Respiration under unusual control Flashcards
What is the partial pressure f oxygen in venous blood and alveolar blood
5.3
alveolar-13.3
What happens at the beginning of exercise
There is a neural mechanism anticipating the extra demand through detection by proprioceptors (these measure your orientation)
Where are chemoreceptors
Medulla in the brain
What leads to an increase in ventilation
High body temperature and metabolic production of acid
How does cardiac output and blood flow change during exercise
Increase
What are you susceptible to at high altitude
Hypoxia
What is acute hypoxia detected by
Peripheral chemoreceptors
What do peripheral chemoreceptors do when hypoxia is detected and what happens as a result
They try to increase breathing
-Reducing carbon dioxide so the cerebrospinal fluid becomes alkaline (which is not good)
How does the body try to reduce the alkalinity caused by an increase in ventilation caused by hypoxia
Choroid plexus cells export HCO3- (bicarbonate ions) from the cerebral spinal fluid
What are the two adaptations to chronic high altitude exposure
- Polycythaemia
- Increased 2,3DPG (which means oxygen is more readily released)
After coming back from normal altitude, what are the health issues which may arise
-Left upper abdomen pain because of enlargement of spleen as it breaks down excess RBCs
What is pressure inversely proportional to
Volume at a constant temperature
What are the results of chronic exposure to space flight
Decrease in blood volume so there is a decrease in cardiac output. There is a decrease in red blood cell mass and a decrease in muscle strength.
Loss of Ca2+ and PO4^3- from bones
When returning to earth, what happens to the body
- Orthostatic hypotension
- Reduction in baroreceptor reflexes
What is orthostatic hypotension
Cardiovascular system not used to responding to gravity hence there is dizziness, fainting
