TOPIC 4B. Pericardium, the heart’s own vessels, impulse generating and conducting systems Flashcards
What is the pericardium
sac enveloping the heart, initial parts of aorta, terminal parts of vena cava cran and caud and vv pulmonalis
layers of the pericardium
pleura, pericardium fibrosum and pericardium serosum
what is lamina visceralis of pericardium serosum attached to
the epicardium
what does pericardium fibrosum continue dorsally into
tunica externa of blood vessels and is therefore connected to fascia endothoracica which suspends the heart to the vertetbrae
what ligament is in ca connecting the heart to the diaphragm
lig phreincopericardiaca
what ligament is in eq,ru,sus connecting the heart to the sternum
lig sternopericardiaca (x2 in ru and sus)
what does cavum pericardii contain
liquer pericardii - moistens the surface
what is vagina serosae arterium et venosum
visceral layer that envelopes the first part of great vessels entering/leaving the heart
sinus transversus pericardii
the pericardial space between aorta, tr pulm and atrial wall
sinus obliquus pericardii
pericardial space bw left and right pulm veins and left atrium
what is the heart supplied with
15% of the blood output of left ventricle
what arteries supply the heart
coronary arteries that originate at sinus coronarius
species with left sided heart
ca, ru
right sided hearts
eq, sus
where does left coronary artery arise from, and pass
left sinus of aortic bulb
passes bw left auricle and pumonary trunk to coronary groove
what does the left coronary artery divide into shortly after its origin (in ca and ru)
ramus iv paraconalis -follows sulcus iv paraconalis to apex of the heart in ca and ru
ramus circumflexa sinistra and
ramus iv subsinosus off this also in ca and ru
what happens in eq, sus
right coronary artery passes bw pulm trunk and right auricle. r circumflexa dextra and r iv subsinosus comes off this.
veins of the heart
v cordis magna
v cordis media
vv cordis minimae
what is v cordis magna parallel with
a coronaria sin
where is v cordis media running
sulcus iv subsinosus
what do vv cordis minimae do
carry blood to the inside of the heart
where does the blood from the heart empty
into the right atrium via sinus coronarius under v cava caud
what does the impulse generating and conducting system consist of
modified myocytes which can conduct spontaneous electrical activity.
the four components of electrical conduction
SA node
AV node
Atrioventricular bundle of His
Purkinje fibres
the sinoatrial node (5)
- the dominant site of the system
- in region of sulcus terminalis of right atrium
- primary pacemaker of the heart
- ensures co-ordinated rhythm
- has sympathetic and parasympathetic fibres
the atrioventricular node (2)
- in the base of septal wall of right atrium
2. penetrates the cardiac region before dividing into 2 bundles
AV bundle of His (4)
- origin is at the av node
- conducts from atria to ventricular, especially papillary muscles
- crus dextrum - right limb ramifies in papillary muscles
- crus sinistrum - left limb ramifies in left papillary muscles
purkinje fibres
final branches of bundles as they ramify inside mm papillaris
where does excitation wave begin
sa node - spreads through entire muscuature of atria and causes them to contract (atrial systole)
which atrium is a tiny bit later
the left atrium
what causes contraction of ventricles (ventricular systole)
av node via bundle of his and purkinje fibres to papillary muscles
