Brainscape's Knowledge GenomeTM

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


See full index

Cardiovascular System > Embryology > Flashcards

Embryology Flashcards

1
Q

What is the first organ in the body to develop?

A

The heart (functions at 4th week) as the rapidly growing embryo requires more nutrition that placenta can provide

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

What week does the heart tube begin to form?

A

3rd week

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

How does the heart tube form?

A
  1. Angiogenic cell (blood) islands collect in the lateral plate mesoderm (splanchnic)
  2. Moves towards midline of the body and coalesce to form two endocardial heart tubes
  3. After lateral folding, fusion of the endocardial tubes to form the primitive heart tube
  4. Cranial folding brings the heart tube dorsal to the pericardial cavity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does the pericardium form?

A 
Serous pericardium (parietal layer) formed from the somatic mesoderm 
Serous pericardium (visceral layer) formed from the splanchnic mesoderm 
Pericardial cavity formed from intra-embryonic coelom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the pericardial cavity derived from?

A

Into-embryonic coelom

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

What occurs at 21 days?

A

Fused primitive heart tube divides into primitive chambers separated by grooves

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

What are the 5 sections to the primitive heart tube?

A 
Truncus arteriosus 
Bulbis cordis 
Ventricle
Atrium 
Sinus venous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the trunchus arterioles divide into?

A

Two pairs of aortic arches

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

Describe the structure trunchus arteriosus

A

Continues cranially with the aortic sac (where aortic arches arise) and terminates in the dorsal aorta and terminates in the dorsal aorta

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

What 3 veins drain into the horns of the sinus venosus?

A

Vitelline vv.
Umbilical vv.
Common cardinal vv.

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

Where does the vitelline vein drain blood from?

A

Poorly oxygenated blood from the yolk sac

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

Where does the umbilical vv. drain blood from?

A

Well oxygenated blood from the placenta

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

Where does the common cardinal vv. drain blood from?

A

Returns poorly oxygenated blood from the body of the embryo
Main venous drainage of embryo
Anterior, poster and common cardinal veins drain into the sinus venosus of heart tube

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

Explain the formation of the cardiac loop

A

Bubus cordis and ventricle grow faster than other regions from a U-shaped bulboventricular loop - the differential growth rates causes folding to the right

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

What is the abnormality in Dextrocardia?

A

Heart tube loops to the left instead of right, so it faces the right instead of the left, so apex beat is on the right
Usually occurs in situs inverses (when all organs reversed)

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

Describe the steps in the positioning of the primordial heart

A
  1. Endocardial cushion formation - separates R and L atrioventricular opening -> R and L AV canals
  2. Septum formation: separated R + L atria and ventricles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does the partitioning or the primordial atria occur?

A
  1. Septum primum grows from the atria roof and forms Foramen Primum with end. cushion
  2. Part of septum primum moves down and fuses with endo. cushion between the septum - forms foramen secundum
  3. Septum secundum forms on the right for septum primum, and overlaps the foramen secundum as it grows towards the endo. cushion
  4. Foramen ovale formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is the foramen secundum found?

A

Between septum primum

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

Where is the foramen ovale found?

A

Between septum secundum and endocushion

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

What happens to the foramen ovale after birth?

A

Close as there is increased pulmonary flow and there is a shift of pressure to the LV
Septum primum and secundum fuse
Becomes fossa ovalis

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

What is the role of the foramen ovale in the embryo?

A

Blood bypasses the lungs and moves straight from the RA to the LA as the lungs are not functioning
Prevents back flow of blood

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

What does the bulbis cordis become in the adult?

A

Aorta

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

What does the truncus arterioles become in the adults?

A

Pulmonary trunk

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

What does partitioning of the BC and TA occur?

A

5th week

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

What are the stages in partitioning of the BC and TA?

A
  1. Proliferation of mesenchymal cells (neural crest) in the walls of BC and TA
  2. Bulbar ridges and truncal ridges form
  3. They undergo 180 spiralling in formation of aorticopulmonary septum
    This septum divides BC and TA into aorta and pulmonary trunk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When does the SA node (pacemaker) develop

A

During 5th week

27
Q

What do the AV node and the bundle of His develop from?

A

Cells in the AV canal and sinus venosus

28
Q

What causes SIDS?

A

Sudden infant death syndrome due to abnormal conduction in the heart

29
Q

What are the more common congenital heart diseases in females?

A

Atrial septal defect

Patent ductus arterioles

30
Q

What are teratogens that cause congenital heart disease?

A 
Rubella -> PDA
Alcohol -> septal defects
Drugs
Radiation 
Genetic (8%)
Chromosomal (2%)
31
Q

How does situs inverses occur?

A

Autosomal recessive inheritance

32
Q

What is transposition of great vessels?

A

I.e. Aorta from RV and pulmonary trunk from LV
Common cause of cyanotic disease in children
Permit exchange of systemic and pulmonary circulation

33
Q

What causes transposition of great vessels?

A

Failure of aorticopulmonary septum to take a spiral course

Defective migration of neural crest cells

34
Q

What is teratology of fallot?

