M2-C1-L48 --> Embryo Musculoskeletal System

Front 1

Paraxial mesoderm forms a series of tissue blocks on either side of the neural tube. What are these called? x2.

Back 1

1. Somatomeres in head
2. Somites from occipital region caudally

Front 2

Lateral plate mesoderm splits into what layers? x2

Back 2

1. Somatic layers
2. Splanchnic layers

Front 3

Somites develop into what? x2

Back 3

1. Sclerotome
2. Dermomyotome

Front 4

Sclerotome gives rise to what?

Back 4

Mesenchyme which become fibroblasts, osteoblasts, and chondroblasts.

Front 5

Dermomyotome develops into what?

Back 5

Skin and muscles.

Front 6

Neural crest cells form what?

Back 6

1. Ganglia
2. Schwann cells
3. Contributes to development of musculoskeletal system.

Front 7

What cells contributes to the development of musculoskeletal system.

Back 7

Neural Crest Cells.

Front 8

The two parts of the skull.

Back 8

1. Neurocranium - around the brain
2. Viscerocranium - forms face

Front 9

Membranous bones of the neurocranium are developed from what?

Back 9

Neural crest cells and paraxial mesoderm.

Front 10

What are the two parts of the neurocranium?

Back 10

1. Membranous portion
2. Cartilaginous portion (chondrocranium)

Front 11

Describe what the membranous portion of the neurocranium is.

Back 11

Flat bones of cranial vault

Front 12

Condrocranium (or cartilaginous portion of neurocranium) formed from what?

Back 12

SEPARATE cartilages derived from neural crest and paraxial mesoderm.

Front 13

Describe what the cartilaginous portion of the neurocranium forms into.

Back 13

Forms base of skull

Front 14

Cartilaginous portion of the neurocranium is also known as what?

Back 14

Chondrocranium

Front 15

Viscerocranium forms what?

Back 15

Face

Front 16

Viscerocranium is formed from what embryonic cells? x3

Back 16

1. Neural Crest
2. Somites/Somitomeres
3. Lateral Plate

Front 17

Anterior portion of skull is from what?

Back 17

Neural crest cells

Front 18

Posterior portion of skull is from what?

Back 18

Paraxial mesoderm

Front 19

What is a major target for teratogens?

Back 19

Neural crest cells

Front 20

Palpation of what gives info if ossification of skull is normal or whether intercranial pressure is normal.

Back 20

Anterior Fontanelle during first few years.

Front 21

What is a fontanelle?

Back 21

Wide areas where more than two bones meet.

Front 22

Where can you find the most prominent fontanelle?

Back 22

Anterior fontanelle

Front 23

What are sutures?

Back 23

Where two bones meet narrow seems of connective tissue

Front 24

How is the base of the skull formed?

Back 24

When cartilages fuse and ossify.

Front 25

The viscerocranium is formed mainly from what two things?

Back 25

1st and 2nd pharyngeal arches.

Front 26

Which pharyngeal arch and process is associated with the dorsal portion?

Back 26

1st arch and maxillary process

Front 27

Which pharyngeal arch and process is associated with the ventral portion?

Back 27

1st arch and mandibular process

Front 28

The first pharyngeal arch give rise to what in the dorsal portion? x3

Back 28

1. Maxilla
2. Zygoma
3. Temporal

Front 29

The second pharyngeal arch (with contributions from 2st arch) give rise to what?

Back 29

1. Incus
2. Malleus
3. Stapes

Front 30

The first pharyngeal arch contains what.......which will give rise to what in the ventral portion?

Back 30

Contains

MECKEL's cartilage

around with

MESENCHYME

which gives rise to

MANDIBLE

Front 31

Why is the face small compared to the neurocranium?

Back 31

Due to absence of sinus, teeth, and small bones.

Front 32

Define cranioschisis.

Back 32

Cranial vault fails to form

or

there are small defects in the skull

Front 33

1. Cranioschisis

2. Anencephaly

3. Vault fails to form and brain tissue exposed to amniotic fluid.

Back 33

What type of condition is this?

What is this condition?

How did this happen?

Front 34

Cranioschisis

Meningocele or Meningoencephalocele

Small defects through which meninges or meninges with brain herniate.

Back 34

What type of condition is this?

What is this condition?

How did this happen?

Front 35

Define craniosynostosis.

Back 35

Caused by premature closure of one or more sutures.

Front 36

What are some examples of craniosynostosis? x3

Back 36

1. Scaphocephaly
2. Acrocephaly
3. Plagiocephaly

Front 37

Craniosynostosis

Scaphocephaly

Premature closure of saggital sutures.

Back 37

Question

Front 38

Craniosynostosis

Acrocephaly

Premature closure of coronal sutures.

Back 38

Question

Front 39

1. Craniosynostosis

2. Plagiocephaly

3. Premature closure of coronal and lamboid suture on one side.

Back 39

Question

Front 40

Achondroplasia affects primarily what part of body?

Back 40

Long bone.

Front 41

At end of 4th week, limb buds consist of what? from where? covered by what?

