Head and Neck: Neuroembryology

Question 1

Trilaminar Embryonic Disc forms because of which process?

Answer 1

Gastrulation - invasion of the epiblast cells

Formation of 3 layers; ecto, endo and mesoderm

Question 2

Notochord induce what change in embryo?

Answer 2

Notochord + paraxial mesoderm induce ectoderm–> neural plate

Question 3

Epidermis and derivatives

Answer 3

Ectoderm

Question 4

Epithelial linings of mouth/rectum

Answer 4

Ectoderm

Question 5

Cornea and lens

Answer 5

Ectoderm

Question 6

Nervous system

Answer 6

Ectoderm

Question 7

Renal medulla

Answer 7

Ectoderm

Question 8

Tooth enamel

Answer 8

Ectoderm

Question 9

Epithelial linings of pituitary and pineal

Answer 9

Ectoderm

Question 10

Epithelial linings of gut, allantois, respiratory tract, urinary bladder/urethra, tympanic cavity and auditory tube

Answer 10

Endoderm

Question 11

Parenchym of thyroid, parathyroids, liver and pancreas

Answer 11

Endoderm

Question 12

Reticular stroma of tonsils and thymus

Answer 12

Endoderm

Question 13

Connective tissue, bone, cartilage

Answer 13

Mesoderm

Question 14

Smooth and striated muscle

Answer 14

Mesoderm

Question 15

Blood and lymph cells/vessels

Answer 15

Mesoderm

Question 16

Kidneys and Gonads

Answer 16

Mesoderm

Question 17

Cortex of adrenal gland

Answer 17

Mesoderm

Question 18

Spleen

Answer 18

Mesoderm

Question 19

Neurulation

Answer 19

Neural plate bunches up and begins to fold first into neural groove and then neural tube + production of neural crest cells

Question 20

How does the neural plate form the neural tube

Answer 20

Due to cadherins and their association to the cytoskeleton of the cell

Question 21

Cadherins

Answer 21

Homophilic binding partners; use Ca2+;

Question 22

Main reason for neural tube formation in that particular pattern

Answer 22

Differential expression of cadherin across the plate results in tubular arrangement eventually

Question 23

Neural tube defect

Answer 23

Lack of closure of either rostral or caudal neuropore

Question 24

Describe the types of NTDs

Answer 24

Spina bifida - occulta

Spina bifida - cystica

Question 25

Spina bifida occulta

Answer 25

Failure of vertebral arch to close (problem with laminae) but spinal cord still enclosed within meningeal coverings

Question 26

Spina bifida cystica

Answer 26

Outpouching of the dura with or without spinal cord

Question 27

Meningomyelocele

Answer 27

Spinal cord + meninges outpouch through opening in vertebral column

Question 28

Myeloschisis

Answer 28

absence of proper signaling to form the neural tube

Question 29

Anencephaly

Answer 29

failure of rostral neural pore to close

Question 30

Role of apoptosis

Answer 30

Needed for neural tube closure in dorsal aspect of tube

Question 31

Paraxial Mesoderm

Answer 31

develop into somites

Question 32

Somites

Answer 32

Dermatome - dermis Scleratome - cartilage/bone Myotome - skeletal muscle

Question 33

3 primary vesicles

Answer 33

Prosencephalon Mesencephalon Rhombencephalon

Question 34

Mesencephalic flexure

Answer 34

between mesencephalon and rhombencephalon

Question 35

Cervical flexure

Answer 35

between rhombencephalon and spinal cord

Question 36

Pontine Flexure

Answer 36

between metencephalon and myelencephalon

Question 37

Prosencephalon

Answer 37

telencephalon | and diencephalon

Question 38

Neural Crest Cells

Answer 38

Multipotent

Question 39

Neural crest cell derivatives

Answer 39

``` Sensory ganglia Parasympathetic ganglia Cartilage and bone Connective tissue Endocrine cells Pigment cells PNS sensory neurons, supportive cells and autonomic ganglia DRG!! ```

Question 40

Germinal neuroepithelium

Answer 40

Pseudostratifed epithelium

Question 41

Mantle zone

Answer 41

Germinal neuroepithelium produces neurons = neuroblasts that migrate laterally

Question 42

Ventricular Zone

Answer 42

Germinal neuroepithelium becomes the Ventricular Zone and eventually the ependymal lining

Question 43

Marginal zone

Answer 43

white matter tracts surrounding the mantle zone

Question 44

Alar plate

Answer 44

Sensory, dorsal portion of developing SC

Question 45

Basal plate

Answer 45

Motor, ventral portion of developing SC

Question 46

Sulcus limitans

Answer 46

dividing line between alar and basal plates

Question 47

Cerebellum formation

Answer 47

Alar plate neuroblasts migrate dorsally and fuse in midline - form cerebellar cortex

Question 48

Diencephalon

Answer 48

formed by alar plate derivatives

Question 49

Diencephalon derivatives/ parts

Answer 49

Epithalamus Thalamus Hypothalamus

Question 50

Sulci in diencephalon

Answer 50

Epithalamic sulcus | Hypothalamic sulcus

Question 51

Telencephalon

Answer 51

Alar plate derivative

Question 52

Basal ganglia

Answer 52

Thickening of the mantle

Question 53

Cerebral Cortex

Answer 53

Marginal layer invaded by migrating neuroblasts

Question 54

Lamina terminalis

Answer 54

Connection between both hemispheres Corpus callosum and anterior commissure