Chapter 13The Respiratory System

Pathology

Homeostatic Imbalance

· Rhinitis: inflammation of the nasal mucosa· Caused by cold viruses and various allergens

· Excessive mucus produced results in nasal congestion and postnasal drip

· Nasal cavity infections often extend to nasolacrimal ducts and paranasal sinuses

· Sinusitis: sinus inflammation· Can cause marked changes in voice quality

Tracheal Obstruction· Life-threatening because trachea is the only way

air can enter the lungs

· Can suffocate if choke on a piece of food

· Heimlich maneuver is a procedure in which the air in a person’s own lungs is used to “pop out” an obstructing piece of food

· Cracked ribs are a possibility if done incorrectly

· Sometimes an emergency tracheostomy (surgical opening of the trachea) is done to provide an alternate route for air to reach the lungs

Homeostatic ImbalancesHypoxia: inadequate oxygen delivery to body tissues (become cyanotic)

– Carbon monoxide poisoning: a type of hypoxia where carbon monoxide competes with oxygen for the same binding sites on hemoglobin; victim becomes confused and has a throbbing headache and then dies

Slide 13.4b

Cleft Palate· Genetic defect· Failure of the bones forming the palate (hard

and sometimes soft) to fuse medially· Results in breathing, chewing, speaking

difficulties

Cleft of hard and softpalate

Cleft Lip· Genetic defect· Failure of the tissue

of upper lip to fuse

Developmental Aspects of the Respiratory System· Important birth defects

· Cystic fibrosis – oversecretion of thick mucus clogs the respiratory system

· Cleft palate

X-Ray of cystic fibrosis

Sudden Infant Death syndrome (SIDS)

· Apparently healthy infant stops breathing and dies during sleep

· Some cases are thought to be a problem of the neural respiratory control center

· One third of cases appear to be due to heart rhythm abnormalities

Asthma· Chronic inflamed hypersensitive

bronchiole passages

· Response to irritants with dyspnea, coughing, and wheezing

Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD)· Exemplified by chronic bronchitis and

emphysema

· Major causes of death and disability in the United States

Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD)· Features of these diseases

· Patients almost always have a history of smoking

· Labored breathing (dyspnea) (“air hunger”) becomes progressively more severe

· Coughing and frequent pulmonary infections are common

· Most victims retain carbon dioxide, are hypoxic, and have respiratory acidosis

· Those infected will ultimately develop respiratory failure

Emphysema· Alveoli enlarge as adjacent chambers break

through· Chronic inflammation promotes lung fibrosis

(less elastic)· Airways collapse during expiration· Patients use a large amount of energy to

exhale· Overinflation of the lungs leads to a

permanently expanded barrel chest· Cyanosis appears late in the disease (“pink

puffers”)

Chronic Bronchitis· Mucosa of the lower respiratory

passages becomes severely inflamed· Mucus production increases· Pooled mucus impairs ventilation and

gas exchange· Risk of lung infection increases· Pneumonia is common· Hypoxia and cyanosis occur early (“blue

bloaters”)

Chronic Obstructive Pulmonary Disease (COPD)

Lung Cancer

· Accounts for 1/3 of all cancer deaths in the United States

· Increased incidence associated with smoking

· Three common types· Squamous cell carcinoma· Adenocarcinoma· Small cell carcinoma

Causes and Symptoms ofLung Cancer

• Causes: tuberculosis, air pollution from motor vehicles, factories, etc. The most common cause is due to cigarette smoking,

• About 15% of all lung cancer cases are small cell lung cancer. Small cell lung cancer is slightly more common in men than women, and is the most aggressive form of lung cancer.

• Symptoms: bloody sputum, chest pain, cough, loss of appetite, shortness of breath, weight loss, wheezing, facial swelling difficulty, and weakness.

Could Lung Cancer Cause Death?

• Lung cancer is a cause of death. The lungs fail to have the ability to exchange gasses properly, which will lead to death either due to a lack of oxygen or a build up of C02. The ventilator or intercostal muscles can fail to contract or the alveoli tissues are so damaged they can no longer perform normal gas exchange.