Lecture 20: Embryology of the Heart, Lungs, and Diaphragm Flashcards Preview

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Flashcards in Lecture 20: Embryology of the Heart, Lungs, and Diaphragm Deck (60):
1

What forms the right and left endocardial tubes and adjacent myocardial plates of the heart?

lateral plate mesoderm

2

What happens with the two endocardial tubes and myocardial plates

they come together to form one heart tube

3

What are the two layers of the heart tube?

endocardial layer surrounded by a myocardial layer

4

Describe the movement (looping) of the heart tube during the first few weeks of embryogenesis

structures forming the right side of the heart (right atrium and ventricle) swing anteriorly and the left swings to the posterior

5

What is septation

The creation of two atria and ventricles and divides the AV canal and ventricular outflow from aorta and pulmonary trunk

6

What is created first the atrium or ventricles?

They are made simultaneously

7

What forms the AV valves (tricuspid and mitral)

endocardial cushion

8

What forms the aortic and pulmonic semilunar valves?

Endocardial cushion

9

Embryological derivative of the medial wall of left atrium

septum primum

10

Embryological derivative of the medial wall of right atrium

septum secundum

11

Ostium primum

hole in the septum premum that leads into the AV canal

12

What closes the ostium primum

endocardial cushion

13

Ostium secundum

Forms in the septum premium as osmium primum closes

14

What closes ostium secundum

septum secundum

15

What happens to the growth of the septum secundum once the ostium secundum closes

It stops growth

16

When septum secundum stops growing, what forms

foramen ovale

17

Role of foramen ovale

Shunts blood from the right atrium to the left atrium

18

Left heart hypoplasia

premature closing of foramen ovale

19

What forms the membranous portion of the inter ventricular septum

endocardial cushion

20

Ostium primum atrial spetal defect

inadequate development of the cushions can cause failure of final closure of the atrial septum

21

Membranous ventricular septal defect

inadequate development of the cushions can cause failure of final closure of the ventricular septum

22

Persistent AV canal

most severe defect involving the endocardial cushion

23

Ventricular septal disease (VSD)

When the muscular and membranous inerventricular septa do no fuse together

24

Defects in septation are often accompanied by...Why?

Defects in the heart because anything that alters blood flow will affect the path or volume of flow

25

Example of how defects in aorticopulmonary septation results in ventricular septal defects underlying one or both great vessels

Tetralogy Fallot

26

Describe the 4 defects from Tetralogy Fallot

(OVEN). Overriding aorta, Ventricular spetal defect, Pulmonary stenosis (narrow right ventricular outflow tract), Right ventricular hypertrophy (due to higher pressures on the right side of the heart)

27

What do the aortic arches arise from

aortic sac

28

Right and Left aortic arch IV

Right: Right subclavian a.
Left: Arch of aorta

29

Connection between the recurrent laryngeal branches and aortic arch IV

The recurrent branches recur around aortic arch IV

30

Aortic Arch VI

Right and left pulmonary arteries and ductus arteriosum on the left side

31

Structures in the respiratory tract that derive from endoderm?

Epithelial linings of
-larynx
-trachea
-bronchi
-bronchioles
-terminal alveoli

32

what structures in the respiratory tract derive from splanchnic mesoderm?

The cartilage, muscle, and CT components of:
-trachea
-lungs
-pulmonary blood vessels

33

Where is there open communication between the respiratory divritiulum and forget in the embryo

Trachea (respiratory divriticulum) and the esophagus (forgut)

34

Which is located more anterior the esophagus or trachea

trachea

35

Tracheoesophageal fistula

esophagus ends in a blind pouch (baby throws up food)

36

What does the main stem of the lung bud (respiratory divriticulum) form

trachea

37

Where do the bronchial buds come from?

lateral outpocketings of the lung buds

38

What do the bronchial buds form

mainstem (or primary) bronchi

39

How many secondary bronchus are formed by the right mainstream bronchi? left?

Right: 3 (one per lobe)
Left: 2 (one per lobe)

40

Type II pneumocyte

type of cells derived from endoderm in the alveolar ducts and alveoli. Produces surfactant

41

What is the role of surfactant

prevents lungs from collapsing during expiration

42

Respirtory Distress Syndrome (RDS)

happens in some premature infants due to inadequate levels of surfactant in lung airways

43

What structures of the diaphragm derived from somatic lateral plate mesoderm

-Septum transverum
-Pleuroperitoneal membranes

44

What structures of the diaphragm derived from myoblasts

skeletal muscle cells

45

What structures of the diaphragm derived from mesenchyme surrounding the forgut

dorsal mesentery of esophagus

46

What did the crura of the diaphragm arise from

dorsal mesentery of esophagus

47

Which portions of the respirator system derived from the forgut?

Trachea, bronchi, alveoli, alveolar ducts

48

How does splanchnic mesoderm contribute to the formation of the lungs

All cartilage, muscle, and CT in the trachea and lungs developed from splanchnic mesoderm

49

How can the esophageotrachea fistula form

An abnormal separation between the trachea and the esophagus uses the esophagus to end in a "blind pouch"

50

What are the cellular derivatives of endoderm in the bronchial tree/lung

Epithelial singing of larynx, trachea, bronchi, brochioles, terminal alveoli

51

How is the diaphragm formed?

Septum transversum, pleuroperitoneal folds, mesoesophagus, myoblasts (skeletal muscle)

52

Where are defects in the diaphragm normally found and why?

In the pleuroperitoneal folds because the pleura and peritoneum fail to fuse

53

Basic formation of the heart

Lateral plate mesoderm forms two endocardial tubes and two adjacent myocardial plates. These come together to form one heart tube with and endocardial and myocardial layer.

54

What is the endocardial cushion? What is its clinical significance?

Forms the tricuspid, mitral, pulmonic, and aortic valve. When there is a deficiency in the endocardial cushion many clinical issues arise (i.e osmium premum atrial septal defect or membranous ventricular septal defect).

55

How is the intertribal septum formed

endocardial cushion

56

What is a common defect of the interatrial septum

Persistent AV canal

57

What is the Tetrology of Fallot

Septum dividing the aorta and pulmonary artery is displaces resulting in the 4 defects: Over-riding aorta, ventricular septal defect, pulmonary stenosis, and right ventricular hypertrophy

58

What are the aortic arches

IV and VI left and right

59

What is derived from the 4th aortic arch on the right and left side

Right: Subclavian a.
Left: Arch of aorta

60

What is derived from the 6th aortic arch

Pulmonary arteries (ductus venosum on the left)