L11 - Gas Transport Flashcards
how is O2 transported in the blood?
O2 is bound to haemoglobin (oxyhaemoglobin)
when blood reached the tissue, oxygen is released from haemoglobin and diffuses into the cells
what is internal respiration?
diffusion of O2 across the capillary membrane into the cells
what 3 ways is CO2 transported in the blood back to the lungs?
23% as carbaminohaemoglobin
70% as bicarbonate ions H2CO3
small amount dissolved in plasma
where is the respiratory control centre located?
medulla oblongata and pons of brainstem
what is the difference between dorsal and ventral respiratory group neurones?
dorsal - inspiratory area
ventral - expiratory area
what are chemoreceptors?
high blood supply - taste the blood for its gas content
what is the function of central chemoreceptors?
detect changes in PCO2 and H+
what is the function of peripheral chemoreceptor?
detect changes in PCO2, H+ and PO2 levels
what is hypercapnia?
increase in PCO2 in blood
what is hypocapnia?
decrease of PCO2 in blood
what is cyanosis?
dusky blueish tinge seen in the extremities due to build up of deoxyhaemoglobin in the blood (associated with hypoxia)
what is hypoxaemia?
lack of O2 in the blood
what is tissue hypoxia?
lack of O2 delivery to the body cells
what is hypoxic hypoxia?
decreased ability to oxygenate the blood - leads to decrease in arterial PO2
what are the 3 causes of hypoxic hypoxia?
- high altitude = reduced O2 levels in atmosphere
- hypoventilation = sufficient O2, person cannot oxygenate blood properly (COPD)
- ventilation/perfusion problems = poor ventilation of alveoli and poor perfusion of lung capillaries
