fetal circulation/heart II

Question 1

blood returns to the fetus from the placenta via the……..

it is ……..% saturated with Oxygen

Answer 1

umbilical vein

80%

Question 2

Blood from the umbilical vein bypasses the liver via the……and flows to the inferior vena cava

Answer 2

ductus venosus

Question 3

most of the blood from the inferior vena cava passes through the right atrium to the left atrium via the ……

Answer 3

foramen ovale

Question 4

some of the blood from the IVC mixes with…….. blood in the right atrium

Answer 4

deoxygenated blood

Question 5

After blood leaves the right ventricle and heads to the pulmonary trunk, instead of going to the lungs via pulmonary arteries, majority of it heads towards the arch of the aorta via the

Answer 5

ductus arteriosus

Question 6

Blood heads down the descending aorta and returns to the placenta by way of two ……
at this point the blood is …….% saturated with O2.

Answer 6

Umbilical arteries

58%

Question 7

Upon an infants first breath two important things happen. The first breath inflates the lungs. The change in pressure in the thorax causes…… This forces the foramen ovale shut.

Answer 7

blood pressure change in RIGHT atrium ( falls lower than left atrium).

Question 8

Other circulatory changes that happen: fetal structures become ligaments.
The ductus arteriosus becomes……

Answer 8

ligamentum arteriosus

Question 9

The umbilical arteries close and form the …..

Answer 9

medial umbilical ligaments and superior vesical arteries.

Question 10

The umbilical vein closes and forms the

Answer 10

ligamentum teres hepatis (round ligament of the liver).

Question 11

The ductus venosus closes and forms the

Answer 11

ligamentum venosum.

Question 12

The heart borders on the left side are:

Answer 12

ribs 2-5 INTERCOSTAL spaces @ midclavicular line

Question 13

The heart borders on the right side are :

Answer 13

ribs 3-6 at costal cartilage

Question 14

what sounds are you listening for when performing a heart auscultation (4 locations)

Answer 14

Listening to the : Aortic valve, pulmonary valve, tricuspid, and mitral

(APTM)

Question 15

The first branch off the aorta to the heart is the…

Answer 15

Left coronary artery ( most common place of occlusion)

Question 16

What distinguishes a right dominant heart from a left dominant heart?

Answer 16

a right dominant heart has the posterior inter ventricular artery coming off the right coronary artery.

a left dominant heart has the posterior inter ventricular artery coming from an enlarged branch of the left circumflex artery.

Question 17

the cardiac skeleton forms a ring around each four valves. It functions to maintain the shape of the valves, electrically isolates the atria from the ventricles, and

Answer 17

maintains attachment for the cusps of the valves

Question 18

Does the heart need innervation from the nervous system to beat?

Answer 18

no! it has myocardial cells…not neural cells.

Question 19

outside input from the nervous system is needed however for:

Answer 19

changing the rate or force of conduction