Respiratory And Cardiac Systems Flashcards
Equation for cardiac output
Cardiac ouput (Q) = stroke volume (sv) X heart rate (HR)
What does systole mean
Contraction
What does diastole mean
Relaxation
Process of conduction system (how heart beats)
- Atrial doastole blood enters atria
- ventricular diastole
- SA node sends impulse to AV node (held for 0.1 to 0.2 seconds)
- atrial systole blood forced to ventricle
- impilse trvaels down bundle of HIS into purlinje fibres
- venteicular systole so blood forced out
What does Q mean
Cardiac ouput = blood leaving heart per minute
What is stroke volume
Blood leaving heart per beat
What effect does training have on resting cardiac output and stroke volume
At rest cardiac output remaian the same. Stroke volume would have increased ~ cardiac hypertrophy
Impacts of venous return increasing during exercise
(means greater stroke volume so)
- heart fills with blood quicker
- chambres will hold more blood
- heart will produce a more powerful contraction
What increases during exercise
Heart rate, Stroke volume, cardiac ouput and venous return
Describe the cardiac cycle
- Total diastole all chambers open. Atrial and ventricular diastole. Pressure higher in arteries than geart so blood enters.
- Atrial systole means volume decreased so an increased pressure so atrioventicular valves open and blood is pumped into ventricles. Ventricles are relaxed.
- then ventricular systole happens increasing pressure. Pressure is higher in ventrical than atria so ateioventricular valves close and semi lunar valves open.
- blood is forced into the arteries
- starts again woth pressure higher in arteries than chambres closing the semi lunar valves
Mechanics of breathing at rest during inspiration
Active proccess External intercostals, diaphragm - Rib cage goes up and out - diagrham flattens - thoratic cavity volume increases - thoratic cavity pressure decreases
Air moves in
Mechanics of inspiration during exercise
Active proccess
Sternocleidomastoid, pectoralis major, external intercostals
- rib cage further up and out
- diaphragm flattens further
- thoratic cavity volume increases more
- thoratic cavity pressure decreases more
More air moves in
Mechanics of expiration at rest
Passive
- rib cage goes down and in
- diaphragm relaxes
- thoratic cavity volume decreases
- thoratic cavity pressure increases
Air moves out
Mechanics of expiration at exercise
Active
Rectus abdominals, internal intercostals
- rib cage forces down and in
- diaphragm relaxes
- thoratic cavity volume decreases quickly
- thoratic cavity pressure increases quickly
Air forced out
Equation for minute ventilation
Minute venitlation (VE) = frequency (f) X tidal volume (TV)
