The RCC

what does rcc stand for and where is is located

respiratory control centre = in medulla oblongata

what are the two key parts of the RCC

1. inspiratory centre

2. expiratory centre

what does inspiratory centre do

stimulates inspiratory muscles to contract at rest and at exercise

what does expiratory centre do

is inactive at rest but will stimulate additional expiratory muscle to contract during exercise

where does the RCC receive information from

sensory nerves and sends direction through motor nerves to change the rate of respiratory muscle contraction

what happens to the IC at rest

• nerve impulses are generated and stimulate the inspiratory muscles causing them to contract via the :

• intercostal nerve stimulates the external intercostals

• phrenic nerve stimulates the diaphragm

• thoracic cavity volume increases so lowers lung air pressure

• after 2 secs, stimulation stops and inspiratory muscles relax

• lung tissues recoil= passive expiration

• repeated 12-15 time per min

why is the EC inactive at rest

due to the natural relaxation of the diaphragm and external intercostals

what happens during exercise to RCC

• breathing rate and depth must be increased to meet demand of oxygen supply and co2 removal.

• Sensory nerve relays information to RCC and both IC and EC are involved

what chemical receptors alert RCC

• chemoreceptors in aorta and carotid artery detect increase in co2 and decrease in o2

• thermoreceptors pick up on increased blood temp

• proprioceptors detect more motor activity

• baroreceptors located in lung tissue inform if the state of lung inflation

which receptors inform the IC

• chemoreceptors

• proprioceptors

• thermoreceptors

what receptors inform the Ec

• baroreceptors

what does IC do at exercise

• increases stimulation of diaphragm and external intercostals to contract with more force

• recruits additional inspiratory muscles eg sternocleidomastoid and pectoralis minor

• increase depth of inspiration

what does the EC do at exercise

• stimulates the additional expiratory muscles eg internal intercostal muscles and rectus abdominus

• reduces volume of thoracic cavity and increasing lung air pressure

• causes a forced expiration

as exercise intensity increases, what do the IC and EC do

• leads to an increased breathing rate and decreased breathing depth to maximise efficient respiration