Embryo T24

Front 1

MATCH THE FOLLOWING WITH ITS CORRECT ORIGIN. ONE ANSWER PER QUESTION. ANSWERS MAY BE USED MORE THAN ONCE.

1. subcorium
2. sebaceous glands
3. epidermis
4. dermis of the back
A. ectoderm
B. mesoderm
C. both

Back 1

1. subcorium B mesoderm
2. sebaceous glands A ectoderm
3. epidermis A ectoderm
4. dermis of the back B mesoder

Front 2

5. Paracrine signaling requires:
A. diffusible signals
B. specific receptor molecules
C. both
D. neither

Back 2

C. both

Front 3

6. Which of the following are used during embryonic induction?
A. juxtacrine signaling
B. paracrine signaling
C. both
D. neither

Back 3

C. both

Front 4

7. Which of the following develops from ectoderm?
A. sebaceous glands
B. arrector pili muscles- mesoderm
C. both
D. neither

Back 4

A. sebaceous glands

Front 5

8. Which of the following is derived from the hypomere?
A. longisimus capitus- epimere; all extensor muscles of back and neck
B. sternohyoid – all other muscles
C. both
D. neither

Back 5

B. sternohyoid – all other muscles

Front 6

9. Which of the following bones ossify by endochondral ossification?
A. femur
B. humerus
C. both
D. neither
Intramembranous ossifications- flat bones of head and neck

Back 6

C. both

Front 7

10. Which of the following form by intramembranous ossification?
A. clavicle
B. humerus- endochondral ossification
C. both
D. neither

Back 7

A. clavicle

Front 8

11. The parietal bone forms by _____ ossification.
A. intramembranous- the parietal bone is a bone of the head and face
B. endochondral
C. both
D. neither

Back 8

A. intramembranous- the parietal bone is a bone of the head and face

Front 9

12. Each vertebra forms from ______ pairs of somite(s).
A. one
B. two
C. three
D. four
Verterbral body from 4 half-sclerotomes

Back 9

B. two

Front 10

13. The proximo/distal axis of the developing limb is determined by the:
A. AER
B. ZPA- anterior/ posterior
C. both
D. neither

Back 10

A. AER

Front 11

14. Which of the following are derived from the neural ectoderm?
A. neurons of the dorsal root ganglion
B. neurons of the ventral horn of the spinal cord
C. both
D. neither

Back 11

C. both

Front 12

15. Localized hypertricosis is associated with spina bifida cystica.
A. true B. false
Spina bifida oculta is accociated with hypertricosis.
Arnold-Chiari malformation is associated with spina bifida cystica.

Back 12

B. false
Spina bifida oculta is accociated with hypertricosis. Arnold-Chiari malformation is associated with spina bifida cystica.

Front 13

16. The periderm disappears at the time of birth.
A. true B. false
It sloughs off at the end of the second trimester.

Back 13

B. false
It sloughs off at the end of the second trimester.

Front 14

17. Which of the following is an anomaly associated with keratinization of the skin?
A. hypertrichosis- excessive hair
B. polythelia- extra nipples
C. both
D. neither
Ichthyosis is excessive keratinization of skin.

Back 14

D. neither
Ichthyosis is excessive keratinization of skin.

Front 15

18. Development of the mammary ridge occurs only in females.
A. true B. false
Because both males and females have nipples.

Back 15

B. false
Because both males and females have nipples.

Front 16

MATCH THE FOLLOWING WITH THE CORRECT ORIGIN. ONE ANSWER PER QUESTION. ANSWERS MAY BE USED MORE THAN ONCE.

19. diaphragm
20. external abdominal oblique
21. masseter muscle
22. superior oblique muscle of the eye
23. splenius capitis muscle

A. cervical somites C3-C5
B. occipital somites
C. preotic myotomes
D. epimere
E. hypomere

Back 16

19. diaphragm A. cervical somites C3-C5

20. external abdominal oblique E. hypomere

21. masseter muscle B. occipital somites

22. superior oblique muscle of the eye C. preotic myotomes


23. splenius capitis muscle D. epimere

Front 17

24. Flexor muscles of the forearm are innervated by _____ rami of spinal nerves.
A. dorsal- extensor muscles of neck and back
B. ventral- all other muscles

Back 17

B. ventral- all other muscles

Front 18

25. Which of the following are associated with sensory function?
A. basal plate- ventral, motor
B. alar plate- dorsal, sensory
C. roof plate- inducers of mesenchyme
D. floor plate- inducers of mesenchyme

Back 18

B. alar plate- dorsal, sensory

Front 19

26. The inferior colliculi are derived from the:
A. diencephalon- roof plate  choroid plexus of 3rd ventricle and pineal gland; alar plate thalamus, hypothalamus, epithalamus, and posterior lobe of pituitary gland
B. metencephalon- pons and cerebellum
C. myelencephalon medulla oblongota
D. mesencephalon- alar platesanterior and posterior colliculi; basal plates motor nuclei innervating structures of the eye

Back 19

D. mesencephalon- alar platesanterior and posterior colliculi; basal plates motor nuclei innervating structures of the eye

