Topic 5

Question 1

is the development of the specific tissues and organs of the body.

Answer 1

Organogenesis

Question 2

Organs that perform related functions are grouped into a - .

Answer 2

system

Question 3

How many organ are there in
systems of the body

Answer 3

11 organ

Question 4

is composed of the brain & spinal cord

Answer 4

Central Nervous System (CNS)

Question 5

are the basic functional units of the CNS. It is a cell specialized to receive
stimuli from the environment and transmit impulses to the spinal cord and brain where
these impulses are interpreted; and then to the effector organs (e.g. muscle, stomach,
etc.) for response.

Answer 5

The neurons
(nerve cells)

Question 6

The connective tissue cells of the CNS are the
(oligodendrocytes, astrocytes, microgliocytes and ependymal cells).

Answer 6

gliocytes

Question 7

A neuron consists of:

Answer 7

nerve cell body
axon
dendrites

Question 8

which contains cytoplasm and nucleus

Answer 8

nerve cell body

Question 9

which conducts impulses away from the cell body. The axon presents at its
end many tiny branches called telodendria, where impulses leave the neuron. Several
axons may be grouped/ bundled together to form nerve tracts in the CNS or nerve
trunks in the peripheral nervous system (PNS). Number of axon in all neurons is constant
and is always one.

Answer 9

axon

Question 10

which receive stimuli from the environment and convert these stimuli into
impulses. Number of dendrites in the neuron varies from none to many.

Answer 10

dendrites

Question 11

Classification of neurons based on the number of dendrites present:

Answer 11

Unipolar neuron
Bipolar neuron
Multipolar neuron

Question 12

> neuron w/ only one process (axon only)

Answer 12

Unipolar neuron

Question 13

> neuron w/ two processes (axon & dendrite)

Answer 13

Bipolar neuron

Question 14

> neuron w/ many processes (one axon & many
dendrites)

Answer 14

Multipolar neuron

Question 15

Enlarged cranial portion of the neural tube becomes the

Answer 15

brain

Question 16

The slender middle and caudal portions become the

Answer 16

spinal cord

Question 17

Neural canal becomes the of the brain and the central canal of the
spinal cord

Answer 17

ventricles

Question 18

Neural crest cells become (1) of the PNS that have their cell bodies in
ganglia, (2) neurolemocytes (Schwann cells) of the PNS, (3) adrenal medulla
cells, (4) melanocytes of skin and (5) a variety of structures in the face

Answer 18

neurons

Question 19

Neural crest cells become (1) of the PNS that have their cell bodies in
ganglia, (2) (Schwann cells) of the PNS, (3) adrenal medulla
cells, (4) melanocytes of skin and (5) a variety of structures in the face

Answer 19

neurolemocytes

Question 20

Neural crest cells become (1) of the PNS that have their cell bodies in
ganglia, (2) (Schwann cells) of the PNS, (3) , (4) melanocytes of skin and (5) a variety of structures in the face

Answer 20

adrenal medulla
cells

Question 21

Neural crest cells become (1)neurolemocytes of the PNS that have their cell bodies in
ganglia, (2) (Schwann cells) of the PNS, (3) adrenal medulla
cells, (4) of skin and (5) a variety of structures in the face

Answer 21

melanocytes

Question 22

Neuroepithelium gives rise to neurons, (astrocytes and oligodendrocytes) and

Answer 22

gliocytes and ependymal cells of the CNS

Question 23

Layers of the Neural Tube Wall

Answer 23

1. Germinal layer or ventricular zone
2. Mantle layer or intermediate zone
3. Marginal layer

Question 24

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

Answer 24

Germinal layer or ventricular zone –

Question 25

– middle layer; zone of high cell density, formed by accumulation of neuroblasts and glioblasts; becomes the gray matter of the CNS w/c contains cell bodies of neurons & several gliocytes.

Answer 25

Mantle layer or intermediate zone

Question 26

– the outer layer surrounding the mantle layer; cell-sparse zone where axons of neurons & some gliocytes are present; becomes the white matter of the CNS which contains mainly myelinated axons of neurons

Answer 26

Marginal layer

Question 27

The lateral wall of the neural tube is divided into 2 plates:

Answer 27

Alar or dorsal plate and basal or ventral plate,

Question 28

, a indentation in the neural cavity that serves as a landmark to divide the wall.

Answer 28

bilateral

Question 29

The contains cell bodies of efferent or motor neurons that send axons into the PNS.