A

Term used to describe when 4 specific defects are present:
Pulmonary stenosis
Ventricular septal defect
Dextroposition of aorta (overriding aorta)
RV hypertrophy

35
Q

What causes teratology of fallot?

A

Unequal division of the conus due to anterior displacement of aorticopulmonary septum

36
Q

What are the two different methods of blood vessel development?

A

Vasculogenesis (new formation of a primitive vascular network)
Angiogenesis (growth of new vessels from pre-existing blood vessels)

37
Q

Describe the formation of the aortic sac

A

Each endocardial tube has a ventral and dorsal aorta, and when they fuse to form the primitive heart tube, the ventral aorta partially fuse to form the aortic sac (gives rise to aortic arches)

38
Q

What form the aortic arches from the aortic sac?

A

Pharyngeal arteries join the aortic branches to form 6 pairs of aortic arches that terminate at the dorsal aorta

39
Q

What are the fates of aortic arches 1 and 2?

A

Disappear early, but remnants of the 1st arch form the maxillary artery

40
Q

What is the fate of aortic arches 3?

A

Commencement of the internal carotid artery - carotid arch

41
Q

What is the fate of aortic arches 4?

A

R - subclavian artery

L - distal part of aortic arch

42
Q

What is the fate of aortic arches 5?

A

Either never forms, or forms incomplete and regresses

43
Q

What is the fat of aortic arches 6?

A

R - R pulmonary artery of pul. trunk

L - L pulmonary artery and form ductus arteriosus

44
Q

What is the fate of ductus arteriosus after birth?

A

Becomes ligamentum arteriosum

45
Q

What is a common reason for defects with the great arteries occur?

A

Due to arches that should disappear not regressing, or one that should not regress, disappear

46
Q

How does the aberrant subclavian artery occur?

A

When the R subclavian (should come form first branch of arch of aorta, but this defect means it arises from the L side and goes behind trachea and oesophagus (can constrict them)
Regression of the R aortic arch 4 and R dorsal aorta

47
Q

How does a double aortic arch arise?

A

Development of abnormal R aortic arch as well as the L aortic arch, surrounding the trachea and oesophagus causing difficulty breathing and swallowing

48
Q

What is the effect of a patent ductus arteriosus?

A

Fails to close after brith
First year work of breathing harder and poor weight gain
If uncorrected, can cause heart failure

49
Q

What is coarctation of the aorta?

A

Aorta is narrowed around the D. arteriosum inserts - post or pre ductal

50
Q

What do the umbilical arteries develop form?

A

Paired branches of the dorsal aorta

51
Q

What is the fate of umbilical arteries after birth?

A

Proximal: internal iliac and superior vesical branches (to urinary bladder)
Distal: degenerates and becomes medial umbilical ligaments

52
Q

Where does the umbilical vein arise from and why does is carry oxygenated blood?

A

Chorionic villi of placenta and carries oxygenated blood to the RA (to bypass hepatic circulation) -> LA due to foramen ovale (to bypass lungs) then arteries deliver it to body and carry deoxygenated blood to placenta

53
Q

What is the fate of vitelline veins?

A

Portal veins
Hepatocardiac channels (liver to heart as part of IVC)
Liver sinusoids
Superior mesenteric vein

54
Q

What is the fate of umbilical veins?

A

R vein: generate completely

L vein: obliterates and forms ligamentum teres hepatic (round ligament) of adult liver

55
Q

What is the function of ductus venosus in the embryo?

A

Shunts portion of blood of the L umbilical vein blood flow directly to the IVC, this allows oxygenated blood to bypass the liver

56
Q

What is the fate of the ductus vensosus?

A

Obliterate and form ligamentum venosum

57
Q

What is the fair of cardinal veins?

A

Form vena caval system (SVC and IVC) by anastomosis among the veins

58
Q

Name 4 venous system abnormalities

A

Double IVC
Absence of IVC
L SVC
Double SVC

59
Q

What develops at the end of the 6th week?

A

Six primary lymph sacs develop at the end of the sixth week around the main veins - end of embryonic period

60
Q

Describe development of the lymphatic system

A

Form lymph sac initially and will canalise to form the two main lymphatic channels; thoracic duct and lymphatic duct

61
Q

What is the function of the ductus arteriosus

A

Allows blood that escapes the RV (does not pass through the foramen ovale) to bypass the lungs and travel from the pulmonary trunk to the aorta

62
Q

State the different vessels from LA to the placenta

A 
Aorta
Descending aorta 
Abdominal sorta 
Common iliac aa.
Umbilical aa. 
 - Placenta - 
Umbilical vv.
63
Q

What is the effect of patent ductus arteriosus?

A

Failure of muscular walls to contract
Respiratory distress syndrome (low O2)
Lack of surfactant

64
Q

What causes coarctation of the aorta?

A

Incorporation of muscle tissue of DA into arch of aorta (during development), so when DA contracts after birth, part of aorta also constricts
Genetic/environmental factors

Cardiovascular System (37 decks)

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