Respiratory system function Flashcards
Carbon Dioxide Transport
- normal active body cells produce about 200ml CO2/min=amount excreted by lungs/min
What are the three forms that CO2 is transported in?
- Dissolved in plasma
- Chemically bound to hemoglobin (carbaminohemoglobin): just over 20%
- As bicarbonate ion in plasma: about 70%
The process is reversed in the lungs
- Dissolved in plasma: moves out
- Bound to Hb: released and moves out
- Bicarbonate ion: back into RBC, back to CO2 and H2O and moves out
What is the influence of CO2 on blood pH?
where are the neurons found that are a part of the respiratory system?
Medulla and pons
The neurons found in the medulla and pons are responsible for what?
controlling respiration
Ventral Respiratory group (VRG): network brain stem-upper end of spinal cord to pons/medulla junction
most responsible for controlling respiration/inspiratory center, responsible for the rate at which we breathe in and out
Eupnea
The normal rate of breathing– 12-15 breaths/min
Dorsal Respiratory group (DRG): cluster of neurons located dorsally near root cranial nerve IX
Pacesetting respiratory center = ?
inspiratory center
What is Depth determined by?
how actively respiratory center stimulate respiratory muscles
Respiratory centers are affected by: (4)
- Chemical factors
- Influence of higher brain centers
- Pulmonary irritant reflexes
- Inflation reflex
What is Rate determined by?
how long center is active
Of the factors that affect the respiratory center, which one is the most important? and why?
Chemical factors
–> they change the
What is this describing?
Most potent resp. stimulant and most closely controlled
CO2
Hypercapnia
increased PCO2
Hyperventilation
increased rate/depth of breathing that excees the body’s need to remove CO2
Why is hyperventilation self-limiting?
ends when PCO2 back to normal
What is PCO2?
Partial pressure Carbon Dioxide
–> the measure of carbon dioxide within arterial or venous blood.
What does the P stand for in PCO2 and PO2?
Partial pressure
What is Partial Pressure?
Why do swimmers sometimes voluntarily hyperventilate?
This allows them to hold their breath longer. Causes a drop in PCO2,, which causes a delay in respiration, as PCO2 levels need to build back up
Can cause dangerous drops in PO2 levels
What may cause hyperventilation?
anxiety attacks
Hyperventilation may lead to?
decreased blood CO2 levels (hypocapnia)
DRG
Not completely understood, it exists, but right now their exact function is unknown
influence of arterial pH
Hyperpnea
Physically more active–>
getting enough oxygen to the capillary beds, so the idea of inhaling pure oxygen is going to spread up the whole process is probably more of a placebo affect than actually working
