Body Cavities

Question 1

Isolated spaces in the _____ will form the Intraembryonic Coelom

Answer 1

Lateral plate mesoderm AND

Cardiogenic mesoderm

Question 2

What shape is the intraembryonic coelom?

Answer 2

Horseshoe-shaped (U)

Question 3

What is the embryonic body cavity?

Answer 3

Intraembryonic coelom

Question 4

The growth of the intraembryonic coelom will separate the lateral plate mesoderm into what 2 layers?

Answer 4

1. Somatic (parietal) lateral mesoderm

2. Splanchnic (visceral) lateral mesoderm

Question 5

Somatic lateral mesoderm + overlying ectoderm =

Answer 5

Somatopleure

Question 6

What will the somatopleure eventually form?

Answer 6

Body wall

Question 7

Splanchnic lateral mesoderm + underlying endoderm =

Answer 7

Splanchnopleure

Question 8

What will the splanchnopleure eventually form?

Answer 8

Gut

Question 9

The intraembryonic coelum will be divided into what 4 cavities?

Answer 9

1. Pericardial cavity
2. 2 Pleural cavities
3. Peritoneal cavity

Question 10

What mesothelium will line the parietal wall (peritoneum)?

Answer 10

Somatic mesoderm

Question 11

What mesothelium will line the visceral wall (peritoneum)?

Answer 11

Splanchnic mesoderm

Question 12

When does head folding occur?

Answer 12

4th week (day 22)

Question 13

Describe head folding

Answer 13

Neural folds project and overgrow the oropharyngeal membrane to push primordial heart and pericardial cavity inferior to correct location

Question 14

Head fold movements reshape the pericardial cavity to what location?

Answer 14

Ventral and anterior to the foregut

Question 15

Head fold movements reshape the 2 pericardioperitoneal canals to which locations?

Answer 15

Dorsal and on each side of the foregut

Question 16

The pericardial cavity opens into what 2 canals?

Answer 16

2 Pericardioperitoneal canals

Question 17

Describe tail folding

Answer 17

Caudal eminence projects over the cloacal membrane

Question 18

After tail folding, where is the primitive streak?

Answer 18

Caudal

Question 19

With lateral folding, what grows rapidly to cause it and the tissues extend which direction?

Answer 19

The spinal cord and somites grow rapidly

- Lateral folds extend ventrally

Question 20

With lateral folding, what wall forms?

Answer 20

Abdominal wall

Question 21

With lateral folding, the connection between the umbilical vesicle and midgut gets reduced to form?

Answer 21

Vitelline duct

Question 22

With lateral folding, the connection between the IE and EE coelom is narrowed to form?

Answer 22

Umbilical cord

Question 23

What will eventually expand and obliterate the EE coelom?

Answer 23

Amniotic cavity

Question 24

Body wall malformations involve the failure of?

Answer 24

Lateral body folds to fuse completely and form the anterior abdominal wall

Question 25

Gastroschisis

Answer 25

Protrusion of viscera to the RIGHT

- Bowel UNcovered

Question 26

Congential Epigastric Hernia

Answer 26

MIDLINE bulge of abdominal wall

- Bowel COVERED with skin and subcutaneous tissues

Question 27

What 2 folds from at the top and bottom of the pericardioperitoneal canals to form separate cavities?

Answer 27

1. Pleuropericardial folds

2. Pleuroperitoneal folds

Question 28

The pleuropericardial folds separate?

Answer 28

Pericardial cavity and pleural cavities

- heart and lungs

Question 29

The pleuroperitoneal folds separate?

Answer 29

Pleural cavities and peritoneal cavity

- lungs and gut

Question 30

The pleuropericardial folds and pleuroperitoneal folds are outgrowths of the?

Answer 30

Lateral body wall

Question 31

As the pleuropericardial folds and pleuroperitoneal folds enlarge, they form?

Answer 31

Pleuropericardial membrane

Pleuroperitoneal membrane

Question 32

The pleuropericardial membranes fuse with ventral mesenchyme at what week?

Answer 32

7th week

Question 33

What causes the pleural cavities to expand?

Answer 33

Outgrowth of bronchial buds (lungs) into the pericardioperitoneal canals

Question 34

As the pleural cavity expands, what does it split the mesenchyme into?

Answer 34

1. Outer layer = thoracic wall

2. Inner layer = fibrous pericardium

Question 35

____ contribute to the pleuroperitoneal membranes to complete their closure

Answer 35

Myoblasts

Question 36

Which pleuroperitoneal opening closes first?

Answer 36

RIGHT one

Question 37

What does the pleuroperitoneal membrane fuse with?

Answer 37

Dorsal mesentary of the esophagus and

Septum transversum

Question 38

The septum transversum creates what part of the diaphragm?

Answer 38

Central tendon

Question 39

The pleuroperitoneal membranes create what part of the diaphragm?

Answer 39

Primordial diaphragm

Question 40

The dorsal mesentary of the esophagus creates what part of the diaphragm?

Answer 40

Median portion

Question 41

The myoblasts create what part of the diaphragm?

Answer 41

Crura of diaphragm

Question 42

Describe how the diaphragm becomes innervated via the phrenic nerve

Answer 42

• Myoblasts pull C3-C5 ventral rami with them
• Pass through the pleuropericardial membranes
• Phrenic nerve subsequently lies on the fibrous pericardium to innervate the diaphragm

Question 43

Congenital diaphragmatic hernia

Answer 43

Lack of myoblasts populating pleuroperitoneal membranes = area of weakness and viscera can bulge into pleural cavities

Question 44

Which side is usually impacted the most by a congenital diaphragmatic hernia?

Answer 44

LEFT side

Question 45

What may be delayed with a congenital diaphragmatic hernia?

Answer 45

Lung development