T5-Embryonic folding

Question 1

In longitudinal folding, ________ and ________end loop ventrally

Answer 1

cranial; caudal

Question 2

Amniotic cavity pinches the_______ to create the ______

Answer 2

yolk sac; gut tube

Question 3

Order of structures at day 21 (head fold; pre-fold)

Answer 3

developing heart is caudal to the septum transversum

Question 4

Order of structures at day 26 (head fold; post-fold)

Answer 4

developing heart is cranial to the septum transversum

Question 5

During longitudinal head folding, the ____________is folded into primative __________ tube with___________ membrane

Answer 5

local endoderm; foregut; oropharyngyeal

Question 6

Direction of brain growth with longitudinal (head) folding

Answer 6

dorsally , cranially, ventrally

Question 7

Direction of caudal emminence growth with longitudinal (tail) folding

Answer 7

dorsally, caudally, wraps ventrally

Question 8

Location of primative streak pre-tail fold

Answer 8

cranial to cloacal membrane

Question 9

Location of primative streak post-tail fold

Answer 9

caudal to cloacal membrane

Question 10

Tail folding brings the ___________ ventrally

Answer 10

connecting stalk

Question 11

During longitudinal tail-folding local endoderm is folded into ___________tube with ____________

Answer 11

primative hindgut; cloacal membrane

Question 12

Transverse folding Lateral edges of ____________ loop _______ and eventually go towards the ___________ of the developing embryo

Answer 12

amniotic cavity; ventrally; center

Question 13

Results of transverse folding

Answer 13

foregut and hind gut are folded into complete circles; midgut is not, and instead remains open to umbillical vessicle

Question 14

In transverse folding local endoderm is folded into what?

Answer 14

primative midgut

Question 15

What is the primative midgut connected to?

Answer 15

the remains of the secondary umbillical vessicle by the yolk stalk

Question 16

At which directions is the gut tube a complete circle

Answer 16

cranially and caudally to the yolk stalk

Question 17

Which day is this?

Answer 17

Day 21

Question 18

Which day is this?

Answer 18

day 26

Question 19

Which day is this?

Answer 19

day 21

Question 20

Which day is this?

Answer 20

day 26

Question 21

Which day is this

Answer 21

Day 17

Question 22

Which day is this

Answer 22

day 19

Question 23

3 fates of the mesoderm

Answer 23

Paraxial mesoderm, intermediate mesoderm, lateral plate mesoderm

Question 24

Paraxial mesoderm

Answer 24

somites form in a craniocaudal direction as paired blocks of cells, flanking the notochord and neural tube

Question 25

Intermediate mesoderm

Answer 25

contributes to the formation of the urinary and reproductive systems

Question 26

Lateral Plate Mesoderm

Answer 26

Divided by intraembryonic coelom into intraembryonic somatic mesoderm and intraembryonic splanchnic mesoderm

Question 27

What will somites develop into

Answer 27

vertebrae - intervertebral discs - ribs - skeletal muscles of body walls and limbs - connective tissue of body wall

Question 28

Intraembryonic somatic mesoderm

Answer 28

supporting ectoderm -contributes to connective tissue, blood vessels, and smooth muscle of body wall and limbs

Question 29

Intraembryonic splanchnic mesoderm

Answer 29

supporting endoderm, contributes to smooth muscles, blood vessels and connective tissue of GIT and associated organs

Question 30

Somatopleure

Answer 30

somatic mesoderm+ectoderm

Question 31

splanchnopleure

Answer 31

Splanchnic mesoderm+ endoderm

Question 32

Fate of ectoderm

Answer 32

neuroectoderm and surface ectoderm

Question 33

Fate of endoderm

Answer 33

- epithelial lining of gastrointestinal tract - the secretory epithelial cells of liver, gall bladder and pancreas - epithelial lining of the respiratory system

Question 34

Methoods of estimation of embryonic age

Answer 34

Mesurement of length and counting of somites

Question 35

What is Greatest length (GL) used for

Answer 35

very early embryo's prior to folding

Question 36

Common gynaecological clinical practice for measuring embryos

Answer 36

crown-rump length (CRL)

Question 37

Carnegie Embryonic Staging System

Answer 37

a 23 stage international system that enables comparisons based on intra and extra-embryonic development