week 2, lecture 1

Question 1

3 cavities service from the intra-embryonic coelom

Answer 1

pericardial cavity
pleural cavity
peritoneal cavity

Question 2

structure that gives rise to the wall of the gut (body wall)

Answer 2

splanchnopleure

Question 3

slide 8 review

Answer 3

x

Question 4

structure that forms the embryonic gut

Answer 4

splanchnopleure

Question 5

what type of folding forms the body wall

Answer 5

lateral folding (horizontal)

Question 6

what type of folding forms the brain vesicles and somites

Answer 6

cranial caudal or cephalo caudal folding (medial) [head to tail]

Question 7

where is the foregut and what separates it from the mouth (stomodeum)

Answer 7

foregut is between the brain and heart

Oropharyngeal membrane separates the the foregut from the stomodeum
(primordium of the mouth)

Question 8

where does the septum transverse lie and what does it develop into (and separates)

Answer 8

its caudal (below) the heart

Develops into the central tendon of the diaphragm and separates the abdominal cavity from the thoracic cavity

Question 9

what does the septum transverse develop into

Answer 9

central tendon of the diaphragm

Question 10

where does the caudal eminence project over to create the future site of the anut

Answer 10

cloacal membrane

Question 11

what becomes the hindgut (the same structure also becomes the midgut)

Answer 11

part of the endodermal germ layer

Question 12

what happens in caudal folding

Answer 12

Theconnectingstalk(primordiumoftheumbilicalcord)isnowattachedtothe ventral surface of the embryo, and the allantois is partially incorporated into the embryo

Question 13

what structure causes lateral folding

Answer 13

rapidly growing spinal cord and somites

Question 14

during lateral folding what duct is formed to lessen the connection between the midgut and umbilical vessel

Answer 14

omphaloenteric (vitelline) duct

Question 15

what is the amnion narrowed to in lateral folding

Answer 15

umbilical region

Question 16

what region of the ventral body wall stays open

Answer 16

connecting stalk

Question 17

what duct of the gut tube that connects the midgut to the yolk Salk is open?

Answer 17

vitelline duct

(eventually degenerates)

Question 18

what does the parietal layer of the lateral plate mesoderm form?

Answer 18

forms the parietal layer of the serous membranes lining outside of the peritoneal, pleural, & pericardial cavities.

Question 19

what does the visceral layer of the lateral plate mesoderm form?

Answer 19

formsthe visceral layerofthe serous membranes lining outside of the abdominal organs, lungs, and heart.

Question 20

how are the visceral and parietal layers continuous with each other

Answer 20

Visceral&parietal layers are continuous with each other as the dorsal mesentery.
▪ Extends from the posterior body wall to the gut tube.

Question 21

where is the ventral mesentery and where does it extend to and what does it create

Answer 21

Ventral mesentery exists from the caudal foregut to the upper portion of the
duodenum.
▪ Extends from the anterior body wall to the gut tube
▪ Results from the thinning of the mesoderm of the septum transversum.

Question 22

what is the septum transverse

Answer 22

Thick mesodermal tissue between the thoracic cavity & stalk of the yolk sac.

This septum does not separate the thoracic and abdominal cavities, but leaves large openings, the pericardioperitoneal canals, on each side of the foregut.

Question 23

what is the septum transverse derived from

Answer 23

Derived from the visceral (splanchnic) mesoderm surrounding the heart and assumes its position between the primitive thoracic and abdominal cavities when the cranial end of the embryo grows and curves into the fetal position

Question 24

how does the diaphragm develop

Answer 24

pleuroperitoneal folds fuse with mesentery of esophagus to form crura of diaphragm

pleuroperitoneal membranes then grow and fuse to cover septum transverse and form central tendon on diaphragm

Question 25

diaphragm is derived from

Answer 25

2 pleuroperitoneal
membranes

Muscular components
from somites
at C3-C5

Mesentery of the
esophagus

Question 26

fistula define

Answer 26

A fistula is an abnormal connection between two body parts, such as an organ or blood vessel and another structure

Question 27

atresia define

Answer 27

Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent

Question 28

slide 17

Question 29

slide 17