2- Body Folding & Cavities

Question 1

Human development is divided into three sequential phases, which are…

Answer 1

Growth
Morphogenesis
Differentiation

Question 2

This phase of human development involves cell division and elaboration of cell products.

Answer 2

Growth

Question 3

This phase of human development is the development of shape, size, and other features of a particular organ or part of the whole body.

Answer 3

Morphogenesis

Question 4

Morphogenesis is controlled by the _______ expression and regulation in an orderly sequence.

Answer 4

Gene

Question 5

Changes in cell fate, cell shape, and cell movement in _________ allow the cells to interact with each other during the formation of tissues and organs.

Answer 5

Morphogenesis

Question 6

This phase of human development is when cells are organized in a precise pattern of tissues and organs that are capable of performing specialized functions.

Answer 6

Differentiation

Question 7

The primordium of the _________ _________ appears, which are isolated coelomic spaces in the lateral plate and cardiogenic mesoderm. This is a horse-shoe shaped cavity.

Answer 7

Intraembryonic Coelom

Question 8

The Intraembryonic Coelom divides the lateral plate mesoderm into what layers?

Answer 8

Somatic (Parietal) Layer of Lateral Plate Mesoderm

Splanchnic (Visceral) Layer of Lateral Plate Mesoderm

Question 9

This layer of Lateral Plate Mesoderm is continuous with extraembryonic mesoderm covering the amnion.

Answer 9

Somatic (Parietal) Layer

Question 10

This layer of Lateral Plate Mesoderm is continuous with extraembryonic mesoderm covering the umbilical vesicle.

Answer 10

Splanchnic (Visceral) Layer

Question 11

This is the term for the Somatic Mesoderm and overlying embryonic Ectoderm that come together to form the body wall.

Answer 11

Somatopleure

Question 12

This is the term for the Splanchnic Mesoderm and underlying embryonic Endoderm that come together to form the embryonic gut.

Answer 12

Splanchnopleure

Question 13

Where does folding occur in the embryonic planes, all simultaneously?

Answer 13

Cranial
Caudal
Lateral

Question 14

What gives constriction for the folding of the embryonic planes?

Answer 14

The junction of the embryo and umbilical vesicle

Question 15

The embryo goes from a flat, trilaminar embryonic disc to a _________ embryo.

Answer 15

Cylindrical

Question 16

________ is significant for creating the correct body form. The embryo increases in length, but the lateral edges cannot keep pace.

Answer 16

Folding

Question 17

Put the following steps in order of embryonic head folding:

A. Overgrowth moves Septum Transversum, Primordial heart, Pericardial Coelom, and Oropharyngeal Membrane to ventral surface.

B. Embryo elongates cranially and caudally (4th week/day 22).

C. Part of the endoderm of the umbilical vesicle is incorporated as the foregut (primordium of pharynx, esophagus, and lower respiratory system).

D. Neural folds project dorsally and overgrow oropharyngeal membrane.

Answer 17

1) B.
2) D.
3) A.
4) C.

Question 18

Before head folding, the ________ consists of a flattened, horse shoe-shaped cavity

Answer 18

Coelom

Question 19

What are the 3 components of the horse shoe-shaped coelom?

Answer 19

Pericardial Cavity
Pericardioperitoneal Canal
Intraembryonic Coelom

Question 20

After head folding occurs, the Pericardial Cavity is ________ and the Pericardioperitoneal Canals run ________ on each side of the foregut.

Answer 20

Ventral

Dorsal

Question 21

Folding of the caudal end of the embryo is due to the growth of the distal _______ _______.

Answer 21

Neural Tube (Spinal Cord Primordium)

Question 22

In embryonic tail folding, the ______ ______ or tail region projects over the ______ ______ (future anus).

Answer 22

Caudal Eminence

Cloacal Membrane

Question 23

In embryonic tail folding, part of the _________ will form the hindgut (descending colon/rectum). The terminal hindgut dilates to form the ________ (rudiment of urinary bladder/rectum).

Answer 23

Endoderm

Cloaca

Question 24

Before folding the _______ _______ lies cranial to the cloacal membrane, but after folding it lies caudal.

Answer 24

Primitive Streak

Question 25

T/F. The rapid growth of the SC and Somites produces the right and left lateral folds, which extends ventrally toward the midline and creates a cylindrical embryo.

Answer 25

True

Question 26

In lateral folding, the abdominal walls form and incorporates endoderm to form the midgut, which is the _______ _______ primordium.

Answer 26

Small Intestine

Question 27

In lateral folding, the connection between the umbilical vesicle and the midgut is reduced, forming the _________ ________.

Answer 27

Omphaloenteric Duct

Question 28

As the umbilical cord forms, the communication between what cavities narrows?

Answer 28

Intraembryonic and Extraembryonic Coelomic Cavities

Question 29

During lateral folding, the amniotic cavity expands and obliterates most of the Extraembryonic Coelom. Amnion forms the epithelial covering of the...

Answer 29

Umbilical Cord

Question 30

This occurs in approximately 1 in 3000 live births and is protrusion of the viscera. This abdominal defect is to the right of the umbilical cord rather than the midline.

Answer 30

Gastroschisis

Question 31

How does Gastroschisis differ from and Umbilical Hernia?

