Module 2 Flashcards
base of the heart
- superior
- wide surface
apex of the heart
- inferior
pericardium
double walled sac
list the 3 structures of the pericardium
- parietal (outer)
- epicardium (inner visceral pericardium)
- pericardinal space (contains fluid)
lis the 3 structures of the heart wall
- epicardium
- myocardium
- endocardium
epicardium
covers the heart = visceral pericardium
myocardium
muscular wall
endocardium
endothelium covers inner surfaces of the heart
coronary circulation
blood to the myocardium
left coronary arteries supplies to
anterior ventricles via anterior IV artery
right coronary arteries supplies to
posterior ventricles via posterior IV artery
great cardiac vein
drain anterior regions + is supplied by anterior IV artery
middle cardiac vein
drains posterior regions + is supplied by posterior IV artery
where do all veins drain into and where does this go
all veins drain into the coronary sinus which supplies the right atrium
list the external structures of the heart
- inferior ventricles
- superior atria
- vesses
characteristics of the 2 inferior ventricles
- receiving or discharging ?
- how are they separated ?
- thick or thin walled ?
- discharging chambers
- seperated via interventricular sulcus
- thick walled
characteristics of the 2 superior atria
- receiving or discharging ?
- how are they separated ?
- thick or thin walled ?
- receiving chambers
- separated from ventricles via coronary sulcus
- thin walled
characteristics of right atria
- what blood does it receive ?
- from where?
- receives deoxygenated blood from superior venca cava from regions superior to diaphragm, and inferior vena cava
- and coronary sinus
characteristics of left atria
- what blood does it receive ?
- from where?
- receives oxygenated blood from R+L pulmonary veins from lungs
characteristics of vessels
- blood from ventricles
- pulmonary trunk to the lungs
- aorta to the body to deliver oxygen
list the internal structures of the heart
- ventricles
- atria
- valves
how are the ventricles separated from the atria
AV valves
how are the AV valves anchored
chordae tendinea - attached to papillary muscles
how does blood exit the ventricles
via SL valves
right av valve (tri or bicuspid)
tricuspid
left av valve bicuspid (tri or bicuspid)
bicuspid
role of the atrioventricular (AV) valves
prevent backflow of blood into the atria when ventricles contract
role of the semilunar (SL) valves
ensure 1 way blood flow
when do AV valves open
when atrial pressure > ventricular pressure
when do AV valves close
when atrial pressure < ventricular pressure
when do SL valves open
when ventricular pressure > arterial pressure
when do SL valves close
when ventricular pressure < arterial pressure
left side of the heart
systemic (thicker ventricle)
right side of the heart
pulmonary
unidirectional bloodflow through the heart
oxygen poor blood
- SVC
IFC
Coronary Sinus - Right Atrium
via tricuspid valve to the
- Right Ventricle
via pulmonary SL valves
- Pulmonary Trunk
- Lungs
oxygen rich blood
to heart
- 4 pulmonary veins
- left atrium
- left ventricle
via aortic SL valve to
- aorta
- body/systemic capillaries
list the 5 structures of the intrinsic conduction system
- sinoatrial node
- atrioventricular node
- atrioventricular bundle
- bundle branches
- purkinje fibres
intrinsic conduction system - sinoatrial node
- pacemaker cell
- depolarises
- located at R atrial wall
intrinsic conduction system - atrioventricular node
- delays impulse by 0.1 sec to allow for atria to complete contraction
- located at the junction b/w atria + ventricles
intrinsic conduction system - atrioventricular bundle
- located in the upper interventricular septum
- only electrical connection between atria + ventricles
intrinsic conduction system - bundle branches
travel in interventicular septum to apex
intrinsic conduction system - purkinje fibres
penetrates ventricle walls + depolarises ventricular myocardium
what are the 2 methods of extrinsic innervation
- cardio acceleratory centre
2. carioinhibitory centre
extrinsic innervation - cardioacceleratory centre
> HR = > contraction
sympathetic input to:
- SA node
- AV node
- Myocardium
- coronary arteries
extrinsic innervation - cardioinhibitory centre
< HR
parasympathetic input via vagus nerve to:
- SA node
- AV node
cardiac output
the volume of blood pumped into circuit per minute
CO = SV X HR
stroke volume
volume of blood ejected from ventricle per beat
SV = EDV-ESV
End Diastolic Volume (EDV)
volume of blood in a ventricle at the end of relaxation
End Systolic Volume (ESV)
volume of blood remaining in ventricle after contraction
list the factors that affect CO
- EDV, ESV
- ANS
- Hormones
(anything that affects SV or HR will affect CO)
factors affecting ESV
- contractility ( > contractility = > SV = < ESV = CO)
- afterload
afterload
the pressure that the ventricles must overcome to open SL valves to eject blood into the arteries
preload
the degree the myocardium is stretched before it contracts
determines contraction, EDV and SV
passive filling time
time both atria + ventricles are in diastole
determines EDV
venous return
amount of blood returning to the heart - depending on:
- total blood volume
- pattern of BF
Heart rate
- short term control of CO
- altered to meet needs of organs/tissues
- average = 75 bpm
factors affecting heart rate
- sympathetic input (> depolarisation of nodes = > HR)
- parasympathetic input (< depolarisation of nodes = < HR)
- adrenalin
- thyroxine
ECG’s
electrical events detected by electrocardiograph
- 12 locations on the body
what does an ECG determine
- heart activity
- composite of all action potentials generated by the heart
list the 3 ECG deflections
- P wave
- QRS complex
- T Wave
ECG - P wave deflection
- atrial depolarisation
- begins at SA node
ECG - QRS complex deflection
- depolarisation of ventricles
ECG - T wave deflection
- repolarisation of ventricles
factors which can change a pattern of an ECG
- damaged regions
- enlarged heart
Heart Sounds - Lubb SI
- closure of AV valves
- ventricles contract
Heart Sounds - Dupp S2
- closure of SL valves
- ventricles relax
cardiac cycle - 8 steps
- 4 chambers relaxed
- atrial systole
- atrial systole ends + atrial diastole begins
- ventricular systole
- Ventricular systole
- ventricular diastole
- isovolumetric relaxation
- ventricular diastole