Lecture 28 - Cardiovascular 1

Question 1

which side of the heart contains the tricuspid, and which side of the heart contains the mitral valve?

Answer 1

left = bicuspid
right = tricuspid

Question 2

true or false, the aortic and pulmonary valves are tricuspid semilunar valves

Answer 2

true

Question 3

what is the ligamentum arteriosum

Answer 3

the closed blood vessel from fetal development that shunted blood from the pulmonary artery to the aorta

Question 4

up until 3 weeks, how does the embryo get its nutrients and why?

Answer 4

because it is small enough, it does diffusion. after three weeks, it is too large to do that

Question 5

which stage of pregnancy is the most important

Answer 5

the first trimester, especially early due to all future cells coming from one, have to be careful not to expose it to toxins etc

Question 6

why are there bulbous sections at the 3 week point in heart development?

Answer 6

all stages grow at different rates

Question 7

what is the most caudal structure of the developing heart at the three week stage?

Answer 7

the sinus venosus
- space where the primitive veins drain into

Question 8

what is located just cranial to the sinus venosus

Answer 8

the primitive atrium

Question 9

what separates the primitive atrium from the primitive ventricle

Answer 9

a restriction in the tube called the artioventricular junction

Question 10

what is located just cranial to the primitive atrium

Answer 10

primitive ventricle

Question 11

true or false, there are two each of the primitive atrium and primitive ventricle

Answer 11

false, there is one of each

Question 12

what is located just cranial to the primitive ventricle

Answer 12

the bulbous cordis

Question 13

what separates the primitive ventricle from the bulbous cordis?

Answer 13

the bulboventricular junction

Question 14

describe blood floow through the 3 week heart

Answer 14

into sinus venosus, through primitive atrium, then primitive ventricle, then bulbous cordis and out to periphery via the aortic arches

Question 15

where does the primitive pericardium come from?

Answer 15

the top of the bulbous cordis to the atrioventricular junction

Question 16

what is cardiac looping

Answer 16

24hrs after previous structure
- happens because the primitive heart is growing longer inside a pericardium which is not growing at the same rate and so the heart kinks and bends

Question 17

during cardiac looping, the primitive ventricle moves where?

Answer 17

to the right
caudally
ventrally

Question 18

during cardiac looping, the primitive atrium moves where?

Answer 18

to the left
cranially
dorsally

Question 19

at 3.5 weeks, what do we see with the sinus venosus

Answer 19

there are horns of the sinus venosus

Question 20

what three veins connect to EACH horn of the SV?

Answer 20

• common cardinal vein (drains the embryo)
• umbilical vein (carries ox blood from placenta to embryo)
• vitelline vein (carries nutrient laden blood from diminishing yolk sac to the SV)

Question 21

what happens at week 4?

Answer 21

cardiac looping has finished
- interatrial septum begins to form
- interventricular septum begins to form

Question 22

where does the right ventricle come from in development?

Answer 22

the bulbous cordis, NOT the primitive ventricle

Question 23

at 4 weeks, the bulboventricular junction begins to resemble which future structure of its?

Answer 23

the interventricular septum

Question 24

after the right ventricle is established, what is the other part of the bulbous cordis called?

Answer 24

the conotruncus

Question 25

what does the conotruncus give rise to?

Answer 25

outlet of both ventricles and the arteries

Question 26

how does atrium formation happen?

Answer 26

primitive atrium continued to grow in diameter and is now behind part of the bulbous cordis and separation of the atria is beginning

Question 27

describe the 5 week heart

Answer 27

- sinus venosus unrecognisable - blood returning to heart drains mostly to right horn and so the left horn diminishes - BC differentiated into the conus truncus, containig a conus cordis and a truncus arteriosis

Question 28

why does blood prefer the right horn at 5 weeks?

Answer 28

due to the liver 'redirecting' blood to drain through the right vitellite vein - umbilical regresses eventually

Question 29

what structure becomes the IVC and the SVC?

Answer 29

right common cardinal vein = SVC right vitelline vein = IVC

Question 30

what is the only part left of our left horn?

Answer 30

gave rise to the coronary sinus, where the cardiac veins drain into

Question 31

what does the conus cordis and truncus arteriosis give rise to?

Answer 31

cc = outflow tracts of both ventricles ta = forms proximal aorta and pulmonary trunk

Question 32

BC = ?

Answer 32

conus cordis + truncus arteriosis + right ventricle

Question 33

where do the pulmonary veins come from?

Answer 33

at 6 weeks, they come from differentiation of mesenchymal cells on the back of the left atrium

Question 34

when do the lungs start to develop

Answer 34

6 weeks

Question 35

How does atrial growth during embryonic development affect the structure of inflow vessels to the heart?

Answer 35

the growth and expansion of the atria incorporate parts of the inflow vessels, resulting in the separation and remodeling of a single venous vessel into two separate vessels

Question 36

the vitelline vein carries ________ blood

Answer 36

oxygenated

Question 37

why is the right atrium have a smooth wall?

Answer 37

because it was part of the right sinus venosus that was incorporated or bored out into the atrium

Question 38

how are the aortic and pulmonary arteries separated from the truncus arteriosis?

Answer 38

a pair of spiralling ridges running down the TA and conus cordis fuse together and eventually separate the two vessels.

Question 39

does the spiralling ridge at the conus cordis form the two separated vessels?

Answer 39

no, it then marks the interventricular septum

Question 40

what was the ligamentum arteriosum during pregnancy/just before birth?

Answer 40

the ductus arteriosis

Question 41

do blurting for atrial internal development?

Answer 41

yes, look in your binder