Answer 31

In Gastroschisis, bowel is uncovered and floating in the amniotic fluid.

Question 32

This is a midline bulge of the abdominal wall, located between the Xiphoid Process and Umbilicus. Bowel is not exposed to the amniotic fluid because it remains covered by skin and subcutaneous tissues.

Answer 32

Congenital Epigastric Hernia

Question 33

The Intraembryonic Coelom will be divided into what cavities?

Answer 33

Pericardial Cavity Pleural Cavities Peritoneal Cavity

Question 34

All the cavities are lined with __________.

Answer 34

Mesothelium ***This is simple squamous

Question 35

The Parietal wall is derived from _________ mesoderm. This is the future Parietal layer of the Peritoneum.

Answer 35

Somatic

Question 36

The Visceral wall is derived from _________ mesoderm. This is the future Visceral layer of the Peritoneum.

Answer 36

Splanchnic

Question 37

Head fold movements reshape the Intraembryonic Coelom, which causes the Pericardial Cavity to relocate ventrally and anterior to the _________.

Answer 37

Foregut

Question 38

The Pericardial Cavity opens into two __________ _________ that are located dorsal to the foregut and the Septum Transversum.

Answer 38

Pericardioperitoneal Canals

Question 39

The caudal Peritoneal Cavity is positioned where?

Answer 39

Where Intraembyronic and Extraembryonic Coeloms are continuous

Question 40

After head folding, the Pericardial Cavity is now cranial to the ________ ________. The heart also repositions and bulges into the Pericardial Cavity.

Answer 40

Septum Transversum

Question 41

The caudal foregut, midgut, and hindgut are suspended in the Peritoneal Cavity by...

Answer 41

Dorsal Mesentery

Question 42

The Pericardioperitoneal Canals are lateral to the foregut but dorsal to the _________ _________, which is the primordium of the central tendon of the diaphragm. Partitions form in each Pericardioperitoneal Canal due to growth of the primordial lungs.

Answer 42

Septum Transversum

Question 43

To divide the body cavity, there is a cranial __________ fold and a caudal ________ fold. The cranial fold is located superior to the lungs and separates Pleural Cavities from the Pericardial Cavity. The caudal fold is located inferior to the lungs and separates Pleural Cavities from the Peritoneal Cavity.

Answer 43

Pleuropericardial | Pleuroperitoneal

Question 44

_________ folds are located superior to the developing lungs. They enlarge and form __________ membrane that project into the Pericardioperitoneal Canals.

Answer 44

Pleuropericardial | Pleuropericardial

Question 45

The Pleuropericardial Membranes fuse with mesenchyme ventral to the esophagus during the ______ week. Now, the Pericardial Cavity and Pleural Cavities are separated.

Answer 45

7th

Question 46

________ _______ will grow into the Pericardioperitoneal Canals and will extend ventrally, causing the cavity to expand.

Answer 46

Bronchial Buds

Question 47

As the Bronchial Buds grow into the cavity, it splits the mesenchyme into what layers?

Answer 47

Outer Layer = Thoracic Wall Inner Layer = Fibrous Pericardium (Outer layer of the Pericardial Sac)

Question 48

Pleuroperitoneal folds enlarge and project into the Pericardioperitoneal Canals, which forms the ________ ________. These form as developing lungs and the Pleural Cavities expand/invade the body wall. Attach dorsolaterally to the abdominal wall.

Answer 48

Pleuroperitoneal Membranes

Question 49

The Pleuroperitoneal Membranes fuse with the dorsal mesentery of the esophagus and Septum Transversum during the ______ week. The Pleural Cavities and Peritoneal Cavity are now separated.

Answer 49

6th ***Remember, the Pleuropericardial Membranes fuse during the 7th week!

Question 50

_________ migrate into the Pleuroperitoneal Membranes and complete the closure process. The Pleuroperitoneal opening on the ________ closes slightly before the ________.

Answer 50

Myoblasts Right Left

Question 51

This expands and fuses with the Dorsal Mesentery of the Esophagus and Pleuroperitoneal Membranes. It becomes the Central Tendon of the Diaphragm.

Answer 51

Septum Transversum

Question 52

This fuses with the Dorsal Mesentery of the Esophagus and Septum Transversum. It becomes the primordial Diaphragm.

Answer 52

Pleuroperitoneal Membranes

Question 53

This becomes the median portion of the Diaphragm.

Answer 53

Dorsal Mesentery

Question 54

These grow into the Dorsal Mesentery and become the Crura of the Diaphragm.

Answer 54

Myoblasts

Question 55

The Pleuropericardial Membranes form partitions that separate separate Pericardial and Pleural Cavities. These membranes contain cardinal _______ and _______ migrating through the Diaphragm.

Answer 55

Veins | Myoblasts

Question 56

Myoblasts pull Ventral Rami _______ with them, then pass through the Pleuropericardial Membranes. The ________ N. subsequently lies on the Fibrous Pericardium.

Answer 56

C3-C5 | Phrenic

Question 57

This is a posterolateral defect in 1 in 2200 live births. It occurs when the viscera bulges into the Pleural Cavity, causing the lung maturation to be delay and polyhydramnios may be present. The left side is typically impacted and can be corrected at birth.

Answer 57

Congenital Diaphragmatic Henria (CDH)