Development of the Nervous and Musculoskeletal Systems for Limb Formation Flashcards Preview

Structure and Function Test 1 > Development of the Nervous and Musculoskeletal Systems for Limb Formation > Flashcards

Flashcards in Development of the Nervous and Musculoskeletal Systems for Limb Formation Deck (81)
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1
Q

Begins soon after gastrulation, with differentiation of the ectoderm to form the neural tube

A

Neurulation

2
Q

Forms the nervous system

A

Neural tube

3
Q

Occurs with induction of ectoderm by factors from the underlying notochord (a midline rod of mesoderm)

A

Neurulation and neural tube formation

4
Q

Neuroectodermal cells organize in the midline as a thickening called the

A

Neural plate

5
Q

Proliferation of neuroectoderm cells of the neural plate results in buckling of the tissue to form a depression called the

A

Neural groove (w/ lateral neural folds)

6
Q

With further proliferation and more buckling, the edges of the neural folds approximate and fuse in the dorsal midline to form the

A

Neural tube

7
Q

Neural tube fusion starts in the cervical region and occurs as a

A

bi-directional “Zipper”

8
Q

Neural tube fusion starts in the cervical region and occurs as a bi-directional “Zipper” that closes the neural tube with fusion moving from

A

Cranial to caudal directions

9
Q

The open (unfused ends) of the neural tube are alled

A

Neuropores

10
Q

The final step of neurulation, which occurs by the end of week 4, is

A

Neuropore closure

11
Q

What day do the following neuropores close?

  1. ) Cranial
  2. ) Caudal
A
  1. ) Day 25

2. ) Day 28

12
Q

Forms the brain and spinal cord of the CNS

A

Neural Tube

13
Q

Detach from the dorsolateral edges of the neural tube and migrate throughout the body to form a wide variety of cell types, including ganglia of the PNS

A

Neural crest cells

14
Q

Defects which mostly result from failure of the neuropores to close

A

Neural tube defects

15
Q

Failed closure of the cranial neuropore results in

A

Anencephaly

16
Q

Failure to form the cranial vault around the cerebral hemispheres

-often lethal

A

Anencephaly

17
Q

Failed closure of the caudal neuropores results in

A

Spina bifida

18
Q

A defective fusion of the vertebral arches, commonly at L4-S1

A

Spina bifida

19
Q

A defect in the fusion of vertebral arches without involvement of underlying neural tissue

A

Spina bifida occulta

20
Q

A defect in the fusion of vertebral arches WITH involvement of underlying neural tissue

A

Spina bifida Cystica

21
Q

In spina bifida cystica with meningocele, there is a protrusion of

A

Meninges

22
Q

In spina bifida cystica with meningomyelocele, there is protrusion of

A

Neural tissues w/ protruding meninges

23
Q

In spina bifida cystica with rachischisis (or myeloschisis), exposed nerve tissue is permanently damaged by

A

Amniotic fluid

24
Q

Most neural tube defects can be prevented by supplementation with

A

Folate

25
Q

The spinal cord’s conus medullaris ends at different locations when comparing the

A

Fetus, newborn, and adult

26
Q

Up until the 3rd month in utero, the spinal cord extends the

A

Entire length of the embryo

27
Q

Up until the 3rd month in utero, spinal nerve roots pass through intervertebral foramina located at the

A

Same level as their segmental origin

28
Q

For example, up until the 3rd month in utero, the short S1 spinal nerve root exits through the

A

S1 intervertebral foramen

29
Q

At birth, the conus medularis ends at the

A

L3-L4 vertebra

30
Q

With further growth during adulthood, the spinal cord ends at the

A

L1-L2 vertebrae

31
Q

Cells of the neural tube that form neurons and neuroglia of the CNS

A

Neuroepithelial cells

32
Q

Primitive neurons that lose the ability to divide as soon as they are formed from neuroepithelium

A

Neuroblasts

33
Q

Neuroblasts move from neuroepithelium to the mantle layer to form nuclei in

A

Gray matter of spinal cord

34
Q

Neuroblast migration into the mantle layer and subsequent differentiation forms which two prenatal thickenings?

A
  1. ) Alar plates (become dorsal sensory horns)

2. ) Basal plates (become ventral & lateral motor horns)

35
Q

Myelinated axon processes (“fibers”) extend from

neuroblasts in mantle layer and into marginal layer to form

A

White matter of spinal cord

36
Q

What do the following prenatal structures of the spinal cord become postnatally?

  1. ) Mantle layer
  2. ) Marginal layer
A
  1. ) CNS gray matter

2. ) CNS white matter

37
Q

Aggregations of neuron cell bodies in the PNS

A

Ganglia

38
Q

Sensory neurons that project processes from receptors and into spinal cord

A

Dorsal root ganglia

39
Q

What are the primary tissues of the musculoskeletal (MSK) system?

