Respiratory System (1.1b) Flashcards
define gaseous exchange
the movement of gases across a membrane
define partial pressure
the pressure exerted by an individual gas held in a mixture of gases
what are the units for partial pressure?
mmHg
define diffusion
the movement of gases across a membrane down a gradient from high to low pressure
define diffusion gradient
the difference in areas of pressure from one side of membrane to the other
the blood is made up of…
45% blood cells
55% plasma
how is CO2 carried in the body?
70% dissolves in H2O as carbonic acid
23% combined with haemoglobin to make carbaminohaemoglobin
7% blood plasma
O2 is carried as…
97% with haemoglobin to make oxyhemoglobin
3% in blood plasma
minute ventilation =
TV x f
what is breathing rates response to exercise?
It increases proportionally to the intensity of the exercise, until reaching max
what is tidal volumes response to exercise?
Increase depth of breathing initially in proportion to exercise
what is minute ventilations response to exercise?
increases in line with intensity when TV and f increase
what happen to minute ventilation at sub max…
- Anticipatory rise
- Rapid increase.
- Steady state
- Rapid then gradual decrease
what happen to minute ventilation at maximal exercise?
- ME doesn’t plateau
- growing demand for O2 strives to meet
- TV will plateau will ME continues to rise due to breathing rate
what happens to minute ventilation during recovery…
rapid then gradual decrease to resting levels
describe the mechanics of inspiration at rest:
diaphragm contracts and flattens
external intercostals contract.
Rib cage moves up and out.
vol of thoracic cavity increases.
Pressure of thoracic cavity decreases.
air dishes in from high-pressure outside to low pressure inside the lung
describe the mechanics of expiration at rest…
diaphragm relaxes and returns domed
external intercostals contract
Rib cage moves down and in
vol of thoracic cavity decreases
Pressure of thoracic cavity increases
air forces out from a high pressure inside lungs to a low pressure outside
describe the mechanics of inspiration during exercise
diaphragm contracts and flattens more than at rest
External intercostals contract more than at rest
Sternocleidomastoid recruited
Rib cage moves up and out further than the rest
Volume of thoracic cavity increases more than the rest
Pressure of thoracic cavity decreases more than a rest
More air moves from a high-pressure to low-pressure
ACTIVE PROCESS
describe the mechanics of expiration during exercise
diaphragm and external intercostals relax
rectus abdominous and internal intercostals contract
Rib cage moves down and in more than at rest
Volume of thoracic cavity decrease is more than at rest
Pressure of thoracic cavity increase as more than at rest
More air moves from high to low pressure
what does the respiratory control centre do?
Receives information from sensory neurons and sends directions through motor neurons to change the rate of respiratory muscle contraction
what does the inspiration center (IC) do?
stimulates inspiratory muscles to contract at rest and exercise
what does the expiratory centre (EC) do?
stimulates additional extra expiratory muscles during exercise