Lect. 13 - Heart and fetal circulation

Question 1

general charact. of the heart (3)

Answer 1

rests on diaphragm
approximately the size of a closed fist
2/3 of the mass lies L of the midline

Question 2

general reference points of the heart (6)

Answer 2

apex
base
superior R point
superior L point
inferior R point
inferior L point

Question 3

what is pericardium

Answer 3

double-layered membrane that surrounds and protects the heart

Question 4

what 2 layers of pericardium

Answer 4

fibrous layer (outermost)
serous layer (innermost)

Question 5

role of fibrous layer of pericardium

Answer 5

prevents overstretching of the heart

Question 6

parts of serous layer of pericardium

Answer 6

outer parietal layer

inner visceral layer “epicardium”

Question 7

pericardium (4 things)

Answer 7

pericardial cavity
pericardial fluid
pericarditis
cardiac tamponade

Question 8

what is the pericardial cavity

Answer 8

space between visceral and parietal serous layers

Question 9

what is pericardial fluid

Answer 9

fills the space

Question 10

what is pericarditis

Answer 10

inflammation of the pericardium

Question 11

what is cardiac tamponade

Answer 11

build up of fluid resulting on pressure on the heart

Question 12

layers of the heart wall from ext. to int.

Answer 12

1. epicardium
2. myocardium
3. endocardium

Question 13

what is epicardium

Answer 13

visceral layer of the pericardium

Question 14

what is myocardium

Answer 14

cardiac muscle tissue

Question 15

what is endorcardium

Answer 15

inner smooth lining of the chambers
covers the valves of the heart
continuous with the endothelial lining of the large blood vessels

Question 16

4 chambers of the heart

Answer 16

2 upper chambers = atria (and auricle)

2 lower chambers = ventricles

Question 17

right atrium receives blood from three major veins

Answer 17

IVC, SVC, coronary sinus

Question 18

parts of right atrium (4)

Answer 18

right auricle
pectinate muscle
interatrial septum (fossa ovalis)
tricuspid valve

Question 19

what is the fossa ovalis

Answer 19

originally a foramen used for babies when they don’t use their lungs so the blood goes directly into the left atrium

Question 20

parts of right ventricle (5)

Answer 20

trabeculae carneae
cordae tendinae
papillary muscles
interventricular septum
pulmonary semilunar valve

Question 21

left atrium receives blood from

Answer 21

pulmonary veins

Question 22

parts of left atrium (3)

Answer 22

left auricle
pectinate muscle
bicuspid “mitral” valve

Question 23

parts of left ventricle (4)

Answer 23

trabeculae carneae
cordae tendinae
papillary muscles
aortic semilunar valve

Question 24

what are the two atrioventricular valves (AV)

Answer 24

bicuspid and tricuspid valves

Question 25

AV valves- when they are open

Answer 25

pointed end projects into ventricles
blood moves into ventricle
papillary muscles are relaxed
cordae tendinae are slack

Question 26

AV valves- when the ventricles contract

Answer 26

pressure drives the cusps upwards
papillary muscles contract
cordae tendinae are tightened and prevent the cusps from opening into the atrium

Question 27

semilunar valves allow ejection of blood into ___ and prevent backflow into ___

Answer 27

vessels, ventricles

Question 28

semilunar valves charact. (3)

Answer 28

each consists of three cusps
outer border is attached to artery wall
valves are open when ventricular pressure exceeds arterial pressure

Question 29

with each beat, blood is pumped into two circuits

Answer 29

pulmonary circulation and systemic circulation

Question 30

t/f the entire body receives blood from the systemic circulation

Answer 30

false, except lungs that are supplied by the pulmonary circulation

Question 31

coronary arteries originate where

Answer 31

at the base of ascending aorta

Question 32

L. coronary artery supplies (2)

Answer 32

both ventricles & left atrium

Question 33

R. coronary artery supplies (1)

Answer 33

both ventricles

Question 34

name the 5 coronary veins

Answer 34

coronary sinus
great cardiac vein
middle cardiac vein
small cardiac vein
anterior cardiac vein

Question 35

3 phases of the cardiac cycle

Answer 35

relaxation period
ventricular filling
ventricular systole

Question 36

what is systole

Answer 36

phase of contraction

Question 37

what is diastole

Answer 37

phase of relaxation

Question 38

what happens at relaxation period (chambers, blood flow, pressure, valves)

Answer 38

all 4 chambers are in diastole
blood flow back towards ventricles closing the SL valves
pressure falls inside the ventricles
AV valves open and ventricle being filling

Question 39

what happens at ventricular filling (% and valves)

Answer 39

75% occurs without atrial systole
25% occurs with contraction of pectinate muscle
AV valves are open while semi-lunar valves are closed

Question 40

what happens at ventricular systole (blood flow, pressure, valves)

Answer 40

ventricular contraction pushes blood up against AV valves (forcing them to shut)
pressure inside ventricles rises sharply
when pressure exceeds that in arteries, both SL valves open

Question 41

one heart cycle - 4 sounds are generated

Answer 41

s1 = lubb
s2 = dupp
s3 = rapid ventricular filling
s4 = atrial systole

Question 42

what happens at s1 lubb

Answer 42

closing of AV valves

beginning of ventricular systole

Question 43

what happens at s2 dupp

Answer 43

closing of SL valves

end of ventricular systole

Question 44

changes in maternal CV system - SV, CO, HR, blood volume

Answer 44

increase SV 30%
increase CO 20-30%
increase in HR 10-15%
increase in blood volume 30-50%

Question 45

2 adjustments of the infant at birth

Answer 45

closure of foramen ovale

closing of ductis arteriosis (becomes ligamentum arteriosum)