3 - Embryology and Development of Nervous System; Aging

Question 1

3 developmental stages in utero?

Answer 1

1. pre-embryonic
2. embryonic
3. fetal

Question 2

Pre-embyronic stage timeline?

Answer 2

0-14 days

Question 3

What stage in utero?
- inner cell mass of sphere of cells becomes embryonic disk with 2 cell layers

Answer 3

pre-embryonic

Question 4

what 2 cell layers found in pre-embryonic stage?

Answer 4

1. ectoderm
2. endoderm

mesoderm follows later

Question 5

embryonic stage timeline?

Answer 5

15 days to 8 weeks

Question 6

Ectoderm develops into what?

Answer 6

1. sensory organs
2. epidermis
3. nervous system

Question 8

endoderm develops into what?

Answer 8

1. gut
2. liver
3. pancreas
4. respiratory system

Question 8

Mesoderm develops into what?

Answer 8

1. dermis
2. muscles
3. skeleton
4. excretory system
5. circulatory system

Question 9

fetal stage timeline?

Answer 9

end of 8 weeks to birth

Question 10

when does myelination start?

Answer 10

at fetal stage

Question 11

neural tube development timeline?

Answer 11

days 18-26

Question 12

Neural tube development:
1. neural plate forms ___ from ectoderm

Answer 12

longitudinally

Question 14

Neural tube development:
1. neural plate forms longitudinally from ectoderm
2. edges of plate fold to make ___ ___

Answer 14

neural groove

Question 15

Neural tube development:
1. neural plate forms longitudinally from ectoderm
2. edges of plate fold to make neural groove
3. folds grow together day ___ forming neural tube

Answer 15

21

Question 16

Neural tube development:
1. neural tube forms longitudinally from ectoderm
2. edges of plate fold to make neural groove
3. folds grow together day 21 forming neural tube
4. tube closes first in ___ region

Answer 16

cervical

Question 17

Neural tube development:
1. neural tube forms longitudinally from ectoderm
2. edges of plate fold to make neural groove
3. folds grow together day 21 forming neural tube
4. tube closes first in cervical region
5. quickly fuses together rostrally/caudally with open ends called _____

Answer 17

neuropores

Question 18

Neural tube development:
1. neural plate forms longitudinally form ectoderm
2. edges of plate fold to make neural groove
3. folds grow together day 21 forming neural tube
4. tube closes first in cervical region
5. quickly fuses together rostrally/caudally with open ends called neuropores
6. neural ___ formed from cells close to tube and ectoderm
7. neural crest moves ___ embryo
8. overlying ectoderm covers the tube/crest

Answer 18

crest, inside

Question 19

Neural tube development:
1. neural plate forms longitudinally from ectoderm
2. edges of plate fold to make neural groove
3. folds grow together day 21 forming neural tube
4. tube closes first in cervical region
5. quickly fuses together rostrally/caudally with open ends called neuropores
6. neural crest formed from cells close to tube and ectoderm
7. neural crest moves inside embryo
8. overlying ectoderm covers tube/crest
9. superior neuropore closes day ___ and inferior neuropore closes day ___

Answer 19

27, 30

Question 20

Neural tube development:
- inner and outer cell layers formed by neural tube by day ___

Answer 20

26

Question 21

inner layer of neural tube cell bodies to become ___ matter

Answer 21

gray

Question 22

Neural tube separates into dorsal and ventral sections.
Ventral = ___ function
Dorsal = ____ function

Answer 22

ventral = motor
dorsal = sensory

Question 23

ventral neural tube > motor plate > ventral horn:
- axons of cell bodies of motor plate extend to innervate ___ > motorneurons

Answer 23

myotome

Question 24

dorsal neural tube > association/alar plate > _____ or ____ neurons > dorsal horm

Answer 24

interneurons or projection neurons

Question 25

Outer layer of neural tube: - processes of cells with ___ in inner layer - becomes ___ matter with axons and glial cells

Answer 25

bodies, white

Question 26

neural crest cells are on both sides of neural tube, separating to correspond with respective parts of ____

Answer 26

somites

Question 27

neural crest cells form what 3 things?

Answer 27

1. peripheral sensory neurons 2. autonomic neurons 3. endocrine organs (ex. adrenal gland, pancreas)

Question 28

Peripheral sensory neurons form from neural crest cells: - cells extend 2 processes, 1 to spinal cord and 1 to dermal part of somite forming ___ - cell bodies of peripheral sensory neurons are outside of spinal cord and located in __ __ __

Answer 28

dermatomes dorsal root ganglion

Question 29

somites first appear in region that will become ___ area, then appear caudally

Answer 29

occipital

Question 30

what comes from the anteriomedial part of somite?

