Module 5

Question 1

The respiratory system can be divided into what 2 structures

Answer 1

Conducting airways, respiratory tissues

Question 2

What’s included in conducting airways

Answer 2

nasal passages, mouth and pharynx, larynx, trachea, bronchi, bronchioles

Question 3

What’s included in respiratory tissues

Answer 3

lungs, respiratory bronchioles, alveolar ducts and sacs (gas exchange)

Question 4

What are the levels of branching

Answer 4

Trachea, bronchi, bronchioles, alveoli

Question 5

Where is the site of gas exchange?

Answer 5

Alveoli

Question 6

What cells are in the alveolar epithelium?

Answer 6

Type 1 and II alveolar cells
(thin squamous; cuboidal, surfactant), macrophages

Question 7

Describe what happens during inspiration

Answer 7

Inspiration: respiratory muscles expand thoracic cavity which reduces internal pressure allowing environmental air to enter lungs

Question 8

Describe what happens during expiration

Answer 8

Expiration: respiratory muscles relax, thoracic cavity retracts which increases internal pressure allowing air to move from lungs to area of lower pressure

Question 9

What occurs with the diaphragm during inspiration and expiration?

Answer 9

The diaphragm is the main muscle of inspiration. When the diaphragm contracts (inspiration), the chest expands. Upon expiration, the chest cavity decreases and pressure inside increases.

Question 10

What is lung compliance? What factors affect it?

Answer 10

Ease of lung inflation, reliant on water content, elastin, collagen, and surface tension that makes it easier for air to expand a compliant lung.

Question 11

lung volumes

Answer 11

refers to the amount of air exchanged from a single event during ventilation; tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume

Question 12

Tidal volume

Answer 12

normal volume of air inhaled with each breath, 500mL

Question 13

Inspiratory reserve volume

Answer 13

amount of air that can be forcibly inspired after taking in normal breath, 3100mL

Question 14

Expiratory reserve volume

Answer 14

amount of air that can be forcibly exhaled after letting out normal breath, 1200mL

Question 15

residual volume

Answer 15

air remaining in lung after forced expiration, 1200mL

Question 16

Lung capacities

Answer 16

Calculated using lung volumes; vital capacity, inspiratory capacity, functional residual capacity, total lung capacity

Question 17

Vital capacity

Answer 17

amount of air exhaled following max inhalation, 4800mL

Question 18

Inspiratory capacity

Answer 18

max amount of air inhaled following normal expiration, 3600mL

Question 19

Functional residual capacity

Answer 19

amount of air remaining in lungs after normal expiration, 2400mL

Question 20

Total lung capacity

Answer 20

Sum of all lung volumes, 6000mL

Question 21

Pulmonary function tests

Answer 21

Look at pulmonary flow rates in relation to time; max voluntary ventilation, forced vital capacity, forced expiratory volume, forced inspiratory vital flow

Question 22

Max. voluntary ventilation

Answer 22

measures volume of air a person can move into and out of lungs during max effort lasting 12-15”, L to min

Question 23

Forced vital capacity

Answer 23

volume of air quickly and forcefully exhaled following full inspiration; lower in obstructive disease

Question 24

Force expiratory volume

Answer 24

measures expiratory volume in a given time; useful in Dx obstructive lung disorders

Question 25

Forced inspiratory vital flow

Answer 25

measures respiratory response during rapid max inspiration

Question 26

ventilation

Answer 26

movement/flow of gases in and out of lungs

Question 27

Perfusion

Answer 27

low of blood to pulmonary capillaries for gas exchange

Question 28

Diffusion

Answer 28

movement of gases between alveolar and pulmonary capillaries

Question 29

Shunt

Answer 29

formed when blood moves from pulmonary circulation to systemic circulation without oxygenation. Anatomic-blood moves from venous to arterial side without moving through lungs. Physiologic shunt blood moves through unventilated parts of lung creating mismatch of ventilation and perfusion

Question 30

Dead air space

Answer 30

ventilation without perfusion, resulting in high ventilation-perfusion ratio

Question 31

oxyhemoglobin

Answer 31

Hemoglobin bound to oxygen

Question 32

affinity

Answer 32

Ability of hemoglobin molecule to bind to oxygen, up to four O2 molecules to become saturated

Question 33

How is carbon dioxide transported in the blood?

Answer 33

dissolved in blood, attached to hemoglobin, and as bicarbonate

Question 34

How is breathing controlled?

Answer 34

The automatic regulation is controlled by both chemoreceptors and lung receptors. Chemoreceptors monitor blood levels of oxygen, carbon dioxide, and pH and adjusts ventilation accordingly. Lung receptors monitor breathing patterns and lung function.

Question 35

What are the characteristics of COPD?

Answer 35

Inflammation and fibrosis of bronchial wall which causes overproduction of mucus and less elasticity of lung tissue. The obstruction of airflow leads to a mismatch in ventilation between ventilation and perfusion which alters the gas exchange at the alveolar level due to decreased surface area.

Question 36

What is the leading risk factor for COPD?

Answer 36

Smoking

Question 37

Emphysema

Answer 37

decreased lung elasticity, enlarged airspaces distal to terminal bronchioles, destruction of alveolar walls and capillary beds; hyperinflation of lungs, increased TLC. Main causes smoking and ATT def.