A
  1. ) Epithelium
  2. ) Connective tissue
  3. ) Muscle
  4. ) Nerve
40
Q

Made up of large, cylinder-shaped cells that are striated and multinucleate

A

Skeletal muscle

41
Q

What gives rise to skeletal muscle and most connective tissue in MSK?

A

Mesoderm cells

42
Q

What are two types of connective tissue in the musculoskeletal system?

A
  1. ) Connective tissue proper

2. ) Specialized connective tissue

43
Q

Includes dermis, tendon, or ligament

A

Connective tissue proper

44
Q

Specialized connective tissue includes

A

Bone and cartilage

45
Q

Immature embryonic connective tissue made up of fibroblast-like cells surrounded by ECM

A

Mesenchyme

46
Q

Differentiate into cells of connective tissue

A

Mesenchymal cells

47
Q

Soon after gastrulation in week 3 of development, mesoderm further differentiates and sets the stage for development of the

A

MSK

48
Q

Bilateral columns of PARAXIAL MESODERM form on on either side of the midline and further differentiate into

A

Somites

49
Q

Within each block/segment, somitic mesoderm cells differentiate and reposition into the

A
  1. ) Sclerotome
  2. ) Dermatome
  3. ) Myatome
50
Q

Forms the axial skeleton

A

Sclerotome

51
Q

Forms the dermis of the skin

A

Dermatome

52
Q

Form skeletal muscles of the body wall and limbs

A

Myotome

53
Q

The mesoderm divides into the

A

Paraxial and lateral plate mesoderms

54
Q

Bilateral columns of lateral plate mesoderm form in the lateral-most parts of the embryo and divides into which two layers?

A
  1. ) Parietal/somatic mesoderm

2. ) visceral/splanchnic mesoderm

55
Q

Like the somite’s mesenchymal cells, SOMATIC MESENCHYMAL CELLS form

A

Connective tissues

56
Q

Forms connective tissues associated with the midline

A

Somitic mesoderm

57
Q

Forms connective tissues away from the midline that include cartilage, bones, tendons, and ligaments of the appendicular skeleton (plus sternum)

A

Somatic mesoderm

58
Q

Skeletal muscle cells ALL initially originate from

A

Somite myotome cells

59
Q

Thus, myotome cells (originally from somite) migrate to the somatic mesoderm to form

A

Skeletal muscles in anterolateral trunk and limbs

60
Q

Folow the course of the migrating myotome cells

A

Nerves

61
Q

More specifically, somatic motor axons from a spinal cord segment level extend with the migrating somite
mesoderm cells from the

A

Same somite level

62
Q

Neural crest cells also form connective tissues in the

A

Head

63
Q

Forms the cartilage, bone, and tendons/ligaments of the axial skeleton, but not the sternum

A

Sclerotome

64
Q

Forms the cartilage, bone, and tendons/ligaments of the appendicular skeleton, PLUS the sternum

A

Somatic mesoderm

65
Q

In direct ossification, or intramembranous ossification, bone-forming osteoblasts can lay down bone directly on

A

Mesenchymal membranes

66
Q

In indirect ossification, or endochondral ossification, bone-forming osteoblasts lay down bone along a previously formed

A

Cartilaginous skeletal template

67
Q

Sclerotome mesenchymal cells migrate to surround the neural tube and notochord. Vertebrae develop from sclerotome of

A

Two adjacent somites

68
Q

Forms the annulus fibrosis of the intervertebral disc

A

Sclerotome

69
Q

Forms the nucleus pulposus of the intervertebral disc

A

Notochord

70
Q

Mesenchymal cells form chondrocytes which form a cartilaginous vertebrate that is quickly replaced by bone via

A

Endochronal ossification

71
Q

Derived from scleretome cells that make up the coastal processes of the developing thoracis vertebrae

A

Ribs

72
Q

Fibroblasts make

A

Dermis, tendons, and ligaments

73
Q

Forms bone, cartilage, and tendons/ligaments associated with the vertebral column, ribs, and flat bones of posterior skull

A

Sclerotome

74
Q

The sternum develops independently of the rest of the axial skeleton and is formed from

A

Somatic mesoderm

75
Q

As the ribs grow laterall and ventrally from the 12 thoracic vertebrae toward the midline, they fuse with

A

Coastal cartilages

76
Q

In 1% of the population, cervical ribs can be seen attached to

A

C7 vertebrae

77
Q

The extra rib may impinge on nerves and arteries associated with innervation into the upper limb, this is called

A

Thoracic outlet syndrome

78
Q

A rare defect that results from incomplete fusion between the sternal mesenchyme bars

-results in an area of soft tissue and skin between the sternal segments

A

Cleft sternum

79
Q

In addition to neurulation, induces formation of the vertebral column around the spinal cord

A

Notochord

80
Q

Many of the flat bones of the skull form from

A

Somite mesoderm

81
Q

Much of the other components of the skull form from

A

Neural crest associated with pharyngeal arches

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