Fate of the germ layers

Question 1

endodermal derivatives

Answer 1

• gut tube (epithelium only)

- lungs, liver, gall bladder, pancreas, urinary bladder

Question 2

3 types of ectodermal derivatives

Answer 2

• surface ectoderm
• neural tube ectoderm
• nueral crest cells

Question 3

surface ectoderm

Answer 3

derived from somatopleure

finger nails and mammary glands

Question 4

epidermal appendages

Answer 4

develop from ectoderm but embed themselves in mesoderm (dermis)

Question 5

keratin

Answer 5

keratinised cells provide a layer of dead skin cells and water proofing

Question 6

atavistic extranumerary nipple

Answer 6

third nipple

Question 7

oropharyngeal membrane forms

Answer 7

stomodeum - lining of the mouth derived from surface ectoderm

Question 8

rathkes pouch

Answer 8

invagination of SE forming anterior pituitary

Question 9

posterior pituitary

Answer 9

neural area derived from forebrain

Question 10

anterior pituitary

Answer 10

from surface ectoderm from rathkes pouch

Question 11

lens of the eye derived from

Answer 11

surface ectoderm

Question 12

enamel of the teeth derived from

Answer 12

surface ectoderm

Question 13

nueral tube ectoderm forms

Answer 13

central nervous system

Question 14

walls of nueral tube ectoderm form

Answer 14

brain and spinal cord

Question 15

tube canal ectoderm forms

Answer 15

ventricles and central canal - a set of spaces that allow fluid to move from the brain through the spinal cord

Question 16

middle of the nueral canal is full of

Answer 16

fluid

Question 17

§ Neural crest cells migrate and form

Answer 17

□ All nerves of peripheral nervous system (PNS)
				□ Dorsal root ganglion (DRG)
				□ Autonomic ganglion 
				□ Adrenal medulla 
			§ Also includes 
				□ Schwann cells (myelin sheaths)
				□ Laptomeninges (Pia and arachnoid mata)
					® Lapto meaning delicate or thin
				□ Melanocytes (epidermis)
				□ Dentine (teeth), and cornea (eye)

Question 18

3 types of mesoderm

Answer 18

paraxial, intermediate, lateral plate

Question 19

intermediate mesoderm forms

Answer 19

paired glands

kidneys, gonads, accessory reproductive organs

Question 20

lateral plate mesoderm forms

Answer 20

§ Somatopleure: body wall
§ splanchnopleure: gut tube connective tissues, cardiogenic mesoderm, spleen, lungs
□ AKA visceropleure
§ Cranial mesoderm, adrenal cortex

Question 21

Somatopleure

Answer 21

body wall

Question 22

splachnopluere

Answer 22

gut tube connective tissues, cardiogenic mesoderm, spleen, lungs
□ AKA visceropleure

Question 23

limbs are an extension of the

Answer 23

body wall/somatopluere

Question 24

skeletal muscle in the limbs are derived from

Answer 24

somites

Question 25

everything other than skeletal muscle in the limbs is derived from

Answer 25

lateral plate component of the somatopleure

Question 26

3 components of somites

Answer 26

sclerotome, dermatome, mermamyotome

Question 27

sclerotome creates

Answer 27

vertebrae and ribs

Question 28

myotome makes

Answer 28

skeletal muscle for limbs and body wall

Question 29

dermatome and myotome exist as

Answer 29

are fused, existing as dermomyotomes