Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IMED3001 > Embryology anatomy and histology of the heart > Flashcards

Embryology anatomy and histology of the heart Flashcards

1
Q

What is the first system to function in embryos?

A

The cardiovascular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When does heart development begin?

A

In the 3rd week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When do contractions of the heart begin?

A

day 21 - 22 and blood begins circulating by the end of week 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the formation of germ layers called?

A

Gastrulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens during gastrulation?

A

Inner cell mass composed of epiblast and hypoblast is converted into a trilaminar embryo. Epiblasts come in and replace hypoblast cells with endoderm as they pinch into the hypoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What layer does the heart form from?

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to mesoderm?

A

spreads sideways to form 3 regions: Paraxial mesoderm which forms the somites made up of sclerotome, myotome, and dermatome/ Intermediate mesoderm which forms kidneys and gonads Lateral mesoderm which forms the splanchnic (circulatory system), somatic (body cavity, and extraembryonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where does cardiac muscle come from?

A

Splanchnic mesoderm of the lateral mesoderm axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How is cardiac muscle different to cardiac muscle?

A

Cardiac muscle does not fuse and instead all cells are individual with intercalated disks between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does heart growth and development happen at the cellular level?

A

The heart increases in size with development and then the cells are split with with more intercalated disks joining them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the early stages of heart formation:

A

Cardiac crescent is formed at the cranial end of embryo Horseshoe-shaped distribution of cardiogenic cells after migration through primitive streak Cardiogenic mesoderm forms as paired tubes that fuse in the midline which happens at the same time as neural tube formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the myocardial primordium?

A

Becomes the future endocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens to endocardial premordia?

A

They fuse and become inner lining of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why does the heart start off near the mouth and end up in the chest?

A

Due to a process called longitudinal folding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does the heart start?

A

Anterior to the oropharyngeal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the heart develop?

A

Starts off as 2 lateral mesoderm derived tubes that fuse in the middle and then fold upon themselves into an S bend. Ventricle folds downward and right whereas atrium and sinus venosum fold upward and left.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is blood pumped in day 22 embryonic heart tube before folding?

A

From bottom to top because at this stage the atria are at the bottom and the ventricles are on top.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is the heart tube developed?

A

Initially the heart tube is symmetrical with paired inflow and outflow tubes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens to embryo as it elongates?

A

More somites start to form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many somites does the embryo have on day 35 of development?

A

10 somites (number of somites is used as an indication of time)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens to atria during development on the 25th day?

A

The atria bend dorsally and twist to allow the outflow arteries to exit anterior to them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the common outflow tract made on the 25th day called?

A

The truncus arteriosis and the bulbis cordis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the truncus arteriosis become?

A

The aortic sac and arch system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the bulbis cordis become?

A

The conus arteriosis (eventually forms the aorta and pulmonary trunk)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What does the middle loop of the S become?

A

The right ventricle and the more caudal part becomes the left ventricle. (Think of folding a tube into an S shape and the ventricles being the neighbouring chambers.)

26
Q

What does the sinus venosum become?

A

Smooth part of R atrium Coronary sinus Oblique vein of L atrium

27
Q

How many aortic arches are formed during development?

A

6

28
Q

From most rostral to most caudal what do the aortic arches form?

A

1st pair forms part of maxillary artery in head 2nd pair disappears 3rd pair becomes common and internal carotid arteries 4th pair becomes the subclavian arteries and the aortic arch 5th pair degenerates 6th pair forms the ductus arteriosis and part of pulmonary arches

29
Q

What does the ductus arteriosis do in embryos?

A

Connects the aorta and pulmonary trunk that bypasses the lungs in the foetus

30
Q

What does the ductus arteriosis become in adults?

A

Ligamentum arteriosum

31
Q

How does the pulmonary trunk give rise to the ductus arteriorsus? What happens to right pulmonary artery?

A

Pulmonary arch develops asymetrically: Part of the left becomes the ductus arteriosus Part of the right disappears.

32
Q

Why does the recurrent laryngeal nerve loop around?

A

Most of the distal part of the right pulmonary artery disappears which explains why the recurrent laryngeal nerve loops under seemingly nothing.

33
Q

Where do pulmonary arches come from?

A

From the 6th arch. Pulmonary plexuses initially form which become discrete vessels.

34
Q

What is the path of cardinal veins?

