Resp 1: Ventilation, Spirometry, Patrial Pressures

Question 1

3 stages respiration

Answer 1

1. ventilation
2. Gas exchange - Co2 and O2 between air and blood in the lungs
3. Gas exchange - exhange of gases CO2 and O2 between blood and cells in the circulatory system
4. cellular respiration - utilisation of O2 to produce energy and CO2

Question 2

conducting zone

Answer 2

primary bronchi - divide into smaller bronchioles

Question 3

respiratory zone

Answer 3

alveoli that cluster at end of terminal bronchioles

Question 4

T/F air moves from regions of low pressure to regions of high pressure

Answer 4

false
air moves regions of high pressure to regions of low pressure

Question 5

how does inspiration occur

Answer 5

reducing the air pressure in lungs to sub atmospheric pressures
acheived by increasing the volume of the lungs

Question 6

how does expiration occur

Answer 6

by increasing the air pressure in the lungs above atmospheric pressure
acheived by decreasing the volume of the lungs

Question 7

T/F: expiration occurs from decreasing the air pressure in lungs & increasing volume of lungs

Answer 7

false
exhalation increases air pressure in lungs by decreasing volume of lungs

Question 8

what are the 2 pleural membranes called

Answer 8

parietal pleura
visceral pleura

Question 9

where is parietal pleura located

Answer 9

inner wall of thoracic cavity

Question 10

where is visceral pleura located

Answer 10

covers the outer surface of the lungs

Question 11

T/F: According to Boyle’s Law, increasing the volume of the lungs increases pressure.

Answer 11

False — It decreases pressure (pressure is inversely related to volume)

Question 12

what is normal (quiet) inspiration driven by

Answer 12

contraction of the diaphragm which causes it to flatten

Question 13

what increases the volume of the thoracic cavity vertically & laterally

Answer 13

vertically - diaphragm pulls on base of thoracic cavity increasing its vol vertically
laterally - contraction of external intercostal muscles on ribcage increase thoracic vol laterally

Question 14

what muscles are needed to drive forced inspiration

Answer 14

muscles in neck (scalenes)
and chest (pectoralis minor)

Question 15

t/F:: Forced inspiration recruits additional muscles, such as the scalenes and pectoralis minor.

Answer 15

true

Question 16

during normal inspiration what does the intrapulmonary pressure drop to

Answer 16

-3mmHG (3mmHg below atmospheric pressure)

Question 17

what does intrapulmonary pressure drop to during forced inspiration

Answer 17

-20 mmHG

Question 18

T/F; normal expiration a passive process

Answer 18

true

Question 19

T/F: Forced expiration is assisted by contraction of internal intercostals and abdominal muscles.

Answer 19

true

Question 20

in normal expiration what does the intrapulmonary pressure increase to

Answer 20

+ 3mmHg & air is forced out

Question 21

during forced expiration what does ingtrapulmonary pressure increase to

Answer 21

+30 mmHg

Question 22

t/f: Intrapleural pressure is always greater than intra alveolar pressure.

Answer 22

false
intrapleural pressure always lower than intra-alveolar pressure - to prevent lung collapse

Question 23

what is pneumothorax

Answer 23

pleural membranes damaged by a broken rib or stab wound

Question 24

what does pneumothorax cause

Answer 24

• entry of air into pleural fluid breaks the bond holding the membranes together
• intrapleural & intra -alveolar pressure equalise
• results in collapsed lung

Question 25

T/F: Surface tension in alveoli opposes lung expansion.

Answer 25

True — It pulls the alveolar walls inward

Question 26

what is surfactant produced by & when

Answer 26

type 2 foetal cells late in foetal development

Question 27

T/F: Surfactant increases surface tension in the alveoli.

Answer 27

False — Surfactant reduces surface tension, making inspiration easier

Question 28

what is it called when infants born w/o surfactant

Answer 28

respiratory distress syndrome (RDS) difficulty in expanding lung vol during inspiration

Question 29

what triggers bronchodilation

Answer 29

noradrenaline released from sympathetic nerves triggers bronchodilation

Question 30

what triggers bronchoconstriction

Answer 30

acetlycholine released from parasympathetic nerves triggers bronchoconstriction

Question 31

T/F: Airway resistance is primarily affected by airway radius.

Answer 31

True — Narrower airways = higher resistance

Question 32

what can inapproptiate bronchoconstriction be triggered by

Answer 32

* reflex stimulation of vagus nerve by smoke, cold air & irritants * products of allergic rxns - histamine etc released by mast cells and neuts/eosins inflame airways

Question 33

T/F: Beta-2 agonists can help treat asthma by causing bronchodilation.

Answer 33

True — They relax bronchiolar smooth muscle

Question 34

what is tidal volume

Answer 34

volume of air that is either inspired or expired during quiet regular breathing average = 500ml

Question 35

what is residual volume

Answer 35

vol of air that remains in normal lungs after max exhalation

Question 36

T/F: residual volume can be measured by conventional spirometry

Answer 36

false

Question 37

total lung capacity

Answer 37

vital capacity & residual vol vol of air that both lungs can contain

Question 38

what is reduced in asthma & is used in diagnosis

Answer 38

vital capacity normal but rates of expiration & inspiration are reduced

Question 39

what is used to diagnose obstructive lung disorders

Answer 39

one second forced expiratory volume (FEV1) measures the % of vital capacity that is exhaled in the first second

Question 40

how to calculate partial pressures

Answer 40

atmospheric pressure x % gas in atmosphere

Question 41

partial pressure of O2 & CO2

Answer 41

O2: 160 mmHg CO2: 0.25 mmHg