Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Embryo Finals > Musculoskeletal > Flashcards

Musculoskeletal Flashcards

1
Q

The musculoskeletal system consists of skeletal muscle, bone & cartilage and is mainly ———— in origin with some ———- contribution

A

mesoderm, neural crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Layer where nearly all the connective tissues of the body are derived

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cells migrate through the ————- to form the —————.

A

Primitive streak, mesoderm layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Subsequently, 3 regions can be recognized in the mesoderm of a cross-sectioned embryo:

A

Paraxial mesoderm
Intermediate mesoderm
Lateral mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Region that gives rise to the urogenital systems

A

Intermediate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Region nearest the neural tube

A

Paraxial mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The region that forms the bulk of tissues of the body wall, the digestive tract and limbs

A

Lateral mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Paraxial mesoderm accumulates under the ————– with thinner mesoderm laterally. This forms 2 thickened streaks running the length of the embryonic disc along the —————.

A

Neural plate

Rostrocaudal axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In humans, during the 3rd week, the paraxial mesoderm begins to segment into tissues called ———-.

A

Somites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

process of segmentation of the paraxial mesoderm within the trilaminar embryo body to form pairs of somites (balls of mesoderm)

A

Somitogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Somites appear ——————– at the same time and form earliest at the ———- end of the neural groove and add sequentially at the ——— end.

A

Bilaterally as pairs, cranial, caudal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The first somite pair appears at day —– and adds caudally at —————— until on average ——- eventually form.

A

20,
1 somite pair/ 90 minutes
44 pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Embryonic transitional organs that are formed through the segmentation of the paraxial mesenchyma.

A

Somites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

They are responsible for the segmental organization of the embryo and contribute to its restructuring.

A

Somites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The —————– fuses dorsally to form a tube at the level of the ——— & “zips” up cranially & caudally & the neural crest migrates into the ———–.

A

Neural groove
4th somite
Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Segmentation of the paraxial mesoderm into somites continues caudally & a cavity (————————) forms in the lateral plate mesoderm separating ——— & ————.

A

Intraembryonic coelom
Somatic mesoderm
Splanchnic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

■ closest to ectoderm
■ forms the body wall
■ osteogenic, chrondrogenic and fibrogenic

A

Somatic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

■ closest to endoderm
■ forms the heart, smooth muscle of GIT & blood vessels
■ heart is the first organ to form in the embryo

A

Splanchnic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cells in the somite differentiate medially to form the ————— (vertebral column) & laterally to form the ————————.

A

Sclerotome, dermatomyotome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The dermatomyotome then forms the ————— & —————.

A

Dermotome (dermis)

Myotome (muscles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The myotome differentiates to form 2 components:

A

■ epimere dorsally —> epaxial muscles

■ hypomere ventrally —> hypaxial muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The bulk of the trunk muscles comes from the ———— muscles.

A

Hypaxial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In the cylindrical embryo, the somatic mesoderm constitutes the ———————-, & the splanchnic mesoderm forms the ——————————-.

A

Lateral & ventral body wall,

Mesentery and the wall of the digestive tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The somatic mesoderm of the lateral plate also forms the ———————–, which begin to appear late in the ———— of pregnancy.

A

Mesenchyme of the limb buds,

4th wk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When do the human limbs form?

A

In the mid-4th week, human upper limb buds first form & lower limbs 2 days later.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The limbs form at vertebra segmental levels ——– (upper limbs)
& ——– (lower limbs).

A

C5-C8 (upper limbs)

L3-L5 (lower limbs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The limb bud is initially ———– with an ———— covering.

A

mesenchyme, ectodermal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Initially, the limb bud consists exclusively of cells derived from —————–.

A

Lateral plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

These cells give rise to the skeleton, connective tissues & blood vessels.

A

Cells dervied from the lateral plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

———– from the somites migrate into the limb bud as precursors of muscle cells.

A

Myoblasts

31
Q

Other cells come from the neural crest which ultimately forms the ?

A

Schwann cells of the nerves

Pigment cells/ melanocytes

32
Q

At the tip of the limb bud lies a thickened ridge of ectoderm, the ————————, which has a role in patterning the structures that form within the limb.

A

Apical ectodermal ridge (AER)

33
Q

The majority of cell division (mitosis) occurs just deep to the AER & this region is known as the _____________.

A

Progress zone

34
Q

Another region at the base of the limb bud beside the body, the _______________________, determines the organization of the limb along its anteroposterior axis.

A

The zone of polarizing activity (ZPA)

35
Q

In the ____________, hand & footplates appear at the ends of limb buds & ridges form _____________.

A

5th wk,

Digital rays

36
Q

Cells between the digital rays are removed by ?

A

Apoptosis

37
Q

during week 8 for both limbs, there is:

A

■ more advanced development of upper limb at all stages (about 2 days).
■ growth in overall length.
■ rotation of limbs.
■ towards the end of this week the more obvious elbow/knee, shoulder/hip are seen.
■ there is development of digits (fingers, toes) from digital rays.
■ there is loss of cells by apoptosis between the digits.

38
Q

______________ is responsible for sculpting the interdigital spaces in the developing hand & foot.

A

Cell death

39
Q

If interdigital cell death does not occur, a soft tissue web connects the digits on either side. This is the basis of formation of _____________.

