Development & Adaptation (Edan) Flashcards
What is the neural plate?
- thickened plate of ectoderm
- goes on to form neural tube and neural crest, subsequently the entire nervous system
- forms day 21
state the time durations pertaining to the following stages of development:
a. ) zygote
b. ) embryo
c. ) fetus
a. ) fertilization to first 2 weeks
b. ) 2 to 8 weeks
c. ) >8 weeks to birth
briefly explain how the neural plate forms the three primary germ layers?
- neural folds (ends of neural plate) push the ends of the neural plate up together
- thus neural tube forms
- this goes on to form 3 primary germ layers: ectoderm (skin), mesoderm (muscle and bone), endoderm (organ lining of digestive/ respiratory tracts)
what day does neural plate form?
21
the forebrain envelopes the midbrain by _ ____
6 months
when do gyri and sulci form?
7 months
explain pre-natal brain at 9 months?
has appearance of adult brain but cellular structure different
Explain the origins of neurons/ glial cells?
- neural stem cells line neural tube (these are self-renewable)
- neural stem cells differentiate into progenitor cells (these may divide a limited number of times)
- after day 40, progenitor cells produce non-dividing cells
- non-dividing cells become neuroblasts and glioblasts
- neuroblasts become neurons and glioblasts become glial cells (specifically astrocytes and oligodendrocytes)
t/f: neuroblasts are the main precursors to neurons during development only, playing no role in adult neurogenesis
false - do play role
define glial cells? provide examples?
- non-neuronal cells in CNS
- maintain homeostasis, form myelin, support and protect neurons
- astrocytes, oligodendrocytes
explain the role of astrocytes?
- form BBB
- provide nutrients
- maintain extracellular ion balance
- reparation of brain and SC post injury
- produce neurotrophins to aid neuronal health
explain the role of oligodendrocytes?
- help produce myelin sheath
- thus provide support and insulation to neurons
- produce neurotrophins to aid neuronal health
both astrocytes and oligodendrocytes produce neurotrophins augmenting neuronal health. What neurotrophins?
- brain derived neurotrophic factor (BDNF)
- glial cell derived neurotrophic factor (GDNF)
- insulin like growth factor (IGF)
In peak development, how many neurons may you grow per minute?
250 000
neurogenesis is complete by __ months
5
brain is most resistant to injury in (early/ mid/ late) development
early
explain stages of brain development? (on neuronal level)
- neurogenesis & gliogenesis
- cell migration - cells travel to correct location
- differentiate appropriately
- maturation - grow axons/ dendrites
- synaptogenesis - form synapses
- cell death & then synaptic pruning - remove redundant/ faulty neuron
- myelogenesis - myelination of axons
t/f: soon after birth babies can flex their joints and direct their hand
true
when do babies begin to make spontaneous hand and finger movements?
1-3 months
dendritic branching AKA?
dendritic aborisation
dendritic aborisation allows a single neuron to receive up to _____ inputs
100 000
explain some physiological developments occurring as baby develops motor skills?
- dendritic aborisation - branching, up to 100 000 to a single neuron
- connections between neocortex and spinal cord
- myelination of axons from motor cortex (when pincer grasp develops)
name a type of grasp baby may develop by around 10 months?
pincer grasp (index and thumb)
as baby undergoes motor development, what may be seen on MRI?
increased cortical thickness in line with baby’s development of dexterity
state the name (and time frame) of all piaget’s stages of development?
- Sensorimotor birth - 24 months
- preoperational 2-6 years
- concrete operational 7-11 years
- formal operational 12+ years
describe, and state the developmental phenomena for the following stage of development (piaget): sensorimotor
- experience world through senses and actions (looking, touching, mouthing)
- object permanence, stranger anxiety
describe, and state the developmental phenomena for the following stage of development (piaget): preoperational
- represents things with words and images but lacks logical reasoning
- pretend play, egocentrism, language development
describe, and state the developmental phenomena for the following stage of development (piaget): concrete operational
- thinks logically about concrete events, grasps concrete analogies and performs arithmetical operations
- conservation, mathematical transformations
describe, and state the developmental phenomena for the following stage of development (piaget): formal operational
- reasons abstractly
- abstract logical, potential for mature moral reasoning