Chapter 15: The Respiratory System

Respiration

Process of bringing Oxygen from the outside air into all of the body's cells and carrying carbon dioxide out in the opposite direction.

Ventilation/Breathing

Drawing air in blowing back out

External respiration

Occurs in the lungs. Exchange of oxygen and carbon dioxide between the air inhaled in the lungs and the blood flowing through the pulmonary capillaries.

Internal respiration

Occurs all over the body. Exchange of oxygen and Carbon dioxide between the blood in the systemic capillaries.

What are the secondary functions of the respiratory system?

Voice production, Body Temp regulation, Acid-base regulation, and sense of smell.

Phonation

Voice production

Nasal passages

The convoluted air passageways in the nose that conduct air between the nostrils and the pharynx.

Nasal septum

The midline barrier that separates the left and right nasal passages.

What bones separate the Nasal and oral Cavity?

Maxilla, Incisive, Palatine

Turbinates

Thin, scroll-like bones covered with nasal epithelium. Two turbinate's: Dorsal and Ventral

Ventral nasal Meatus

Located between ventral turbinate and the floor of the nasal passage

Middle Nasal Meatus

Located between the two sets of turbinate's

Dorsal Nasal meatus

Located between the dorsal turbinate and the nasal passage

Common nasal Meatus

Located on either side of the nasal septum

What are the nasal passages lined with?

Pseudostratified columnar epithelium

What are the three main conditioning roles of the nasal lining?

Warming, Humidifying, Filtering

Sinuses

Outpouchings of the nasal passages that are contained within spaces in certain skull bones.

What are the two divisions of the Pharynx?

- Nasopharynx (respiratory passageway)

-Oropharynx(digestive passageway)

Epiglottis

-Projects forward from the ventral portion of the larynx and has a bluntly pointed tip.

Covers opening of larynx when animal swallows.

What are the major cartilages of the Larynx?

Epiglottis, arytenoid cartilage, Thyroid cartilage , and Cricoid cartilage

What are the three main functions of the Larynx?

Voice production, Prevention of foreign material inhaled , control airflow to and from lungs.

Higher-Pitched voice happens when?

Tension lessened on cords

Lower-Pitched voice happens when?

Tension tightened on cords

Trachea

From the larynx to thorax. Transports air and is Y shaped.

Bifurcation of trachea

Division occurring at the level of the base of the heart of the trachea into the bronchi.

What is the trachea held open by?

C-shaped Cartilage rings made up of hyaline cartilage

What cartilage is the epiglottis made of?

Elastic cartilage

Lower respiratory Tract

Starts with the bronchi and ends with alveoli. Includes all air passages in between. Located within the lungs.

Bronchioles

Small air passageways.

Alveolar ducts

Smallest air passageways- Microscopic

Bronchi

Largest air passageways in lungs

Alveolar sacs

Groups of Alveoli

Where does external respiration take place?

Alveoli

What is the wall of the alveolus composed of?

Simple squamous epithelium. Thinnest epithelium in the body.

Surfactant

A substance that helps reduce tension and prevents collapsing of alveoli.

Lobes

Right- Cranial, Middle, Caudal, Accessory

Left- Cranial, Middle, Caudal

What Lobes does a Horse not have?

Middle

Hilus

Only area of the lung fastened in place. Where air, blood, lymph , and nerves enter and leave the lung.

Fetus vs Adult lung

Fetus is solid and will sink in water whereas adult is light and spongy and will float.

What happens to the respiratory system at Birth?

Lungs become light and spongy and Alveoli expand into sac like shapes

What are the contents of the thoracic cavity?

Heart, Lungs, Trachea, Large blood vessels, Nerves, Esophagus, Lymphatic Vessels, and Lymph nodes.

Inspiration

Pulling air into lungs

Expiration

Exhaling air out of lungs

What are the inspiratory muscles?

External Intercostal muscles and diaphragm

What happens to the thoracis cavity during inspiration?

Increase thoracic cavity size and diaphragm becomes a flat shape

What are the expiratory muscles?

Internal intercostal muscles and abdominal muscles

What happens to the thoracic cavity during Expiration?

Decreases thoracic cavity size and diaphragm expands to cone shape.

Tidal volume

Volume of air inspired and expired during one breath

Minute volume

Volume of air inspired and expired during one minute

Residual volume

Volume of air remaining in the lungs after maximum expiration

Partial pressure

The pressure of each individual gas

Mechanical system

Set routine inspiration and expiration limits

Chemical system

Monitors levels of substances in the blood and directs adjustments in breathing if unbalanced.

What is the Normal PH of blood?

7.4

Olfactory Sense

Sense of smell

Upper Respiratory system

Structures outside the lungs. Nose, nasal passages, pharynx, larynx, trachea.

Nares

Nostrils

Larynx

Voice box and is the entrance to the trachea. Contains: two fibrous connective tissues called vocal cords.