Exam 3: Circulatory System: Heart

Question 1

2 pathways of circulation

Answer 1

pulmonary: deoxygenated blood directed to lungs for gas exchange
systemic: oxygenated blood directed to organs and tissues of body to undergo gas exchange and transport of various materials/nutrients

Question 2

bronchial circulation

Answer 2

blood vessels feeding bronchi and trachea - tissues of the lungs

Question 3

carry blood away from heart
carry blood to heart
allow for exchange between blood and tissues

Answer 3

artery
vein
capillary

Question 4

right side vs left side of heart

Answer 4

right side: collects and pumps deoxygenated blood

left side: collects and pumps oxygenated blood

Question 5

embryonic development of heart

Answer 5

-begins in third week when diffusion no longer sufficient
-heart begins as tube, by looping to the right it starts to form pockets which become the chambers
-septum formation between chambers begins at end of the 4th week but may not complete until birth
atria separate by 5th week
separation of ventricles 6th/7th week

Question 6

coronary sinus

Answer 6

collects all of the blood returning and feeding the heart muscle - need blood vessels to go on outside of heart to feed the muscle, not the chambers

Question 7

chordae tendinae

Answer 7

attach AV valves to the floor of the ventricle

Question 8

papillary muscles

Answer 8

raised muscles that attach to chordae tendinae - help it slam shut

Question 9

ligamentum arteriosum

Answer 9

only remnant you have left from when fetus and blood went straight from the RV to the aorta bc oxygen was retrieved from the placenta, not the lungs

Question 10

atrioventricular valves prevent backflow of

Answer 10

blood from ventricles to the atrium

Question 11

semilunar valves prevent backflow from

Answer 11

pulmonary trunk and aorta in the ventricles

Question 12

S1 heart sound

Answer 12

“lub”
closing of the AV valves
prevents backflow into atria while ventricles contracting
S1 marks beginning of ventricular systole

Question 13

S2 heart sound

Answer 13

“dub”
closing of semilunar valves
prevents backflow from aorta and pulmonary artery while ventricles are relaxing to fill
S2 marks beginning of ventricular diastole

Question 14

how to drain deoxygenated blood?

Answer 14

interventricular sulcus at front of heart runs between the ventricles

great cardiac vein comes up and goes around drains on backside - posterior cardiac vein

middle cardiac vein comes up and fuses with coronary sinus
into cardiac vein and then sinus and then RA

Question 15

Feeding the heart

Answer 15

systemic circulation LV to aorta

1st muscles off aorta before arch: R coronary artery and L coronary artery

Question 16

Right coronary artery

Answer 16

goes around coronary sulcus

posterior descending arteries feed back of eart

Question 17

2 branches of the Left coronary artery

Answer 17

• left anterior descending artery (LAD) : widow maker, if block in this you can detect on ECG and trace, this is the main artery for feeding!!!!! it goes down the interventricular sulcus
• left circumflex: small, feeds posterior regions

Question 18

outermost toughest layer of the heart

Answer 18

fibrous pericardium

Question 19

2 parts of the serous pericardium

Answer 19

secretes serous fluid filtered from plasma - keeps friction low in heart
parietal pericardium: lines inside fibrous portion

visceral pericardium (epicardium): surface of heart

Question 20

protective layers of heart if get inflammation or bleeding

Answer 20

fluid impairs ability of heart to function

fibrous pericardium is tough and does not give which makes it harder for heart to relax and fill

Question 21

how are cardiac muscle cells connected to eachother

Answer 21

intercalated discs

Question 22

each cell is capable of automaticity because of…

Answer 22

hyperpolarization activated cyclic nucleotide (HCN) channels in the cell membrane

when hyperpolarized you are opening a bunch of channels - constantly filling and contracting

Question 23

the rapid depolarizing cells become the _____ of the heart

Answer 23

pacemaker

Question 24

ectopic pacemakers

Answer 24

dangerous to heart function

regions that can cause contractions if the signals from the pacemaker (SA node) are blocked

Question 25

funny channel

Answer 25

the decrease in membrane potential to -60 activates different population of channels

dropping to -60 triggers cAMP which activates funny channels to open allowing Na+ enter the cells
starts conduction cycle and sets pace
aka pacemaker current

Question 26

electrical conduction and pacemakers

Answer 26

conductive pathway begins at -60
allows influx of Na into cell until threshold use
at threshold Ca channels open causing influx and depolarization
influx channels close and K+ channels open and K goes out
when membrane potential returns to -60 K channels close, Na open
no RMP

Question 27

surrounding muscle tissue has RMP of _____

Answer 27

-90 and conducts action potential via Na flow through gap junctions

Question 28

SA node depolarizes and has three tracts down RA to atrial ventricular node
bacchmans bundle goes to LA
delay in conduction between atria and ventricles

Answer 28

gives time for ventricles to fill

Question 29

purkinje fibers

Answer 29

bundle of hiss divides into right and left bundle branches ad they go into purkinje fibers

they branch into th muscular walls of ventricles ; start depolarization for contraction

Question 30

is the conductive tissue in the heart cardiac or nerve tissue

Answer 30

cardiac

Question 31

the atrial conduction system consists of

Answer 31

3 internodal tracts

Bachmans bundle

Question 32

the ventricular conduction system consists of

Answer 32

bundle of his
left and right bundle branches
purkinje fibers

Question 33

the SA node sets the

Answer 33

normal sinus rhythm

Question 34

overdrive suppression

Answer 34

bc the SA node depolarizes faster it activates other conductive tissue suppressing their slower pace from being expressed

Question 35

sympathetic neurons

Answer 35

release NE targeting B1 receptors in SA node

increases rate, force, sensitivity to depolarization

Question 36

parasympathetic neurons

Answer 36

releas Ach targeting cholinergic receptors in SA and AV nodes
decreases rate, force, sensitivity