Question 38

Bronchitis

Answer 38

Hypersecretion of mucus in large airways, hypertrophy of submucosal glands in trachea and bronchi. Chronic irritation from smoking, recurrent infections.CO

Question 39

COPD

Answer 39

Airflow obstruction, inflammation and fibrosis of bronchial wall, hypertrophy of submucosal glands, overproduction of mucus. Loss of elasticity of lung fibers and alveolar tissue, mismatch in vent. and perfusion, lower surface area for gas exchange

Question 40

COPD Dx and Tx

Answer 40

H&P, PFTs, chest exray, FVC prolonged and decreased, FEV decreased. Stop smoking, avoid RT infections, vaccines, pulmonary rehab. Inhaled bronchodilators, corticosteroids, O2 therapy to keep sats above 90%.

Question 41

What are the characteristics of asthma?

Answer 41

Airway obstruction, bronchial hyperresponsiveness, airway inflammation (latter two promoted by IgE), sometimes airway remodeling

Question 42

What is atopy?

Answer 42

Genetic predisposition for development of IgE mediated hypersensitive reactions as a response to environmental allergens

Question 43

Asthma risk, pathology, presentation, Dx, Tx

Answer 43

Family Hx, allergies, antenatal exposure to smoke and pollution, GERD, exercise, cold air, AA or Puerto Rican. Inflammatory actions occur in bronchi where no infection, toxins etc exist, causing airflow obstruction (inflammation, hyperresponsiveness, then obstruction). Smooth muscle contraction, increase in inflammatory cells and cytokines which cause epi. injury. Sx wheezing, accessory muscle usage, distant breath sounds, SOB, anxiety. Dx PFTs, H&P. Tx avoid triggers, use of bronchodilators like albuterol or advair.

Question 44

What is pneumothorax?

Answer 44

Pneumothorax is the presence of air in the pleural space that causes partial or complete collapse of the affected lung. Dx by chest xray or CT scan, pulse ox, ABGs. Sx chest pain, increased resp. rate, SOB, decreased/absent breath sounds.

Question 45

Spontaneous pneumothorax

Answer 45

rupture of alveolus or air-filled bleb/blister on surface of lung, difference in pleural pressure from top to bottom of lung in taller people that creates blebs. Seen also in people with emphysema.

Question 46

Traumatic pneumothorax

Answer 46

penetrating chest would or rib fracture puncturing lung. Hemothorax present too. Caused by needle aspirations, central line insertion, intubation, positive pressure vent, CPR

Question 47

Tension pneumothorax

Answer 47

Air enters pleural space but can't exit, collapses lung which compresses mediastinal structures and shifts them to unaffected side. HR increases, CO decreased, jugular neck vein distention, subcu. emphysema, shock, hypoxemia. Treated with large bore needle or chest tube inserted into affected side with drainage or suction.

Question 48

What is atelectasis?

Answer 48

Atelectasis is an incomplete expansion of a lung, or portion of lung, caused by airway obstruction or lung compression.

Question 49

Atelectasis pathology etc

Answer 49

mucous plug in airway, compression by fluid, tumor, exudate, any obstruction. Risk increases after surgery. Tachypnea, tachycardia, dyspnea, cyanosis, hypoxemia, decreased chest expansion, decreased breath sounds, intercostal retractions. Mediastinum may shift away from affected lung. Dx chest xray/ct scan, Tx reduce obstruction/compression, reinflate collapsed area, O2, ambulation, deep breathing, body positioning.

Question 50

What type of substance causes a pulmonary embolism?

Answer 50

thrombus, air accidentally injected into an intravenous infusion, fat from the bone marrow after a fracture or trauma, or amniotic fluid that enters the maternal circulation after rupture of membranes.

Question 51

PE pathology etc

Answer 51

Virchow triad-venous stasis, endothelial injury, hypercoag states. Chest pain, SOB, cough, increased resp rate, hypoxemia, death. Dx H&P, ABGs, venous thrombosis studies, troponin, D dimer, lung scan, ECG, helical chest CT scan. Ultrasonography to locate cause. Tx anticoags (lovenox) or thrombolytic therapy. Increase mobility.

Question 52

What causes ARDs

Answer 52

aspiration, drugs/toxins (cocaine, heroin, smoke, high concentrations of O2, radiation), infection, trauma/shock (burns, fat emboli, chest trauma), DIC, multiple blood transfusions

Question 53

ARDs patho

Answer 53

Epi cell injury with increased permeability of alveolar capillary membrane resistant to gas exchange. Lung stiffens, SOB, shunting of blood, impaired gas exchange, hypoxemia, alveolar collapse from inactivated surfactant, fibrosis. Resp. distress, increased RR, resp. failure, hypoxemia, organ failure. Dx chest xray shows diffuse bilateral infiltrates (white out), normal card. Fx. Tx O2, vent support until lungs heal.

Question 54

Causes and manifestations of respiratory acidosis

Answer 54

Depression of respiratory system (drugs, head injury), lung disease (COPD, asthma, pneumonia), obstruction/disorder of muscles (paralysis of resp. muscles, chest injury, extreme obesity, paralytic drugs), breathing high CO2. pH decreased, PCO2 and HCO3 increased, depressed neural Fx, headache, weakness, confusion, hallucinations, tremors, paralysis, coma, skin warm and flushed, acidic urine

Question 55

Respiratory acidosis patho

Answer 55

Don't supplement with too much O2 if on O2 therapy, may suppress resp. drive. Sx of hypoxemia, vasodilation from CO2 crossing BBB. Dx with pH below 7.35, PCO2 >45mmHg. Tx improve ventilation, sometimes mech. vent.