Cardiovascular and Respiratory Systems Flashcards
What do the pulmonary circuit and systemic circuit do?
Pulmonary Circuit - Carries deoxygenated blood to the lungs and oxygenated blood back to the heart
Systemic Circuit - Carries oxygenated blood to the body and deoxygenated blood back to the heart
Describe the structure of the heart.
Did you mention?
- Left and right atria
- Left and right ventricles
- pulmonary artery
- pulmonary vein
- vena cava
- aorta
- semi lunar valves
- atrio ventricular valves
What are the stages for ‘The Conduction System’?
- SA Node generates the electrical impulse and fires it through the atria wall, causing them to contract.
- AV Node collects the impulse and delays it for approximately 0.1 seconds to allow the atria to finish contracting.
- AV Node releases the impulse to the Bundle of His.
- Bundle of His splits the impulse in two , ready to be distributed through each seperate ventricle.
- The bundle brances carry the impulse to the base of each ventricle.
- The purkynje fibres distribute the impulse through the ventricle walls causing them to contract.
What are the stages for ‘The Cardiac Cycle’?
- Diastole - atria and ventricles relax
- AV valves open
- SL valves are closed - Atrial Systole - Atria contracts (blood forced into ventricles)
- Ventricular Systole - Ventricles contract
- AV valves close
- SL valves are forced open
What is the calculation for Cardiac Output?
Cardiac Output (Q) = Heart Rate (HR) x Stroke Volume (SV)
What is venous return?
The return of the blood to the right atria through the veins
Compare between trained and untrained:
- Heart Rate
- Stroke Volume
- Cardiac Output
UNTRAINED:
HR = 70 -72 bpm
SV = 70 ml
Q = 5 l/min
TRAINED:
HR = 50 bpm
SV = 100 ml
Q = 5 l/min
Describe the heart rate at SUB MAX exercise.
- Resting HR
- Anticipatory Rise
- Rapid increase
- Plateau
- Rapid decrease
- Steady decrease
- Resting HR
Describe the heart rate at MAX exercise.
- Resting HR
- Anticipatory rise
- Rapid increase
- Steady increase
- Rapid decrease
- Steady decrease
- Resting HR
What is Starling’s Law?
increased venous return = increased stroke volume
Describe these for an UNTRAINED athlete at rest, sub-max and max:
- Heart Rate
- Stroke Volume
- Cardiac Output
REST:
HR = 70 - 72 bpm
SV = 70 ml
Q = 5 l/min
SUB MAX:
HR = 100 - 130 bpm
SV = 100 - 120 ml
Q = 10 - 15 l/min
MAX:
HR = 220 - age
SV = 100 - 120 ml
Q = 20 - 30 l/min
Describe these for a TRAINED athlete at rest, sub-max and max:
- Heart Rate
- Stroke Volume
- Cardiac Output
REST:
HR = 50 bpm
SV = 100 ml
Q = 5 l/min
SUB MAX:
HR = 95 - 120 bpm
SV = 160 -200 ml
Q = 15 - 20 l/min
MAX:
HR = 220 - age
SV = 160 - 200 ml
Q = 30 - 40 l/min
What are the 3 types of control mechanism for the heart?
- Neural
- Intrinsic
- Hormonal
Describe the NEURAL controls.
Chemoreceptors - located in muscles
- inform CCC of any chemical changes (lactic acid / carbon
dioxide)
Proprioreceptors - located in muscles
- informs CCC of movement
Baroreceptors - located in blood vessels
- informs CCC of preesure change in blood
Describe the INTRINSIC controls.
- Temperature changes will affect viscosity of the blood, and the speed of nerve impulse transmission
- Venous return changes will affect the stretch in the ventricle wall
Describe HORMONAL controls.
Adrenaline and Noradrenaline are released from the adrenal glands increasing the force of ventricular contraction and increasing the spread of electrical activity
What are the sympathetic and parasympathetic nervous systems?
SNS = Gets the body ready for fight or flight (increase HR)
PNS = Gets the body ready for rest (decrease HR)
What are the venous return mechanisms?
- Pocket Valves (prevent backflow)
- Smooth Muscle (vasoconstricts to aid movement)
- Gravity (blood helped to move from upper body)
- Muscle Pump (muscles contract, compressing veins)
- Respiratory Pump (pressure difference between thoratic cavity and abdominal cavity)
What is the vascular shunt mechanism?
The redistribution of cardiac output around the body from rest to exercise which increases the percentage of blood flow to the skeletal muscles
How is cardiac output distributed during exercise?
