Body Cavities, Mesenteries, And Diaphragm

Question 1

Early int he fourth week of development, the ___ __-the primordium of the body cavities-appears as a horseshoe-shaped cavity

Answer 1

Intraembryonic coelom

Question 2

The bend in this cavity at the cranial end of the embryo represents the future ___ ___, and its limbs indicate the future pleural and peritoneal cavities

Answer 2

Pericardial cavity

Question 3

The distal part of each limb of the intraembryonic coelom is continuous with the ___ ___ at the lateral edges of the embryonic disc

Answer 3

Extraembryonic coelom

Question 4

This communication is important because most of the midgut normally herniated through this communication into the __ ___

Answer 4

Umbilical cord

Question 5

The intraembryonic coelom provides room for the abdominal organs to __ and ___

Answer 5

Develop

Move

Question 6

During the embryonic lateral folding, the limbs of the coelom are brought together on the __ aspect of the embryo

Answer 6

Ventral

Question 7

The ___ ___ becomes the embryonic body cavity, which is divided into three well-defined body cavities during the fourth week: a pericardial cavity, two pericardioperitoneal canals connecting the pericardial and peritoneal cavities, and a large peritoneal cavity.

Answer 7

Intraembryonic coelom

Question 8

These body cavities are lined by the mesothelium- a parietal wall derived from the ___ ___ and a visceral wall derived from the ___ ___

Answer 8

Somatic mesoderm

Splanchnic mesoderm

Question 9

The mesothelium forms the major portion of the ___

Answer 9

Peritoneum

Question 10

The peritoneal cavity is connected to the extraembryonic coelom at the ___

Answer 10

Umbilicus

Question 11

The peritoneal cavity loses its connection with the extraembryonic coelom during the 10th week as the intestines return to the abdomen from the umbilical cord

Answer 11

Ok

Question 12

During formation of the head fold, the heart and __ __ are relocated ventrocaudally, anterior to the foregut.

Answer 12

Pericardial cavity

Question 13

As a result , the pericardial cavity opens into the ___ ___, which pass dorsal to the foregut

Answer 13

Pericardioperitoneal canals

Question 14

After embryonic folding, the caudal parts of the __, __, and ___ are suspended into the peritoneal cavity from the dorsal abdominal wall by the __ ___

Answer 14

Foregut, midgut, and hindgut

Dorsal mesentery

Question 15

A mesentery is a double layer of ___ that begins as an extension of the visceral peritoneum that covers an organ

Answer 15

Peritoneum

Question 16

The mesentery connects the organ to the body wall and conveys its __ and __

Answer 16

Vessels and nerves

Question 17

Transiently, the dorsal and ventral Mesenteries divide the peritoneal cavity into right and left halves

Answer 17

The ventral mesentery soon disappears, except where it is attached to the caudal part of the foregut

Question 18

The peritoneal cavity then becomes a continuous space

Answer 18

The peritoneal cavity then becomes a continuous space

Question 19

The arteries supplying the primordial gut-what are they-pass between the layers of the dorsal mesentery

Answer 19

Celiac arterial trunk
Superior mesenteric artery
Inferior mesenteric artery

Question 20

Each pericardioperitoneal canal lies ___ to the proximal part of the foregut and __ to the septum transversum

Answer 20

Lateral

Dorsal

Question 21

What is the septum transversum

Answer 21

A thick plate of mesoderm that occupies the space between the thoracic cavity and the omphaloenteric duct

Question 22

The septum transversum is the primordium of the central tendon of the ___

Answer 22

Diaphragm

Question 23

Partitions form in each pericardioperitoneal canal, separating the pericardial cavit from the pleural cavities, and the pleural cavities from the peritoneal cavity

Answer 23

Ok

Question 24

Because of the growth of the __ ___ into the pericardioperitoneal canals

Answer 24

Bronchial buds

Question 25

What are the pericardioperitoneal canals

Answer 25

Pair of membranous ridges is produced int he lateral wall of each canal

Question 26

The cranial ridges-the __ __-are located superior to the developing lungs, and the caudal ridges- the __ __- are located inferior to the lungs

Answer 26

Pleuropericardial folds | Pleuroperitoneal folds

Question 27

As the pleuropericardial folds enlarge, they form partitions that separate the pericardial cavity fromt he pleural cavities. What are the partitions called

Answer 27

Pleuropericardial membranes

Question 28

What do pleuropericardial membranes contain

Answer 28

Common cardinal veins , which drain the venous system into the sinus venosus of the primordial heart

Question 29

Initially the bronchial buds are small relative to the heart and pericardial cavity.