Front 20

27. Anencephaly occurs when the _____ neuropore fails to close.
A. cranial
B. caudal

Back 20

A. cranial

Front 21

28. The developing spinal nerve contains neural processes from neurons derived from the:
A. alar plate
B. basal plate
C. both
D. neither

Back 21

B. basal plate

Front 22

29. The pontine flexure occurs at the site of the formation of the:
A. thalamus
B. colliculi
C. cerebellum
D. cerebrum- cervical flexure

Back 22

C. cerebellum

Front 23

30. The thalamus develops from the:
A. metencephalon
B. mesencephalon
C. diencephalon
D. myelencephalon
Look at question #26

Back 23

C. diencephalon

Front 24

31. The cauda equina occurs as a consequence of the unequal growth rates of the spinal cord and vertebral column.
A. true B. false

Back 24

A. true

Front 25

32. In the developing spinal cord, which of the following appears earlier?
A. marginal layer- This results from nerve fibers from developing neurons of mantle
B. mantle layer
C. they appear at the same time

Back 25

B. mantle layer

Front 26

33. The Arnold-Chiari malformation is often associated with individuals who also have:
A. spina bifida occulta- associated with hypertrichosis
B. spina bifida cystica
C. both
D. neither

Back 26

B. spina bifida cystica

Front 27

34. Neurons in the _____ ganglia are derived from neural crest cells.
A. sympathetic
B. parasympathetic
C. dorsal root
D. all of the above

Back 27

D. all of the above

Front 28

35. The site of the closure of the anterior neuropore is called the:
A. sulcus limitans separates the basal and alar layers in the mantle
B. lamina limitans
C. sulcus terminalis
D. lamina terminalis

Back 28

D. lamina terminalis

Front 29

36. There are distinct basal and alar plates in the:
A. telencephalon there are no plates evident
B. metencephalon and also mesencephalon
C. both
D. neither

Back 29

B. metencephalon and also mesencephalon

Front 30

37. The third ventricle develops in the:
A. mesencephalon
B. diencephalon
C. metencephalon
D. myelencephalon
Look at question # 26

Back 30

B. diencephalon

Front 31

38. Part of the pituitary gland is derived from the mesencephalon.
A. true B. false
It is derived from the diencephalon.

Back 31

B. false
It is derived from the diencephalon.

Front 32

39. Vertebra develop from the _____ division of the somite.
A. dermatome- dermis of the skin
B. myotome- skeletal muscle
C. sclerotome- vertebral bone
D. none of the above

Back 32

C. sclerotome- vertebral bone

Front 33

40. Ribs are derived from the ______ division of the somite.
A. dermatome
B. myotome
C. sclerotome
D. none of the above
Look at question #41!

Back 33

C. sclerotome

Front 34

41. The bones of the upper limb are derived from the ______ division of the somite.
A. dermatome
B. myotome
C. sclerotome
D. none of the above
It is derived from somatic mesoderm(lateral plate)

Back 34

D. none of the above
It is derived from somatic mesoderm(lateral plate)

Front 35

42. Craniosynostosis refers to the condition when:
A. the bones of the skull are incomplete- cranioscchisis
B. the bones of the skull fuse prematurely
C. the posterior cranial fossa is too shallow to accommodate the cerebellum
D. none of the above

Back 35

B. the bones of the skull fuse prematurely

Front 36

43. Components of the skeletal system are derived from:
A. ectoderm (neural crest)
B. mesoderm
C. both
D. neither

Back 36

C. both

Front 37

44. Bones of the neurocranium develop by _____ ossification.
A. endochondral- cranial base
B. intramembranous- cranial vault
C. both
D. neither

Back 37

C. both

Front 38

45. Apoptosis plays a role in the formation of the digits of the extremities.
A. true B. false
Flattened hand plate and foot plate at ~week 6
Digital rays formed by end of week 6; AER confined to tips of rays
Intervening regions unergo apoptosis (programmed cell death) to form digits
ZPA at caudal tip of plate determines order of digits

Back 38

A. true

Front 39

46. Digit #1 is on the ____ side of the adult foot.
A. lateral
B. medial
The big toe and thumb are digit #1.

Back 39

B. medial
The big toe and thumb are digit #1.

Front 40

47. Remnants of the notochord are present in the adult:
A. vertebral body
B. intervertebral disc- this is the nucleus pulposus
C. both
D. neither

Back 40

B. intervertebral disc- this is the nucleus pulposus

Front 41

48. Which of the following develops along the inferior margin of the developing limb?
A. AER- responsible for Proximal to Distal development
B. ZPA
C. both
D. neither

Back 41

B. ZPA

Front 42

49 In the Klippel-Feil anomaly, there is a malformation of lumbar vertebrae.
A. true B. false

Back 42

B. false
Klippel-Feil is a reduced number of cervical vertebrae; others fused or abnormal
Spina bifida occulta (cleft vertebra)- vertebral arches do not form
Spinal bifida cystica- accompanied by spinal anomalies
Hemivertebra- congenital scoliosis