Skeletal And Muscular System

Front 1

Located at the tip of each limb bud and induces the mesenchyme beneath it to elongate

Back 1

Apical Ectodermal Ridge

Front 2

Limb buds are made up of (2 things):

Back 2

Mesenchyme (somatic mesoderm) covered by surface ectoderm

Front 3

Which Spinal Roots supply the upper limb

Back 3

C5-T1

Front 4

Which Spinal Roots supply the lower limb bud

Back 4

L2-S3

Front 5

Cartilaginous bones begin to develop from ----- early in week ------

Back 5

Chondrification Centers, week 5

Front 6

During what time do limb buds descend to their adult height

Back 6

Weeks 6-8

Front 7

Ossification of long bones

Back 7

osteogenesis

Front 8

osteogenesis begins from

Back 8

primary ossification centers in the middle of the long bone

Front 9

When does osteogenesis begin?

Back 9

Week 7

Front 10

The skeletal muscle of the limb is derived from ------------- that migrates into the limbs

Back 10

myotomal cells

Front 11

The complete absence of one or more limbs

Back 11

amelia

Front 12

Defect where the upper portion of a limb is absent or poorly developed

Back 12

Phocomelia

Front 13

Congenital anomaly characterized by two or more fused together fingers or toes

Back 13

Syndactyly

Front 14

Enlargement of one or more digits

Back 14

Macrodactyly

Front 15

Condition in which one has extra digits

Back 15

Polydactyly

Front 16

Condition in which one has fewer than normal digits

Back 16

Ectrodactyly

Front 17

Malformation characterized by abnormal positions of the foot

Back 17

Clubfoot (talipes equinovarus)

Front 18

One form of congenital dwarfism resulting from improper development of cartilage at the end of long bones

Back 18

Achondroplasia

Front 19

Segmented series of tissue blocks adjacent to the neural tube

Back 19

Somites

Front 20

Somites are made from:

Back 20

paraxial mesoderm

Front 21

Somites develop into two segments:

Back 21

Sclerotome & Dermomyotome

Front 22

Three layers contributing to skeletal system formation

Back 22

Paraxial mesoderm, lateral plate mesoderm, and neural crest

Front 23

Ventromedial portion of the somite gives rise to

Back 23

Sclerotome cells

Front 24

These cells become polymorphous and and form loosely woven tissue (mesenchyme)

Back 24

Sclerotome cells

Front 25

Cells that migrate and give rise to fibroblasts, chondroblasts, and osteoblasts

Back 25

Mesenchymal cells (from sclerotome)

Front 26

Dorsolateral portion of the somites gives rise to:

Back 26

Dermomyotome cells

Front 27

Cells that give rise to the dermis and mucle

Back 27

Dermomyotome cells

Front 28

The somatic mesoderm layer comes from

Back 28

Lateral plate mesoderm

Front 29

Gives rise to appendicular skeletal bones (pelvic, shoulder girdles, long bones, sternum)

Back 29

Somatic mesoderm layer (lateral plate mesoderm)

Front 30

Cells in the head that give rise to mesenchyme participating in the formation of the bones of the face and skull

Back 30

Neural Crest

Front 31

Contributes to the formation of the cranial vault and the base of the skull

Back 31

Occipital Somites (paraxial mesoderm)

Front 32

Mesenchyme in the dermis differentiates directly into bone

Back 32

intramembranous ossification

Front 33

Flat bones of the skull are formed through (mandible, skull, clavicle)

Back 33

intramembranous ossification

Front 34

Part of the skull encasing the brain, made up of membranous vault and cartilaginous base

Back 34

Neurocranium

Front 35

Mesenchymal cells give rise to hyaline cartilage models which are then ossified

Back 35

Endochondral ossification (most bones)

Front 36

Mesenchyme in the membranous neurocranium comes from ---------&---------

Back 36

Neural Crest and Paraxial mesoderm

Front 37

The membranous neurocranium undergoes what type of ossification?

