Embryology - Dev. Of Nervous System

Front 1

notocord induces the ______ to thicken and form the ________.

Back 1

surface ectoderm; neural plate

Front 2

_______ differentiates into the brain (cranially) and spinal cord.

Back 2

neural tube

Front 3

What is origin of neural crest cells and/or how do they form?

Back 3

During fusion [of neural fold] and formation of neural tube, a group of cells detach from neural tube & differentiate into the neural crest cells.

Front 4

Neural Crest Cells contribute to: ?

Hint: 7 structures

Mrs-Nickles-Glanced-At-My-Coin-Purse

Back 4

- Melanoblasts (precursor to melanocyte)
- Neurolemmal cells (membranous covering that forms myelin sheath in PNS)

- Ganglia (sensory and autonomic)
- Mesenchymal cells of head
- Chromaffin cells of adrenal medulla
- Arachnoid & Pia mater

Front 5

1.) Epithelial lining of the neural
tube?

2.) What 2 types of cells proliferate outwards from this?

Back 5

1. neuroepithelium

2. Neuroblasts and gliablasts (supporting cells)

Front 6

cell bodies of the neuroblast (cells in the embryonic brain and spinal cord) form the ______ whereas their processes (axon and dendrites) form the ________.

Later they develop into ______?

Back 6

mantle zone; marginal zone

Later they develop into the grey and white matter, respectively.

Front 7

Background Question:
1. What is a neuroglia cell (as found in adult)?

2. Name 4 types of neuroglia cells?

Back 7

1. Neuroglia: are the supporting or accessory cells of the nervous system.

2. a. Astrocytes: most abundant glial cells, blood-brain barrier

b. Microglial cells: phagocytic
c. Ependymal cells.
d. Oligodendrocytes: produce myelin sheaths within CNS

Front 8

_____ differentiate into astrocytes and oligodendrocytes

Microglia is _______ in origin.

Back 8

GLIABLASTS differentiate into astrocytes and oligodendrocytes;

Microglia is MESODERMAL in origin.

Front 9

Further Development of Neural Tube (Spinal Cord):

_____ is a groove in lateral wall of the neural tube marks the division into dorsal (__ plate) and ventral (___ plate) halves. Later the ____ plates develop with combined...

Back 9

sulcus limitans

division into dorsal (alar plate) and ventral (basal plate) halves. Later, the lateral plates develop with combined alar and basal plate.

Front 10

alar plate has ____(1), the basal plate has ____(2) and the lateral plate has _____(3).

These subsequently develop into _______?

Back 10

1. alar plate has SENSORY
2. basal plate has MOTOR
3. lateral plate have AUTONOMIC neurons

These subsequently develop into the dorsal, ventral and lateral horns of spinal cord.

Front 11

What is medial fissure in dorsal part of spinal cord ____?

What is medial fissure in ventral part of spinal cord segment ____?

Back 11

dorsal median sulcus

ventral median fissure

Separate white matter into D,V,L funiculi

Front 12

sensory fibers are in ____ ?

sensory neurons are _____ ?

Back 12

dorsal funiculus

dorsal horn

Front 13

dorsal root carries ?

dorsal roots have axons originating from ?

Back 13

afferent or sensory fibers

unipolar neurons of the dorsal root ganglion (derived from the neural crest cells)

More information: (not for test)
Many types of primary sensory neurons are unipolar. Typically these have special structures for transducing some type of physical stimulus (light, sound, temperature, etc) into electrical activity, no dendrites, and a single axon that conveys the resulting signals into the spinal cord or brain.

Front 14

Four cell columns are recognizable in the grey matter of spinal cord:

Back 14

1. Dorsal horn: carries somatic afferent
2. intermediate horn: carries visceral afferent
3. Lateral horn: has visceral efferent or sympathetic fibers
4. Ventral horn:: has somatic efferent

Front 15

In the grey matter, the lateral horn contain what kind of fibers?

Back 15

visceral efferent

note: do not confuse with lateral plate of developing spinal cord which
carriers autonomic neurons

Front 16

dorsal horn contain ?

Back 16

somatic afferent

Front 17

lateral or intermediale horn contain ?

