Brainscape's Knowledge GenomeTM

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


See full index

CM Week 2 > Musculoskeletal Embryology > Flashcards

Musculoskeletal Embryology Flashcards

1
Q

What do embryonic genes determine?

A

The pattern of the body including that of the limbs

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

What embryonic genes have roles in patterning and have been well characterized?

A

FGF, Qnt-7a, Shh, band Homeobox (Hox) genes

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

When do limbs for after fertilization?

A

after then end of the 4th week as buds along the body wall and are pattered along 3 planes.

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

What are the 3 planes of limb development?

A

proximal to distal, dorsal-ventral, anterior posterior

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

What gene is proximal to distal limb development dependent on?

A

FGF (fibroblast growth factor) gene

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

What produces the FGF protein in proximal to distal development?

A

the mesoderm causing proliferation of the ectoderm at the site where the limbs form

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

What forms the apical ectoderm ridge (AER) in proximal to distal development?

A

proliferating ectoderm

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

What does the AER begin to produce in proximal to distal development?

A

FGF causing proliferation of the mesoderm called the progress zone

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

What happens with the AER in proximal to distal development is removed?

A

mesoderm stops proliferating and the limb stops growing but if you add back FGF you get normal growth

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

How do digits form?

A

in proximal to distal limb development digits form when apoptosis occurs in the AER to separate it into 5 separate ridges, final separation of the digits is achieve by additional apoptosis in the interdigital spaces.

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

Dorsal to ventral limb development is depended on what genes?

A

Want-7a it is a signaling protein expressed by the AER, it activates LMX-1 gene in the mesoderm causing it to form dorsal structures.

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

What does deletion of the LMX-1 gene cause in dorsal to ventral limb development?

A

causes the limb to form with 2 ventral sides

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

What does ectoderm on the ventral side of the limb bud express?

A

transcription factor Engrailed1 which represses Wnt-7a expression on the ventral side of the limb

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

What makes the dorsal side of the limb dorsal and the ventral side ventral

A

presence of Wnt-7a dorsal and absence of Wit-7a ventral

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

What gene does anterior-posterior development depend on?

A

Shh (sonic hedgehog) gene

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

What is Shh (sonic hedgehog) gene?

A

a signaling protein produced at the posterior base of the limb buts .

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

What cells produce Shh?

A

zone of polarizing activity (ZPA)

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

What results in mirror image duplication of limb structures?

A

transplantation of the ZPA or implantation off a Shh bead to the anterior side of the limb bud

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

When Shh diffuses across the limb bud it activates the expression of what family of transcription factors?

A

Homeobox (Hox) gene

20
Q

What is a Hox gene?

A

Hox genes define the pattern of differentiation from the thumb (anterior or cranial) to little finger (posterior or caudal) as well as segmental organization of the entire embryo in a cranial to caudal direction

21
Q

How does bone develop?

A

Either intramembranous (membranous or dermal) or endochondral ossification

22
Q

What bones are formed by intramembranous ossification?

A

flat bones of the skin and bones of the face

23
Q

What do mesenchyme cells differentiate into in intramembranous ossification?

A

directly into osteoblasts.

24
Q

What is mesenchyme?

A

loosely organized tissue mainly mesodermal tissue that develops into connective and skeletal tissue including blood and lymph

25
Q

What type of bone do osteoblast lay down?

A

primary or woven bone (irregularly arranged collagen fibers) that is removed Ito lamellar bone (parallel alignment of collagen into sheets)

26
Q

What bones are formed by endochondral ossification?

A

long bones and vertebral column, pelvis, sternum and skill base

27
Q

In endochrondral ossification mesenchyme differentiates into what?

A

chondroblasts which produce a cartilage model. cartilage becomes vascularized bringing in osteoblast and restricting proliferating chondrocytes to the ends (epiphysis) of the bone.

28
Q

What is the region called between the epiphysis and diaphysis where the bone grows in length?

A

epiphyseal (growth) plate or the physics

29
Q

During endochrondral ossification where does proliferation occur?

A

the epiphyseal side of the plate (zone of proliferating cartilage). Chondrocytes towards the shaft side (diaphysis) undergo hypertrophy and apoptosis (zones of hypertrophic cartilage) as they mineralize the surround matrix (zone of calcified cartilage)

30
Q

Where do osteoblasts bind during endochrondral ossification?

A

bind to the mineralized matrix and deposit bone matrix (zone of ossification).

31
Q

The long bone will continue to go as long as….

A

the rate of proliferating equals the rate of cell health and ossification

32
Q

Where does skeletal muscle develop from?

A

mesoderm closest to the notochord and neural tube, called the paraxial mesoderm.

33
Q

The paraxial mesoderm becomes organized into segments that form what?

A

craniocaudal sequence

34
Q

Segments in the head and neck from the carniocaudal sequence are called?

A

somitomeres

35
Q

Segments in the trunk from the carniocaudal sequence are called?

A

somites

36
Q

What doe the smites differentiate into?

A

axial skeleton, all skeletal muscle and some of the dermis of the skin

37
Q

During the 5th week of development what do the axons of motor neurons do?

A

axon of the motor neurons from the spinal cord enter the limb bud and now into the developing skeletal muscles at the same segmental level.

38
Q

When do axons of sensory neurons enter the limb bud?

A

after the motor axon and supply the segmental regions of the skin.

39
Q

What is a dermatome?

A

it is an area of skin innervated by a single spinal nerve and its dorsal root ganglion.

40
Q

As the limbs grow in length what happens to the original segmental dermatome?

A

The pattern changes

41
Q

During 6-8 weeks in development how do limbs rotate?

A

lower limbs medially rotate and the upper limbs laterally rotate causing the dermatomes to spiral down the limb, especially the lower limb.

42
Q

What are the 3 categories of limb defects in humans?

A

reduction defects, duplication deficits, dysplasia

43
Q

What are reduction defects?

A

are when part of (meromelia) or the entire limb (amelia) is missing, phocomelia is a type of mermelia when hands or feet project directly from the shoulder or hip.

44
Q

What are duplication defects?

A

when extra limb elements are present. Polydactyly (extra digits)

45
Q

What are duplication defects?

A

is a malformation of part of the limb, example of this is abnormal fusion of the digits resulting from reduced apoptosis (syndactyly).

CM Week 2 (4 decks)

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