Respiratory System • Breath in oxygen and

supply to the blood• Expel carbon dioxide

(waste product of cellular respiration) into the atmosphere

• Filter, moisten, warm the air during inhalation/exhalation

Upper Respiratory Tract• Nasal Cavity

– Hollow space behind the nose – Lined with mucus to trap foreign

particles• Pharynx (Throat)

– Air and food pass through – Conducts air towards the larynx and

food towards the esophagus• Epiglottis

– Flap of tissue that covers the entrance to larynx

• Larynx (voice box)– Contains two bands of tissue called

the vocal cords • Trachea (windpipe)

– Made of cartilaginous rings– Lined with cilia, secrete mucus

Lower Respiratory Tract• Lungs

– Right/Left– Right has three lobes– Left has two lobes

• Bronchi– Two tubes that branch from

the trachea – Lead into the lungs

• Bronchioles – Smaller tubes branch from

bronchi– Connect to the alveoli

• Alveoli– Air sacs within the lungs

where gas exchange occurs

Gas Exchange • Difference in Concentration

Gradient– Inhaled air has greater

concentration of O₂– Deoxygenated blood in body

has greater concentration of CO₂

• Diffusion of O₂/CO₂ across membrane happens simultaneously

• Occurs in Alveoli and somatic cells

• Surfactant – Lowers surface tension in alveoli

Breathing• Involves changes of

pressure in lungs • Inhalation

– Diaphragm and rib muscles contract

– Chest cavity expands – Air pressure decreases – Lungs expand

• Exhalation – Diaphragm and rib

muscles relax – Chest cavity contracts – Air pressure increases – Lungs contract

Dyspnea• Shortness of breath (SOB)• Causes (85% of cases)– Asthma, pneumonia, cardiac ischemia, interstitial

lung disease, congestive heart failure, chronic obstructive pulmonary disease

Asthma • Chronic inflammatory

disease of the airways • Symptoms– Wheezing, coughing,

chest tightness, shortness of breath

• Causes – Genetics, pollution,

smoking, allergies • Treatment (Albuterol)– Puffer, pill, syrup

Chronic Obstructive Pulmonary Disease (COPD)• Persistently poor airflow as a

result of breakdown of lung tissue • Emphysema

– Damage to alveoli• Chronic Bronchitis

– Inflammation of bronchi, airways become narrow and clogged with mucus

• Causes – Smoking, occupation, air pollution

• Treatment – No cure– Steroids, anti-inflammatory drugs,

oxygen therapy, quit smoking

Diagnostic Test For Respiratory Health• Chest X-ray

– Uses x-ray radiation to form images of bones, tumors, TB inside the chest

– Lung cancer, pneumonia, TB• MRI

– Uses magnetic fields to form cross-section images of bones and soft tissues

– Blood clot in lungs, lung cancer, cystic fibrosis

• Sputum Test – Used to test mucus from the lungs

and bronchi for bacteria and other microbes

– TB, pneumonia

Diagnostic Test For Respiratory Health• Arterial Blood Gas Test– Test blood sample for oxygen

and carbon dioxide concentrations

– Asthma, cystic fibrosis• Stethoscope– Amplify and listen to lung

sounds while person breathes • Pulmonary function test– Measures amount of air moving

in and out of lungs during different types of breathing

– Asthma, bronchitis, emphysema