Exam 3 Chapter 9 Flashcards
The dividing somite is made up of mesodermal cells, these give rise to:
Mesenchyme
The skeletal system is derived from ______. & mesenchyme of the head & limbs
Sclerotomes
Condensation of the mesenchyme gives rise to the bone models:
Cartilage: Endochondral or intercartilagenous
Membrane: Intramembranous
Neurocranium: Develops from what surrounding the brain?
Mesenchyme
What are the 2 types of neurocranium development?
- Neurochondrocranium
- Neuromembranocranium
Neurochondrocranium builds what?
cartilage base for growing brain
Neuromembranocranuim forms what?
the sides & the roof of the neurocranium.
Anterior fontanelle - closes end of:
2nd yr.
Posterior & anterolateral fontaelle- closes:
2-3 months
Posterolateral closes:
End of the 1st year
- 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
Vertebra Development
- Doesn’t fuse untio 3rd month after birth
Spinous process
5 Ossification centers @ puberty
- 1 @ tip of spinous process
- 1 @ each tip of transverse process
- 2 on the rim of the epiphyseal center
- Intramembranous
- Ossifies before other bones in the body
Clavicle development
- Small stature
- Craniofacial- large face & head
- Skeletal- short tubular bones
- Hyper lordosis in lumbars
- Etiology: autosomal dominate
Achondroplasia syndrome - slow growth of cartilage
- Lipids accumulate in the mesenchyme & nervous system
- Grow is stunted & nervous system is compromised - Lower IQ
- Hunter’s & Hurler’s Syndrome
Mucopolysaccaridosis
What types of Spina Bifida are there?
Occulta- Can’t see on the outside
Cystica - with a cyst
Occulta (Spina bifida)
Limited to the vertrbra
usually spinous process
Cystica (spina bifida)
Meninges only - meningocoele
Meninges & spinal cord- Meningomyelocoele
- Abnormal curvature of the spine
- Number of vertebra varies
- Morphological variation- did not develop correctly
Congenital Scoliosis
Premature closure of the sutures of the skull
Craniostenosis
Oxycephaly
All sutures are closed - symmetrical
Plagiocephaly
Sutures close asymmetrical
Scaphocephaly
Sagittal sutures close prematurely - long narrow cranium
