03b: Body Cavity Development

Question 1

Septum transversum is thick plate of (X) that separates which two developing organs?

Answer 1

X = mesoderm

Heart and liver

Question 2

T/F: The septum transvedsum completely separates thoracic and abdominal cavities during development.

Answer 2

False - not completely

Question 3

Septum transvedsum leaves large opening(s) in (foregut/midgut/hindgut) called (X). What grows into the space?

Answer 3

Foregut;
X = pericardioperitoneal (aka pleural) canals

Lungs

Question 4

Which folds of tissue in developing embryo define the pericardioperitoneal canals?

Answer 4

1. Pleuropericardial (cranial)

2. Pleuroperitoneal (caudal)

Question 5

In embryonic development of thoracic cavity, (X) folds grows into (Y) membranes. Which important structures are found in this membrane?

Answer 5

X = Y = pleuropericardial

1. Common cardinal veins
2. Phrenic nerves

Question 6

T/F: As development proceeds, the pleuropericardial membranes eventually fuse.

Answer 6

True

Question 7

Pleuropericardial membranes, in an adult, are:

Answer 7

Fibrous pericardium

Question 8

In general, pleuropericardial membranes separate which cavities?

Answer 8

Pleural and pericardial

Question 9

In general, pleuroperitoneal membranes separate which cavities?

Answer 9

Pleural and peritoneal

Question 10

Pleuroperitoneal membranes fuse with (X) to form (Y).

Answer 10

X = septum transversum
Y = diaphragm

Question 11

Rim of diaphragm formed from which tissue type?

Answer 11

Mesenchyme (muscular ingrowth) from body wall

Question 12

List the various contributors that build diaphragm in embryonic development. Star the one(s) that regress in adult.

Answer 12

1. Septum transversum
2. Pleuroperitoneal membrane*
3. Body wall (mesenchyme)
4. Dorsal mesentery of esophagus

Question 13

Congenital diaphragmatic hernia results from failure of (X) to close (Y).

Answer 13

X = Pleuroperitoneal membranes 
Y = pericardioperitoneal canals