Answer 30

sclerotome > vertebrae and skull

Question 31

what comes from the posteromedial part of somite?

Answer 31

muscles of myotome

Question 32

what comes from lateral part of somite?

Answer 32

dermatome becomes dermis

Question 33

what is the end of the spinal cord called?

Answer 33

conus medullaris

Question 34

what is the connection of pia, arachnoid and dura mater form end of spinal ford to coccyx?

Answer 34

filum terminale

Question 35

when does the spinal cord stop growing?

Answer 35

4-5 years

Question 37

When does the vertebral column stop growing?

Answer 37

16-18 years

Question 38

when does brain development begin in utero?

Answer 38

day 28

Question 39

brain region starts to develop after closure of what?

Answer 39

superior neuropore

Question 40

when brain begins development what 3 fluid filled englargements form?

Answer 40

1. hindbrain 2. midbrain 3. forebrain

Question 41

brain development: what does the hindbrain consist of?

Answer 41

medulla, pons, cerebellum, with central canal forming 4th ventricle

Question 42

what happens in hindbrain during brain development?

Answer 42

inner layer cell bodies migrate through white matter to outside

Question 43

brain development: ____: central canal forms cerebral aqueduct connecting 3rd and 4th ventricles

Answer 43

midbrain

Question 44

5th lobe of brain?

Answer 44

insula (deep to lateral sulcus)

Question 45

brain development: forebrain - ___ region remains near midline forming diencephalon to include thalamus and hypothalamus - ____ region forms telencephalon to become cerebral hemispheres (includes deep nuclei of basal ganglia, white matter of axons and myelin, cortex(layers of cell bodies on surface of hemispheres)) - central canal forms bilateral ___ ventricles

Answer 45

posterior, anterior, lateral

Question 46

___ hemispheric areas do not grow as much as others

Answer 46

lateral

Question 47

2 possible ways neurons travel to final destinations during brain development?

Answer 47

1. sending an extension to brain surface and then pulling self along the extension 2. climbing along glial cells that reach from center of brain to its surface

Question 48

Do neurons differentiate into special functions before or after reaching final destination? predetermined or function based on location

Answer 48

AFTER - function depends on where cell lands

Question 49

Cellular level development: - neurons sprout ___ ___ from processes that samples potential environment, recoiling from some areas and attracted to others - when growth cones contact their target cells, synaptic vesicles form, microtubules extend beyond growth cone to ___ ___ - as neurotransmitters are released, neighboring post-synaptic membrane creates ____ ___

Answer 49

growth cones, presynaptic membrane, receptor sites

Question 50

How many neurons may go to a single muscle cell during development? during adulthood?

Answer 50

several, only 1

Question 51

Neuron connections also shape development of muscles: experimentally, muscle fiber type is dependent on type of ___

Answer 51

innervation

Question 52

Myelination of long axons begins in ___ fetal month with most finished at ___ years, depending on the system

Answer 52

4th, 3 - motor roots of SC are myelinated at 1 month old, but nerves from cortex to motor neurons are not fully myelinated until 2 years (children may "grow into deficits") - critical periods seem to exist where synapses are competing to establish optimal neural outcomes

Question 53

possible neural tube defects?

Answer 53

1. anencephaly: brain has not developed 2. arnold chiari malformation - part of brain (cerebellum) pushed down into foramen magnum 3. spina bifida - cord does not close

Question 54

when abnormal events occur prior to ___ weeks gestation, major deformities of nervous system will be present

Answer 54

20

Question 55

Some cognitive abilities decline with age, which 3?

Answer 55

1. working and long term memories 2. visiospatial memories 3. verbal fluency

Question 56

Some cognitive abilities seem to be preserved with aging, which 2?

Answer 56

1. vocabulary 2. comprehension

Question 57

Neural death within aging: - ___% of motorneurons die in healthy older adults - ___ loss of brain neurons in healthy brains of older adults

Answer 57

25%, minimal

Question 58

Causes of changes with aging: - myelin fragmented compromising white matter (particularly present in ___ and ___ lobes) - ___ density loss - decline in ____ - declines in ___ number and structure in brain and periphery

Answer 58

frontal and temporal dendrite neurotransmitters synapse - healthy 80 year old brain doesn't look like 20 year old brain (shrinkage in volume and weight)

Question 59

Normal age related cognitive changes dont markedly hinder __ ___ __

Answer 59

quality of life

Question 60

Mild cognitive involvement (MCI) includes memory loss with/without other cognitive involvement - may be able to do most ADL but others starting to notice issues - about ___% develop alzheimers disease within 5 years

Answer 60

90%