A

Paired anterior cardinal veins meet posterior cardinal veins and form the common cardinal veins and these empty into sinus venosus which collects blood initially into atrium before true atria are formed

35
Q

What is the course of the brachiocephalic vein?

A

left brachiocephalic vein forms later as a new channel. Left side of head ends up draining to right common cardinal vein (which is the future superior vena cava)

36
Q

What does the left common cardinal vein become?

A

The coronary sinus

37
Q

Where does the inferior vena cava come from?

A

Subcardinal plexus tied in with liver and kidney development (FFS)

38
Q

What does the sinus venosus do?

A

Sinus venosus is located under the heart and over all the other abdominal organs

39
Q

Where do the pulmonary veins come from?

A

Pulmonary veins form a separate vessel system as they bud from future left atrium. initially as 4 openings.

40
Q

How is the heart partitioned?

A

After folding the atria are separated from ventricles by folding in of the walls and then the valve is made later on in development. Same happens between ventricles. Interatrial septum is formed as well. Outflow system is developed by the arch systems

41
Q

How are the valves formed?

A

Epicardial tissue.

42
Q

How is the framework of the heart formed?

A

Dorsal and ventral AV cushions form dense connective tissue. These are an important part of the supporting framework of the heart and they are responsible for tethering the valves

43
Q

What is the right AV valve called?

A

tricuspid valve

44
Q

What is the left AV valve called?

A

Mitral valve

45
Q

How are atria split up?

A

Septum primum forms from roof of primitive atria which leaves a hole called the foramen primum. 30% of blood moves to left atrium from right atrium in embryonic heart. Foramen secundum forms on the right of the septum primum from cell death just as foramen primum closes at endocardial cushion. Septum secundum forms on the right of the septum primum which forms a flap like valve between atria. When pulmonary circulation opens the amount of blood that returns from the lungs is drastically increased and so the pressure from the left atrium forces the septum secundom shut over the foramen ovale to form the fossa ovale.

46
Q

https://www.youtube.com/watch?v=5DIUk9IXUaI

A

https://www.youtube.com/watch?v=5DIUk9IXUaI

47
Q

When are septa complete by?

A

5th week

48
Q

What happens to sinus venosum as septation occurs?

A

it shifts towards the right atrium.

49
Q

How are the ventricles separated?

A

IV septum begins at the apex of the loop where L&R ventricle ballooning is taking place.

50
Q

How are 2 outflow tracts made from the bulbis cordis?

A

2 outflow tracts are made called the bulbis cordis which separates via a spiral septum that forms.

51
Q

What is the spiral septum in the bulbis cordis made from?

A

Neural crest derived mesenchyme

52
Q

What kind of tissue does neural crest derived mesenchyme become?

A

Elastic fibers which will be needed for aorta and other great vessels

53
Q

Where does foetus recieve oxygenated blood?

A

Umbilical vein

54
Q

How does blood bypass liver in foetus?

A

Ductus arteriosus

55
Q

How are valves of aortic and pulmonary trunk formed?

A

Mesoderm and neural crest cells contribute to valves. Aortic and pulmonary trunk valves.

56
Q

What kind of valve is the aortic valve?

A

Tricuspid valve. Can be bicuspid which is the most common congenital disorder.

57
Q

What are the most common congenital abnormalities?

A

Interatrial and IV septal defects account for ~50% of abnormalities Abnormal septum secundum so open foramen primum allows mixing of atrial blood which can lead to right atrial hypertrophy increasing blood flow to lungs and causing pulmonary hypertension and increase pressure in right atrium and then cyanosis. Premature closure of foramen ovale causes right sided hypertrophy and babies usually die at birth as left side cannot cope with normal load.

58
Q

What is tetralogy of Fallot?

A

A type of aortic and pulmonary stenosis with the following symptoms: Pulmonary stenosis Membranous IV septal defect Large aorta whose opening extends over the R ventricle R ventricular hypertrophy Result of abnormality of asymmetrical fusion of truncoconal ridges and malalignment of aortic and pulmonary valves

59
Q

What is the incidence of congenital heart defects?

A

4/1000 - 50/1000 varies from study to study.

60
Q

What are the most common congenital heart conditions?

A

Ventricular septal defects (33%) Ostium secundum atrial septal defects (18%) Pulmonary valve abnormalities (10%)

61
Q

Where do developing hearts come from in terms of cell lineages?

A

Cardiogenic mesodermal cels Cellular contributions from neural crest and proepicardium

IMED3001 (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions