Brain Development: Learning this is Killing My BRRAAAAAINNN!!!

Question 1

Forebrain = Prosencephalon becomes

Answer 1

Telencephalon and Diencephalon

Question 2

Adult Derivatives: Telencephalon
Wall?
Cavity?

Answer 2

Walls: cerebral hemispheres
Cavity: lateral ventricles

Question 3

Adult Derivatives: Diencephalon
Wall?
Cavity?

Answer 3

Walls: thalamus
Cavity: 3rd ventricle

Question 4

Midbrain = Mesencephalon becomes…

Answer 4

Mesencephalon

Question 5

Adult Derivatives: Mesencephalon
Wall?
Cavity?

Answer 5

Walls: midbrain
Cavity: aqueduct

Question 6

Hindbrain = Rhombencephalon becomes

Answer 6

Metencephalon and Myelencephalon

Question 7

Adult Derivatives: Metencephalon
Wall?
Cavity?

Answer 7

Walls: pons and cerebellum
Cavity: upper part of the 4th ventricle

Question 8

Adult Derivatives: Myelencephalon
Wall?
Cavity?

Answer 8

Walls: medulla
Cavity: lower part of the 4th ventricle

Question 9

Adult Derivatives: Myelencephalon
Wall?
Cavity?

Answer 9

Walls: medulla
Cavity: lower part of the 4th ventricle

Question 10

Adult Derivatives: Neuroectoderm

Answer 10

CNS neurons
ependymal cells (makes CSF; inner lining of the ventricles

Question 11

Adult Derivatives: Neural Crest

Answer 11

PNS neurons, Schwann cells

Question 12

Adult Derivatives: Mesoderm

Answer 12

Microglia (like Macrophages, originate from Mesoderm)

Question 13

Adult Derivatives: Neural Crest

Answer 13

• cranial nerve ganglia
• PNS neurons
• Schwann and satellite cells
• pia and arachnoid mater (leptomeninges)
• craniofacial mesoderm (give rise to muscles and skeletal structures of the head)
• melanocytes
• chromaffin (neuroendocrine) cells of adrenal medulla

Question 14

Adult Derivatives: Telencephalon
Wall?
Cavity?

Answer 14

Walls: cerebral hemispheres
Cavity: lateral ventricles (makes sense because they are just underneath the cerebral cortex and subcortial white matter)

Question 15

Adult Derivatives: Diencephalon
Wall?
Cavity?

Answer 15

Walls: thalamus
Cavity: 3rd ventricle between the thalamuses

anything that has “thalamus” in its name:
-hypothalamus, epithalamus, subthalamus

-retina and optic nerve

Question 16

Cranial flexure appears at the

Answer 16

Mesenchephalon

Question 17

Cervical flexure appears at the

Answer 17

Myelencephalon

Question 18

Cervical flexure appears at the

Answer 18

Myelencephalon

Question 19

Pontine Flexure appears ate the

Answer 19

Metencephalon

Question 20

Pontine Flexure appears at the

Answer 20

Metencephalon

Question 21

Meningomyelocele:

Answer 21

the spinal cord and/or spinal nerves (e.g. cauda equina) and meninges protrude through the bony defect

-Treatment consists of surgical sac closure shortly after birth

Question 22

Meningomyelocele

Answer 22

the spinal cord and/or spinal nerves (e.g. cauda equina) and meninges protrude through the bony defect

-Treatment consists of surgical sac closure shortly after birth

Question 23

Meningocele

Answer 23

only the meninges protrude through the bony defect

Question 24

Anencephaly

Answer 24

• failure of the cephalic part of the neural tube (anterior neuropore) to close: absent brain structures above brainstem
• the skull does not close leaving the malformed brain exposed
• condition incompatible with life

Question 25

Spina Bifida Cystica

Answer 25

• More severe neural tube defect
• neural tissue and/or meninges protrude through a defect in the vertebral arches to form a cyst-like sac.
• Dural sac filled with CSF, meninges and/or nervous tissue (may or may not be covered by skin).
• Most occur in the lumbosacral region

Question 26

Spina bifida occulta

Answer 26

• Failure of bony spinal canal to close
• No structural herniation.
• Dura is intact
• Associated with tuft of hair or skin dimple at level of bony defect

Question 27

Tethered cord syndrome

Answer 27

• Any form of Spina Bifida can be associated with this
• due to the spinal lesion itself or scarring from sac surgery;
• the spinal cord gets tethered during growth leading to progressive neurological signs

Question 28

Arnold-Chiari Malformations

Answer 28

• Cerebellar and posterior cranial fossa abnormalities
• causes herniation of cerebellar tissue and possibly brainstem through the foramen magnum.
• Hydrocephalus from obstruction of the CSF outflow pathway through the foramina of Luschka & Magendie by herniated brain tissue.

Question 29

Holoprosencephaly

Answer 29

• failure of the left and right hemispheres to separate

- partial or complete failure of prosencephalon to separate into the paired telencephalon vesicles and the diencephalon

Question 30

Holoprosencephaly

Answer 30

• failure of the left and right hemispheres to separate
• partial or complete failure of prosencephalon to separate into the paired telencephalon vesicles and the diencephalon

-Disorder seen in Sonic Hedgehog (SHH) gene mutations and
Patau Syndrome: Trisomy 13

Question 31

Dandy Walker Syndrome

Answer 31

• agenesis of
  the cerebellar vermis and possibly the corpus callosum
  -large posterior cranial fossa
  -enlargement of the 4th ventricle
  -associated with hydrocephalus and spin bificda

Question 32

Lissencephaly

Answer 32

• smooth brain: cortex does not develop gyri or sulci
• neuronal migration disorder from genetic defects
• frequently associated with callosal agenesis and heterotopias