Respiratory System I

Question 1

major arteries out of the heart from ventricles and what they connect to

Answer 1

aorta: rest of the body
pulmonary trunk L&R arteries: pulmonary circulation

Question 2

upper respiratory system

Answer 2

nares (nostrils)
nasal cavity
pharynx

Question 3

lower respiratory system

Answer 3

larynx
trachea
main bronchus
lungs
diaphragm

Question 4

protection of respiratory epithelium (mucosa)

Answer 4

humidification and warming of air in upper passages
mucous secretion

Question 5

protection of lungs

Answer 5

mucociliary trapping of foreign matter
ciliary escalator
alveolar macrophages
airway reflexes (cough, sneeze, epiglottis closes glottis during swallowing
goblet cells secrete mucous

Question 6

conducting zone

Answer 6

nasal cavity to larger bronchioles

Question 7

function of smooth muscle in bronchiole walls

Answer 7

facilitate airflow regulation

Question 8

respiratory zone

Answer 8

respiratory bronchiole
alveolar sac
alveoli

Question 9

what cells is alveolus epithelium composed of
describe them

Answer 9

type I pneumocytes: thin walled simple squamous epithelium facilitates gas exchange

type II: larger surfactant secreting cell

Question 10

what type of cells are within alveoli
role

Answer 10

macrophages
clear debris and pathogens

Question 11

surfactant

Answer 11

a mixture of proteins and phospholipids
reduces surface tension from alveolar fluid lining inner surface
prevents alveolar collapse

Question 12

respiratory membrane layers

Answer 12

simple squamous epithelium of alveolus
alveolar basement membrane
capillary basement membrane
simple squamous epithelium of capillary

Question 13

contact time between blood and alveolus at rest
minimum time for blood to be fully oxygenated

Answer 13

contact time between blood and alveolus at rest: 0.75s

minimum time for blood to be fully oxygenated: 0.25s

Question 14

respiratory membrane features

Answer 14

little or no interstitial fluid
elastic with collagen fibres
few fibroblasts

Question 15

Hb - O2 saturation curve

Answer 15

sigmoidal curve
gentle slope at high pO2
steep slope at low pO2

Question 16

difference in saturation of haemoglobin at sea level and high altitude

Answer 16

3%
(98 - 95%)

Question 17

arterial pO2 of blood perfusing resting vs exercising muscle

Answer 17

resting: 40 mmHg
exercising: 20 mmHg
greater proportion of O2 dissociated from Hb in order to meet needs

Question 18

factors affecting O2 - Hb affinity

Answer 18

pH
temperature
pCO2
2,3-bisphosphoglycerate (BPG)

Question 19

decrease in pH effect on saturation curve
decreased pH effect on O2 unloading

Answer 19

shifts to the right
decreased pH leads to greater O2 unloading from Hb

Question 20

decrease in temperature effect on saturation curve
decreased temperature effect on O2 unloading

Answer 20

shifts to the left
decreased temperature leads to decreased O2 unloading from Hb

Question 21

CO2 transport modes

Answer 21

93% diffuses into RBCs
(23% combines with Hb, 70% is converted to bicarbonate ions)
7% dissolves in plasma

Question 22

where is carbaminohaemoglobin formed

Answer 22

regions of high pCO2
at the tissues

Question 23

where does carbaminohaemoglobin dissociate to Hb + CO2

Answer 23

at the lungs

Question 24

carbonic anhydrase reaction
where and when does this occur

Answer 24

70% of CO2 + H2O <=> H2CO3 (carbonic acid), becomes bicarbonate
within RBCs at the tissues when pCO2 is high

Question 25

H2CO3 (carbonic acid) spontaneous dissociation at the tissues
why can this continuously occur

Answer 25

forms H+ and HCO3- (bicarbonate ions)
HCO3- ions are exchanged out of RBCs for Cl- ions, maintains neutrality and acts as a buffer

Question 26

what happens to bicarbonate at the lungs

Answer 26

re-enters RBCs in exchange fro Cl- and reacts with H+ released from Hb
forms carbonic acid (H2CO3)
H2CO3 is broken down to CO2 and H2O by carbonic anhydrase

Question 27

what do visceral and parietal pleura cover

Answer 27

visceral: surface of the lungs
parietal: mediastinum, superior diaphragm, thoracic wall