A

Syndactyly

40
Q

Presence of additional toes or fingers. The condition is often treated surgically in the infant.

A

Polydactilia/ polydactylism

41
Q

1st major tissue of the limb to show differentiation

A

Skeleton

42
Q

Formation of the skeleton is seen as a ________________________________________.

A

condensation of mesenchymal cells in the central core of the proximal part of the limb bud.

43
Q

Initially, a cartilage of a bone is formed from the ______________.

A

Mesenchymal cells

44
Q

By the process of ________________, there is replacement of cartilage with bone (week ?).

A

Endochondral ossification

Wk 5-12

45
Q

Early ossification occurs where?

A

At the ends of long bones

46
Q

Another process of bone formation is ________________, where bone is formed from a mesenchymal membrane.

A

Intramembranous ossification

47
Q

Specialized form of ossification that occurs in the skull & clavicle.

A

Intramembranous ossification

48
Q

Differentiation of the cartilaginous skeleton occurs in a ________________.

A

proximodistal sequence

In mammals the postaxial structures of the distal limb segments differentiate before the preaxial structures.

49
Q

The postaxial skeleton of the arm

A

Ulna,
Digits 4 & 5,
The corresponding carpal elements

50
Q

the preaxial skeleton

A

Radius,
Digits 1,2,3
Corresponding carpal bones

51
Q

many or all of the preaxial or postaxial components of the limb are missing

A

Hemimelia

52
Q

(Joints)

Earliest mesenchymal rudiments of long bones are essentially __________.

A

Continous

53
Q

As they pass into the _______________, the sites of the future joints can be discerned as intervals of less concentrated mesenchyme.

A

Precartilage stage

54
Q

The mesenchymal tissue between the cartilage rudiments ___________ & a __________ is formed.

A

Disappear

Joint cavity

55
Q

In most joints, a complete joint cavity is formed. In other joints, instead of disappearing, mesenchymal tissue gives rise to a fibrous sheet (_______________) that completely divides the joint into 2 separate compartments.

A

Intraarticular disc

Ex. Temporal bone & mandible

56
Q

In others, the fibrous sheet is incomplete centrally forming a crescentic sheet that projects into the single joint cavity.

A

Articular menisci

Ex. Knee joint

57
Q

The muscles are from __________ that migrate into the very early limb bud from the somites.

The fusion of __________ into early _________ begin to occur during these early stages of muscle development

A

Myogenic cells
Myoblasts
Myotubes

58
Q

These myogenic cells begin to coalesce into 2 common muscle masses:

A

■ precursor of flexor muscles

■ precursor of the extensor muscles

59
Q

Next stage is the splitting of the ___________________ into anatomically recognizable precursors of the definitive muscles of the limb.

A

Common muscle masses

60
Q

Earliest vasculature of the limb bud is derived from:

A
  • endothelial cells: from several segmental branches of the aorta & the cardinal veins
  • angioblasts: endogenous to the limb bud mesoderm.
61
Q

Initially, the limb vasculature consists of fine capillary network, but soon some channels are preferentially enlarged, resulting in a _______________ that supplies blood to the limb bud.

A

Central artery

62
Q

From the central artery, blood is distributed to the periphery via a mesh of capillaries & then collects into a _____________, which is located _________________________.

A

marginal sinus, beneath the apical ectodermal ridge

63
Q

With the establishment of the digital rays, the _____________ of the marginal breaks up, but the _____________ persists into adulthood as the _______________________ of the arm.

A

Apical portion
Proximal portion
Basilic & cephalic veins

64
Q

Branches arising from the ________________ ultimately take ascendancy especially in the forearm, leaving the original artery a relatively minor vessel (the ________________ ) in the forearm.

A

Primary axial artery

Interosseus artery

65
Q

When do the motor axons from the spinal cord enter the limb bud?

A

5th wk

66
Q

Neurons in the medial positions in the spinal cord send axons to the _______________ , whereas those located more laterally in the spinal cord supply the _________________.

A

Ventral muscle mass

Dorsal muscle mass

67
Q

_____________ enter the limb bud after the motor axons & use them for guidance.

A

Sensory axons

68
Q

These cells of the neural crest surround both motor & sensory nerve fibers to form the coverings of the nerves in the limbs.

A

Schwann cells

69
Q

? Wks : Upper & lower limbs have formed as finlike appendages pointing ____________ & ___________.

A

5 wks

Laterally & caudally

70
Q

At ? weeks – Limbs bend _________, so that elbows & knees point __________, palms & soles face the ________.

A

6 wks
Anteriorly
Laterally
Trunk

71
Q

At ? weeks – Upper & lower limbs have undergone ________ about their long axes, but in opposite direction, so that elbows point _________ & knees point _______.

A

7 wks
90* torsion
Caudally
Cranially

72
Q

At ? weeks – Torsion of lower limbs results in ____________ arrangement of their cutaneous innervation.

A

Twisted or “barber pole”

73
Q

3 basic germ layers in the embryo

A
  1. ectoderm - CNS
  2. mesoderm – skin, limbs, circulatory & urogenital systems
  3. endoderm – digestive system

Embryo Finals (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions