lecture 21: resp. 3

Question 1

define respiration

Answer 1

the extraction of oxygen from air and the transport of it to respiring tissues with the aid of the cardiovascular system. also the removal carbon dioxide from respiring tissues

Question 2

innervation of diaphram

Answer 2

phrenic nerve that comes from the phrenic motor nucleus at C3-C5. produces ~70% of inspiratory effort

Question 3

innervation of intercostal muscles

Answer 3

both internal and external muscles are innervated by the internal and external intercostal nerves from the T1 to L1 (intercostal motor neurones)

Question 4

innervation of rectus abdominus (exhalation)

Answer 4

abdominal nerve from abdominal motor neurones in T7-L1. only contracts on forced exhalation

Question 5

inspiration process

Answer 5

• ribs move up and out
• diaphragm flattens
• volume increases, pressure decreases
• active process

Question 6

expiration process

Answer 6

• ribs move down and in
• diphragm domes up
• volume decrease, pressure increases
• passive process at rest, when exercies, abdominal muscles make it active

Question 7

pulmonary and pleural pressure changes during inspiration

Answer 7

• volume increases
• plueral pressure becomes more negative (it is already negative, causing lungs to be sucked to chest wall).
• pulmonary pressure, goes from zero and becomes negative before rising back to zero as air moves in to stabilise pressure

Question 8

pulmonary and pleural pressure changes during expiration

Answer 8

• volume decreases
• plueral pressure becomes less negative
• pulmonary pressure becomes positive and rises before falling back to 0 as air moves out and equalises pressure

Question 9

pneumothorax

Answer 9

• thoracic puncture wound
• pleural pressure is now same as atmospheric and lung collapes

Question 10

spirometer measues

Answer 10

• tidal breath
• respiratory frequency
• minute ventilation (Ve = Vt x F)
• inspiratory reserve volume
• expiratory reserve volume
  thus it can also measure:
• inspiratory capacity
• vital capacity
  you cannot measure total lung capacity or residual volume

Question 11

hyper ventilation

Answer 11

> 6L/min

Question 12

hypoventilation

Answer 12

<6L/min

Question 13

clinical tests for assessing respiratory function

Answer 13

vitalographs give forced expiratory volume and forced vital capacity.
gives FEV1/FVC. should eqaual ~80%