Cardiovascular System Flashcards
Path of blood through the heart
DeOxygenated blood to right atrium via inferior/superior cava
DeO2 blood through tricuspid valve
DeO2 blood through pulmonary artery through pulmonary valve
Blood then taken to lungs to get oxygen
Oxygen diffuses into hb
Pulmonary vein takes oxygenated blood to left atrium
Transported by bicuspid valve to left ventricle
O2 blood through aorta to body
Oxygenated blood then used up and becomes deoxygenated in body
Back to start
Heart
Located in thoracic cavity
Atrium and ventricle
Chambers of heart
Septum divided them
Atrium and ventricle
Right chamber- deoxygenated blood
Left chamber- oxygenated blood
Tricuspid valve
Right AV
shuts when chamber filling to stop blood into right ventricle
Bicuspid valve
Stops blood leaking into left ventricle
Pulmonary valve
Prevents blood going to lungs to soon
Aortic valve
Prevents blood going to body to soon
Superior inferior vena cava
Transports deoxygenated blood to right atrium
Pulmonary artery
Takes blood away from right ventricle to lungs
Pulmonary veins
Oxygenated blood from lungs to left atrium
Aorta
Oxygenated blood from left ventricle to rest of body
Coronary arteries
Left and right branches from aorta encircle and supply heart and muscles with oxygen and glucose
Coronary veins
Alongside the coronary arteries, drain deoxygenated blood directly back into right atrium via coronary sinus
Conduction system
Set of structures in cardiac muscle which creates and transmits an electrical impulse forcing Atria and ventricle to contract
Conduction system process
SA node sends an electrical impulse through atrea causing contraction
AV node delays passage of signal to allow atrea to contract 1st
Receives signal from SA node and passes down bundle of his
Bundle of his splits the signal down 2 branches
The purkyne fibres distribute the impulse through the ventricle walls causing them to contract
Once process over, all contracts And heart fills with blood
Cardiac cycle
Cardiac muscle contraction and of blood through chambers
One complete cardiac cycle reps sequence of events involved in single heartbeat
Diastole
Filling stage
Atria and ventricles relax - draw blood onto atria
Pressure in atria increase opens AV Valves
Blood enters ventricles
SL valves closed to prevent blood leaving heart
Atrial systole
Atria contract
Forces remaining blood into ventricles
Ventricular systole
Ventricles contract
Increasing pressure closing AV to prevent back flow to atria
SL valves are forced open as blood ejected from ventricles into aorta and pulmonary artery
Conduction
-no electrical impulse
Diastole
Heart relaxes
Blood drawn into atria
All valves open slightly to allow ventricular filling
Conduction
-signal sent from SA node across atrea
Aerial systole
Atrea contracts
Blood forced into ventricles
Conduction
-AV Node passes signal to bundle of his
Ventricular systole
Ventricles contracts
Ventricles contract
Force aortic/pulmonary valve open blood to lungs
Heart rate
Number of times the heart beats (cardiac cycles) per min
Calculate HR
220-age = max HR
Bradycardia
Having heart rate below 60bpm
Larger stroke volume
Regularly train build extra strong heart walls
Adaptation know as left ventricular hypertrophic
Impact on health and aerobic performance
Heart pumps oxygen and blood in bigger amounts phb
Reach muscles quicker
More capillaries oxygen
Reduce chance of cardiovascular disease
Stroke volume
Volume of blood ejected from left ventricle per beat
End diastolic volume - end systolic volume = stroke volume
Untrained- 70ml @ rest
Trained - 100ml @ rest
Higher as more blood with each contraction
Venous return
Volume of blood returning to the heart
Cardiac output
Volume of blood ejected from the left ventricle per min
Sub maximal work
Low intensity work
Meet o2 demands
Aerobic
Maximal
High intensity work
Anaerobic
O2 demands aren’t met
Sub maximal exercise heart rate
1) anticipatory rise Heart rate increase due to adrenaline 2) rapid increase Meet o2 demand 3)steady state/plateau O2 demands met, level off 4) demand for o2 much lower 5) HR return to resting levels when body totally recovered
Maximal exercise heart rate
1) anticipatory rise
2) meet o2 demands rapidly
3)rate of increase decreases, heart has to fill more to meet o2 demands
4) recovery longer
Body built up huge o2 debt
Frank starling mechanism
More blood returned to hear greater stretch on the heart wall meaning stronger contraction
Increased venous return
More blood returning to heart more gets squeezed out
Stroke volume maximal exercise
Untrained- 100-120ml
Trained- 160-200ml
Trained have bigger hearts
Ccc
Cardiac control centre
Controls heart rate
Located in medulla oblongata Controlled by automatic nervous system ANS and it stimulates the SA node in order to regulate heart rate.
