By: Dr. Pamela Josefina T. Fabie

Main Function Interchange of gases between the

organism and the environment

External Respiration

- gas exchange between

the blood and the air taken

into the lungs

Internal Respiration

- gas exchange between

the blood and the cells of

the body

I. UPPER RESPIRATORY TRACT

a. Nose, Nasal Cavities,

Paranasal Sinuses

b. Pharynx

II. LOWER RESPIRATORY TRACT

a. Larynx

b. Trachea

c. Bronchi

d. Lungs

III. IMPORATNT PARTS/ORGANS

a. Diaphragm

b. Thoracic cavity,

Mediastenum, Pleural

Cavities

Functions:

• Olfactory sense

• Filters, warms, moistens the

entering air

• Phonation

Lateral Walls of the Nasal Cavity

The nose filters substances in 2 ways:

1. Vibrissae (Nasal Hairs) – filters out the coarsiest bosied

like insects

2. Air currents passing over the moist mucosa in curved

pathways deposit fine particles like dust, powder and

smoke.

Wave back and

forth about 12

times per minute

These are hollow cavities located around

the nasal cavities, lined by mucous membranes

continuous with that of the nasal cavities.

FUNCTIONS:

a. Lightens the bones of the skull

b. Provide mucous for the nasal cavity

c. Act as resonating chambers during

phonation

- 5 inches in length; extends from the base of the skull to the esophagus

• Nasopharynx• Oropharynx• Laryngopharynx

PHARYNX

Respiratory

DigestivePhonation (vowel

sounds

- Aka “VOICEBOX”

- Connects the pharynx

to the trachea

- Function:

- a. phonation

- b. protective sphincter

CARTILAGES:

UNPAIRED – thyroid, cricoid and epiglottis

PAIRED – arytenoid, cuneiform and corniculate

THYROID CARTILAGE- largest;

triangular in shape,; aka “Adam’s

apple”

CRICOID CARTILAGE – most

inferior; shaped like a signet ring

ARYTENOIDS – small; attached to

the superior portion of the

cricoid; pyramidal in shape

CUNEIFORMS – small elastic

cartilages at the base of the

epiglottis

EPIGLOTTIS – perforated leaf-

shaped lamina of firbroelastic

cartilage

CORNICULATE – smalll; conical in

shape

MUSCLES OF THE LARYNX:

1. EXTRINSIC – originate from the surrounding

structures and move the entire larynx

2. INTRINSIC – found within the larynx (open and close

the vocal folds during respiration and phonation)

• RIMA GLOTTIS – space between the true vocal cords

• RIMA VESTIBULI – space between the false vocal

cords/vestibular folds (keep the true vocal cords moist in

holding the breath and in protecting the larynx during

swallowing of food

CN 10

FEMALE MALE

Cords are shorter Cords are longer

More taut Less Taut

Closer together Farther apart

High voice Low voice

- “windpipe”

- 4.5in long, 1in diameter

- Function: Passageway of air to reach the lungs

• continuation of the larynx, and extend to approx. the level

of the 5th thoracic vertebra where it divides into right and

left bronchi

• membranous and cartilaginous tube cylindrical, about

11cm in length and about 2-2.5cm in diameter

• Composed of 12-20 incomplete or C-shapes hyaline

cartilages

TRACHEOSTOMY – a procedure in

which the trachea is surgically

opened and a tube is placed inside to

maintain a patent airway

RIGHT BRONCHI

- wider, shorter tube, lies

in a more vertical position

(25 degrees)

LEFT BRONCHI

- narrower, longer than in

the right(5cm), lies in almost

horizontal position (45

degrees)

- Bifurcation

(Carina) at the

level of the 5th

thoracic vertebra

- smaller branches of bronchi; diameter of 1mm; no

cartilage in their walls

Bronchi Bronchioles

Terminal

Bronchioles

Alveolar

DuctsAlveoli

Trachea

- The most essential

organ of respiration

ADULT LUNG – spongy; frequently blue-gray in color because of

the inhaled dust and soot in the pulmonary lymphatics

INFANT LUNG– pink, since no foreign material has yet entered

- thin, muscular and

tendinous septum that

separates the chest cavity

from the abdominal cavity

- most important muscle of

repsiration

Esopahageal

Aortic

Vena Cava

3 Major

Openings

- The domes support the

right and left lungs

- Right dome is higher

because of the larger size

of the right lobe of the

liver

Function:

- Protection not only for the lungs, but also to other life-sustaining organs of the body (heart and major blood vessels, etc.)

- Bounded by chest wall and below by the diaphragm

- Divides the thoracic cavity into

two pleural cavities

MIDDLE COMPARTMENT – Boundaries

Anterior – Sternum

Posterior – Bodies of the 2 thoracic vertebrae

Inferior – Diaphragm

Superior – Thoracic inlet

INFERIOR COMPARTMENT

– subdivided by the heart in 3 Divisions

Anterior

Middle (where the heart is)

Posterior

The 2 Pleural Cavities

are lined with pleura

on either side of the

mediastenum.

Each lung is enclosed

by Visceral pleura.

Parietal Pleura (serous

membrane), is in close

contact with the

diaphragm and

internal aspect of the

thoracic cavity.