Day 2 - Respiratory

Question 1

What are the 3 types of alveolar cells and their function?

Answer 1

Type 1 - The inside layer of alveolus
* Allows gas exchange!!

Type 2 - Creates type 1 cells & surfactant
* requires constant oxygen supply

Type 3 - Macrophages - protects / defends alveolar

Question 2

What is surfactant?

Answer 2

Keeps alveoli open by decreasing surface tension / repelling water

lube

Question 3

Differentiate upper and lower respiratory systems

Answer 3

Upper - above larynx
* conditions air from upper to lower
* warms, dehumidifies , filters

Lower - anything in chest cavity
* 2 pleural cavities and 1 mediastinal
* gas exchange through alveoli
* air distribution

Question 4

What organs are included in the URS?

What are the functions?

Answer 4

Pharynx
* passageway for food and air
* aids in speech

Larynx
* voice box
* true and false vocal cords
* stops objects from entering trachea

Epiglottis
* opens during inhalation to allow air through
* closes to prevent food from entering LRS

Question 5

What does the pharynx consist of?

Answer 5

1. Nasopharynx
2. Oropharynx
3. Laryngopharyx

Question 6

Why are there two vocal cords? What is this structure called?

Answer 6

Larynx - Passageway for air
Houses vocal cords
* true - produce sound
* false - lubricate and protect

Question 7

What is the LRS composed of?

What are their functions?

Answer 7

Trachea
Broncial tree
Lungs
Pleural cavity
* between parietal / visceral pleura
* fluid for lubrication

Question 8

What is and in the mediastinal cavity?

Answer 8

Below and between lungs
* Esophagus
* Trachea
* Heart
* Large blood vessels / lymphatic vessels

Question 9

What are the 2 primary blood flow systems that supply structures of the pulmonary system?

Answer 9

Broncial arteries
* carry oxygenated blood
* supplies trachea, bronchi, lymph nodes, outer layers of pulmonary artery and vein

Pulmonary arteries
* carry deoxygenated blood
* supplies alveoli and bronchioles

Question 10

Whats the role of the brain stem, ANS, and phrenic nerve in the regulation of breathing?

Answer 10

Brain stem
* Medulla and pons regulate rate and rhythm.
* They work with stretch receptors to prevent overinflation

ANS
* the bronchial muscle responds by contricting (PSNS) or dilating (SNS) to meet oxygen demands

Phrenic nerve
* stimulates the diaphragm to contract

Question 11

What are the muscles of ventilation?

Explain their actions

Answer 11

For Inspiration
* Diaphragm
* External intercoastal muscles

For expiration
* Intercostal muscles
* Abdominal wall muscles

Accessory muscles

Question 12

How do peripheral and central chemoreceptors assist in the regulation of breathing?

Answer 12

Central - brain / medulla
* 1st response to changes in CO2, sensative
* increase resp. rate and depth to blow off CO2

Peripheral - aorta / carotid arteries
* mainly responds to pO2 changes (hypoxic)
* 2nd to larger CO2 changes
* increase resp. rate to bring in more O2

Question 13

Explain the intrathoracic pressure changes for inspiration and expiration

Answer 13

Inspiration
* inside lung has negative pressure to drive air in, outside positive

Expiration
* inside has positive pressure to push air out, outside negative

Question 14

What makes up the respiratory unit?

Question 15

What is hydrostatic pressure, colloid oncotic pressure and capillary membrane permeability?

Explain their significance to gas exchange.

Answer 15

Colloidal oncotic pressure - attracts water into capillary to keep interstitium dry
* albumin related issues
* liver disease ^

Hydrostatic pressure - forces fluid out of capillary into interstitium
* opposite of oncotic
* Hypovolemic causes
* ^ shock, edema

Capillary wall permeability - keep water, plasma proteins, RBC etc. in the capillary
* infection

good gas exchange occurs when interstitium is dry

Question 16

Define compliance, elastance and airway resistance
What are some patient conditions that may cause a change in these parameters?

Answer 16

Compliance
* how easily the lung expands
* good compliance = healthy / stretches easily
* poor compliance = stiff lung/ hard to stretch

Elastance
* how easily the lung returns to resting stage
* bounces back

Airway resistance
* dependent on the amount of pressure needed to move air in / out of the lungs
* resistance increases = compliance decreases

Question 17

What are the modes of O2 and CO2 transport?

Answer 17

1. Ventilation - movement of gas from atmosphere into large airways
2. Distribution - from large airways into small airways
3. Diffusion - from small airways into capillary membranes
   Perfusion - good blood flow throughout lungs to diffuse these gases

Transport of O2 - absorbs into the cells after
* 3% travels freely in plasma (p02)
* travels via hemoglobin molecule (SaO2)

Transport of CO2
* 5% freely travels within plasma
* 25% travels bound to hemoglobin, releases CO2 at the lung to be exhaled
* 70% travels as bicarbonate, converted with carbonic acid

• Cellular level - creates bicarb. by connecting CO2 bonds with H2O to create Carbonic acid
• Lung level - combines with hygroden to create CO2

Question 18

What is the significance of SpO2?
Why it is monitored?

Answer 18

It measures the level of oxygen in the left side of the heart before cell absorption

Ensures enough oxygen is reaching the cells

Question 19

Whats the difference between aerobic and anaerobic respiration?

Answer 19

Aerobic - normal, oxygen creates 38 ATP
Anaerobic - abnormal, back up when oxygen is low
* increase lactic acid, 2 ATP

Question 20

What is ventilation and perfusion in relation to gas exchange?

Answer 20

Ventilation is the flow of air into the lungs
Perfusion (Q) is the flow of blood to the pulmonary artery and alveolar capillaries

Question 21

What is ventilation perfusion mismatch?

Answer 21

Perfusion problem - takes a volume of gas into the lungs but cannot perfuse to lungs
Ventilation problem - not ventilating well therefore no perfusion