embryologic development

Question 1

otocyte

Answer 1

egg

Question 2

mitosis

Answer 2

cell division

Question 3

gastrulation

Answer 3

creation of the germ layers
-all growth is the result of cell division of preexisiting cells

Question 4

3 germ layers

Answer 4

ectoderm, mesoderm, endoderm

Question 5

ectoderm

Answer 5

outer skin layers, nervous system and sense organs
-early neural groove leads to entire CN
-the part that gets pinched off from the outside becomes the nervous system and CNS

Question 6

mesoderm

Answer 6

skeletal structures, circulatory structures, meninges, notochord, reproductive organs and cartilage
-including ossicles and temporal bone
-in between two other germ layers

Question 7

endoderm

Answer 7

digestive canal and respiratory organs (viscera)
-including middle ear, mastoid cavities, and ET
-most internal

Question 8

neurulation

Answer 8

neural tube development
-within third week the ectoderm thickens to form the neural plalte
-fold inward forming a groove at midline with a fold on both sides
-neural folds begin to fuse midway along the groove which forms the tube
-fusion occurs along the tube (zipper action)
-then the tube separates from the surface ectoderm and is enclosed inside the body

Question 9

spina bifida

Answer 9

failure of the caudal neuralpore to close
-vertebrae does not form over the spinal cord
-more route for infection

Question 10

crania bifida

Answer 10

failure of the rostral neuropore (end of neural tube) to close
-central cavity is exposed
-not conductive to postnatal life

Question 11

notochord

Answer 11

lies outside of the neural tube near the ventral surface and is the precursor for the skeletal axis, helping to form the vertebral column

Question 12

crest cells

Answer 12

what is left behind by each neural fold
-forms sensory neurons of the dorsal root ganglia, some CN, postganglionic neurons of the autonomic nervous system, and schwann cells of the PNS

Question 13

sulcus limitans

Answer 13

longitudinal groove in the lateral wall of the neural tube, separating the dorsal/alar half from the ventral/basal half in the future spinal cord and brainstem

Question 14

ventral/basal division

Answer 14

anterior (ventral) horns in gray matter with somatic and autonomic motor neuron cell bodies

Question 15

dorsal/alar division

Answer 15

posterior dorsal horns in the gray matter with ascending pathway cells

Question 16

flexures of neural tube

Answer 16

cervical, cephalic, and pontine

Question 17

cervical flexure

Answer 17

where future brainstem meets future spinal cord
-straightens out through development

Question 18

cephalic flexure

Answer 18

at the level of the future midbrain and remains as the bend between the axis of the brainstem and the axis of the cerebrum in the adult CNS
-making a T shape meeting point

Question 19

pontine flexure

Answer 19

on the posterior/dorsal surface in the area of the pons and 4th ventricle

Question 20

secondary vesicles

Answer 20

encephalon, diencephalon, metencephalon, and myelencephalon

Question 21

telencephalon

Answer 21

cerebrum/cerebral hemispheres
-lateral ventricles
-comes off the prosencephalon (primary vesicle)

Question 22

diencephalon

Answer 22

thalamus (and hypothalamus and surrounding)
-third ventricle
-comes off the prosencephalon (primary vesicle)

Question 23

mesencephalon

Answer 23

midbrain
-forms cerebral aqueduct

Question 24

metencephalon

Answer 24

cerebellum and pons
-part of 4th ventricle
-comes off the rhombencephalon (primary vesicle)

Question 25

myelencephalon

Answer 25

medulla
-part of 4th ventricle and central canal
-comes off the rhombencephalon (primary vesicle)

Question 26

monogenic deficits

Answer 26

single mutant gene, mendelian inheritance pattern

Question 27

multifactorial deficits

Answer 27

mendelian inheritance pattern, exogenous environmental factors
-multiple things caused it

Question 28

mitochondrial deficits

Answer 28

alteration in mitochondrial DNA, nonmendelian
-mainly maternal transmission
-affects enzymes of mitochondria

Question 29

nonmendelian chromosomal aberrations

Answer 29

excess, lack or structural alteration of one or more of the 23 pairs of chromosomes
-i.e. down syndrome

Question 30

what ways can infants be assessed for abnormal functions

Answer 30

monitoring of infants
-respiration
-control of body temp
-regulation of thirst and appetite
-rooting
-sucking, swallowing and grasping
-movements and postures of neck, trunk, and limbs

Question 31

tay-sachs disease

Answer 31

lysosomal storage disease
-inability to break down ganglioside which accumulates in neurons causing them to swell or burst

Question 32

niemann-pick disease

Answer 32

autosomal recessive inheritance
-inability to break down sphingomyelinase which accumulates in neurons causing them to swell and burst

Question 33

what do the germ layers become in AVS

Answer 33

ectoderm : outer and inner ear, membranous labyrinth
mesoderm : ossicles, temporal bone, and bony labyrinth
endoderm : middle ear epithelial lining, mastoid cavities and eustachian tube

Question 34

branchial/pharyngeal arch structures

Answer 34

arches - external humps
clefts/grooves - external
pouches - internal
membrane - point of contact of the groove and pouch

Question 35

what do the archs become

Answer 35

first arch - rise to CN 5
second arch - rise to CN 7
third arch - rise to CN 4
fourth arch - rise to CN 10
sixth arch - rise to CN 11