homeostasis (gas concentration) Flashcards
why is the regulation of gas concentration so important?
Body Needs constant supply of O2 and
Constant removal of CO2
what controls gas concentrations
- Controlled by lungs and respiratory system
- Carried out by circulatory system
how do muscles control breathing?
Via Diaphragm and intercostal muscles
Skeletal muscles -> needs stimulation from nervous system to contract
- Diaphragm: phrenic nerve
- Intercostal: spinal nerves
How does the nervous system control gas?
Through the Respiratory centre which is in the middle of the medulla oblongata
- control nerve impulses to diaphragm and intercostal muscles
what are the 2 regions and function of the respiratory centre?
- Expiration
- Inspiration
coordinated by passing messages between neurons
Breathing rate effected by O2 and CO2 concentrations
How does Co2concentration impact pH?
CO2 concencetration affects hydrogen concentration in the blood (pH) by denaturing enzymes
A high concentration = low pH
what receptors observe o2 levels?
- Chemoreceptors:
- Peripheral: cells in walls of aorta and carotid arteries
- Central: medulla oblangata
how does body respond to low o2?
s
stimulates the chemoreceptors
- Nerve impulses to respiratory center
- Message to diaphragm and intercostal muscles
how does CO2 impact breathing?
Increased CO2 and Hydrogen stimulates central and peripheral chemoreceptors
- Medulla oblangata most sensitive
how does pH impact breathing?
Hydrogen immediately increase produced by stimulation of aortic and carotid bodies
- Stimulated by increased hydrogen; impulse sent to respiratory center to
Increase hydrogen, decrease pH of blood, increasing breathing rate
How does voluntary breathing work?
Via connections between cerebral cortex and descending tract of spinal cord
In Bypass respiratory center there’s protective behavior preventing irritating gas and water vapor entering lungs
When CO2 builds up in plasma it stimulates inspiration center causing impulse to respiratory muscles
how will exercise impact breathing?
Contracting muscles require large amounts of O2 and produce large amounts of CO2
- increases rate of breathing + depth
