Development of the Nervous System

Question 1

pre-embryonic stage

Answer 1

0-14 days

Question 2

embryonic stage

Answer 2

15-56 days

Question 3

fetal stage

Answer 3

57 days and to birth

Question 4

where is the ovum fertilized

Answer 4

uterine tube

Question 5

monozygotic twins

Answer 5

starts with one egg and one sperm

Question 6

twins divide at days 1-4

Answer 6

dichorionic-diamniotic

Question 7

twins divide at days 4-8

Answer 7

monochorionic-diamniotic

Question 8

twins divide at 8-12 days

Answer 8

monochorionic-monoamniotic

Question 9

twins divide after 12 days results in what

Answer 9

conjoined twins

Question 10

what is the only spilt that we see in dizygotic twins

Answer 10

dichorionic- diamniotic

Question 11

superfecundation

Answer 11

two ova fertilized by two sperm in more than one act (twins with two different parents)

Question 12

superfetation

Answer 12

second fertilized ovum implants in uterus already with embryo (at least one month apart)

Question 13

during what stage are organs formed

Answer 13

embryonic stage

Question 14

what does the ectoderm form

Answer 14

sensory organs, epidermis, nervous system

Question 15

what does the mesoderm form

Answer 15

dermis, muscles, skeleton, circulatory, and excretory systems

Question 16

what does the endoderm form

Answer 16

digestive, liver, pancreas, and respiratory

Question 17

where does the neural tube close first

Answer 17

cervical

Question 18

what are the open ends of the neural tube called

Answer 18

neuropores

Question 19

where do somites appear first

Answer 19

occipital region

Question 20

anteriomedial portion of somites

Answer 20

sclerotome
-become skull and vertebrae

Question 21

posteromedial portion of somites

Answer 21

myotome
-becomes skeletal muscle

Question 22

lateral portion of the somites

Answer 22

dermatome
-becomes dermis

Question 23

what does the association plate contain

Answer 23

peripheral sensory neurons, myelin cells, autonomic neurons, and endocrine organs

Question 24

Arnold Chiari malformation type 1

Answer 24

herniation of cerebellar tonsils through foramen magnum into vertebral canal

Question 25

Arnold Chiari malformation type 2

Answer 25

herniation of cerebellum and brainstem through foramen magnum

Question 26

craniorachischisis

Answer 26

completely open brain and spinal cord

Question 27

anencephaly

Answer 27

open brain and lack of skull vault

Question 28

encephalocele

Answer 28

herniation of the meninges

Question 29

iniencephaly

Answer 29

occipital skull and spine defects with extreme retroflexion of the head

Question 30

what do caudal neural tube defects arise from

Answer 30

inferior neuropore does not close

Question 31

spina bifida occulta

Answer 31

closed asymptomatic NTD in which some of the vertebrae are not completely closed (tuft of hair grows as a protective mechanism)

Question 32

closed spinal dyraphism

Answer 32

deficiency of at least two vertebral arches, here covered with a lipoma

Question 33

spina bifida meningocele

Answer 33

protrusion of the meninges (filled with CSF) through a defect in the skull or spine

Question 34

spina bifida myelomeningocele

Answer 34

open spinal cord with a meningeal cyst (neural tissue exposed)

Question 35

hydrocephalus

Answer 35

abnormal accumulation of cerebrospinal fluid

Question 36

conus medullaris

Answer 36

end of spinal cord

Question 37

what level is conus medullaris at birth

Answer 37

L3-L4

Question 38

what level is conus medullaris in adulthood

Answer 38

L1-L2

Question 39

what tethers the spinal cord to coccyx

Answer 39

filum terminale

Question 40

what does the cauda equina provide sensory and motor to

Answer 40

motor of LE and internal and external anal sphincter sensory to perineum part parasympathetic to bladder

Question 41

brain formation occurs after what closes

Answer 41

after superior neuropore closes

Question 42

where are epithelial cells located

Answer 42

neural tube

Question 43

what do epithelial cells divide into

Answer 43

neurons and glia

Question 44

how do neurons migrate

Answer 44

-sending slender processes to the brain surface and pulling themselves along the processes -climbing along radial glia

Question 45

autism

Answer 45

disorganized arrangement of cells in prefrontal and temporal cortex

Question 46

what is abnormally shaped in autism

Answer 46

caudate and putamen

Question 47

what is larger than normal in children with autism

Answer 47

amygdala

Question 48

myelination begins when

Answer 48

16 weeks

Question 49

when is myelination complete

Answer 49

2 years of age

Question 50

ADHD has reduced volume of...

Answer 50

prefrontal cortex, caudate and putamen, dorsal cingulate, and cerebellum

Question 51

why does neuronal death occur

Answer 51

neurons failed to establish connections with target cells too inactive to main connection

Question 52

spinal muscular atrophy

Answer 52

genetic autosomal recessive degeneration of motor neurons in the spinal cord

Question 53

what type of spinal muscular atrophy is most severe

Answer 53

type 1, werdnig hoffman

Question 54

critical period

Answer 54

when axons are competing for synaptic sites

Question 55

asymmetric tonic neck reflex

Answer 55

rotation of head results in extension of limbs on nose side and flexion of limbs on skull side

Question 56

symmetric tonic neck reflex

Answer 56

neck flexion results in UE flexion and LE extension neck extension results in UE extension and LE flexion

Question 57

cerebral palsy

Answer 57

movement and postural disorder nonprogressive brain damage

Question 58

spastic cerebral palsy

Answer 58

damage to axons adjacent to the lateral ventricals

Question 59

dyskinetic cerebral palsy

Answer 59

damage to basal ganglia

Question 60

ataxic cerebral palsy

Answer 60

damage to cerebellum

Question 61

craniosynostosis

Answer 61

premature closure of cranial sutures