Lecture 2

Question 1

Name the three parts of the embryonic brain.

Answer 1

prosencephalon, mesencephalon and rhombencephalon

Question 2

During gastrulation chemical signals released from the _____ near the mesoderm cause the ectoderm to thicken and for the neural plate

Answer 2

notochord

Question 3

Shortly after the neural plate plate begins to fold inward to form the neural groove, fold cells migrate to form _____ _____ cells

Answer 3

neural crest

Question 4

These areas of specialized cells in and around the early neural tube “tell” other cells what to become in the spinal cord and brainstem. (3)

Answer 4

roof plate cells, floor plate cells and notochord

Question 5

Common disorder that results from improper folding of the neural folds to form the neural tube during neurulation.

Answer 5

spina bifida

Question 6

What is the difference between primary and secondary neurulation regarding its location.

Answer 6

primary neuralation occurs in the more cranial sections of the posterior midline while secondary neurulation occurs at the S2 spinal levels and below

Question 7

What is the difference between primary and secondary neurulation regarding the embryonic tissues involved.

Answer 7

primary neurulation is derived in ectoderm while secondary neurualtion is derive in loose mesoderm that becomes mesenchymal to epithelia transition tissue as it converts to neural epithelium which further cavities to form the neural tube

Question 8

Name the three layers of neural tissue from the lumen moving exteriorly

Answer 8

ventricular/ germinal/ matrix zone containing stem cells and neuroblasts; mantle which contains the neurons and glia that become grey matter; marginal zone which contains the axons that become white matter

Question 9

The neural lumen becomes what in adults?

Answer 9

ventricles

Question 10

Name adult derivatives of the neural crest cells.

Answer 10

neurons and glia of the cranial glia, cartilage, bone and connective tissue in the head, sympathy-adreenal cells, sensory neurons and glia and pigment cells

Question 11

What cells do the autonomic and sensory lineage of neural crest cells become (both traveling medial to the somite)?

Answer 11

postganglionic cells (adrenergic and cholinergic neurons) and sensory neurons respectively … along each path they encounter signaling molecule that “tell them” what to become

Question 12

During development of the neural tube, the tube becomes segmented (neuromeres) and _____ in each segment encode transcription factors that tell the cells what to become.

Answer 12

(HOX) genes

Question 13

Name the 5 transitional subdivisions of the embryonic brain.

Answer 13

telecephalon (prosencephalon), diencephalon (prosencephalon), mesencephalon (mesencephalon), mentencephalon (rhombeencephalon), mylencephalon (rhombencephalon)

Question 14

What is the adult derivative of the telecephalon?

Answer 14

cerebrum which surrounds the lateral ventricles

Question 15

What is the adult derivative of the diencephalon?

Answer 15

thalamus, hypothalamus and retina surrounds the 3rd ventricle

Question 16

What is the adult derivative of the mesencephalon

Answer 16

midbrain, surrounds the cerebral aqueduct

Question 17

What is the adult derivative of the mentencephalon?

Answer 17

middle brainstem: pons and cerebellum (surrounds the 4th ventricle)

Question 18

What is the adult derivative of the mylencephalon

Answer 18

the medulla surrounds the outlet to the central canal

Question 19

Name 2 other structure that are associated with the development of the cerebrum (also made from telecephalon)

Answer 19

(cortex), insula, basal ganglia, corpus callosum (connects hemispheres) occurs due to an immense growth of cells , including the tethering of the cortex (insula) which rests right on the basal ganglia

Question 20

Why are the lateral ventricles so oddly shaped?

Answer 20

as the cerebral cortex enlarges lateral it also rotates causing the C shape of the ventricles

Question 21

How is chord plexus form (hint describe two structure that come together)

Answer 21

pia mater abuts the ependymal cells of the ventricles and the blood vessels of the subarachnoid space are pushed up agains the ependymal cells, in this way CSF is derived from fluid leaking from vessels that is conditioned by ependymal cells

Question 22

Ependymal cells are linked together by ___ ____

Answer 22

tight junctions

Question 23

Describe how uncontrolled blood flow can lead to cerebral palsy in premature infants

Answer 23

premature infants cannot regulate blood flow well and vessels can rupture near a lateral ventricle because the germinal matrix zones around the ventricles becomes very vascularized. Bleeding can damage the motor cortex axons that run down to the body.

Question 24

What specialized structures signal to the spinal cord regions what type of cell they should become?

Answer 24

the notochord, floor plate and specialized roof plate cause functional subdivisions of cells into alar and basal plates

Question 25

What separates the subdivisions of the alar and basal plates?

Answer 25

sulcus limitans

Question 26

In which region of the spinal cord do interneurons form?

Answer 26

in mostly in the alar plate

Question 27

The alar plate becomes which two functional divisions of the CNS

Answer 27

general somatosensory and general viserosensory

Question 28

The basal plate becomes which two divisions of the CNS

Answer 28

viseromotor and somatomotor

Question 29

What is the significance of the pontine flexure

Answer 29

because of the bending of this region in the brainstem, the brainstem splits down the middle partially which causes the sensory portions to be more lateral to the motor portions in the medulla (located between the mentencephalon and myelencephalon)

Question 30

Name special senses in the head that require special innervation

Answer 30

branchiomoter to muscles derived form the branchial arches, somatosensory in the ears, viscerosensory from tastebud and olfactory receptors

Question 31

Migration of alar plate cells around the 4th ventricle forms the ___ ___ . Cells in posterior to this area become the _______.

Answer 31

rhombic lip; cerebellum

Question 32

Describe the movement of sclerotome that causes the development of the vertebrae

Answer 32

sclerotome cells migrate to surround the notochord and then later migrate up around the spinal cord with the sclerotome forming the annulus fibrosis of the disc and most of the vertebrae

Question 33

In the head some neural crest cells migrate into the __ ___ that form the facial bones.

Answer 33

branchial arches

Question 34

In the head sclerotome par of the somite form the ____ .

Answer 34

skull

Question 35

Midline evagination in the forebrain floor forms the ____ pituitary

Answer 35

posterior

Question 36

Midline caudal roof of the forebrain becomes the _____ gland

Answer 36

pineal

Question 37

The notochord lumen or neuroceoel becomes what in the adult?

Answer 37

ventricular system