The Respiratory

System

By Mr. Danilo Villar Rogayan Jr.

Instructor I, Department of Natural Sciences

RMTU San Marcelino

Introduction

• Function • Move air in an out of lungs (ventilation)

• Delivers oxygen (O2)

• Removes carbon dioxide (CO2)

• External respiration• Occurs in the lungs

• Internal respiration• Occurs in the hemoglobin

O2

O2

O2

CO2

CO2

CO2

Lungs

Organs of the Respiratory System

Nose

Pharynx

Larynx

Trachea

Bronchial tree

Lungs

Organs of the Respiratory System(cont.)

• Nasal cavity• Nasal septum divides the cavity into right and left

portions• Nares – openings of the nose

• Nasal conchae extend from walls of nasal cavity

• Mucous membrane warms and moistens the air

• Cilia help eliminate particles

Organs of the Respiratory System(cont.)

• Paranasal sinuses• Air-filled spaces

within the skull bones• Open into the nasal

cavity

• Reduce the weight of the skull

• Equalizes pressure

• Gives the voice its certain tone

• Skull bones with sinuses include:

• Frontal

• Sphenoid

• Ethmoid

• Maxillae bones

• Pharynx• Serves both the respiratory and digestive system

• Larynx

• Also called the “voice box”

• Moves air in and out of the trachea and produces voice

• Composed of three cartilages:

• Thyroid cartilage

• Epiglottic cartilage

• Cricoid cartilage

Organs of the Respiratory System(cont.)

Organs of the Respiratory System(cont.)

• Vocal cords• Stretched between the

thyroid cartilage and the cricoid cartilage

• Upper – false cords

• Lower – true vocal cords

• Glottis – the opening between the vocal cords

• Stretch = pitch of voice

Glottis

True

Vocal

Cords

False

Vocal

Cords

Posterior

Portion

of

Tongue

Cilia move mucus up to the throat, where

it is swallowed. Smoking destroys cilia.

Organs of the Respiratory System(cont.)

• Trachea• Referred to as the windpipe

• Tubular organ made of rings of cartilage and smooth muscle

• Extends from the larynx to the bronchi

• Lined with cells possessingcilia (microscopic hair-like projections)

Trachea

Organs of the Respiratory System(cont.)

• Bronchial tree• Bronchi

• First branches off trachea

•

• Bronchioles• Secondary branches

• Alveoli• Thin sacs of cells

surrounded by capillaries

• Secrete surfactant

Bronchi

Bronchioles

Organs of the Respiratory System(cont.)

• Bronchial tree • Alveoli

• Thin sacs of cells surrounded by capillaries

• Secrete surfactant

• Fatty substance

• Helps maintains the inflation of the alveoli between inspirations

The lungs contain connective tissue, the bronchial

tree, nerves, lymphatic vessels, and blood vessels.

Organs of the Respiratory System(cont.)

• Lungs• Cone-shaped organs

• Right lung – three lobes

• Left lung – two lobes

• Pleura – membranes surrounding the lungs

Apply Your Knowledge

Which of the following sites would be the most

lethal if obstructed by a foreign body?

a. Right bronchus

b. Left bronchus

c. Trachea

ANSWER:

The Mechanisms of Breathing

Inspiration Expiration

Breathing, or pulmonary ventilation, consist of inspiration

(inhalation) and expiration (exhalation).

Air rich in O2 enters the lungs from the atmosphere

The diaphragm contracts or flattens

The intercostal muscles raise the ribs

Air rich in C02 exits the lungs

The diaphragm relaxes

The intercostal muscles lower the ribs

The Mechanisms of Breathing (cont.)

• Respiratory center of the brain

• Medulla oblongata –controls rhythm and depth of breathing

• Pons – controls the rate of breathing

• Other factors

• CO2 levels in the blood

• pH of the blood

• Fear and pain

• Inflation reflex

The Mechanisms of Breathing (cont.)

• Causes of altered breathing patterns• Coughing

• Sneezing

• Laughing

• Crying

• Hiccups

• Yawning

• Speaking

The Transport of Oxygen and Carbon Dioxide in the Blood

• Most of the oxygen binds to hemoglobin

• Oxyhemoglobin

• Bright red in color

• Some oxygen remains dissolved in plasma

• If CO2 combines with hemoglobin at O2 sites, it forms carboxyhemoglobin

The Transport of Oxygen and Carbon Dioxide in the Blood

• Carbon dioxide gets into the bloodstream• Reacts with water in plasma and forms carbonic acid

• Carbonic acid ionizes and releases hydrogen and bicarbonate ions

• Bicarbonate ions attach to hemoglobin • Exhaled as waste product in the lungs

Apply Your Knowledge

Describe what happens to carbon dioxide in the

blood.

