Respiratory System

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Structure and Function

The respiratory system performs two major tasks:

•Exchanging air between the body and the outside environment known as external respiration

•Bringing oxygen to the cells and removing carbon dioxide from them referred to as internal respiration

The Pathway of Oxygen to the Internal Cell• Mouth and nose• Pharynx (throat)• Larynx (voice box)• Trachea (windpipe)• Bronchi• Bronchioles• Alveoli (air sacs)

The Structure and Function of the Nose• The nose is a cavity that is divided by a wall of cartilage called

the septum.• The structures inside the nose warm and filter the air.• Cilia (hairs that warm the air)• Mucous membranes (trap dust and bacteria)

The Structure and Function of the Pharynx• Also called the throat• Passageway for food and air• Connects the mouth to the larynx

The Structure and Function of the Epiglottis• Lid on the top of the larynx• When food is swallowed, the lid closes so that food is directed

down the esophagus and not into the lungs.• Air passes over the open epiglottis and enters the larynx.

Larynx, Trachea, and Bronchi

The Structure and Function of the Larynx• Also called the voice

box• A tube made up of

nine separate cartilages to maintain openness• Lined with mucous

membranes that form two folds called the vocal cords

The Structure and Function of the Trachea• Also called the windpipe• Held open by C-shaped rings of cartilage• The wall between the rings is elastic to adjust for body

positions.• Above the middle of the sternum, the trachea divides into two

sections called bronchi.

The Structure and Function of the Bronchus and Bronchiole• The bronchus connects the trachea to the lungs.• Once inside the lungs, the bronchus divides and divides again

to become microscopic bronchioles that act as tiny air passageways.

The Structure and Function of the Alveolus• Also called the air

sacs• Clusters of capillaries

located at the ends of each bronchiole• The body contains

approximately 500 million alveoli

The Diaphragm and the Brain and How They Relate to Breathing• The main muscle of respiration is called the diaphragm.• When the diaphragm contracts, it produces a vacuum that

causes air to be drawn in.• When the diaphragm relaxes, air is forced out of the lungs.

Occurrences That Alter Breathing• Coughing• Deep breaths followed by forceful exhalation that can clear

mucus from the lower respiratory tract• Hiccoughs• Caused by spasm of the diaphragm, possibly the result of an

irritation to the diaphragm

Occurrences That Alter Breathing• Sneezing– Air is forced through the nose to clear the upper respiratory

structures• Yawning– Deep, prolonged breath that can be caused by a drop in oxygen

levels• Crying– A change in the breathing pattern that is in response to emotions

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Diagnostic, Procedural & Laboratory Tests

Methods Used to Diagnose Respiratory Disorders:

•Auscultation (stethoscope)

•Assessing respiratory rate

•Percussion

•Sputum analysis

Normal Adult respiratory rate is 15 to 20 respirations per minute.

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Pulmonary Function TestsPulmonary function tests measure the mechanics of breathing.

Peak flow meter•measures the capacity for breathing

Spirometer•a pulmonary function testing machine that measures the lungs volume and capacity

Forced Vital Capacity

Highest breathing capacity following the deepest breath

Forced Expiratory Volume

Shows breathing capacity at different parts of the respiratory cycle

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Abnormalities/Masses

Abnormalities such as masses and restricted blood flow within the lungs can be detected via:

•Chest x-rays•MRI•Lung scans Structures of the

respiratory system can be observed via:•Endoscopy •Bronchoscopy

Bronchoscopy and Chest X-Ray• Bronchoscopy• A tube is inserted into the trachea to view the airways or to

remove a foreign body• Chest x-rays• Studies that tell the general health of the lungs and surrounding

tissue

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Laboratory Tests Laboratory Tests

•Throat Cultures

•Sputum Sample

•Arterial Blood Gases

•Sweat Test

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Pathology

Inflammatory

Conditions

adenoiditisbronchitis

epiglottitis

laryngitis

laryngotracheobronchitis

pharyngitis

rhinitis pneumonitis

sinusitistonsillitis

Atelectasis and Bronchitis• Atelectasis• Lack of air in the lungs resulting from collapse of the alveolus

• Bronchitis• Acute or chronic disease that results in inflammation of the

bronchial walls and narrowing of the airways

Chronic Obstructive Pulmonary Disease (COPD)