- Arterioles to to the muscles vasodilate, and arterioles to the organs vasoconstrict
- Pre Capillary Sphinctors constrict/close and the capillary beds dilate
What are the controls for the lungs?
Chemoreceptors = detect chemical changes
Baroreceptors = detect pressure changes on the arterial wall
How is oxygen carried?
97% with haemoglobin (oxyhaemoglobin)
3% dissolved in plasma
How is carbon dioxide carried?
70% dissolved in water (carbonic acid)
23% carried wih haemoglobin (carbaminohaemoglobin)
7% dissolved in plasma
How is minute ventilation calculated?
Minute Ventilation (VE) = Breathing Rate (f) x Tidal Volume (TV)
Compare a trained and untrained athlete for:
- Breathing Rate
- Tidal Volume
- Minute Ventilation
UNTRAINED:
f = 12 - 15 breaths/min
TV = 500 ml
VE = 6 -7.5 l/min
TRAINED:
f = 11 - 12 breaths/min
TV = 500 ml
VE = 5.5 - 6 l/m
What is the breathing rate response to exercise?
Breathing rate increases in proportion to the intensity of exercise until we approach our maximum of 50 -60 breaths/min.
In sub-max, breathing rate can plateau due to supply of oxygen meeting the demand from working muscles.
What is the tidal volume response to exercise?
Tidal volume increases initially in proportion to exercise intensity at sub-max . It reaches a plateau during sub max because increased breathing towards max intensities does not allow enough time and requires too much muscular effort.
What is the minute ventilation response to exercise ?
Minute ventilation increases in line with exercise intensity, whereby breathing rate and tidal volume will both increase.
What is the minute ventilation response to recovery?
In recovery, there is a rapid decrease followed by a slower decrease to resting levels.
Describe these for an UNTRAINED athlete at rest and max:
- Breathing Rate
- Tidal Volume
- Minute Ventilation
REST:
f = 12 -15 breaths/min
TV = 0.5 l
VE = 6 - 7.5 l/min
MAX:
f = 40 - 50 breaths/ min
TV = 2.5 - 3 l
VE = 100 -150 l/min
Describe these for an TRAINED athlete at rest and max:
- Breathing Rate
- Tidal Volume
- Minute Ventilation
REST:
f = 11 - 12 breaths/ min
TV = 0.5 l
VE = 5.5 - 6 l/min
MAX:
f = 50 - 60 breaths/min
TV = 3 -3.5 l
VE = 160 - 210 l/min
What are the mechanics of INSPIRATION at REST?
- External intercostals contract
- diapragm contracts
- Ribs move up and out
- Thoratic cavity volume increases
- Thoratic cavity pressure decreases
- Air moves in
What are the mechanics of INSPIRATION during EXERCISE?
- External intercostals contract
- Diaphragm contracts
- Sternocleidomastoid contracts
- Pectoralis minor contracts
- Ribs move further up and out
- Thoratic cavity volume increases more
- Thoratic cavity pressure decreases more
- More air moves in
What are the mechanics of EXPIRATION at REST?
- All muscles relax
- Thoratic cavity volume decreases
- Thoratic cavity pressure increases
- Air moves out
What are the mechanics of EXPIRATION during EXERCISE?
- Internal intercostals contract
- Rectus abdominus contracts
- Thoratic cavity volume decreases more
- Thoratic cavity pressure increases more
- Air forced out
Describe what happens at external respiration (gaseous exchange).
Oxygen moves from a high partial pressure in the alveoli to a low partial pressure in the capillary down the diffusion gradient.
The oxygen associates with the haemoglobin to form oxyhaemoglobin.
Carbon dioxide moves from a high partial pressure in the capillary to a low partial pressure in the alveoli.
Describe what happens at internal respiration (gaseous exchange).
Oxygen moves from a high partial pressure in the capillary to a low partial pressure in the muscle cell.
Oxygen dissociates from the haemoglobin.
Carbon dioxide moves from a high partial pressure in the muscle cell to a low partial pressure in the capillary.
What does the ‘oxyhaemoglobin dissociation curve’ show?
The relationship between partial pressure of oxygen and percentage saturation of haemoglobin.
What is the ‘Bohr Shift’?
A move in the oxyhaemoglobin dissociation curve to the right caused by increased acidity in the blood stream.
What factors create the ‘Bohr Shift’?
- increases in temperature
- increased production of carbon dioxide
- increased production of lactic acid
