internal heart

Question 1

interatrial septum

Answer 1

remains partially patent until after birth

Question 2

interventricular septum is comprised of:

Answer 2

muscle (myocardium) & membranous portions of fibrous skeleton of heart

Question 3

fxn of interventricular septum

Answer 3

prevent mixing of oxygenated & deoxygenated blood
pathway for conduction fibers

Question 4

openings of right atrium

Answer 4

superior vena cava
inferior vena cava

Question 5

anterior wall of right atrium:

Answer 5

pectinate muscles (end in crista terminalis)
crista terminalis (smooth ridge)

Question 6

posterior wall of right atrium

inferior surface

Answer 6

orifice (opening) & valve for coronary sinus

Question 7

components of interatrial septum

Answer 7

fossa ovalis
sinoatrial (SA) node
atrioventricular (AV) node

Question 8

fossa ovalis

Answer 8

remnant of foramen ovale
should be closed in adulthood

Question 9

sinoatrial node (SA) location

Answer 9

medial termination of crista terminalis

Question 10

atrioventricular node (AV) location

Answer 10

between fossa ovalis & opening for the coronary sinus

Question 11

right atrioventricular orifice (tricuspid orifice) & what type of blood

Answer 11

opening from R atrium into R ventricle
deoxygenated

Question 12

define

trabeculae carnae

Answer 12

muscle fibers lining walls

Question 13

define

chordae tendinae

Answer 13

connect tricuspid & bicuspid valves to their papillary muscles

Question 14

name the papillary muscles of the right ventricle

Answer 14

anterior
posterior
septal

Question 15

define

tricuspid valve

Answer 15

cusps (leaflets) attach to fibrous ring of skeleton of heart

Question 16

tricuspid valve is opening during _ and closed during _

Answer 16

diastole
systole

Question 17

define

diastole

Answer 17

ventricular filling

Question 18

define

systole

Answer 18

ventricular contraction

Question 19

what causes the “lub” sound?

Answer 19

closure of atrioventricular valvles during systole

both tricuspid & bicuspid (mitral)

Question 20

name the type of valve and define it: pulmonary valve

Answer 20

semilunar valve - 3 pocket shaped semilunar cusps

Question 21

what happens to the pulmonary valve during diastole?

Answer 21

electric recoil of pulmonary trunk walls forces blood back towards heart:
- semilunar cusps fill with blood & close the valve

Question 22

what causes the “dub” sound?

Answer 22

both semilunar valves closing

pulmonary & atrial

Question 23

what are the openings & orifices of the left atrium?

Answer 23

openings:
- L superior & inferior pulmonary veins
- R superior & inferior pulmonary veins

orifices:
- bicuspid (mitral) orifice

Question 24

name the papillary muscles of the L ventricle:

Answer 24

anterior
posterior

Question 25

what is different regarding the L & R ventricles?

Answer 25

L wall is thicker L is bicuspid, R is tricuspid L has 2 papillary muscles, R has 3 papillary muscles

Question 26

the tricuspid valve is open during _ & closed during _

Answer 26

diastole systole

Question 27

how do the tricuspid & bicuspid valves close?

Answer 27

papillary muscles contract, tightening chordae tendinae & pulling cusps of valve closed

Question 28

name the type of valve and define it: aortic valve

Answer 28

semilunar valve - 3 pocket shaped semilunar cusps

Question 29

when are the semilunar valves open?

Answer 29

pushed open during systole via outflow of blood from ventricles

Question 30

what happens to the aortic valve during diastole?

Answer 30

elastic recoil of walls of aorta forces blood back toward heart - semilunar cusps fill with blood & close it

Question 31

sinoatrial node

Answer 31

initiates & regulates impulses for contractions of the heart | pacemaker of the heart

Question 32

describe the signaling of the SA node | where it goes & how it gets there

Answer 32

transmits through musculature of atria goes to atrioventricular (AV) node

Question 33

where does the atrioventricular (AV) node send signals to?

Answer 33

AV bundle (Bundle of His) spreads to L & R bundle branches which end in purkinjie fibers (subendocaridal branches) in ventricle walls

Question 34

what contracts from signals of the L bundle branch/purkinjie fibers?

Answer 34

interventricular septum papillary muscles walls of L ventricle | NO moderator band here!

Question 35

what contracts from the signals of R bundle branch/purkinjie fibers?

Answer 35

interventricular septum anterior papillary muscle (**via moderator band**) walls of R ventricle

Question 36

what controls the conduction system of the heart?

Answer 36

autonomic nervous system via cardiac plexus

Question 37

where is the cardiac plexus located? what controls the sympathetics & parasympathetics?

Answer 37

anterior to bifurcation of trachea symp - sympathetic trunk parasym - CN X Vagus