Embryology - Muscles, Somites, Limbs, Lung Flashcards Preview

IUSM Anatomy > Embryology - Muscles, Somites, Limbs, Lung > Flashcards

Flashcards in Embryology - Muscles, Somites, Limbs, Lung Deck (45)
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1

A somite starts off as mesenchymal cells. they then differentiate into ___, ___, and ___

sclerotome, dermatome, and myotomes (sometimes the last two are combined : dermomyotome)

2

Sclerotome cells surround ___

the notochord and neural tube

3

__sclerotomes split and recombine to form __

segmental; intersegmental vertebral rudiments and ribs

4

What are somites made from? What do they establish?

paraxial mesoderm; segmental org. of the body

5

paraxial mesoderm is from what?

the intraembryonic mesoderm lateral to the notochord and neural tube

6

what embryonic tissue forms cartilage

mesenchyme

7

what are the two embryonic types of connective tissue that form bone

mesenchyme and cartilage

8

embryonic intramembranous ossification ossifies_____.

mesenchyme

9

embryonic intracartilaginous ossification ossifies ___.

cartilage

10

synovial joints are made from what? What about the joint capsule and synovial membrane?

interzonal mesenchyme located between developing bones. the other parts are also interzonal mesenchyme

11

cartilagenous joints are made from what?

interzonal mesenchyme that differentiates into hyaline or fibrocartilage

12

fibrous joints are made from what?

interzonal mesenchyme that differentiates into fibrous connective tissue

13

during the 4th week, mesenchymal cells from somites are found in the ____, ____, and ___.

surrounding notochord, surrounding the neural tube, and in body wall.

14

limb buds appear from ____.

lateral plate mesoderm

15

each limb bud contains what two things?

apical ectodermal ridge and mesenchyme

16

what is the apical ectodermal ridge? what is a possible modulator?

it is a thickening of ectoderm at the apex of a limb bud. It is possibly modulated by retinoic acid

17

which muscle is NOT from mesoderm

iris muscles

18

developmental tissues leading to muscle

mesenchyme > myoblasts > muscle

19

each myotome splits into two structures?

dorsal epimere and ventral hypomere

20

visceral muscles (iris, sweat gland muscles etc) are from what?

spanchnic mesoderm

21

Cardiac muscle is from what? Are purkinje fibers from that as well?

splanchnic mesoderm. NO. Purkinje fibers are from a different dvpmntal pathway

22

Name the 5 things that are derived from sclerotomes

vertebral bodies, vertebral arches, annulus fibrosis, costal processes, sternum/sternal bars

23

what 3 things are derived from costal processes?

Ribs, transverse processes, and sacral mass

24

Epimeres give rise to___

deep epaxial m of back

25

Hypomeres give rise to what muscles

lateral and ventral body wall: intercostals, abdominal girdle muscles and rectus abdominus

26

In the limb, what makes the bones, tendons, ligaments and vasculature?

Lateral plate mesoderm

27

appendicular skeleton is formed with what type of ossification?

endochondral

28

Which bones appear in weeks 7-12

Clavicle> upper limb> lower limb> scapula and ilium> phalanges> ischium and pubis> tarsals and carpals

(basically starts with arm and alternates from arm to legs, going distally)

29

the upper limb rotates ___(direction) so that the extenors are on the __ and __ aspects

laterally; lateral; dorsal

30

the lower limb rotates ___(direction) so that the extenors are on the __ aspect

medially; ventral