Answer 29

Ok

Question 30

They grow laterally from the caudal end of the trachea into the ___ ___

Answer 30

Pericardioperitoneal canals

Question 31

As the primordial pleural cavities expand ventrally around the heart, they extend into the body wall, splitting the mesenchyme into two layers

Answer 31

An outer later that becomes the thoracic wall An inner layer (pleuropericardial membrane) that becomes the fibrous pericardium, the outer layer of the pericardial sac that encloses the heart

Question 32

The pleuropericardial membranes project into the cranial ends of the pericardioperitoneal canals

Answer 32

With subsequent growth of the common cardinal veins, positional displacement of the heart and expansion of the pleural cavities , the pleuropericardial membranes become mesentery-like folds extending fromt he lateral thoracic wall

Question 33

By the seventh week, the pleuropericardial membranes fuse with the mesenchyme ventral to the esophagus, separating the pericardial cavity from the pleural cavities

Answer 33

The primordial mediastinum consists of a mass of mesenchyme that extends from the sternum to the vertebral column, separating the developing lungs

Question 34

The right pleuropericardial opening closes slightly earlier than the left one and produces a larger __ __-

Answer 34

Pleuropericardial membrane

Question 35

The pleuroperitoneal folds enlarge, they project into the ___ __

Answer 35

Pericardioperitoneal canals

Question 36

Gradually, the folds become membranous , forming the ___ ___

Answer 36

Pleuroperitoneal membranes

Question 37

Eventually, these membranes separate the pleural cavities from the peritoneal cavity.

Answer 37

The pleuroperitoneal membranes are produced as the developing lungs and pleural cavities expand and invade the body wall. They are attached dorsolaterally to the abdominal wall and their crescentic free edges initially project into the caudal ends of the pericardioperitoneal canals

Question 38

During the 6th week, the pleuroperitoneal membranes extend ventromedial until their free edges fuse with the dorsal mesentery of the esophagus and the __ __

Answer 38

Septum transversum

Question 39

The pleuroperitoneal membranes separates the pleural cavities from the peritoneal cavity

Answer 39

Closure of. The pleuroperitoneal openings is completed by the migration of myoblasts into the pleuroperitoneal membranes

Question 40

The pleuroperitoneal opening on the r__side closes slightly before the __ one

Answer 40

Right left

Question 41

The diaphragm is a

Answer 41

Dome shaped , musculotendinous partition that separates the thoracic and abdominal cavities

Question 42

The diaphragm develops from four embryonic components

Answer 42

Septum transversum Pleuroperitoneal membranes Dorsal mesentery esophagus Muscular ingrowth from the lateral body walls

Question 43

This transverse septum , which is composed of mesodermal tissue, is the primordium of the central tendon of the ___

Answer 43

Diaphragm

Question 44

The septum transversum grows dorsally from the ventrolateral body wall and forms a semicircular shelf that separates the heart from the __

Answer 44

Liver

Question 45

After the head folds ventrally during the fourth week, the septum transversum forms a thick, incomplete connective tissue partition between the pericardial and abdominal cavities

Answer 45

The septum transversum expands and fuses with the mesenchyme ventral to the esophagus and the pleuroperitoneal membranes

Question 46

These membranes fuse with the dorsal mesentery of the esophagus and the septum transversum

Answer 46

This fusion completes the partition between the thoracic and abdominal cavities and forms the primordial diaphragm

Question 47

The pleuroperitoneal membranes represent relatively small portions of the neonates ___

Answer 47

Diaphragm

Question 48

The septum transversum and pleuroperitoneal membranes fuse with the dorsal mesentery of the ___

Answer 48

Esophagus

Question 49

During the 9th and 12th weeks, the lungs and pleural cavities enlarge, burrowing into the lateral body walls. During this process , the tissue of the body wall is split into two layers. What are they

Answer 49

External layer that becomes part of the definitive abdominal wall An internal layer that contributes to the peripheral parts of the diaphragm , external to the parts derived fromt he pleuroperitoneal membranes

Question 50

Further extension of the developing pleural cavities into the lateral body walls forms the right and left __ ___, establishing the characteristic dome-shaped configuration of the diaphragm

Answer 50

Costodiaphragmetic recesses

Question 51

During the fourth week of development, the septum transversum lies opposite the third and did the ___ ___