Back 37

Intramembranous

Front 38

In intramembranous ossification --------- appears and radiates from primary ossification centers toward the periphery

Back 38

bone spicules

Front 39

Flat bones are separated by seams of connective tissue known as

Back 39

Sutures

Front 40

Sagittal Suture derived from

Back 40

Neural Crest

Front 41

Coronal Suture is derived from

Back 41

paraxial mesoderm

Front 42

Points where more than two bones meet in the cranium

Back 42

fontanelles

Front 43

Gives rise to the base of the skull

Back 43

Cartilaginous neurocranium

Front 44

Bones arising anterior to the anterior half of the sella turcica are from:

Back 44

Neural Crest

Front 45

The bones arising from neural crest in the skull make up the

Back 45

prochordal chondrocranium

Front 46

Bones arising posterior to the posterior 1/2 of the sella turcica are from:

Back 46

paraxial mesoderm (occipital sclerotomes)

Front 47

Paraxial mesoderm in the cranium forms:

Back 47

Chordal Chondrocranium

Front 48

Bones of the face are primarily derived from

Back 48

The first two branchial arches (nerual crest)

Front 49

Forms the maxilla, zygomatic bone, and the squamous part of the temporal bone

Back 49

Dorsal portion of first branchial arch

Front 50

Forms the mandibular process containing meckel's cartilage

Back 50

Ventral portion of the 1st branchial arch

Front 51

Meckel's Cartilage condenses and ossifies by ----------- to give rise to the --------------

Back 51

intramembranous ossification, mandible

Front 52

Gives rise to the sphenomandibular ligament

Back 52

Meckel's Cartilage

Front 53

Induces mandibular development and then disappears

Back 53

Meckel's Cartilage

Front 54

First Bones to be ossified

Back 54

bones of the inner ear (4th month)

Front 55

Gives rise to the incus, malleus, and stapes

Back 55

The second branchial arch (& dorsal end of 1st arch)

Front 56

Mesenchymal core of the limb bud is formed from:

Back 56

somatic layer of lateral plate mesoderm

Front 57

Gives rise to the bones and CT of the limbs

Back 57

mesenchymal core

Front 58

The mesenchymal core of the limb bud is covered by

Back 58

cuboidal ectoderm

Front 59

Ectoderm at the distal border of the limbs thickens to give:

Back 59

Apical Ectodermal Ridge (AER)

Front 60

Terminal portions of the limb bud flatten to form hand and foot plates when?

Back 60

6th week

Front 61

Mesenchyme in the limb buds condenses and the cells differentiate to give rise to (2 things)

Back 61

Chondrocytes and the first hyaline cartilage models

Front 62

When do the limbs rotate in opposite directions

Back 62

7th week

Front 63

Exerts inductive influence on adjacent mesenchyme causing cells to remain undifferentiated but rapidly proliferating

Back 63

Apical Ectodermal Ridge

Front 64

Which limb rotates 90 degrees laterally

Back 64

Upper limb

Front 65

After rotation, which direction does the thumb lie?

Back 65

Laterally

Front 66

Which limb rotates 90 degrees medially

Back 66

Lower limb

Front 67

Cell death in the joint interzone gives rise to

Back 67

joint cavities

Front 68

What is formed in the cartilaginous condensations when chondrogenesis is arrested?

Back 68

joints

Front 69

ossification of the bones of the extremities occurs via what mechanism?

Back 69

endochondral ossification

Front 70

When do primary ossification centers appear in the shaft of the long bone?

Back 70

week 12

Front 71

Vertebrae form from what part of the somite?

Back 71

Sclerotome

Front 72

When do vertebrae start to form?

Back 72

4th week

Front 73

Mesenchyme between developing vertebral bodies does not proliferate but gives rise to:

Back 73

intervertebral disks

Front 74

Ribs are derived from what tissue?

Back 74

sclerotome portions of paraxial mesoderm (costal processes of thoracic vertebrae)

Front 75

The sternum is formed independent of the ribs by:

Back 75

somatic mesoderm (ventral body wall)

Front 76

Gives rise to skeletal muscle of the axial skeleton, body walls, limbs, and head

Back 76

Paraxial mesoderm

Front 77

Destined to contribute to myotome progenitor cells or limb and body wall muscles

Back 77

Ventrolateral lip (VLL)

Front 78

Destined to contribute to dermatome and myotome progenitor cells of back mm

Back 78

Dorsomedial lip (DML)

Front 79

Gives rise to smooth muslce surrounding the gut and its derivatives

Back 79

somatic mesoderm

Front 80

gives rise to cardiac muscles surrounding the endothelial heart tube

Back 80

somatic mesoderm

Front 81

gives rise to smooth muscle in pupillary regions, mammallary glads and sweat glands

Back 81

ectoderm

Front 82

Gives rise to dorsal aorta, large arteries and coronary artery muscles

Back 82

Neural crest and lateral plate mesoderm