TOPIC 4B. Pericardium, the heart’s own vessels, impulse generating and conducting systems

Question 1

What is the pericardium

Answer 1

sac enveloping the heart, initial parts of aorta, terminal parts of vena cava cran and caud and vv pulmonalis

Question 2

layers of the pericardium

Answer 2

pleura, pericardium fibrosum and pericardium serosum

Question 3

what is lamina visceralis of pericardium serosum attached to

Answer 3

the epicardium

Question 4

what does pericardium fibrosum continue dorsally into

Answer 4

tunica externa of blood vessels and is therefore connected to fascia endothoracica which suspends the heart to the vertetbrae

Question 5

what ligament is in ca connecting the heart to the diaphragm

Answer 5

lig phreincopericardiaca

Question 6

what ligament is in eq,ru,sus connecting the heart to the sternum

Answer 6

lig sternopericardiaca (x2 in ru and sus)

Question 7

what does cavum pericardii contain

Answer 7

liquer pericardii - moistens the surface

Question 8

what is vagina serosae arterium et venosum

Answer 8

visceral layer that envelopes the first part of great vessels entering/leaving the heart

Question 9

sinus transversus pericardii

Answer 9

the pericardial space between aorta, tr pulm and atrial wall

Question 10

sinus obliquus pericardii

Answer 10

pericardial space bw left and right pulm veins and left atrium

Question 11

what is the heart supplied with

Answer 11

15% of the blood output of left ventricle

Question 12

what arteries supply the heart

Answer 12

coronary arteries that originate at sinus coronarius

Question 13

species with left sided heart

Answer 13

ca, ru

Question 14

right sided hearts

Answer 14

eq, sus

Question 15

where does left coronary artery arise from, and pass

Answer 15

left sinus of aortic bulb

passes bw left auricle and pumonary trunk to coronary groove

Question 16

what does the left coronary artery divide into shortly after its origin (in ca and ru)

Answer 16

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

Question 17

what happens in eq, sus

Answer 17

right coronary artery passes bw pulm trunk and right auricle. r circumflexa dextra and r iv subsinosus comes off this.

Question 18

veins of the heart

Answer 18

v cordis magna
v cordis media
vv cordis minimae

Question 19

what is v cordis magna parallel with

Answer 19

a coronaria sin

Question 20

where is v cordis media running

Answer 20

sulcus iv subsinosus

Question 21

what do vv cordis minimae do

Answer 21

carry blood to the inside of the heart

Question 22

where does the blood from the heart empty

Answer 22

into the right atrium via sinus coronarius under v cava caud

Question 23

what does the impulse generating and conducting system consist of

Answer 23

modified myocytes which can conduct spontaneous electrical activity.

Question 24

the four components of electrical conduction

Answer 24

SA node
AV node
Atrioventricular bundle of His
Purkinje fibres

Question 25

the sinoatrial node (5)

Answer 25

1. the dominant site of the system
2. in region of sulcus terminalis of right atrium
3. primary pacemaker of the heart
4. ensures co-ordinated rhythm
5. has sympathetic and parasympathetic fibres

Question 26

the atrioventricular node (2)

Answer 26

1. in the base of septal wall of right atrium

2. penetrates the cardiac region before dividing into 2 bundles

Question 27

AV bundle of His (4)

Answer 27

1. origin is at the av node
2. conducts from atria to ventricular, especially papillary muscles
3. crus dextrum - right limb ramifies in papillary muscles
4. crus sinistrum - left limb ramifies in left papillary muscles

Question 28

purkinje fibres

Answer 28

final branches of bundles as they ramify inside mm papillaris

Question 29

where does excitation wave begin

Answer 29

sa node - spreads through entire muscuature of atria and causes them to contract (atrial systole)

Question 30

which atrium is a tiny bit later

Answer 30

the left atrium

Question 31

what causes contraction of ventricles (ventricular systole)

Answer 31

av node via bundle of his and purkinje fibres to papillary muscles