Answer 29

basal plate

Question 30

contains neurons that receive afferent or sensory input from the PNS.

Answer 30

Alar plate

Question 31

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

Answer 31

roof plate

Question 32

counterpart wall ventral to the neural canal is the

Answer 32

floor plate.

Question 33

By of incubaton of chick embryo the enlarged cranial end of the neural tube forms 3 brain vesicles:

Answer 33

27 hours

Question 34

- occupies the rostral part of the head

Answer 34

Prosencephalon(forebrain)

Question 35

is prosocoele; presents a depression on its floor, the infundibulum

Answer 35

Neural canal

Question 36

) - located posterior to and marked off from the prosencephalon by constriction; Neural canal is mesocoele.

Answer 36

Mesencephalon (midbrain

Question 37

- located posteriorly and marked off from the mesencephalon by a slight constriction. Neural canal is rhombocoele; continuous posteriorly w/ the spinal cord.

Answer 37

Rhombencephalon (hindbrain)

Question 38

The cranial neural tube that will develop into brain presents 11 enlargements called

Answer 38

neuromeres separated by constrictions.

Question 39

are a sign of metamerism or segmentation in the embryo.

Answer 39

Neuromeres

Question 40

– occurs at the level of the midbrain; concave ventrally.

Answer 40

Midbrain flexure

Question 41

– occurs between the midbrain and the hindbrain; concave dorsally.

Answer 41

Pontine flexure

Question 42

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

Answer 42

Cervical flexure

Question 43

Rhombocoele of metencephalon is ;

Answer 43

metacoele

Question 44

the myelencephalon is the .

Answer 44

myelocoele

Question 45

, the latter being composed of the optic vesicles and part of prosencephalon lying between the optic vesicles.

Answer 45

cephalic telencephalon and caudal diencephalon

Question 46

telencephalon presents a median portion called

Answer 46

median telencephalon

Question 47

2 lateral evagination called

Answer 47

lateral telencephalic vesicles.

Question 48

The paired ganglia of cranial nerves w/ sensory components have developed from cephalic neural crests. These are:

Answer 48

Semilunar ganglion Geniculate ganglion Superior ganglion Jugular ganglion

Question 49

Neural canal becomes the

Answer 49

central canal.

Question 50

Malformations of the Brain

Answer 50

Cerebellar hypoplasia and atrophy Cerebellar abiotrophy Hydrocephalus Hydranencephaly

Question 51

- failure of cerebellum to develop due to destruction of cerebellar cortex.

Answer 51

Cerebellar hypoplasia and atrophy

Question 52

- premature degeneration of Purkinje cell layer of cerebellar cortex.

Answer 52

Cerebellar abiotrophy

Question 53

– accumulation of excessive amount of cerebrospinal fluid in the cranial cavity.

Answer 53

Hydrocephalus

Question 54

– thin walled and greatly enlarged lateral ventricle filled with CSF.

Answer 54

Hydranencephaly

Question 55

Malformations of the Spinal Cord

Answer 55

Myelodysplasia Myeloschisis Meningocoele Meningomyelocoele

Question 56

Types of Myelodysplasia

Answer 56

Hypoplasia (aplasia) Hydromyelia Syrinomyelia Diplomyelia Diastematomyelia

Question 57

– general term for a malformation of the spinal cord. Originates during neurula.

Answer 57

Myelodysplasia

Question 58

– reduced or absence of development of one or more segments of spinal cord.

Answer 58

Hypoplasia (aplasia)

Question 59

– dilation of central canal due to excess accumulation of CSF.

Answer 59

Hydromyelia

Question 60

– abnormal cavitation of the spinal cord.

Answer 60

Syrinomyelia

Question 61

– 2 spinal cords develop beside each other usually in one set or meninges and in one vertebral canal.

Answer 61

Diplomyelia

Question 62

- 2 spinal cords develop w/ a partition between them. Usually in separate vertebral canals and have separate meninges.

Answer 62

Diastematomyelia

Question 63

– cleft in the neural tube brought about by the failure of this part to close during neurulation.

Answer 63

Myeloschisis

Question 64

– protrusion of the meninges through an opening in the vertebral arches to form a cyst beneath the skin

Answer 64

Meningocoele

Question 65

– similar to meningocoele except that both meninges and spinal cord protrudes.

Answer 65

Meningomyelocoele

Question 66

} - are associated with Meningocoele

Answer 66

Myeloschisis

Question 67

– the failure of vertebral arches to close dorsal to spinal cord.

Answer 67

Spina bifida