Control mechanisms controlling heart rate
Neural control
- proprioceptors
- chemoreceptors
- baroreceptors
Intrinsic control
- temp
- venous return
Hormonal control
-adrenaline
Proprioceptors
Detects movement
Signal sent to medulla oblongata
Chemoreceptors
Detects chemicals
Lactic acid
Located in aorta and carotid artery
Baroreceptors
Detect increase in blood pressure
Placated in arterial wallss
Temperature
Change the viscosity of blood
Speeds up nerve transmission
Hangs stretch in ventricle walls
Impact on force of ventricular contraction me stroke volume
Adrenaline
Stimulates SA node
Secreted from arterial glands
Increase stroke volume
Exercise to increase HR
-Proprioceptors- detect movement
-Chemoreceptors- LA & PCO2 increase
All info back to CCC
Decrease in o2 and PO2
-baroreceptors
Pressure increased tries to slow HR
need for o2 overrides it
-temp- increased , info sent to CCC, viscosity decreases
-Venus return- increases
- adrenaline - SA node stimulated
Recovery to decrease HR
- Proprioceptors- detect decrease in moment
- Chemoreceptors- LA & PCO2 decrease, increase in PO2
- baroreceptors- BP drops
- Temp- decrease, viscosity increases
- Venus return- decrease , info sent to CCC to slow it down
- adrenaline - Resuced, info back to CCC
Venous return mechanism
Pocket valves Muscle pump Respiratory pump Smooth muscle Gravity
Muscle pump
Muscles contract
Squeeze vein and force blood up through valves
Gravity
Blood above heart
Gravity brings it back down to heart
Respiratory pump
Changes in pressure in thoracic cavity when breathing
Squeezing effect on veins
Blood pooling
Occurs when walls and valves of veins don’t work effectively making it difficult for blood to return to heart
Artery
Thick middle smooth layer of muscle
Vasoconstriction
Vasodilation
Arterioles
Smaller arteries Thick layer Pre capillary sphincter Helps direct blood flow to where it's needed Vascular shunt
Capillaries
1 cell thick
Endothelia cells
Gaseous exchange of gas/nutrients
Venules
Smaller veins
Thin smooth middle layer muscle
Vasodilation
Vasoconstriction
Veins
Think smooth layer of muscle
Pocket valves
Allow blood flow in one direction to heart
Vasomotor control centre
VCC
Controls vascular shunt
Sends signals to blood vessels
Change in blood flow from rest to exercise
More oxygenated blood to muscle during exercise
Pre capillary sphincter
Band of smooth muscle
Adjusts blood flow into capillaries
What happens to blood flow during exercise
Pre capillary sphincter close so there is reduction in blood flow
What structures made that change happen
Pre capillary sphincter think they’re open so they use vasoconstriction to close blood supply off
Sympathetic stimulator
VCC alters the level is stimulation sent to the arterioles and PCS at different sites in the body
Receptors for VCC
Chemoreceptors
Baroreceptors
Increased sympathetic stimulation
Close pcs
Makes muscle harder and construct
Redirects blood away from where it’s not needed
Blood flow reduces
Decreases sympathetic stimulation
Decreases stimulation opens pcs
Muscle softer and dilated
Vasodilation of pcs
Sympathetic stimulation during rest
Chemoreceptors tell VCC o2 and PH steady
No change from baroreceptors
Increasing blood flow to organs
Decreases SS
pcs open relaxes
Decreasing blood flow to muscles
Increased SS
Pcs closes
Sympathetic stimulation during exercise
Chemo- increase in LA and CO2, decrease in PH and O2
Baro- BP Increase
Decrease blood flow to organs
Increase SA
Pcs vasoconstriction
Increase blood flow to muscles
Decrease SS
pcs dilates