Answer 51

Cervical somites

Question 52

During the fifth week, myoblasts from these somites migrate into the developing diaphragm, bringing their nerve fibers with them

Answer 52

Ok

Question 53

Consequently, the __ nerves that supply motor innervation to the diaphragm arise fromt he ventral primary rami of the 3rd, 4th, and 5th cervical spinal nerves, which join together on each side to form a phrenic nerve

Answer 53

Phrenic

Question 54

The phrenic nerve also supply sensory fibers to the superior and inferior surfaces of the right and left domes of the ___

Answer 54

Diaphragm

Question 55

Rapid growth of the dorsal part of the embryo;s body results in an ___ ___ of the diaphragm

Answer 55

Apparent descent

Question 56

By the sixth week, the developing diaphragm is at the level of the __ ___

Answer 56

Thoracic somites

Question 57

The phrenic nerves now have a __ course

Answer 57

Descending

Question 58

By the beginning of the _ week, the dorsal part of the diaphragm lies at the level of the first lumbar vertebra

Answer 58

8

Question 59

The phrenic nerves in the embryo enter the diaphragm by passing through the ___ ___

Answer 59

Pleuropericardial membranes

Question 60

For this reason, the phrenic nerves subsequently lie on the fibrous pericardium of the heart, which is derived from the pleuropericardial membranes

Answer 60

The costal border of the diaphragm receives sensory fibers from the lower intercostal nerves because of the origin of the peripheral part of the diaphragm from the lateral body walls

Question 61

Posterolateral defect of the diaphragm is the only relatively common congenital anomaly involving the ___

Answer 61

Diaphragm

Question 62

Posterolateral diaphragmetic defects occur in 1/3000 neonates ___ ___ ___

Answer 62

Congenital diaphragmatic hernia

Question 63

What is congenital diaphragmatic hernia

Answer 63

Herniation of abdominal contents into the thoracic cavity

Question 64

CDH is the most common cause of __ __

Answer 64

Pulmonary hypoplasia

Question 65

CHD can lead to what

Answer 65

Life threatening respiratory difficulties

Question 66

If severe lung hypoplasia is present, some primordial alveoli may rupture, casing air to enter the pleural cavity, what is this called

Answer 66

Pneumothorax

Question 67

What causes unilateral CDH

Answer 67

Defective formation or fusion of the pleuroperitoneal membrane with the other three parts of the diaphragm

Question 68

CDH produces a large opening in the ___ region of the diaphragm

Answer 68

Posterolateral

Question 69

If a pleuroperitoneal canal is still open when he intestines return tot he abdomen from the umbilical cord in the _ week, some intestine and other viscera may pass into the thorax and compress the ___

Answer 69

10 | Lungs

Question 70

Often the stomach, spleen, and most of the intestines __ in CHD

Answer 70

Herniate

Question 71

CHD usually occurs on the _ side and is likely related to the earlier closure of the right pleuroperitoneal opening

Answer 71

Left

Question 72

In CHD chromosomal abnormalities and gene mutations, including those of the zinc finger factor __, have been implicated in cases of CDH

Answer 72

GATA6

Question 73

How diagnose prenatal CDH

Answer 73

Ultrasonography and magnetic resonance imaging

Question 74

Ina. Relatively uncommon condition, __ __, half the diaphragm has defective musculature, causing it to balloon into the thoracic cavity as an aponeurotic sheet, forming a diaphragmatic pouch

Answer 74

Diaphragmatic eventration

Question 75

Consequently in diaphragmatic eventration, the abdominal viscera are displaced superiorly into the what

Answer 75

The pocket like outpouching of the diaphragm

Question 76

What causes diaphragmatic eventration

Answer 76

Failure of the muscular tissue from the body wall toe xtend into the pleuroperitoneal membrane on the affected side

Question 77

What does a retrosternal(parasternal) hernia, herniate through

Answer 77

Sternocostal hiatus

Question 78

What is the sternocostal hiatus

Answer 78

Opening for the superior epigastric vessels in the retrosternal area

Question 79

Where is the sternocostal hiatus

Answer 79

Between the sternal and costal parts of the diaphragm

Question 80

Herniation of the intestine into the pericardial sac may occur or part of the heart may descend into the peritoneal cavity in the __ region

Answer 80

Epigastric

Question 81

Large birth defects are commonly associated with body wall defects in the ___ region (omphalocele)

Answer 81

Umbilical