ANSWER: Carbon dioxide can combine with hemoglobin and

form carboxyhemoglobin. Most reacts with water in plasma to

form carbonic acid. The carbonic acid ionizes and releases

hydrogen and bicarbonate ions. The bicarbonate ions then

attach to hemoglobin and are exhaled as a waste product from

the lungs.

Super!

Respiratory Volumes

• Different volumes of air move in and out of lungs with different intensities of breathing

• Measured to assess health of respiratory system

Respiratory Volumes (cont.)

Amount of air that moves in or out of

the lungs during a normal breath

Amount of air that can be forcefully

inhaled following a normal inhalation

Amount of air that can be forcefully

exhaled following a normal exhalation

Tidal Volume

Inspiratory

Reserve

Volume

Expiratory

Reserve

Volume

Respiratory Volumes (cont.)

Amount of air that can be forcefully

exhaled after the deepest inhalation

possible

Volume of air that always remains in

the lungs even after a forceful

exhalation

The total amount of air the lungs can

hold

Residual

Volume

Total Lung

Capacity

Vital

Capacity

Snoring

• Due to vibration of soft tissues when muscles of the palate, tongue, and throat relax

• Affects approximately 50% of men and 25% of women over the age of 40

• Causes daytime sleepiness

• May be associated with obstructive sleep apnea

• Common Causes• Enlargement of tonsils

or adenoids

• Being overweight

• Alcohol consumption

• Nasal congestion

• Deviated nasal septum

Snoring (cont.)

Mayo Clinic’s Sleep Disorders Center rating of snoring:

Heard from close proximity

Heard from anywhere in the bedroom

Heard from just outside the bedroom door

with door open

Heard outside the bedroom door with the

door closed

Snoring (cont.)

• Lifestyle modifications to reduce snoring• Lose weight

• Change sleeping position

• Avoid using alcohol or medications that induce sleep

• Use nasal strips to widen the nasal passages

• Use dental devices to keep airways open

• Treatments• CPAP

• Surgery (uvulotomy)

• Laser surgery

Common Diseases and Disorders

Disease Description

Allergic

Rhinitis

Hypersensitivity reaction to various airborne

allergens

Asthma A condition in which the tubes of the bronchial

tree become obstructed due to inflammation

Atelectasis Collapsed lung

Bronchitis Inflammation of the bronchi often follows a

cold; one type of COPD

Common Diseases and Disorders (cont.)

Disease Description

Chronic Obstructive

Pulmonary Disease

(COPD)

A group of lung disorders that limit airflow

to lungs and usually cause enlargement of

the alveoli

Emphysema A chronic condition associated with

smoking that damages the alveoli; one type

of COPD

Influenza A viral disease that attacks the respiratory

system; commonly called the flu

Common Diseases and Disorders (cont.)

Disease Description

Laryngitis An acute inflammation of the larynx causing

hoarseness (dysphonia)

Legionnaire’s

Disease

Acute bacterial pneumonia caused by

Legionnaire bacteria that usually grows in the

standing water of air conditioning systems

Lung Cancer Cancer closely associated with smoking and

exposure to second-hand smoke; four types

of lung cancers

Pleural Effusion A buildup of fluid in the pleural cavity

Common Diseases and Disorders (cont.)

Disease Description

Pleuritis / Pleurisy Inflammation of the membranes that cover

the lungs, known as pleura

Pneumoconiosis Lung diseases that result from years

environmental or occupational exposure to

different types of dust; three types

Pneumonia /

Pneumonitis

An inflammation of the lungs that is most

often caused by a a bacterial, or viral, or

fungal infection

Common Diseases and Disorders (cont.)

Disease Description

Pneumothorax A collection of air in the chest around the

lungs, which may cause atelectasis

Pulmonary

Edema

A condition in which fluids fill spaces within

the lungs, making it very difficult for the

lungs to oxygenate the blood

Pulmonary

Embolism

A blood clot (embolism) that travels usually

from the legs and blocks an artery in the lungs

Common Diseases and Disorders (cont.)

Disease Description

Respiratory Distress

Syndrome (RDS)

Syndrome in which a lack of surfactant in

the lungs allows the alveoli to collapse on

exhalation, resulting in poor oxygenation

Severe Acute

Respiratory

Syndrome (SARS)

A viral respiratory disease that is very

contagious and sometimes fatal

Sinusitis An inflammation of the membranes lining

the sinuses of the skull

Common Diseases and Disorders (cont.)

Disease Description

Sudden infant death

syndrome (SIDS)

A syndrome without characteristic signs or

symptoms; usually a baby with this

disorder simply goes to sleep and never

wakes up

Tuberculosis Primarily a respiratory disease caused by

various strains of the bacterium

Mycobacterium tuberculosis

Upper Respiratory

(Tract) Infection

(URI)

Coryza, or the common cold

~Edith Wharton