Embryology

Front 1

musculo system from?

Back 1

ectoderm, mesoderm, neural crest

Front 2

inducing center?

Back 2

notochord

Front 3

pharyngeal arches

Back 3

involved in structures of the face

Front 4

somitomeres

Back 4

"head somites"; less well-developed and in head region

Front 5

somites

Back 5

ectodermally covered and mesodermally cored; arranged in segmental distribution

Front 6

limb buds

Back 6

one for upper and one for lower extremity

Front 7

paraxial mesoderm

Back 7

assoc with somites and somitomeres, forming vertebra, ribs, and all striated skeletal muscle

Front 8

lateral plate mesoderm

Back 8

body wall structures

Front 9

neural crest cells

Back 9

bones and connective tissues of skull

Front 10

notochord

Back 10

ends up as nucleus pulposis of intervertebral discs

Front 11

skull development: membranous neurocranium

Back 11

membranous neurocranium; membranous ossification, most derived from neural crest cells; back portion of skull from somitomeres and jaw and maxilla are neural crest; exception: inferior part of occipital and otic capsule derived from paraxial mesoderm somitomeres

Front 12

skull deformities assoc with premature closure of sutures

Back 12

scaphocephaly wedge skull: premature sagittal closure
acrocephaly (tower skull): premature closure of coronal suture

Front 13

somites in musculo development

Back 13

1. sclerotome fuse and form vertebra
2. myotome cells migrate to lateral plate, limb buds, and pharyngeal arches to form muscle cells--epimere forms dorsal portion of myotome and intrinsic muscles of spine; hypomere forms ventral portion
3. dermatome cells from dermis of skin

Front 14

spinal cord development

Back 14

each vertebra formed from two somites

Front 15

spinal bifida

Back 15

vertebral arch fails to form
1. occulta: involves only bone, spinal cord intact.
2. cystica: protrusion of meninges and possibly spinal cor out over skin; more common in baby girls; most severe form involves failure of neural tube to fuse

Front 16

cranial meningocoele

Back 16

protrusions of the contents of cranial bulb out onto skin- occipital and frontal

Front 17

limb development- external

Back 17

starts at 4th week; AER induces rapid prolif of underlying mesenchyme; apoptosis in AER leads to 5 zones and fomration of fingers; ZPA induces patterning by releasing sonic hedgehog; digital rays-->notches--webbed fingers--separate fingers

Front 18

internal events

Back 18

1. myoblasts migrate and differentiate
2. motor neurons establish connections
3. sensory axons follow
4. neural crest cells form Schwann cells
5. mesenchyme farthest from AER forms cartilaginous model of bones
process proceeds from proximal to distal

Front 19

POU gene family

Back 19

homologous to segmentation genes in flies; Pit and Oct (materally derived Oct3 maintains the undiffernetiated state up to morula stage)

Front 20

PAX

Back 20

1,9: sclerotome prevertebral mesenchyme
3,7: dermamyotome, neural crest, muscle

Front 21

HOX gene family

Back 21

homo to fly homeobox genes;

Front 22

Mater

Back 22

mammalian maternal effect genes which have recently been described in mice and humans to initate activation of embryonic genome

Front 23

homeobox genes

Back 23

discovered in fruit flies; specify differences between body segments from head to rear; genes on chromosome in same order as activation on body axis; code for DNA binding proteins

Front 24

HoxD genes 8-13

Back 24

limb development

Front 25

HoxD8

Back 25

sets craniocaudal axis

Front 26

HoxD9,10,11,13

Back 26

sets proximal to distal axis

Front 27

HoxD11,12,13

Back 27

sets the anterior to posterior axis

Front 28

morphogens

Back 28

establish a chemical gradient that provides positional info to migrating cells

Front 29

cell adhesion molecules

Back 29

cadherins (cell to cell)
integrin (transmembrane- cell to ECM)

Front 30

txn factors

Back 30

remain in cell of origin, bind to promotor or enhancer region; ex) zinc fingers

Front 31

signaling molecules

Back 31

produced by one cell and affect another cell; ex? growth factors and hedgehog proteins

Front 32

receptor molecules

Back 32

interact with signalers and gernerate 2nd messengers to alter DNA txn

Front 33

causes of malfomration

Back 33

genetic factors, environmental factors, mechanical factors

Front 34

congenital anomalies

Back 34

anencephaly, meningocoele, spina bifida, achondroplasia, cleft hand or foot, congenital absence of radius, brachydactyly, poly, syn, clubfoot, congenital dislocation of hips, Hox13 mutation (thumb and large toe displaced proximally, phalanges shortened, nails underdeveloped), amniotic banding, drugs