Brainscape's Knowledge GenomeTM

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


See full index

2 CVS > 5&6 Embryology > Flashcards

5&6 Embryology Flashcards

1
Q

By what week is the cardiovascular system active in the embryo?

A
  • Beginning of 4th week
  • (Placenta unable to meet demands of of growing embryo)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the development of the heart begin with the formation of?

A

Primitive heart tube

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

Lateral folding is the first type of folding to occur.

What does it achieve?

A
  • Creates heart tube
  • Brings two precursor regions together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The second type of folding to occur is cephalocaudal folding.

What does this achieve?

A
  • Positions heart tube in future thorax
    • Initially suspended in pericardial cavity by membrane
    • Membrane subsequently degenerates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name the 6 regions of the primitive heart tube?

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

After lateral and cephalocaudal folding, what are the next two steps in the development of the heart?

A
  1. Heart tube elongates
  2. Looping begins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

On roughly what day of development does looping of the primitive heart tube begin?

A

23 days

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

In 2 steps, with reference to the bulbis cordis and the caudal portion (primitive ventricle), how does looping occur?

A
  1. Bulbus cordis:
    1. ​Moves ventrally, caudally, right (forward, down and right)
  2. Caudal portion:
    1. ​Moves dorsally, cranially, left (backwards, up and left)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

At the fourth week where does the primitive atrium receive venous blood from?

A
  • Right and left sinous horns
  • Sinus venosus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What eventually happens to the right and left sinus horns?

(Formation of venous return to the right atrium)

A

Left: recedes as venous return shifts to right side of heart- forms coronary sinus

(responsible for drainage of venous blood from heart itself)

Right: Absorbed by growing right atrium- eventually forms part of inferior vena cava

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

How is venous return to the left atrium formed?

A

4 pulmonary veins incorporated into left atrium

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

Describe the early arterial system.

A
  • Bilaterally symmetrical system
  • Arched vessels

(Undergo extensive remodelling)

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

Each of the aortic arches has a corresponding nerve during development.

Which nerve is the 6th aortic arch associated with?

A

Recurrent laryngeal nerve

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

What happens to the right and left laryngeal nerves?

A
  • Right:
    • Hooks around right 6th aortic arch
    • Distal part of right 6th arch eventually disappears
    • Nerve moves up
    • Hooks around right subclavian artery (4th arch)
  • Left:
    • ​
    • Hooks around left 6th aortic arch
    • Distal part of left 6th aortic arch persists as ductus arteriosus
    • Nerve remains in position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The left recurrent larygeal nerve has a long course, why might this be relevant clinically?

A

Susceptible to pathology in chest

eg. compression by aortic aneurysm

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

Fill in the missing labels:

A
17
Q

What is Patent Ductus Arteriosus (PDA)

A

Persistent communication between:

descending aorta and pulmonary artery

18
Q

In which direction does blood shunt in Patent ductus arteriosus?

A

Left to Right

19
Q

The septation of the primitive atrium requires the formation of how many septa and how many holes?

(Formation of left and right atria)

A
  • Two septa
  • Three ‘holes’
20
Q

Outline how the first septum of the primitive artrium forms.

A
  1. Septum primum forms
    1. Extends towards endocardial cushions
21
Q

Outline how the ostium primum is formed.

A
  1. Ostium primum = hole (before septum primum completes fusion with endocardial cushions)
22
Q

Outline how the ostium secundum is formed.

A
  • Before ostium primum closes
  • Ostium secundum appears in septum primum
23
Q

What happens after the ostium secundum has closed?

A

Second septum begins to grow

24
Q

What is the hole that is present in the second septum called?

A

Foramen ovale

25
Q

What does the presence of the foramen ovale and the ostium secundum allow for?

A

Right to left shunt

(Bypassing non-functional lungs)

26
Q

How does the muscular portion of the interventricular septum form?

A
  • Grows up from floor of ventricles towards fused endocardial cushions
27
Q

What gap does the membranous portion of the interventricular foramen fill?

A

Primary interventricular foramen

(Membranous portion= comprised of CT from endocardial cushions)

28
Q

How is the outflow tract divided into left and right sides?

A
  • Endocardial cushions appear in truncus arteriosus
  • Grow towards each other
  • Twist around each other
  • Form spiral septum
29
Q

Why are vascular shunts required in fetal circulation?

A
  • Bypass liver
  • Bypass non-functioning lungs
30
Q

Name the two shunts which allow the fetal circulation to bypass the lungs.

A
  1. Foramen ovale between 2 atria
  2. Ductus arteriosus between pulmonary trunk and arch of aorta
31
Q

Name the shunt which allow the fetal circulation to bypass the liver.

A
  • Ductus venosus : shunts 30% of umbilical blood directly into inferior vena cava
32
Q

What are the 2 shunts which occur at birth to allow normal adult circulation to be established?

A
  1. Foramen ovale
    1. Intake of air-pulmonary resistance falls
    2. Pressure in left atrium higher than right
    3. Shunt closes due to pressure change
    4. Shunt should fuse by 1yr
  2. Ductus arteriosus
    1. ​Muscular wall contracts to close after birth (mediated by bradykinin)
33
Q

Fill in the missing labels:

A

2 CVS (16 decks)

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