tissue damage or death

Cyanosis

A bluish or purplish discoloration of the skin or mucous membranes that occurs when there's a decrease in the amount of oxygen in the blood

Agonal Breathing

When an animal that is not getting enough oxygen is gasping for air

Hypercapnia

Increase in partial pressure of carbon dioxide

Hypocapnea

A decrease in alveolar and blood carbon dioxide

Orthopnea

Shortness of breath while lying down

Hemothorax

Occurs when blood enters the pleural space

Pneumothorax

A condition that occurs when air leaks into the space between the lung and chest wall

Pyothorax

The presence of inflammatory fluid or pus within the chest cavity

Productive Cough

A cough that produces mucus or phlegm

Unproductive Cough

A cough that doesn't produce phlegm or mucus

Rhinitis

Inflammation of nasal cavity. Can also include the sinuses. May result from infection. Clinical signs: sneezing, nasal discharge and epistaxis

Epistaxis

The medical term for a nosebleed

Reverse Sneezing

Paroxysmal respiration. Epiglottis gets stuck. Air is pulled into the nose. No treatment is necessary

Paroxysmal Respiration

A condition in dogs that causes them to rapidly inhale air through their nose

Infectious Tracheobronchitis

Kennel cough. Affects the trachea and bronchial passages. Caused by bacteria bordetella bronchiseptica. Can be vaccinated. Highly contagious to other dogs

Bordetella Bronchiseptica

A highly contagious, gram-negative bacteria that causes respiratory disease in dogs, cats and rabbits

Brachycephalic Airway Syndrome

Severe cases will have hypoplastic trachea, elongated soft palate, stenotic nares, everted saccules or shortened nasal passages. Can suffer from hyperthermia

Stenotic Nares

A condition in which an animal's nostrils are narrow or malformed, making it difficult to breathe

Pneumonia

Inflammation caused by an infection. Alveoli fill with fluid or pus. Can be a primary condition or secondary to several conditions. Can be due to: bacteria, fungi, viruses, aspiration or irritants

Aspiration

The action or process of drawing breath

Emphysema

“Heaves.” Not bacterial or viral. Usually secondary to other obstructive disease. Causes destruction of alveolar walls. Can develop following other respiratory inflammation conditions

Heaves

A common, allergic respiratory disease that's similar to human asthma