gas exchange Flashcards
GAS EXCHANGE
what type of epithelium is is alveolar epithelium?
what type of cells make this?
simple squamous epithelium
type 1 cells
GAS EXCHANGE
1) what cells is the alveolar epithelium patrolled by?
2) what type of cells produce surfactant?
1) alveolar macrophages
2) type 2 cells, produce surfactant
GAS EXCHANGE - henrys law
gas dissolves in liquid until equilibrium is reached
GAS EXCHANGE
5 reasons for gas exchange efficiency
- substantial difference in partial pressure across membrane
- short distance in gas exchange
- o2 + co2 = lipid soluble
- total SA = large
- blood flow + air flow are coordinated
GAS EXCHANGE
- PULMONARY CIRCUIT
- SYSTEMIC CIRCUIT
PULMONARY:
blood vessels to and from lungs
SYSTEMIC:
blood vessels serve rest of body
GAS EXCHANGE
how does altitude effect alveolar air
reduces partial pressures
GAS EXCHANGE
describe partial pressures in pulmonary artery blood
low po2
high pco2
conc gradient = o2 enter, co2 leave
GAS EXCHANGE
why is the oxygen-haemoglobin saturation curve curved not straight?
Hb changes shape each time o2 molecule binds
makes next o2 easier to bind
GAS EXCHANGE
1) haemoglobin release o2 easier in _____ temp
2) haemoglobin release o2 less easily in _______ temp
3) where are temp effects significant?
1) high temp
2) low temp
3) active tissue
GAS EXCHANGE
1) what is the BOHR EFFECT a result of?
2) what enzyme catalyses reaction of co2 with h2O?
3) what is formed from this?
1) pH
pH effected by co2
2) carbonic anhydrase
3) carbonic acid
GAS EXCHANGE
1) what BPG produced from?
2) what does BPG effect?
3) when do BPG levels rise?
4) what happens when BPG levels low?
1) RBC producing atp
2) o2 release
3) ph increase
hormones
4) haem not release o2
GAS EXCHANGE
3 transport pathways for co2
1) dissolve in plasma
2) bind to haem
3) converted to carbonic acid
GAS EXCHANGE
if po2 increases, haemoglobin ______ oxygen
If po2 decreases haemoglobin ______ oxygen
binds
releases
GAS EXCHANGE - control of respiration
what are the 2 types of neural control from the brain?
involuntary
voluntary
GAS EXCHANGE
what does involuntary respiratory control do?
- regulate respiratory muscle activity
- frequency + depth
- respond to info from lungs + respiratory tract
GAS EXCHANGE
what does voluntary respiratory control do?
reflect activity in cerebral cortex
affect output of respiratory centres + motor neurones
GAS EXCHANGE
what are the 2 centres of the pons and what do they do?
APNEUSTIC: promote inhalation, stimulate DRG
PNEUMOTAXIC: inhibit apneustic, promote passive/active exhalation
GAS EXCHANGE
what are the 2 sections of the medulla oblongata?
DORSAL RESPIRATORY GROUP (DRG):
inspiratory centre
- quiet + forced breathing
VENTRAL RESPIRATORY GROUP (VRG):
inspiratory + expiratory centre
- only in forced breathing
GAS EXCHANGE
role of chemoreceptors
respond to pco2, po2, pH of blood or cerebral spinal fluid
GAS EXCHANGE
role of baroreceptors
change in blood pressure
GAS EXCHANGE
how to chemoreceptors respond to INCREASE pco2
what does pco2 increase cause
- decrease pH in CSF
- CSF chemoreceptors stimulated @ medulla
- respiratory muscles stimulated
- increase respiratory rate
- restore homeostasis
GAS EXCHANGE
how do chemoreceptors respond to DECREASE pco2
- increase pH in CSF
- arterial chemoreceptors inhibited
- decrease stimulation of CSF chemoreceptors
- inhibit respiratory muscles
- decrease respiratory rate
GAS EXCHANGE - respiratory changes @ birth
what happens:
1) before birth
2) at birth
1) pulmonary vessels collapsed . no air in lungs
2) surface tension force inflate bronchial tree + alveoli
GAS EXCHANGE - respiratory changes in elderly
2 things that happen
name of smoking
- elastic tissue deteriorate
- decrease flexibility, arthritic changes
EMPHYSEMA