Back 17

visceral afferent and visceral efferent

Front 18

Which is true?
A. growth of spinal cord exceeds that of vert.column

B. growth of the vertebral column exceeds with that of the spinal cord.

Back 18

B. growth of the vertebral column exceeds with that of the spinal cord.

Front 19

The caudal end of the spinal cord tapers to form ____?

Their arrangement is referred to as the _____?

Back 19

conus medullaris (and most caudal spinal nerves pass obliquely)

This arrangement is termed cauda equina (horse-tail)

Front 20

1st cervical spinal nerves comes from where/what vertebrae?

Back 20

before C1; emerges from the vertebral canal between the occipital bone and the atlas

Front 21

8th thoracic spinal nerve emerges _____?

Back 21

between seventh cervical and first thoracic vertebræ.

Front 22

Midbrain develops from

Hindbrain develops from

Back 22

Mesencephalon

Rhombencephalon

Front 23

Prosencephalon differentiates into what structures?

What cavities present?

Back 23

1. Telencephalon w/lateral ventricle (cavity)
AND
2. diencephalon w/3rd ventricle

Front 24

What originates from telencephalon?

Nerves?

Back 24

olfactory bulb (CN1) and cerebral hemispheres and lateral ventricle (cavity)

-CN#1

Front 25

What originates from diencephalon?

What cavity? What nerve(s)?

Back 25

epithalmus, thalmus, hypothalmus

also cavity - third ventricle
AND
optic nerve

Front 26

CN originating from diencephalon?

Back 26

optic nerve

Front 27

Derivatives of Mesencephalon

Cavity?
Cranial nerves?

Back 27

Corpora quadrigemina & Cerebral peduncles

Cavity : Cerebral aqueduct

Cranial nerves: Occulomotor, Trochlear

Front 28

Rhombencephalon form?

Back 28

1. Metencephalon (not mesencephalon)

2. Pontine flexure (between the metencephalon & myelencephalon)

3. Myelencephalon

Front 29

Cranial nerves 6-12 come from?

Back 29

Myelencephalon

Front 30

1. Derivatives of Mesencephalon
2. Derivatives of Metencephalon
3. Derivatives of Myelencephalon

Back 30

1. Midbrain (Corpora quadrigemina & Cerebral peduncles)
2. Derivatives: Pons and Cerebellum
3. Medulla oblongata

Extra Info to help remember:
Corpora quadrigemina (Latin for "quadruplet bodies") are four colliculi—located on dorsal aspect of the midbrain; are reflex centers involving vision and hearing.

Cerebral peduncles (also known as the cerebral crus) are part of midbrain that link remainder of brainstem to diencephalon,etc. above.

Front 31

Medulla oblongata comes from?

Back 31

Myelencephalon

Front 32

Piamater and Arachnoid derived from the _____.

Back 32

neural crest cells

Front 33

Duramater derived from the surrounding _____.

Back 33

mesoderm

Front 34

Nervous System develops from?

Back 34

Derived from the Ectoderm

Front 35

Developmental abnormality:

Identify Cerebellar hypoplasia

Back 35

found in cats and dogs in which the cerebellum is not completely mature at birth.

can by caused by congenital or environmental factors

Additional Info:
Bacterial infections and viral infections such as feline panleukopenia, caused by feline parvovirus, that can result in disorder in both cats and dogs. However, disease can also be caused by malnutrition, poisoning, injury during dev. of fetus. causes jerky movements, tremors and generally uncoordinated motion

Front 36

Spina bifida or myeloschisis

Back 36

incomplete closure of neural tube, spinal cord exposed. May or may not be a fluid-filled sac surrounding the spinal cord.

Spina bifida: caudal neuropore fails to fuse
myeloschisis: neural tube fails to close in middle region
anenocephalus: rostral neuropore fails to fuse

Front 37

Hydrocephalus

Back 37

abnormal accumulation of CSF in ventricles, or cavities, of brain.

one of most common acquired etiologies being brain hemorrhage associated with premature birth.

Front 38

Name some neural tube abnormalities?

