Respiratory System Lecture Flashcards

Comprehensive vocabulary flashcards covering the anatomy, physiology, and variations of the respiratory system in domestic animals, birds, and other species.

Respiratory System

An integrated system of organs involved in the intake and exchange of oxygen ($O_2$) and carbon dioxide ($CO_2$) between the body and the environment.

Primary Function of Respiratory System

Gas exchange.

Secondary Functions of Respiratory System

Phonation, thermoregulation, pH balance regulation, and sense of smell.

Respiration (Etymology)

Derived from Latin roots: "re-" meaning "again" and "spirare" meaning "to breathe."

Respiration (Process)

The process of bringing oxygen ($O_2$) from the outside air into all body cells and carrying carbon dioxide ($CO_2$) out in the opposite direction.

-pnea / -pnoea

A suffix referring to breathing.

-phonia

A suffix referring to difficulty speaking.

-oxia

A suffix referring to the level of oxygen ($O_2$).

capnia

A suffix referring to the level of carbon dioxide ($CO_2$).

External Respiration

Gas exchange occurring in the pulmonary capillaries.

Internal Respiration

Cell respiration occurring in the systemic capillaries.

Nostrils (nares)

External openings of the respiratory tube that lead into the nasal passages; they are the most rostral end of the respiratory tract.

Horse vs. Pig Nostrils

Nostrils are most pliable and dilatable in the horse and most rigid in the pig.

Nasal Passages

Passageways between the nares and the pharynx lined with pseudostratified epithelium.

Nasal Septum

The midline divider of the nasal passages.

Nasal Turbinate

Structure within the nasal passages that acts as a humidifier.

Nasal Meatus

Passageway within the nasal cavity.

Paranasal Sinuses

Outpouchings associated with the nasal passages.

Pharynx (throat)

Structure that separates food and air passageways; supported by striated muscles that assist in deglutition (swallowing) and phonation.

Guttural Pouches

Air-filled sacs in horses positioned dorsal to the nasopharynx and medial to the mandible and parotid salivary glands.

Larynx (voice-box)

A short, irregular tube that serves as the gatekeeper to the entrance of the trachea and connects the pharynx with the trachea; supported by the hyoid bone.

Glottis

The official opening of the larynx.

Epiglottis

A leaf-shaped plate of cartilage that is the most rostral part of the larynx, located at the root of the tongue.

Trachea (windpipe)

A wide tube that is the primary passageway for air to the lungs, containing incomplete cartilaginous rings to prevent airway collapse.

Bronchi

Large tubes that lead air into the lungs.

Bronchial Tree

The network of passageways that lead from the bronchi to the alveoli.

Bronchioles

Airways within the bronchial tree that are smaller than $1\,mm$ in diameter.

Bronchodilation

Widening of the airways, stimulated by the Sympathetic Nervous System (SNS).

Bronchoconstriction

Narrowing of the airways, stimulated by the Parasympathetic Nervous System (PNS).

Alveolar Ducts

The smallest air passageways leading to the alveolar sacs.

Alveolar Sacs

Groups of alveoli located at the ends of alveolar ducts that resemble bunches of grapes.

Alveolus

The site of gas exchange made of simple squamous epithelium.

Type I Pneumocytes

Cells that form the alveolar wall.

Type II Pneumocytes

Cells that secrete surfactant.

Type III Pneumocytes

Alveolar macrophages (dust cells) that represent the first line of defense against respiratory pathogens.

Surfactant

A substance that reduces surface tension of the fluid in the alveoli, preventing them from collapsing during breathing.

Lungs

The principal structures of the respiratory system; paired structures in the thorax having a base, an apex, and a convex lateral surface.

Pleura

A membrane that covers organs in the thorax (visceral pleura) and lines the inside of the thoracic cavity (parietal pleura).

Mediastinum

The space located between the lungs containing the heart, large blood vessels, nerves, trachea, esophagus, and lymph structures.

Hilus

The area of the lung where air, blood, lymph, and nerves enter and leave; it is the only part of the lung fastened in place.

Dolichocephalic

Dog head shape characterized by extremely long skulls with long, slender noses (e.g., Greyhound, Dachshund).

Brachycephalic

Dog head shape characterized by short-nosed, flat-faced breeds with broad skulls (e.g., Pug, Boxer, Pekingese).

Mesocephalic

Dog head shape with intermediate length and width (e.g., Beagle, Labrador, Irish Setter).

Respiratory Cycle

The process of inhaling and exhaling air to bring oxygen in and expel carbon dioxide.

Inspiration

An active process that drives air from the environment into the lungs.

Expiration

A passive process that occurs when the diaphragm and inspiratory muscles relax, returning the thoracic cavity to normal size.

Abdominal Breathing

Breathing characterized by visible movements of the abdomen, usually predominating except in painful conditions of the thorax like Pleuritis.

Costal Breathing

Breathing characterized by pronounced rib movements, often seen in painful conditions of the abdomen like Peritonitis.

Eupnea

Normal, quiet breathing with no deviation in frequency or depth.

Dyspnea

Difficult breathing requiring visible effort; common in Brachycephalic dogs.

Hyperpnea

Breathing with increased depth, frequency, or both, typically noticeable after physical exertion.

Polypnea

Rapid, shallow breathing similar to panting; term frequently used in veterinary science.

Apnea

The cessation of breathing.

Tachypnea

Excessive rapidity of breathing.

Bradypnea

Abnormal slowness of breathing.

Respiratory Frequency

The number of respiratory cycles occurring each minute.

Auscultation

Listening to lung sounds (normal or abnormal) with the aid of a stethoscope over the thoracic wall.

Avian Trachea

The primary airway in birds connecting to the syrinx.

Syrinx

The specialized vocal organ found in birds.

Parabronchi

The site of gas exchange within the avian respiratory system.

Avian Air Sacs

Structures that allow for unidirectional flow of air through lungs and assist in thermoregulation; most birds have 9.

Cloacal Respiration

Intestinal respiration where gas exchange occurs in the posterior cavity of the enteral system (e.g., Fitzroy River Turtle).

Panting

Breathing quickly and loudly through the mouth to cool the brain and body.

Ram Gill Ventilation

A method of breathing in fish where they swim in straight lines at high speed with the mouth open (e.g., sharks).

Buccal Pumping

A method of ventilation where the animal moves the floor of its mouth in a rhythmic manner, also known as "breathing with one’s cheeks."