Back 41

1. Core of Mesenchyme
2. From somatic layer of lateral plate mesoderm
3. Cuboidal ectoderm

Front 42

In limb buds at the 5th week, ectoderm at distal end forms what?

Back 42

Apical ectoderm ridge.

Front 43

Describe the development of cartilage and muscle in limbs.

Back 43

Development in a proximal to distal direction.

Front 44

Upper limb rotates how?

Back 44

Laterally 90 degrees

Front 45

With upper limb rotation, describe the position of the extensor muscles and thumb.

Back 45

Lateral & Posterior surface

with

Thumb lateral

Front 46

Describe lower limb rotation.

Back 46

Medial rotation of 90 degrees.

Front 47

With lower limb rotation, describe the position of the extensors and big toe.

Back 47

Anterior surface

with

Big toe medial

Front 48

What is a joint interzone?

Back 48

Where joints formed where cartilage development inhibited.

Front 49

How are joint cavities created?

Back 49

Cell death.

Front 50

How does joint capsules form?

Back 50

Surrounding tissue of joint cavity forms it.

Front 51

Describe finger and toes formation.

Back 51

Cell death separates the apical ectodermal ridges into five parts.

Front 52

Embryo called a fetus when?

Back 52

At beginning of 9th week.

Front 53

How many epiphyseal plates in long bones? small bones (e.g. - phalanges)? or irregular bones (e.g. - vertebrate)?

Back 53

1. At each end
2. Only at one end of extremity
3. One or more primary centers & several secondary centers.

Front 54

Define amelia.

Back 54

Complete absence of one or more limbs.

Front 55

Define Meromelia

Back 55

Partial absence of limb

Front 56

Phocomelia defined.

Back 56

Hands and feet attached to trunk by irregular bones.

Front 57

Micromelia defined.

Back 57

All segments of limbs present but abnormally short.

Front 58

Ectrodactyly defined

Back 58

Absence of digit

Front 59

Syndactyly defined

Back 59

Fusion of digits or toes.

Front 60

Describe lobster claw formation.

Back 60

Abnormal cleft in 2nd and 4th MCP

Absent 3rd MCP & phalanges

Thumb & index fused

4th and 5th digit fused

Front 61

Describe clubfoot.

Back 61

Sole of foot turned inward.

Foot adducted.

Plantar flexed.

Front 62

Clubfoot occurs primarily in which gender?

Back 62

Males

Front 63

Amniotic bands may cause what in limb defects?

Back 63

Ring constriction & amputation of limbs or digits

Front 64

Congenital hip dislocations occur primarily in which gender.

Back 64

Females.

Front 65

Describe the formation of the vertebrae.

Back 65

Sclerotomes surround the notocord and spinal cord.

Caudal half of a sclerotome binds to the subjacent cephalic half of another sclerotome.

This forms precartilaginous vertebral body.

Front 66

Describe the role of myotomes in vertebral formation.

Back 66

Myotomes bridge the intervertebral discs, allowing the spine to have movement ability.

Front 67

Describe Klippel-Feil anomaly.

Back 67

Pts have fewer Cervical vertebrae. Other vertebrae are fused or abnormal in shape.

Usually associated with other abnormalities.

Front 68

Describe spina bifida.

Back 68

Cleft vertebra usually in bony arch

Front 69

Describe scoliosis

Back 69

Lateral curving of spine

Resulting from two successive vertebrae fusing asymmetrically

or half a vertebrae missing.

Front 70

Describe rib formation

Back 70

Develop from costal processes of thoracic vertebrae,

from sclerotome portion of paraxial mesoderm

Front 71

Describe sternum formation

Back 71

Develops from somatic mesoderm in ventral body wall as two sternal bands which fuse.

Front 72

What is unique about clavicle formation.

Back 72

Only postcranial bone that develops in mesenchyme instead of cartilage.

Front 73

Skeletal muscle develop from what embryonic cells?

Back 73

Paraxial mesoderm (somites & somatomere)

Front 74

Myotomes form what two muscle forming regions?

Back 74

Epimere and Hypomere

Front 75

Describe epimere innervation.

Back 75

Innervated by dorsal primary rami.

Front 76

Describe hypomere innervation

Back 76

Innvervated by ventral primary rami.

Front 77

What is the association with nerves and muscle segments?

Back 77

Nerves will remain with original muscle segment throughout its migration

Front 78

Skeletal myoblast precursor cells fuse forming what?

Back 78

Long multinucleated fibers.

Front 79

Describe Prune-belly syndrome.

Back 79

Absence of abdominal musculature, usually associated with malformation of bladder.

Front 80

Cardiac muscles develop from what embryonic tissue?

Back 80

Splanchnic mesoderm surrounding endothelial heart tube.

Front 81

Cardiac myoblasts adhere to one another and develop into what?

Back 81

Intercalated discs.

Some cells form Purkinje fibers.

Front 82

Common partial or complete absence of muscles occur in what muscles? x3

Back 82

1. Pectoralis major
2. Palmaris longus
3. Abdominal (prune-belly)