9.29 Germ Layers 1

Question 1

the notochord induces overlying ectodermal tissue to form the _______ (the precursor of the CNS)

Answer 1

neural plate

Question 2

peripheral neurons are formed from the _________ cells

Answer 2

neural crest cells

Question 3

failure of fusion of the neural tube at the cranial end

Answer 3

anencephaly

Question 4

failure of fusion of the neural tube at the caudal end

Answer 4

spina bifida

Question 5

where are neural crest cells located?

Answer 5

at the crests of the neural plate that form the neural folds

Question 6

the dorsal root ganglia come from what kinds of neural precursor cells?

Answer 6

neural crest cells

Question 7

the PNS come from what kinds of neural precursor cells?

Answer 7

neural crest cells

Question 8

most of the bones and cartilage of the face come from what kinds of neural precursor cells? NOTE: NOT MUSCLE

Answer 8

neural crest cells

Question 9

melanocytes come from what precursor cell?

Answer 9

neural crest cells

Question 10

the CT of the aortic arch arteries and the septum separating aorta and pulmonary vessel come from what kinds of neural precursor cells?

Answer 10

neural crest cells

Question 11

cells of the CNS come from what kinds of neural precursor cells?

Answer 11

neural plate cells

Question 12

cells migrate through the _______ arches, which are the routes of neural crest cells into their facial structures

Answer 12

pharyngeal arches

Question 13

neural crest cells in neurofibromatosis ________. What does this cause?

Answer 13

over proliferate.

It causes benign tumors in the brain (Schwann cells) and the skin (melanocytes)

Question 14

insufficient neural crest contribution to the face. Deficiency in neural crest cells, causes severe facial defects.

Answer 14

Trencher-Collins Syndrome

Question 15

Teacher-Collins Syndrome shows ________ neural crest cell contribution to the ______

Answer 15

insufficient

face

Question 16

in ___________ syndrome, facial alterations, hair pigmentation abnormalities. Mostly due to defects in Sox10 of Pax3 genes

Answer 16

Waardenberg Syndrome

Question 17

mammary glands and the pituitary gland, and sweat glands come from which germ layer?

Answer 17

ectoderm

Question 18

the paraxial mesoderm eventually forms ______

Answer 18

somites

Question 19

the intermediate mesoderm eventually forms what? (2 things)

Answer 19

the urinary and reproductive system

Question 20

what are the three regions of mesoderm?

Answer 20

paraxial, intermediate, and lateral mesoderm

Question 21

what do somites form in the embryo?

Answer 21

primitive musculature

Question 22

somites are next to the __________

Answer 22

neural tube

Question 23

the formation of a somite involves a transient structure: the __________

Answer 23

somitomere

Question 24

except for the ___ pairs of somitomeres at the _______ end, all somitomeres become somites

Answer 24

7

cranial

Question 25

________, a region of tissue from the somite, migrates all around the neural tube and makes the bones of the vertebra

Answer 25

sclerotome

Question 26

after the sclerotome leaves from the somite, the dermamyotome differentiates into the ________ and the _________

Answer 26

dermatome

myotome

Question 27

the ______ (a section of the somite) makes the dermis of the skin

Answer 27

dermatome

Question 28

the _________ (a section of the somite) makes the body muscles

Answer 28

myotome

Question 29

what are two examples of segmentation in the human embryonic body plan?

Answer 29

1. repeating structure of the somites
2. Rhombomeres of the brain

Spine, etc.

Question 30

muscle of the face comes from ________ ___________

Answer 30

cranial somitomeres