(3) Formation Of The Body Cavity (Keim)

Question 1

What weeks are embryonic development occuring?

Answer 1

3-8

Question 2

What events are occuring during embryonic development?

Answer 2

Growth

Morphogenesis

Differentiation

Question 3

When does folding of the embryo occur?

Answer 3

Week 4

Question 4

Within what plane do the head and tail folding occur?

Answer 4

Median plane

Question 5

Describe when and where the heart can initially be seen:

Answer 5

Heart can be seen in front of the oropharyngeal membrane

in the EARLY 4th week

Question 6

What is the septum transversum going to become?

Answer 6

The diaphragm

Question 7

Describe the folding relationship between the developing heart and the septum transversum

Answer 7

The septum transversum flips under the heart

This causes final location UNDER THE HEART

Question 8

The foregut gives rise to:

Answer 8

Some GI Structures

Question 9

The _______ overgrows the heart and septum transversum

Answer 9

Forebrain

Question 10

The ______ overgrows the cloaca and connecting stalk

Answer 10

Forebrain

Question 11

During week 4, describe a major communication event:

Answer 11

Intraembryonic coelom is communicating with the extraembryonic coelom

Question 12

HORIZONTAL FOLDING

Where would the somatic and splanchnic layers of lateral plate mesoderm be located in the inital stage of horizontal folding?

Answer 12

Question 13

HORIZONTAL FOLDING

Where is the intraembryonic coelom?

Answer 13

Question 14

HORIZONTAL FOLDING

What is the end result?

Answer 14

Formation of the Intraembryonic Coelom

(Midgut)

Question 15

HORIZONTAL FOLDING

Technically, what is the intraembryonic coelom?

Answer 15

Space b/w the splanchnic and somatic portions of lateral plate mesoderm

Question 16

HORIZONTAL FOLDING

What does the intraembryonic coelom communicate with?

Answer 16

Extraembryonic coelom

Question 17

What is the splanchnopleura?

Answer 17

Splanchnic layer of the lateral plate mesoderm and the endoderm making up the yolk sack adjacent

Question 18

What is the somatopleura?

Answer 18

Made up of somatic lateral plate mesoderm and ectoderm surrounding the amniotic cavity

Question 19

Where is the splanchnic portion of the lateral plate mesoderm?

Answer 19

Adjacent to the yolk sac

Question 20

Where does pinching off and formation of body cavities occur?

Answer 20

Where the umbillical cord IS NOT!!!

The sides come down and pinch off, forming the structures seen in the image

Question 21

Label the diagram

Answer 21

Question 22

Label the diagram

Answer 22

Question 23

What is ectopia cordis?

Answer 23

Heart forms outside the body

Question 24

What are the results of ectopia cordis?

Answer 24

• Heart formed outside body
• No pericardium
• Will be a bifed sternum
• Can result in death

Question 25

Clinically, how can **ectopia cordis** be identified?

Answer 25

Ultrasound

Question 26

The somatic layer of the lateral plate mesoderm is going to give rise to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 26

The **parietal part** of any organ

Question 27

The **splanchnic** layer gives rise to the _________ layer

Answer 27

Visceral

Question 28

The **pericardial cavity** houses the:

Answer 28

Heart

Question 29

The **peritoneal cavity** comprises:

Answer 29

The abdomen

Question 30

Pericardial Cavity Formation Describe

Answer 30

Lateral folds produce the heart! Combination of **endocardial primordia** that initially has 2 segments, then merges cogether amongst the **pericardial coelom**

Question 31

What is the Somatic Layer? Splanchnic Layer?

Answer 31

Somatic Layer = Parietal Pericardium Splanchnic Layer = Visceral Pericardium

Question 32

What innervates the diaphragm? What nerve roots does it come from?

Answer 32

Phrenic nerves C3, C4, C5

Question 33

The pericardial cavity is separated from the pleural canals by \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 33

Pleuropericardial Folds (Membrane)

Question 34

The pleuropericardial folds come from ________ layer of the \_\_\_\_\_\_\_

Answer 34

SOMATIC; LATERAL PLATE MESODERM

Question 35

Describe the development of lungs:

Answer 35

When the bronchial buds enter the pericardial peritoneal canals, they are immersed in the **splanchnic layer lateral plate mesoderm**. Once those pleuralpericardial folds have separated everything, the pleural cavity for the lungs and mediastinum is formed.

Question 36

Label the diagram

Answer 36

Question 37

Look where the mouse cursor is: What is this derived from?

Answer 37

Parietal pericardium is made from the **somatic layer of lateral place mesoderm**

Question 38

What is the fibrous layer of the parietal pericardium made of?

Answer 38

Somatic layer of the lungs

Question 39

Describe the formation of the diaphragm

Answer 39

The septum transversum requires **pleuralperitoneal folds** to meet the posterior body

Question 40

Closure of the Pericardioperitoneal Canal

Answer 40

The _pericardioperitoneal canal_ is closed by the approximation of the **pleuroperitoneal folds** with the *septum transversum*

Question 41

The septum transversum gives rise to:

Answer 41

Central tendon

Question 42

What are **pleuroperitoneal membranes?**

Answer 42

Overgrown by the muscle walls, don't give rise to adult structures

Question 43

Dorsal mesentary of the esophagus gies rise to:

Answer 43

The **crura**

Question 44

The body wall give rise to:

Answer 44

Peripheral muscles