The Respiratory System

Medical TerminologyChapter 7

Functions of the Respiratory System

• Bring oxygen-rich air into the body for delivery to the blood cells

• Expel waste products (carbon dioxide and water) that have been returned to the lungs by the blood.

• Produce the air flow through the larynx that makes speech happen.

Word Parts

• nas/o, rhin/o = nose• sinus/o = sinuses• epiglott/o = epiglottis• pharyng/o = pharynx (throat)• laryng/o = larynx (voice box /

vocal cords)

• trache/o = trachea• bronch/o, bronchi/o = bronchi• alveol/o = alveoli• pneum/o, pneumon/o,

pulmon/o = lungs• thorac/o, -thorax = chest• -ectasis = stretching, opening• -pnea = breathing• Ox/o = oxygen

Structures of the Respiratory System

• Upper Respiratory Tract consists of the nose, mouth, pharynx, epiglottis, larynx and trachea.

• Lower Respiratory Tract consists of the bronchial tree and the lungs. These structures are protected by the thoracic cavity.

Sinuses

• A sinus is an air-filled cavity within a bone, and it is lined with mucous membrane.

• They make the skull lighter, help produce sound by giving resonance to the voice, and produce mucus that drains into the nasal cavity.

• There are four sinuses in the bones of the skull, called the paranasal sinuses. (para- = near, nas = nose, -al = pertaining to).

• Air enters the body through the nose and passes through the nasal cavity.

• Then, the air reaches the pharynx which has 3 divisions:

• nasopharynx• oropharynx – part you can see• laryngopharynx

Protective Swallowing Mechanisms

• Two mechanisms act automatically during swallowing to ensure that only air goes into the lungs.

• The soft palate, the posterior part of the roof of the mouth, moves up and backward to prevent food from going up into the nose.

• At the same time, the epiglottis, which is a lid-like structure at the base of the tongue, swings downward and closes off the laryngopharynx so food does not enter the trachea or the lungs.

The Larynx (laryng/o)

• The “voice box” – located between the pharynx and the trachea

• Protected & held open by a series of 9 separate cartilages. The thyroid cartilage is the largest. Its prominent projection is commonly known as the Adam’s apple.

• The larynx contains the vocal cords

• During breathing, the cords are separated to let air pass.

• During speech, they are together, and sound is produced as air is expelled from the lungs, causing the cords to vibrate against each other and make your voice noise.

• Air passes from the larynx into the trachea, also known as the windpipe.

• It is held open by a series of C-shaped cartilage rings.

• The trachea divides into two branches called bronchi (singular = bronchus).

• Within the lung, the bronchus divides and subdivides into smaller branches called bronchioles.

• Because of the similarity of these branching structures to a tree, this is referred to as the bronchial tree.

• Alveoli, also known as air sacs, are small grapelike clusters found at the end of each bronchiole.

• The thin alveoli walls are surrounded by microscopic pulmonary capillaries.

• This is where the gas exchange occurs.

The Lungs• A lobe is a division of the

lungs.• The right lung has three lobes,

the superior, middle and inferior.

• The left lung has two lobes, the superior and the inferior.

• The mediastinum is the space between the lungs.

Pleura• The pleura is a membrane that

surrounds each lung.• The parietal pleura is the outer

layer of the pleura; forms the sac containing each lung.

• The visceral pleura is the inner layere of the pleura. It closely surrounds the lung tissue.

• The pleural space, also known as the pleural cavity, is the airtight space between the folds of the pleural membrane.

• It contains a watery lubricating fluid that prevents friction when the membranes rub together during respiration.

The Diaphragm (phren/o)• The diaphragm is the muscle

separating the thoracic and abdominal cavities.

• When this contracts & relaxes, breathing is possible.

• The phrenic nerve stimulates the diaphragm and causes it to contract.

Respiration• This is the exchange of gases

essential to life.• This occurs in the lungs as

external respiration and in the cells as internal respiration.

• Inhalation – breathing in• Exhalation – breathing out

• As air is inhaled into the alveoli, oxygen passes into the surrounding capillaries and is carried by the RBCs to all body cells.

• At the same time, the waste product carbon dioxide passes from the capillaries into the airspaces of the lungs to be exhaled.

• Internal respiration is the exchange of gases within the cells of all body organs and tissues.

• Oxygen (O2) passes from the bloodstream into the tissue cells, and carbon dioxide passes from the tissue cells into the bloodstream.

