Embryology 2

Question 1

Signaling from the primitive streak induces the formation of the ______

Answer 1

Notochord

Question 2

Notochord

Answer 2

a longitudinal cellular tube within the mesoderm

Question 3

Notochord process elongates by invagination of cells from the ______

Answer 3

Primitive pit

Question 4

What are the functions of the notochord? (3)

Answer 4

• Induces overlying ectoderm to differentiate into neuroectoderm (Neural Plate)
• Induces formation of vertebral bodies
• Forms the nucleus pulposus of intervertebral disks

Question 5

Notochord process extends _____ to the prechordal plate

Answer 5

Cranially

Question 6

What are the stages of neurulation?

Answer 6

• Formation of the neural plate
• Formation of the neural folds
• Closure of neural folds to form neural tube
• Formation of neural crest

Question 7

_____ gives rise to the central nervous system

Answer 7

Neural Tube

Question 8

____ gives rise to the peripheral nervous system

Answer 8

Neural crest

Question 9

The notochord induces overlaying _____ to form the ____

Answer 9

Ectoderm

Neural Plate

Question 10

The neural plate invaginates to form the ____

Answer 10

neural groove

Question 11

_____ flank the neural groove

Answer 11

Neural folds

Question 12

Answer 12

Question 13

______ fuse to form the neural tube

Answer 13

Neural folds

Question 14

Describe closure of the neural tube

Answer 14

Closure begins in the midline and extends in both cranial and caudal directions

Question 15

Cranial end of the neural tube becomes the ____, ___ and ____

Answer 15

Forebrain, midbrain and hindbrain

Question 16

Caudal end of hte neural tube becomes the _____

Answer 16

Spinal cord

Question 17

Describe the formation of the neural crest.

Answer 17

The neural folds begin to fuse and cells on the inner margin separate to form the neural crest, which lies between the neural tube and the overlaying surface ectoderm.

Question 18

neural crest cells ultimately form what 2 things?

Answer 18

Spinal ganglia and ganglia of autonomic nervous sytem

Question 19

What are the clinical implications of neural tube defects?

Answer 19

Failure of the neural tube to close at either end may result in defects of the brain and spinal cord

Question 20

_____ mesoderm cells condense to form paired bodies called somites

Answer 20

Paraxial

Question 21

Answer 21

Question 22

In what directon do somites form?

Answer 22

Cranial to caudal

Question 23

Answer 23

Question 24

When does somite formation end?

Answer 24

End of week 5

Question 25

What is the Coelom?

Answer 25

Horse-shoe shaped structure that is the precursor for the bodies cavities (pericardial, pleural, peritoneal)

Question 26

What embryonic tissue layer gives rise to the coelom?

Answer 26

The lateral mesoderm

Question 27

\_\_\_\_\_ forms the embryonic body wall

Answer 27

Somatopleure (layer of coelom)

Question 28

\_\_\_\_\_ forms the embryonic gut

Answer 28

Splanchnopleure (layer of coelom)

Question 29

When does the Coelom form?

Answer 29

Week 4

Question 30

Folding of the embryo occurs in the ___ and ____ planes as a result of rapid growth

Answer 30

Median and Horizontal

Question 31

Median folding produces ___ and ___ folds and results in the formation of what 2 embryonic structures?

Answer 31

Head and tail Foregut and hindgut

Question 32

Horizontal folding produces ____ and ____ folds and results in the formation of what embryonic structure?

Answer 32

Right and left Midgut

Question 33

Describe the process of the formation of the primordial heart.

Answer 33

Through median folding, cardiogenic mesoderm moves toward the ventral surface and gives rise to primordial heart.

Question 34

\_\_\_\_\_ forms the urogenital ridge \_\_\_\_\_ folding is responsible for the formation of the urogenital ridge.

Answer 34

Intermediate mesoderm Horizontal

Question 35

What are the 2 components of the urogenital ridge.

Answer 35

1) Nephrogenic cord (urinary system) 2) Gonadal ridge (internal genitalia)

Question 36

Answer 36

Question 37

What part of the developing embryo gives rise to the pharangeal arches?

Answer 37

Neural crest cells

Question 38

What do the pharangeal arches ultimately become?

Answer 38

The structures of the face and neck