Pleural Membranes & Pleural Cavity

• Visceral pleura covers lungs --- parietal pleura lines ribcage & covers upper surface of diaphragm

• Pleural cavity is potential space between ribs & lungs

Gross Anatomy of Lungs

• Base, apex (cupula), costal surface, cardiac notch• Oblique & horizontal fissure in right lung results in 3

lobes• Oblique fissure only in left lung produces 2 lobes

Trachea and Bronchial TreeWRITE THIS

BOYLE’S LAW

• Pressure vs. volume

Volume Pressure

Volume Pressure

Expiration

• Diaphragm up – relaxed – dome shaped

• Volume Pressure

• Lungs decrease in size as the air goes out

Inspiration

• Diaphragm down – flat

• Volume Pressure

• Lungs increase in size as air comes in

Respiratory Infections

• Locations of infections– upper respiratory tract is above vocal cords– lower respiratory tract is below vocal cords

Mechanics of Respiration1. External respiration – exchange of

gases between the air outside and the bloodstream

2. Internal respiration – exchange of gases between the bloodstream and cells that make up tissues – converts oxygenated to deoxygenated

a. Inspiration- the diaphragm increases volume in a superior to

inferior direction- intercostal muscles increase volume anterior to

posterior

b. Expiration - opposite

Double Blood Supply to the Lungs

• Deoxygenated blood comes from the body to the heart

• Heart pumps blood to the lungs to pick up O2

• Oxygenated blood comes back to the heart and then is pumped to the entire body including the lungs again

Oxygen Transport in the Blood

• hemoglobin carries oxygen inside red blood cells

Tracheotomy and Intubation

• Reestablishing airflow past an airway obstruction– crushing injury to larynx or chest– swelling that closes airway– vomit or foreign object

• Tracheotomy is incision in trachea below cricoid cartilage if larynx is obstructed

• Intubation is passing a tube from mouth or nose through larynx and trachea

Types of Hypoxia

• Deficiency of O2 at tissue level• Types of hypoxia

– hypoxic hypoxia--low O2 in arterial blood• high altitude, fluid in lungs & obstructions

– anemic hypoxia--too little functioning hemoglobin

• hemorrhage or anemia

– ischemic hypoxia--blood flow is too low– histotoxic hypoxia--cyanide poisoning

• blocks metabolic stages & O2 usage

Carbon Monoxide Poisoning

• Binds to heme group of hemoglobin more successfully than O2

Smokers Lowered Respiratory Efficiency

• Smoker is easily “winded” with moderate exercise– nicotine constricts terminal bronchioles– irritants in smoke cause excess mucus

secretion– irritants inhibit movements of cilia– in time destroys elastic fibers in lungs & leads

to emphysema• trapping of air in alveoli & reduced gas exchange

Effects of smoking

Asthma

• Bronchial tree constrictsSYMPTOMS: wheezing,

coughing, lips and fingers may turn light blue

WHAT BRINGS IT ON: exercise, stress, allergies, possible genetic predisposition

TREATMENT: Inhaler – releases a steroid that relaxes the smooth muscles in lungs

Medication

Chronic Obstructive Pulmonary Disease (COPD) – 3 types

1. Emphysema – enlargement of alveoli, deterioration of alveolar walls – leads to lung fibrosus: lungs get firmer, less flexible, causes labored breathing

• - ankles swell – heart not working as well, fluids pool in feet

• - may become barrel chested

2. Chronic bronchitis – inflammation of bronchi and bronchioles – constant

3. Lung cancer – cause of 1/3 of ALL cancer deaths

- 90% are smokers – low cure rate

- Difficult to control metastasis

- Most are malignant

Tuberculosis

• Can be acute or chronic - VERY contagious

• Caused by a bacteria

• Characterized by necrotic tissue (dead tissue)

Cystic Fibrosis

• Genetic disease - found a lot in children

• Accounts for 5% of childhood deaths

• Characterized by thick, sticky mucous build-up in the lungs and the pancreas

• Have isolated the gene for CF