• A chronic condition that is usually the result of a combination of respiratory disorders

• A progressive disease that causes dyspnea, respiratory failure, and death

Emphysema and Epistaxis• Emphysema• Irreversible enlargement of the air spaces in the lungs caused by

destruction of the alveolar walls• Results in the inability to exchange oxygen and carbon dioxide

• Epistaxis• Nosebleeds

Laryngitis and Pleurisy• Laryngitis• Acute or chronic inflammation of the vocal cords

• Pleurisy• Inflammation of the pleura that results as a complication of

infections, pneumonia, tuberculosis, or injury

Paroxysmal Nocturnal Dyspnea• Associated with chronic lung disease or left ventricular heart

failure• Individuals awaken at night with a sensation of suffocation

that is probably caused by an accumulation of fluid in the lungs

Pneumonia and Pneumothorax• Pneumonia• Acute infection of the lung tissues• The leading cause of death among patients already in a

weakened state• Pneumothorax• Air or gas that has accumulated between the two pleural layers,

causing collapse of the lung tissue

Tuberculosis• Acute or chronic bacterial lung infection that is highly

contagious• The body reacts to the bacteria by converting destroyed tissue

into a cheeselike material that can develop into fiber optic obstruction of the lung cavities.

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Upper Respiratory InfectionUpper respiratory infection is a term that covers an infection of some or all of the respiratory tract.

Other Conditions:

•Croup•Diptheria

•Epistaxis•Rhinorrhea

•Pertussis

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Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is a term for any disease with chronic obstruction of the bronchial tubes and lungs such as:

•Emphysema•Chronic Bronchitis

Asthma causes narrowing of the bronchi leading to dyspnea, wheezing and coughing.

Normal bronchiole

Asthmatic bronchiole, showing constriction

Allergic Rhinitis and Asthma• Allergic rhinitis• A reaction of the eyes, nose, and sinuses to airborne allergens

• Asthma• A chronic disorder that causes swelling, inflammation, and

constriction of the bronchi and bronchioles• Can be caused by exposure to allergens

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HemoptysisHemoptysis

Lung or bronchial hemorrhage that results in the spitting of blood.

Cystic Fibrosis

Disease of the exocrine glands that causes secretion of abnormally thick mucus which leads to chronic obstruction.

AtelectasisCollapsed alveoli leading to collapse of a lung or part of a lung.

Pneumonia

Acute infection of the alveoli.

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Environmental ConditionsConditions caused by environmental agents

Pneumoconiosis•Caused by dust in the lungs

Anthracosis•Caused by coal dust

Asbestosis•Caused by asbestos particles released during construction of ships and buildings

Silicosis•Caused by the silica dust from grinding rocks or glass

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OtorhinolaryngologistsOtorhinolaryngologists are physicians that specialize in disorders of the upper respiratory tract.

Surgical Removal Conditions

•Tonsillectomy •Laryngectomy

•Lobectomy

•Adenoidectomy •Pneumonectomy

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Surgical IncisionsSurgical Incisions

Tracheostomy tube

•Laryngotracheotomy

•Sinusotomy

•Thoracotomy

•Tracheotomy

•Endotracheal intubation is the insertion of a tube through the nose or mouth, pharynx, larynx and into the trachea to establish an airway.

Respiratory Distress Syndrome• Can kill infants between the ages of birth and 8 months of age• Normal breathing becomes rapid and shallow.• The nostrils flare and the sternum retracts.• The infant “grunts.”

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Pharmacology

Antibiotics, antihistamines and anticoagulants are used for respiratory disorders just as with other system disorders.

Medications specific to Respiratory Conditions:

Bronchodilators•Dilate the bronchial walls

Expectorants

•Promote coughing and expulsion of mucus

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Mechanical DevicesMechanical Devices that aid in Respiration

Ventilators•Actually serve as a breathing substitute for patients who can not breathe on their own.

Nebulizers

•Deliver medication through the mouth or nose to ease breathing problems

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Agents to Treat Respiratory Conditions Agents Used to Treat Respiratory Conditions

Antitussive

Decongestants

Expectorants(relieves coughing)

(decreases and prevents mucus buildup)

(promotes coughing and expelling of mucus)