Central Nervous System

Question 1

At what hour of incubation of chick embryo the enlarged cranial end of the neural tube forms 3 brain vesicles namely prosencephalon, mesencephalon, and rhombencephalon?

Answer 1

27 hours of incubation

Question 2

sign of metamerism or segmentation in the embryo

Answer 2

neuromeres

Question 3

At what hour the lateral walls of prosencephalon evaginate to form two primary optic vesicles?

Answer 3

29-30 hours

Question 4

occupies the rostral part of the head

Answer 4

forebrain or prosencephalon

Question 5

The neural canal of prosencephalon is prosocoele and it presents a depression on its floor, where the notochord extends up its level.

Answer 5

infundibulum

Question 6

located posterior to and marked off from the
prosencephalon by constriction; it neural canal is mesocoele

Answer 6

mesencephalon or midbrain

Question 7

Midline region of the wall dorsal to the neural canal constitutes the?

Answer 7

roof plate

Question 8

If midline region of the wall dorsal to the neural canal constitutes the roof plate; counterpart wall ventral to the neural canal is?

Answer 8

floor plate

Question 9

located posteriorly and marked off from the
mesencephalon by a slight constriction

Answer 9

rhombencephalon

Question 10

What is the neural canal of rhombencephalon?

Answer 10

rhombocoele

Question 11

rostral end of prosencephalon presents the
anterior neuropore which is almost closed at what hour of incubation?

Answer 11

33 hours

Question 12

flexure that occurs at the level of the midbrain; concave ventrally

Answer 12

midbrain flexure

Question 13

flexure that occurs between the midbrain and the hindbrain; concave dorsally

Answer 13

pontine flexure

Question 14

appears at the junction of the hindbrain and spinal cord; persists slightly in domestic animals; concave ventrally

Answer 14

cervical flexure

Question 15

At what hour of incubation, does the three brain vesicles become four due to the division of
the rhombencephalon into metencephalon and myelencephalon?

Answer 15

38 hours

Question 16

part of neuron which contains cytoplasm and nucleus

Answer 16

nerve cell body

Question 17

conducts impulses away from the cell body

Answer 17

axon

Question 18

The axon presents at its end many tiny branches where impulses leave the neuron.

Answer 18

telodendria

Question 19

part of neuron which receive stimuli from the environment and convert these stimuli into impulses

Answer 19

dendrites

Question 20

Classification of neurons based on the number of dendrites present (3)

Answer 20

unipolar, bipolar, multipolar

Question 21

Enlarged cranial portion of the neural tube becomes the?

Answer 21

brain

Question 22

The slender middle and caudal portions of neural tube become the?

Answer 22

spinal cord

Question 23

Neural canal becomes the?

Answer 23

ventricles of the brain and the central canal of the spinal cord

Question 24

Neural crest cells become (5)

Answer 24

1. neurons of the PNS
2. neurolemocytes (Schwann cells)
3. adrenal medulla cells,
4. melanocytes of skin
5. a variety of structures in the face.

Question 25

composed of the brain & spinal cord

Answer 25

central nervous system

Question 26

a cell specialized to receive stimuli from the environment and transmit impulses to the spinal cord and brain where these impulses are interpreted

Answer 26

neurons or nerve cells

Question 27

What are the basic functional unit of CNS?

Answer 27

neurons or nerve cells

Question 28

What are the three layers of the neural tube wall?

Answer 28

germinal layer or ventricular zone mantle layer or intermediate layer marginal layer

Question 29

inner layer; composed of neuroepithelial cells that remain lining the central canal and designated as ependymal cells

Answer 29

germinal or ventricular zone

Question 30

middle layer; zone of high cell density, formed by accumulation of neuroblasts and glioblasts;

Answer 30

mantle layer or intermediate zone

Question 30

becomes the gray matter of the CNS w/c contains cell bodies of neurons & several gliocytes

Answer 30

mantle layer or intermediate zone

Question 31

the outer layer surrounding the mantle layer; cell-sparse zone where axons of neurons & some gliocytes are present

Answer 31

marginal layer

Question 32

becomes the white matter of the CNS which contains mainly myelinated axons of neurons

Answer 32

marginal layer

Question 33

a bilateral indentation in the neural cavity that serves as a landmark to divide the wall between alar plate and basal plate

Answer 33

sulcus limitans

Question 34

At what hour of incubation the prosencephalon shows evidence of division into the cephalic telencephalon and caudal diencephalon?

Answer 34

55 hours

Question 35

At what hour of incubation, the telencephalon presents a median portion called median telencephalon and 2 lateral evagination called lateral telencephalic vesicles?

Answer 35

72 hours of incubation

Question 36

ventral opening of the double-walled optic cup?

Answer 36

choroid fissure

Question 37

At what hour of incubation the infundibulum at the floor of diencephalon has deepened and contacts w/ the Rathke’s pocket?

Answer 37

96 hours

Question 38

ganglion of CN X

Answer 38

jugular

Question 39

ganglion of CN IX

Answer 39

superior

Question 40

ganglion of CN VII

Answer 40

geniculate

Question 41

ganglion of 5th (trigeminal) cranial nerve (Ganglion V) and the opthalmic and mandibulomaxillary divisions of trigeminal nerve

Answer 41

semilunar (gasserian)

Question 42

origin of thalamus and hypothalamus

Answer 42

mantle layer of diencehalon

Question 43

develops from an outgrowth of the wall of the diencephalon

Answer 43

optic nerve

Question 44

the failure of vertebral arches to close dorsal to spinal cord

Answer 44

spina bifida

Question 45

failure of cerebellum to develop due to destruction of cerebellar cortex

Answer 45

Cerebellar hypoplasia and atrophy

Question 46

premature degeneration of Purkinje cell layer of cerebellar cortex

Answer 46

Cerebellar abiotrophy

Question 47

accumulation of excessive amount of cerebrospinal fluid in the cranial cavity

Answer 47

hydrocephalus