Embryology Flashcards
3 germ cells layer
Endoderm
Mesoderm
Ectoderm
The nervous system is derived from this germ layer
Ectoderm
Neural plate is formed during
3rd week
Name of longitudinal formation that appears in neural plates
Neural groove
These structures bound both sides of neural plate
Neural folds
How is the neural tube formed
The neural folds fuse which converts the neural groove into the neural tube
How is the neural crest formed
Lateral margin of neural plate do not get incorporated in neural tube and form a strip of ectodermal cells between the neural tube and covering ectoderm
What do neural crest differentiate into
Posterior roots ganglia sensory ganglia of cranial nerves Autonomic ganglia Cells of suprarenal medulla melanocytes
What does the cephalic ends of the neural tube form after dilatation
Three primary brain vesicles
forebrain vesicles
midbrain vesicles
hidbrsin vesicle
What does the rest of the neural tube form after elongation
Spinal cord
When does myelin sheath start forming
Before birth and first year postnatally
What is the embryonic period
Period Up to ninth week of gestation
What is the fetal period
When external genitalia are distinguishable
At what time does the neural plate form
Third week of life fetal life
From what germ layer does the neural plate forms
The ectodermal surface
What structure are formed from the infolding of the neural plates
The neural tube
the neural crest
What does the neural tube form in the future
The central nervous system
What does the neural crest form in the future
The peripheral nervous system
What do the neuroectodermal cells differentiate into
Neurons e, astrocytes, oligodendrocytes, ependymal cells
What’s neurological sells there is derived from the mesoderm
Microglial cells
In what week of fetal life can you see the subdivisions of forebrain midbrain and Hindbrain , the dorsal and ventral horn of the spinal cord , and peripheral and sensory nerves
5th week
When does Myelinization begins and how long does it last
Midgestation and continues for years
When does myelinization of the cortex starts
7 to 8 months Gestation
What nutrients are required for myelinization to occur
Cholesterol
iron
What week of gestation is the gross structure of the nervous system established
Eighth week
Why what month is the behavioral evidence of neural function detectable
The third month
Can physicist respond to external stimuli and if yes by what time
By the third trimester they respond to external stimuli by raising heart rates and having body movements
When do Fetuses open their eyes
By the seventh month
What are the primitive reflexes of fetuses
Palmar grasp
Rooting
Moro
What is the palmar grasp reflex
The infants fingers reflexively grasp an object placed into their palm
When does the palmar grasp start and how long does it last
By 32 week and last for 2 to 3 months
What is the rooting reflex
Baby turned ahead and opened her mouth to follow and routes in the direction of the stroking of their mouth so that they can breasts or bottle feed
When does the rooting reflex start and how long does it last
Starts at 36 weeks and last for 10 months
What is the Moro reflex
Baby spread their arms out
Pulls their arms back in tight to the chest
cry
When does the moro reflex start and how long does it last
37 week
Last for six months
What is the behavior pattern of a baby
1 month - watches person 2 month - smile 4 month - lol 7 month - roll over, reach and grasp 10 months - sit with no support, responds to name, says mama dada , waves bye 1 yr - walks 2 yrs - walks up and down 18-24 months - Balance ,agility ,85% of adult head circumference ,object permanence ,cause-and-effect understood
What determines the growth and shape of skull
The brain
One month total brain percentage
36% of adult brain
One year total brain percentage
72% of adults brain
Two years total brain percentage
83% of adult brain
When do you complete 90% of your brain growth
By age 6 age 6
What is a fontanelle
Non ossified areas of newborn skull
What are the major fontanelles
Anterior
posterior
At what age does the posterior fontanelle close
2-6 month
At what time does the Anterior fontanelle close
By age 18 month
What can cause delayed closure of the anterior fontanelle
Increased intracranial pressure
hypothyroidism
What can cause premature closure of the anterior fontanelle
Craniosynostosis
hypophosphatemia
What is the most dramatic developments in the. 18 to 24 month
Speech development
What are the two components of language development
Receptive - auditory comprehension
expressive - speech and language production
What is adolescence
Period of concrete thinking of school age children to form a logical operations of adults
they develop moral thinking’s parallels general cognitive development
What are some causes of dysfunction of the neuro system
Genetic Perinatal Medical psychologic environmental social cultural
What are some chromosomal abnormalities that leads to neurological dysfunction
Trisomies
What are the perinatal risk factors
Low birthweight severe intrauterine growth restriction birth asphyxia prenatal exposure to alcohol drugs lead teratogenesis
What are some learning disorder
Dyslexia
dysgraphia
spelling
mathematics dyscalculia
Type of brain waves in infancy
Delta waves
Type of brain waves at 3 yearsold
Alpha waves
Type of brain waves at four years old
Beta waves
Type of brain waves Between four and eight years old
Theta waves
How do you measure the electrical activity of a brain
Electroencephalogram EEG
How does abnormal electrical activity of the brain manifest
TTonic clonic attack
atonic attack( abscehces )
abnormal Posturing such as infantile spasms
What is cerebral palsy
Disorder of movement and posture due to dysfunction of the brain before age 2 years old
What are the clinical signs and symptoms of cerebral palsy
Spastic hemiplegia spastic diplegia spastic quadriplagia Choreoathetoid ataxic and mixed
What are the steps of the formation the brain and the spinal cord
Dorsal induction Ventral induction Neuronal proliferation Differentiation , histogenesis Neuronal migration Axonal myelination
What is dorsal induction
Formation of notochord, neural plate, neural groove, neural folds, neural tube
When does dorsal induction occur
Between week 4-7
What is primary neurulation in dorsal induction
Neural plate creases inward
Edges come into contactand fuse
Form future brain and spinal cord
What is secondary neurulation in dorsal induction
Hollowing process leading to formation of lower sacral and coccygeal cord
When does ventral induction occur
5-10 weeks
What is ventral induction
Formation of vesicles
What are the brain vesicles forned in ventral induction
Prosencephalon (Telencephalon , Diencephalon)
mesencephalon
Rhombencephalon (Metencephalon , Myelencephalon )
