3.3 Oxygen Study Guide

3.3.f. How do we measure lung capacity? 3.3.i. How do we measure oxygen capture?

Lung capacity is measured using a spirometer: It can also be used to measure oxygen content of inhalations (~20.8%) & oxygen content of exhalations (~15.3%) & the difference is oxygen capture (~5.5%)

3.3.j. What are examples of diseases or medical conditions that would affect breathing and/or oxygen capture?

Bronchitis ("inflammation of bronchi"): Bronchial tubes are inflamed, irritated membrane swells & blocks air flow [Forms of COPD (chronic obstructive pulmonary disease)] Emphysema: The alveoli are destroyed, smoking is the primary cause (can also be genetic), causes shortness of breath[The alveoli are destroyed, smoking is the primary cause (can also be genetic), causes shortness of breath] Lung cancer: There's uncontrolled growth of tissue, persistent coughing is common sign, main causes is smoking Asthma: Environmental triggers cause inflammation or tightening of bronchial tubes and/or excess mucus production, blocking air flow

3.3.h. Why might some people be more efficient at capturing oxygen than others?

Efficiency is increased by: 1) Regular cardiovascular exercise 2) Daily deep breathing 3) Avoiding cleaners, pollution & smoke 4) Eating fruits/veggies with antioxidants

3.3.l. What are the components of an effective resume?

It should be concise, targeted to the specific job & should list education, professional qualifications and relevant experiences in a reader-friendly format.

Respitory Tract

Nasal Cavity- pharynx- larynx- trachea- bronchi -bronchioles- alveoli

3.3.g. How efficient are our lungs at capturing oxygen from the air?

Normal humans use about 10% of their lung capacity at rest. 21% of the air around us is oxygen & the air we breathe out is about 15% oxygen, so we use about 25% of the oxygen in the air & expel about 75% of it.

3.3.c. How does the oxygen we inhale get to all of our cells?

Our respiratory system, found in our abdominal cavity (along with parts of the digestive, excretory, and reproductive systems) brings in oxygen. The lungs are found in the thoracic cavity, along with the heart. The diaphragm is a sheet of muscles that contracts to let us breath in and relaxes to let us exhale. The intercostal ("between ribs") muscles also help with the process. The oxygen is carried away from the alveoli by the hemoglobin in the red blood cells to capillary beds that are found in all the body tissues. The capillaries ("hairlike") are tiny vessels where arterioles ("little arteries") meet venules ("little veins") & are the place where oxygen, nutrients and hormones get dropped off & cellular waste gets picked up and carried away.

3.3.a. Why do we need oxygen?

Oxygen is needed for cell respiration & energy metabolism.

3.3.k. How does a respiratory therapist assist patients with ventilation and utilization of oxygen?

Respiratory therapists diagnose respiratory problems (see below) and council patients and provide treatment (supplemental oxygen, inhalers, removal of mucus from lungs, artificial respiration, etc)

3.3.b. How do we breathe?

We take in air through our nasal cavity. It then passes through the pharynx (along with food) and through the larynx (voice box) into the trachea (wind pipe). The trachea branches into a left and right bronchus, which enter the left and right lung, respectively. The 2 bronchi branch into smaller bronchioles, much like the branches of a tree get smaller as the extend away from the trunk. The bronchioles get smaller and smaller, ending in 300-500 alveoli (the "hollow" sites of gas exchange). The alveoli are wrapped in capillaries that carry oxygen away from the alveoli (to all the body tissues) and bring carbon dioxide to the alveoli (for removal from the body).

Total Lung Capacity (TLC):

VC + RV

3.3.d. How much air do we normally breathe in and out?

We breathe in and out 15-20x/min, ~22,000x/day. We process ~300 cubic feet (2,100-2,400 gallons) of air per day.

Minute Volume:

air breathed in one min. w/out conscious effort TV x (breaths/minute).

Tidal Volume (TV):

air breathed in/out without conscious effort

Residual Volume (RV):

air in lungs after max. exhalation

Vital Capacity (VC):

air that can be exhaled after maximal inhalation = TV + IRV + ERV

Reserve Volume (RV):

air that can be inhaled/exhaled with max. effort