Session 1- Intro to the unit

Question 1

conducting portion of respiratory tract

Answer 1

nasal cavity to terminal brochioles

Question 2

respiratory portion

Answer 2

respiratory bonchioles to alveoli

Question 3

what is ventilation

Answer 3

process of inspiration and expiration not the same as respiration

movement of a volume of gas into and out the lungs. Respiration is the exchange of oxygen and Co2 across a membrane either in the lungs or at the cellular level

Question 4

tidal volume

Answer 4

volume of air being moved during quiet inspiration and expiration

Question 5

boyle’s law

Answer 5

inverse relationship between pressure of a gas and voume it occupies

Question 6

lung mechanics in quiet inspiration

Answer 6

requires active expansion of thoracic cavity expands the lungs- increase in volume causes decrease in pressure relative t atmosphere- gas moves from greater to lower pressure- air is drawn in

Question 7

lung mechanics in quiet expiration

Answer 7

air expelled from the airways passivly by relaxing muscles used in inspiration- reduces volume of thoracic cavity- reduces volume of lungs as they return to original volume, this increases pressure inside lungs relative to atmosphere and air expelled

Question 8

what connects lungs to chest wall

Answer 8

pleura

Question 9

pleura

Answer 9

each of a pair of serous membranes lining thorax and enveloping the lungs

Parietal pleura lines the inside of each hemi-thorax

visceral lines outside of lung

Question 10

what is the pleural seal

Answer 10

surface tension between the pleural surfaces created by the presence of thin film of parietal fluid holds outer surface of lung to inner surface of chest wall

Question 11

what creates the negative pressure between pleura

Answer 11

lungs have a natural inward elastic recoil, chest wall has a natural outward recoil

this 2 opposing forces create a negative pressure in the intrapleural space

Question 12

What does the intrapleural pressure remain

Answer 12

Remains negative which prevents alveoli from fully collapsing

Question 13

What does positive pressure mean

Answer 13

More than atmospheric pressure

Question 14

What does negative pressure mean

Answer 14

Less than atmospheric pressure

Question 15

What does 0 pressure mean

Answer 15

Same at atmospheric

Question 16

What does trabspulmonary pressure mean

Answer 16

Difference between intrapulmonary pressure minus intrapleural pressure

Question 17

What is compliance

Answer 17

A measure of distensibility change in volume relative to change i pressure

How much pressure do i have to exert to make something stretch out

volume change per unit pressure change

Question 18

What is elastance

Answer 18

Measure of elastic recon= the tendency of something that has been distended to return to its original size

Question 19

Relationship between compliance and elastance

Answer 19

Inversely related

Question 20

what is the relationship between Lung compliance

Answer 20

Inversely related to connective tissue surrounding alveoli- elastic fibres including collagen and other matrix elements within the lung parenchyma

Inversely related to alveolar fluid surface tension

Question 21

What is resting expiratory level

Answer 21

When we have just expired and before we start inspiring

Question 22

What occcurs during resting expiratory level

Answer 22

Lungs collapse inwards- elastic recoil

Chest wall pulls out- chest elastic recoil

Forces are equal and opposite

Volume air at resting expiratory level is called FRC

Question 23

What is the effect of surface tensio

Answer 23

Limits expansion of the alveoli

Decreases compliance making g i more difficult to expand them

Surface tension increases as alveoli increase in size

Question 24

Function of surfactant

Answer 24

Counteracts surface tension

Acts to disrupt interaction between fluid molecules on alveolus surface…reducing surface tension

Better at this when molecules are closer together

Question 25

Difference between distribution of surfactant in sizes of alveoli

Answer 25

Farther apart in larger less surface tension

Closer together in smaller- more surface tension

Question 26

Accessory muscles of inspiration

Answer 26

SCM 
Scalene 
Serratus anterior 
Pectoral is major
external intercostal muscles

Question 27

Accessory muscles of expiration

Answer 27

Internal intercostal

Abdominal walls muscles

external oblique

Question 28

Functional residual capacity

Answer 28

Volume of air in lungs at resting expiratory level

Question 29

what percentage of chest expansion is the diaphragm responsible for during quiet respiration

Answer 29

80% the diaphragm is the cheif muscle for chest expansion

Question 30

what is the most likely cause of reduced lung compliance

Answer 30

increased amount of collagen in the alveolar interstitium which makes the lungs stuiff