Embryo Test 2 09

Front 1

1. Which of the following can act as an inducer? Pg 25
A. epithelia
B. mesenchyme
C. both
D. neither

*epithelial-mesenchymal interactions
*epithelial-epithelial interactions

Back 1

C. both

Front 2

2. Which of the following requires a specific receptor on the plasma membrane of the target cell? Pg 25
A. paracrine signaling
B. juxtacrine signaling
C. both
D. neither

*Paracrine – diffusable proteins travel short distances to target cell (4 types)
*Juxtacrine – acts over short distances; non-diffusable factors; direct transmission of signal b/t cells via gap junctions

Back 2

C. both

Front 3

3. The epidermis of the skin is derived from: pg 26
A. ectoderm - initially a single layer of ectoderm (2 layers during month 2)
B. mesoderm – dermis and arrector pilli muscle are from mesoderm
C. both
D. neither

Back 3

A. ectoderm - initially a single layer of ectoderm (2 layers during month 2)

Front 4

4. The periderm is found in the dermis of the skin. Pg 26
A. true B. false

*mesoderm is found in the dermis; periderm is found in the epidermis

Back 4

B. false

Front 5

5. Place the following in order from earliest to latest to appear. Pg 26-27
(1) vernix caseosa
(2) periderm
(3) hair
A. 1, 2, 3
B. 3, 2, 1
C. 2, 3, 1
D. 2, 1, 3

*periderm , hair , vernix caseosa

Back 5

C. 2, 3, 1

Front 6

6. The reticular dermis of the skin is derived from the: pg 27
A. corium – upper layer forms dermal papillae
B. subcorium – lower layer containing fat deposits; also called hypodermis in adult
C. both
D. neither

Back 6

A. corium – upper layer forms dermal papillae

Front 7

7. Sebaceous glands are derived from: pg 28
A. mesoderm
B. ectoderm – as well as sweat glands, hair shaft and epidermal root sheath
C. both

Back 7

B. ectoderm – as well as sweat glands, hair shaft and epidermal root sheath

Front 8

8. Sweat glands are derived from: pg 28
A. mesoderm
B. ectoderm
C. both

Back 8

B. ectoderm

Front 9

9. The mammary pit is present at birth. Pg 28
A. true B. false

Back 9

A. true

Front 10

10. Polymastia refers to extra: pg 29
A. nipples – polythelia – extra nipples and inverted nipple – failure of mammary pit to evert
B. breast tissue

*albinism – melanocytes don’t produce melanin
*ichthyosis – excessive keratinization of skin
*hair
-hypertrichosis – excessive hair; localized or general
-atrichia – absense of hair

Back 10

B. breast tissue

Front 11

11. Skeletal muscle is derived from ______ mesoderm. Pg 30
A. somatic
B. splanchnic
C. both
D. neither

*skeletal muscle – derived from paraxial along with preotic myotomes and occipital myotomes

Back 11

D. neither

Front 12

12. In order for muscle cells to develop into definitive muscles, they must be innervated by motor neurons.
A. true B. false

Back 12

A. true

Front 13

13. Which of the following is innervated by the dorsal ramus of a spinal nerve? Pg 31
A. hypomere – ventral ramus – thorax, abdomen, diaphragm and limbs
B. epimere – extensor muscles of neck and back
C. both
D. neither

Back 13

B. epimere – extensor muscles of neck and back

Front 14

14. The musculature of the limbs develops from the: pg 31
A. epimere
B. hypomere
C. both

Back 14

B. hypomere

Front 15

15. Which of the following develop from preotic myotomes? Pg 30
A. muscles of the tongue – occipital myotomes
B. muscles of mastication – occipital myotomes
C. muscles of the eye
D. muscles of facial expression – occipital myotomes

Back 15

C. muscles of the eye

Front 16

16. Cardiac muscle is derived from paraxial mesoderm. Pg 30
A. true B. false

*cardiac muscle is derived from splanchnic mesoderm
*skeletal muscle is derived from paraxial mesoderm

Back 16

B. false

Front 17

17. Which of the following pairs is incorrect? Pg 32-33
A. sclerotome – vertebrae
B. myotome – smooth muscle – smooth muscle is splanchnic (smooth muscle associated with viscera) and is somatic (smooth muscles of blood vessels)
C. dermatome – dermis
D. all are correct

Back 17

B. myotome – smooth muscle – smooth muscle is splanchnic (smooth muscle associated with viscera) and is somatic (smooth muscles of blood vessels)

Front 18

18. Most intramembranous ossification occurs in the skull. Pg 33-34
A. true B. false

*intramembranous – flat bones of head and face (viscerocranium and vault of neurocranium))
*endochondral – most of skeleton; uses cartilage model (base of neurocranium and limbs)

Back 18

A. true

Front 19

19. The base of the neurocranium develops by ______ ossification. Pg 34
A. intramembranous
B. endochondral

Back 19

B. endochondral

Front 20

20. The term viscerocranium refers to the bones that surround and protect the brain. Pg 33-34
A. true B. false

*viscerocranium – face
*neurocranium – surrounds and protects the brain

Back 20

B. false

Front 21

21. The apical ectodermal ridge (AER) determines the order of the digits. Pg 35
A. true B. false

*AER – induced by mesoderm, develops within ectoderm, essential for limb growth (proximal to distal)
*ZPA – at caudal tip of plate, determines order of digits (superior to inferior)

Back 21

B. false

Front 22

22. Vertebra form from ______ mesoderm. Pg 33
A. somatic
B. paraxial
C. both
D. neither

Back 22

B. paraxial

Front 23

23. Cells that arise from the neuroepithelium of the neural tube include all of the following except: pg 37
A. motor neurons.
B. ependymal cells.
C. glial cells.
D. all of the above arise from the neuroepithelium of the neural tube.

