heart development

Question 1

the cardiovascular system is the _____ major organ system to function in the embryo at the _____

Answer 1

-first
-end of week 3

Question 2

what is the origin of blood vessels

Answer 2

blood islands: mesodermal mesenchyme cells, gives rise to blood cells, vessels and the heart
-collect at the cranial end

Question 3

middle end of W3:
-day 20:

Answer 3

the embryonic heart reaches the thorax and isa pair of endothelial tubes in the body midline
-the tubes fuse together and pushes blood out of both ends.
-all four chambers arise from tubes

Question 4

day 22:

Answer 4

heart starts pumping
-4 buldges have dev along the heart tube: sinus venosus, atrium, ventricle, bulbus cordis

Question 5

sinus venosus

Answer 5

initially receives all blood from the veins of the embryo
-becomes: smooth walled part of the right atrium, coronary sinus, and the SA node, also the posterior wall of left atrium
-collects deox blood

Question 6

atrium

Answer 6

gives rise to pectinate muscles of right and left atria

Question 7

ventricle:

Answer 7

strongest pumping chamber
-becomes the left ventricle

Question 8

bulbus cordis and truncus arteriosis (cranial extension)

Answer 8

gives rise to the right ventricle, pulmonary trunk, and first part of the aorta

Question 9

when does bending of the heart occur and why

Answer 9

days 23-28
-rapid growth of ventricle and bulbus cordis cause bending

Question 10

bending
what direction do the ventricle and atrium move

Answer 10

-s shape
-ventricle: caudally
-atrium
-cranially

Question 11

result of cardiac looping

Answer 11

the heart fold on itself and assumes its normal position of the left part of the thorax with atria: posteriorly and ventricles: anterior

Question 12

by month 2

Answer 12

the heart divides into a series of chambers by formation of midline atrial and ventricular septa and valves

Question 13

month 2
endocardial cushions

Answer 13

help form the hearts midline septum and valves

Question 14

month 2
interatrial septum

Answer 14

forms by growing caudally from the hearts roof

Question 15

month 2
interventricular septum

Answer 15

grows cranially from the hearts apex

Question 16

month 2
neural crest cells

Answer 16

migrate where the atrium meets ventricle and make valves, base of pulmonary trunk, and descending aorta

Question 17

what are the 3 vascular systems during fetal development

Answer 17

1. intra-embryonic
2. vitelline
3. placental

Question 18

intra-embryonic function and 2 vessels that belong to it

Answer 18

vessels supply blood to and drain blood from embryonic tissues
-dorsal aorta: supplies blood to embryonic tissues
-cardinal veins: return deoxy blood from the body of embryo to the heart tube

Question 19

vitelline function and two vessels

Answer 19

vessels supply blood to and drain blood from the yolk sac, which contributes to blood supply in the GI tract in adults
-paired vitelline arteries
-veins to yolk sac

Question 20

placental vasc system function and 2 vessels

Answer 20

-includes paired umbilical arteries that deliver deoxy blood and fetal wastes to the placenta and umbilical vein that transports highly oxygenated, nutrient rich blood from the placenta.
-umbilical arteries: carries deoxy blood from the heart to the placenta
-veins to placenta: carries oxygenated blood from the placenta to the heart.

Question 21

placental and pulmonary vein

Answer 21

only veins that carry oxygenated blood

Question 22

placental artery and pulmonary artery

Answer 22

only arteries that carry deoxy blood

Question 23

all blood vessels are in place by

Answer 23

month 3

Question 24

during pregnancy the placenta

Answer 24

provides both O2 and nutrients to fetus
-fetal circulation bypass the liver and lungs

Question 25

where does blood filter through in fetal circulation

Answer 25

liver of the mother via the placenta

Question 26

vessels to and from the placenta

Answer 26

-umbilical vein -ductus venosus -IVC and SVC

Question 27

vessels to and from the placenta -umbilical vein

Answer 27

provides oxyg blood from the placenta

Question 28

vessels to and from the placenta -ductus venosus

Answer 28

a shunt that bypasses the liver and enters the IVC, drains to IVC where oxygen rich blood mizes with deox blood returning to heart from caudal region of the body

Question 29

vessels to and from the placenta IVC and SVC

Answer 29

drain moderately oxygenated blood into the right atrium

Question 30

shunts away from the pulmonary circuit

Answer 30

-foramen ovale -ductus artiosis

Question 31

shunts away from the pulmonary circuit -foramen ovale

Answer 31

hole in the interatrial septum; blood can travel from the right atrium- to the left atrium- to left ventricle-aorta- then body

Question 32

shunts away from the pulmonary circuit -ductus arteriosis

Answer 32

between the pulmonary trunk and the aorta, any blood that passes the right atrium follows to the right ventricle- pulmonary trunk- diverts to the aorta-then to the body

Question 33

after birth

Answer 33

alveolar pressure in the lungs causes physiological changes in pulmonary arteries and veins

Question 34

pressure increases in both of the atria and cause the foramen ovale to

Answer 34

close and become the fossa ovalis

Question 35

after birth -ductus arteriosis

Answer 35

degrades and becomes ligamentum arteriosum: CT

Question 36

clamping of the umbilical cord: -umbilical cord

Answer 36

umbilical cord constricts and becomes ligamentum teres that anchors liver to body wall

Question 37

clamping of umbilical cord: -ductus venosus

Answer 37

closes and becomes ligamentum venosum on the inferior surface of the liver

Question 38

clamping of umbilical cord: -umbilical arteries

Answer 38

no longer functions, persist as medial umbilical ligaments

Question 39

the embryo has _____ oxygen levels

Answer 39

lower -due to mixing

Question 40

ventricular septal defect

Answer 40

superior part of interventricular septum fails to form -blood mixes between ventricles

Question 41

transposition of the great vessels

Answer 41

bulbus cordis does not divide properly, aorta comes from right ventricle and pulmonary trunk comes from left ventricle -pumps deox blood to the body

Question 42

tetralogy fallot

Answer 42

-multiple defects -pulmonary infundibulum stenosis: septum with a hole -large IV septal defect: narrow opening -overriding aorta arising directly above the septal defect: misplaced -R ventricular wall hypertrophy due to high R side pressure