Exam 3 Chapter 9

Question 1

The dividing somite is made up of mesodermal cells, these give rise to:

Answer 1

Mesenchyme

Question 2

The skeletal system is derived from ______. & mesenchyme of the head & limbs

Answer 2

Sclerotomes

Question 3

Condensation of the mesenchyme gives rise to the bone models:

Answer 3

Cartilage: Endochondral or intercartilagenous
Membrane: Intramembranous

Question 4

Neurocranium: Develops from what surrounding the brain?

Answer 4

Mesenchyme

Question 5

What are the 2 types of neurocranium development?

Answer 5

• Neurochondrocranium

- Neuromembranocranium

Question 6

Neurochondrocranium builds what?

Answer 6

cartilage base for growing brain

Question 7

Neuromembranocranuim forms what?

Answer 7

the sides & the roof of the neurocranium.

Question 8

Anterior fontanelle - closes end of:

Answer 8

2nd yr.

Question 9

Posterior & anterolateral fontaelle- closes:

Answer 9

2-3 months

Question 10

Posterolateral closes:

Answer 10

End of the 1st year

Question 11

• Develops from mesenchyme of the sclerotome
• Caudal portion densely packed
• Cranial part loosely packed
• Cranial portion moves up the caudal portion
• These portions fuse to make the vertebra
• This action makes room for the vessels & muscles

Answer 11

Vertebra Development

Question 12

• Doesn’t fuse untio 3rd month after birth

Answer 12

Spinous process

Question 13

5 Ossification centers @ puberty

Answer 13

• 1 @ tip of spinous process
• 1 @ each tip of transverse process
• 2 on the rim of the epiphyseal center

Question 14

• Intramembranous

- Ossifies before other bones in the body

Answer 14

Clavicle development

Question 15

• Small stature
• Craniofacial- large face & head
• Skeletal- short tubular bones
• Hyper lordosis in lumbars
• Etiology: autosomal dominate

Answer 15

Achondroplasia syndrome - slow growth of cartilage

Question 16

• Lipids accumulate in the mesenchyme & nervous system
• Grow is stunted & nervous system is compromised - Lower IQ
• Hunter’s & Hurler’s Syndrome

Answer 16

Mucopolysaccaridosis

Question 17

What types of Spina Bifida are there?

Answer 17

Occulta- Can’t see on the outside

Cystica - with a cyst

Question 18

Occulta (Spina bifida)

Answer 18

Limited to the vertrbra

usually spinous process

Question 19

Cystica (spina bifida)

Answer 19

Meninges only - meningocoele

Meninges & spinal cord- Meningomyelocoele

Question 20

• Abnormal curvature of the spine
• Number of vertebra varies
• Morphological variation- did not develop correctly

Answer 20

Congenital Scoliosis

Question 21

Premature closure of the sutures of the skull

Answer 21

Craniostenosis

Question 22

Oxycephaly

Answer 22

All sutures are closed - symmetrical

Question 23

Plagiocephaly

Answer 23

Sutures close asymmetrical

Question 24

Scaphocephaly

Answer 24

Sagittal sutures close prematurely - long narrow cranium

Question 25

Acrocephaly

Answer 25

Coronal sutures close - shorten wide cranium

Question 26

Absence of limbs

Answer 26

Amelia

Question 27

Absence or reduction of proximal limb

Answer 27

Phocomelia

Question 28

Absence or reduction of distal part of limb

Answer 28

Meromelia

Question 29

Fusion of lower limb

Answer 29

Sympodia (mermaid syndrome)

Question 30

Duplication of distal part of limbs- Can be addition of hands & feet

Answer 30

Dichiria

Question 31

Presence of extra digits

Answer 31

Polydactyly

Question 32

Fusion of digits or digit

Answer 32

Syndactyly