Back 23

D. all of the above arise from the neuroepithelium of the neural tube.

Front 24

24. All of the following are derived from the diencephalon except: pg 40
A. thalamus
B. adenohypophysis
C. hypothalamus
D. neurohypophysis

Back 24

B. adenohypophysis

Front 25

25. Motor neurons innervating skeletal muscles arise from neuroblasts in the: pg 38
A. basal plate marginal layer.
B. alar plate marginal layer.
C. basal plate mantle layer.
D. alar plate mantle layer. - dorsal; sensory

*marginal layer – becomes white matter

Back 25

C. basal plate mantle layer.

Front 26

26. Bones of the body are derived from: pg 33
A. paraxial mesoderm -
B. somatic mesoderm
C. ectoderm
D. all of the above

Back 26

D. all of the above

Front 27

27. pons
28. thalamus
29. superior colliculi
30. medulla oblongata
31. cerebral hemispheres
32. cerebellum


A. telencephalon
B. diencephalon
C. mesencephalon
D. metencephalon
E. myelencephalon

Back 27

27. pons D. metencephalon

28. thalamus B. diencephalon

29. superior colliculi C. mesencephalon

30. medulla oblongata E. myelencephalon

31. cerebral hemispheres A. telencephalon

32. cerebellum D. metencephalon

Front 28

33. Apoptosis plays a role in the formation of the digits of the hand. Pg 35
A. true B. false

Back 28

true

Front 29

34. The ____ induces outgrowth of the limb bud from the body wall. Pg 35
A. ZPA
B. AER
C. both
D. neither

Back 29

B. AER

Front 30

35. The notochord persists in the vertebral body.
A. true B. false

Back 30

false

Front 31

36. As it develops, the lower limb rotates 90°: pg 35
A. laterally – upper limb
B. medially
C. it does not rotate

Back 31

B. medially

Front 32

37. Which of the following describes the premature closure of cranial sutures? Pg 35
A. Klippel-Feil syndrome – reduced # of cervical vertebrae; others fused or abnormal
B. microcephaly – small skull due to failure of brain to grow
C. cranioscchisis – cranial vault incomplete; anencephaly
D. craniosynostosis

Back 32

D. craniosynostosis

Front 33

38. Place the following in order from earliest to latest to appear: pg 38
(1) spinal nerve
(2) mantle layer
(3) marginal layer
A. 1, 2, 3
B. 3, 2, 1
C. 2, 3, 1
D. 3, 1, 2

*mantle layer , marginal layer , spinal layer

Back 33

C. 2, 3, 1

Front 34

39. Neural crest cells can develop into: pg 37
A. neurons
B. supporting cells of the nervous system
C. coverings of the nervous system
D. all of the above

Back 34

D. all of the above

Front 35

40. Cranial and caudal neuropores normally close during week: pg 37
A. two
B. three
C. four – cranial day 25 and caudal day 27
D. five

Back 35

C. four – cranial day 25 and caudal day 27

Front 36

41. Which of the following results from failure of the cranial neuropore to close? Pg 41 & 35
A. Arnold-Chiari malformation – herniation of cerebellar tissue through foramen magnum; frequently associated with spina bifida cystica
B. craniosynostosis – premature closure of sutures
C. hydrocephalus – abnormal accumulation of cerebrospinal fluid due to obstruction of drainage into subarachnoid space
D. anencephaly

Back 36

D. anencephaly

Front 37

42. The flexure that develops in the region of the metencephalon is called the: pg 39
A. cephalic flexure
B. mesencephalic flexure
C. pontine flexure
D. cervical flexure

Back 37

C. pontine flexure

Front 38

43. The sulcus limitans: pg 38
A. separates the medulla oblongata from the pons
B. marks the site of closure of the cranial neuropore
C. separates the alar and basal plates
D. separates the diencephalon from the telencephalon

Back 38

C. separates the alar and basal plates

Front 39

44. The choroid plexus of the fourth ventricle is derived from the ____ plate. Pg 39
A. alar
B. basal
C. floor
D. roof of rhombencephalon

Back 39

D. roof of rhombencephalon

Front 40

45. Which of the following represent persistence of the lumen of the neural tube in the adult? Pg 37
A. ventricle of the brain
B. central canal of the spinal cord
C. both
D. neither

Back 40

C. both

Front 41

46. Ossification of all bones in the body is completed at birth.
A. true B. false

Back 41

false

Front 42

47. Which of the following usually has more severe consequences for the affected individual? Pg 36
A. spina bifida oculta – cleft vertebra – vertebral arches do not form
B. spina bifida cystica – accompanied by spinal cord anomalies
C. they are equally severe

Back 42

B. spina bifida cystica – accompanied by spinal cord anomalies

Front 43

48. There are distinct alar and basal plates in all of the following except: pg 40
A. spinal cord
B. mesencephalon
C. myelencephalon & metencephalon
D. telencephalon – plates not evident

Back 43

D. telencephalon – plates not evident

Front 44

49. Arnold-Chiari malformation is frequently associated with spina bifida cystica. Pg 41
A. true B. false

Back 44

true