Development

Question 1

Determination in development

Answer 1

Neurons are formed
Neurons assume correct positions
Neurons produce primary processes (cell body (soma), axon)

basic neuron

Question 2

Differentiation in development

Answer 2

the neuron gains unique characteristics for its futurerole

Increasesin size

Producesterminal dendrites

Makesspecific connections *NEURAL CIRCUITS ARE FORMED! Whichis the beginning of the emergence of behavior!

Question 3

Morphogens

Answer 3

compounds that influence a tissue to become something

part of the dynamic processes of differentiation

Question 4

Environment and the dynamic process of differentiation

Answer 4

These factors recruitsecond messengersacting within the neurons to influence the specifics of neurondevelopment, circuits and functioning.

Question 5

NS embryonic development is determined by

Answer 5

Determinedby four weeks

Thus, the NS is vulnerable to insults early in pregnancy

Question 6

Critical periods

Answer 6

Time in which external influences have thegreatest impact

Question 7

Critical periods in the NS

Answer 7

Times when axons are competing for synaptic sites. Normal function of neural systems are dependent on appropriate experience during the critical periods

Question 8

2 weeks – 5months what influences the NS

Answer 8

Abnormal development influenced by drugs, alcohol, folic acid

Question 9

pre-embryonic stage

Answer 9

One cell> mass of cells > 2-layered embryonic disk (ecto and endo)

Question 10

Process of development in the NS

Answer 10

make cells, form tissues, cells move& fold to form NS structure

Question 11

embryonic stage

Answer 11

3-layered embryonic disk

Endoderm, ectoderm, andmesoderm (between the E, key role)

Meso – induces the ectoderm to becomes a NS

Question 12

GASTRULATION

Answer 12

Formation of 3 layers is Gastrulation

Question 13

NEURULATION overall

Answer 13

fundamental neural elements are formed

process of differentiating neural elements (neural plate, neural tube, neural crest).

Mesoderm forms the notochord

Question 14

Cell migration

Answer 14

Primitive streak arises midline - path of migrating cells, cell movement

Appearance of primitive streak starts Gastrulation

Question 15

Then presence of notochord induces changes in the

Answer 15

ectoderm,part of it becomes neuroectoderm

Question 16

notochord parts

Answer 16

Neural plate
Neural tube: Spinal cord and brain
Neural crest - PNS

Question 17

Brian at 4 weeks- vesicles

Answer 17

The rostral end of the neural tube expands to form three vesicles

Forebrain
Midbrain
Hindbrain

Question 18

Cephalicflexure locations

Answer 18

between the midbrain and the hind brains

the only on flexure seen in the adult brain

Question 19

3 to 5 vesicles

Answer 19

Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon

Question 20

Telencephalon becomes

Answer 20

Cerebralhemispheres
Basal ganglia

Question 21

Diencephalon becomes

Answer 21

Thalamus, hypothalamus

Question 22

Mesencephalonbecomes

Answer 22

Midbrain

Question 23

Metencephalonbecomes

Answer 23

Pons and cerebellum

Question 24

Myelencephalonbecomes

Answer 24

Medulla oblongata

Question 25

Cell movement is often a signal for what

Answer 25

differentiation - when neurons are getting their characteristics Results in cells moving to positions important for their differentiation

Question 26

what is Induction in terms of NS development

Answer 26

One tissue influences the differentiation of another tissue

Question 27

Diffusable substance of Induction

Answer 27

Bone morphogenetic protein (BMP) Sonic hedgehog (SHH)

Question 28

Ventricular layer of the tube is important for

Answer 28

neurons multiply; ‘born’ when move away

Question 29

Mantle layer of the tube

Answer 29

grey matter; neurons locate once born (cortical plate in forebrain dev)

Question 30

Marginal layer in the tube

Answer 30

white matter; neurons send processes into this layer

Question 31

Floor plate releases

Answer 31

SHH Diffusable substance

Question 32

Roof plate releases

Answer 32

Roof plate diffusible substance

Question 33

what is the Sulcus limitans

Answer 33

a groove between the alar (sensory) and basal (motor) plate regions

Question 34

Neural crest cell migration Dorsolateral path

Answer 34

Pigmented cells of the skin

Question 35

Neural crest cell migration Ventral path

Answer 35

Sensory ganglia (DRG)  Primary sensory neuron Schwann cells –myelin of PNS paravertebral ganglia Postganglionic sympathetic neurons prevertebral ganglia Postganglionic parasympathetic neurons Adrenal medulla

Question 36

Spinal cord neurons: sequence of development of connections

Answer 36

Motoneurons connect onto muscles Spontaneous movements Interneurons connections to MNs Synchronous activity of a limb Descending (and ascending) projection neurons connect to MNs and INs Interlimb coordinated patterns Sensory neurons connections to MNs Monosynaptic (stretch) reflex (knee jerk)

Question 37

insult I the first four weeks of neural development

Answer 37

Spina bifida Anencephaly

Question 38

Spina bifida types

Answer 38

Occulta: vertebral arch defect Meningocele: meninges herniate through defect Myelomeningocele: spinal cord & meninges herniate Myelochisis: open spinal cord

Question 39

what is Anencephal

Answer 39

open brain

Question 40

what is secondary neurulation

Answer 40

Development of the most caudal end of the neural tube 

Question 41

what is secondary neurulation associated with

Answer 41

problems at L5/S1 spinal cord level may exist: disorders of canalization Spondylolisthesis- L5 slipping on S1 Spina bifida in lumbosacral region Lumbosacral lipoma

Question 42

CFS is made and stored where

Answer 42

made in the ventricles and stored in the subarchnoid space

Question 43

if there is a build up of CFS (blocked, over made, or under drained) the result is what

Answer 43

is hydrocephalus

Question 44

what is hydrocephalus often associated with

Answer 44

spina bifida

Question 45

Over production of CSF by what cells

Answer 45

by cells of choroid plexus

Question 46

Cortical region movement of cells

Answer 46

“inside-out” pattern of development first cells to move locate in deepest layers of the cortex

Question 47

Disorder of cytogenesis

Answer 47

didn’t make enough cells’ = microencephaly, small brain

Question 48

Disorder of neuron migration

Answer 48

‘didn’t, couldn’t, or wouldn’t move enough’ = lissencephaly, smooth brain

Question 49

what is Axon guidance

Answer 49

orderly consequence of local or long-distance interactions that instruct the developing axon to grow, turn, or stop.

Question 50

extracellular matrix adhesion axon guidance

Answer 50

local at some point in development ECM allows spinal tissue to move through It before that is does not allow this movement

Question 51

cell surface adhesion axon guidance

Answer 51

local some type of tissue that leads the axon in the right direction step by step

Question 52

fasciculation axon travel

Answer 52

pioneer local growing axon encounters another axon from a 'pioneer' neuron (previously traveled to same target) and follows alongside of it

Question 53

chemoattraction axon travel

Answer 53

long distance concentration gradient of a tropic factor

Question 54

contact inhibition axon guidance

Answer 54

local repulse growth cones

Question 55

chemorepulsion axon guidance

Answer 55

long distance soluable factors which inhibit axons