Terminology Practice• Allergic rhinitis – inflammation

of the nose due to an allergy; increased flow of mucus.

• Rhinorrhea - runny nose• Sinusitis – inflammation of

sinuses• Pharyngitis – inflammation of

the pharynx; aka sore throat.

• pharyngorrhagia – bleeding from pharynx

• laryngoplegia – paralysis of the larynx

• laryngospasm – sudden spasmodic closure of the larynx

• laryngitis – inflammation of the larynx; usually causes voice loss

• tracheitis – inflammation of trachea

• tracheorrhagia – bleeding from trachea

• bronchitis – inflammation of the bronchi

• bronchorrhea – excessive discharge of mucus from the bronchi

• pleuralgia – pain in the pleura or side

• pneumorrhagia – bleeding from lungs

• pneumonia – condition of having inflammation of lungs with pus and other liquids in the alveoli.

• tachypnea – fast breathing (>20)

• bradypnea – slow breathing (<10)

• apnea – absence of breathing• dyspnea – difficulty breathing

• hyper/pnea – abnormal increase in depth & rate of breathing.

• hypo/pnea – shallow or slow respiration

• hyperventilation – abnormally rapid deep breathing.

• pharyngoplasty – surgical repair of the pharynx

• laryngotomy – incision into larynx

• tracheostomy – creation of a new opening into the trachea; a tube is inserted which may be temporary or permanent.

• lobectomy – surgical removal of a lobe of the lung

• thoracentesis – puncture of chest wall to obtain fluid from the pleural cavity.

Pathology of the Respiratory System

• Chronic Obstructive Pulmonary Disease (COPD): a general term used to describe respiratory conditions characterized by chronic airflow limitations.

• Asthma – a chronic, allergic disorder characterized by episodes of severe breathing difficulty, coughing, wheezing.

• Dyspnea can be caused by:• swelling / inflammation of

lining of the airways• production of thick mucus• tightening of muscles around

airways

• Bronchi/ectasis : chronic dilation (enlargement, stretching) of bronchi or bronchioles from an earlier lung infection that was not cured.

• Emphysema – progressive loss of lung function due to a decrease in the total number of alveoli, the enlargement of the remaining alveoli, and then the progressive destruction of their walls.

• Breathing becomes more rapid, shallow, and difficult.

• In an effort to compensate for the

• loss of capacity, the lungs expand and the chest assumes an enlarged barrel shape as air is trapped in the airways.

• Prevention of emphysema – stop smoking.

• Epistaxis – nosebleed. Usually from an injury, excessive use of blood thinners, or bleeding disorders.

• Sit straight up, tilt head slightly forward, pinch your nose for 10 minutes.

• May apply an ice pack.

• Pneumothorax – an accumulation of air or gas in the pleural space, causing the lung to collapse.

• Hemothorax – accumulation of blood in the pleural cavity.

• Pleural effusion – abnormal escape of fluid into the pleural cavity that prevents the lung from fully expanding.

• Atelectasis – also known as a “collapsed lung”

• It is a condition in which the lung fails to expand because air cannot pass beyond the bronchioles that are blocked by secretions.

Types of Pneumonia• Bacterial – commonly caused

by streptococcus pneumonia – only type of pneumonia that can be prevented by a vaccination.

• Viral – approx. ½ of all pneumonias

• Lobar - affects one or more lobes

• Double – involves both lungs

• Aspiration – may occur when a foreign substance, such as vomit or food, is inhaled into the lungs.

• Mycoplasma – also known as “walking pneumonia”. Is a milder but longer lasting form, caused by the fungus mycoplasma.

Lack of Oxygen

• Anoxia – the absence or almost complete absence of oxygen from inspired gases, arterial blood or tissues. (ox/o = oxygen).

• If it occurs for more than 4-6 minutes, irreversible brain damage may occur.

• Asphyxia – the pathologic changes caused by a lack of oxygen in air that is breathed in. It causes anoxia and hypoxia.

• Asphyxiation – suffocation. An interruption of breathing resulting in the loss of consciousness or death. Drowning, smothering, choking, inhaling carbon dioxide.

• Cyanosis – a bluish discoloration of the skin caused by a lack of adequate oxygen. (cyan/o = blue, -osis = a condition of.)

• Hypoxia – the condition of having subnormal oxygen levels in the cells.

Respiratory secretions

• Phlegm – the thick mucus secreted by tissues lining the respiratory passages.

• Sputum – phlegm that is ejected (coughed up) through the mouth. May be used for diagnostic purposes.