Back 38

Spina bifida, myeloschisis, anencephalus

Spina bifida: caudal neuropore fails to fuse
myeloschisis: neural tube fails to close in middle region
anenocephalus: rostral neuropore fails to fuse

Front 39

2 parts of Hypophysis Cerebri (Pituitary Gland)?

Where found?

Back 39

1, Adenohypophysis (anterior pituitary):

2. Neurohypophysis (posterior pituitary)

Front 40

Adenohypophysis Development from?
(be specific)

Back 40

develops from stomodeal ectoderm as a dorsal evagination of dev mouth, termed Rathke’s pouch.

Front 41

Neurohypophysis development from?

Back 41

(posterior pituitary): develops as a ventral downgrowth from the floor of the diencephalon, the infundibulum.

Front 42

The hypophysis (pituitary) has dual origin.
Early in gestation, finger of ectoderm grows upward from roof of mouth (stomodeal ectoderm). This protrusion is called ?

It is develop into what part ?

Back 42

Rathke's pouch and will develop into the anterior pituitary or adenohypophysis.

Front 43

At the same time that Rathke's pouch is developing, another finger of ectodermal tissue evaginates from where?

This becomes what structure?

Back 43

At same time that Rathke's pouch is developing, another finger of ectodermal tissue evaginates VENTRALLY (infundibulum) from DIENCEPHALON of developing brain.

This extension of ventral brain will become posterior pituitary or neurohypophysis.

Front 44

Rathke’s pouch joins the_____ and looses its connection with the ______.

Back 44

Rathke’s pouch joins the INFUNDIBULUM and looses its connection with the STOMODEUM.

Front 45

Rathke’s pouch differentiates into (be specific...what parts)?

Back 45

Rathke’s pouch will develop into the anterior pituitary or ADENOHYPHYSIS, differentiating into the pars distalis, pars media and pars tuberalis.
(these are 3 parts of adenohypophysis)

Front 46

Adrenal Gland develops from what two sources?

Back 46

- adrenal CORTEX develops from intermediate MESODERM.

- Adrenal MEDULLA (chromaffin cells) develops from neural crest cells (ECTODERM)...after N.C. cells continue from sympathetic ganglion

Front 47

Development of Eye:

(1) lens, lacrimal gland, corneal and conjunctival epithelium develops from _______?

(2) ________ contributes to the retina and optic nerve.

(3) Remaining structures (e.g. sclera) develop from?

Back 47

1) lens, lacrimal gland, corneal and conjunctival epithelium develops from SURFACE ECTODERM.

(2) NEUROECTODERM contributes to the retina and optic nerve.

(3) Remaining structures (e.g. sclera) develop from mesoderm.

Front 48

1. optic vesicle develops from ? (hard)

2. optic vesicle makes contact with the _____ and induces it to thickens and form ______.

3. optic vesicle invaginates to form a ______ and then develops the _______

Back 48

1. optic vesicle develops from developing forebrain (diencephlon) as a lateral outgrowth.

2. optic vesicle makes contact with the OVERLYING ECTODERM and induces it to thickens and form LENS PLACODES.

3. optic vesicle invaginates to form a DBL.WALLED OPTIC CUP and then develops the CHOROID FISSURE FOR PASSAGE OF HYLOID ARTERY.

Front 49

pigmented and sensory layers of the retina arise from ?
(be specific)

Back 49

two walls of the optic cup

Inner layer of optic cup becomes NERVOUS LAYER OF RETINA
Outer layer of optic cup becomes PIGMENT LAYER " "

note: all originate from neuroectoderm

Front 50

The remaining fibrous (sclera) and vascular (choroid) coats develops ?

Back 50

develops by local condensation of the mesoderm.

Front 51

Smooth muscle of the iris develops from

Back 51

the ectoderm at the margin of the optic cup.

Front 52

Occular muscles are develop from the

Back 52

paraxial mesoderm

Front 53

Failure of the choroidal fissure to close

Back 53

Coloboma

Hole in one of structures of the eye, such as the iris, retina, choroid or optic disc; congenital and can be caused when gap called the choroid fissure between two structures in eye fail to close during development

Front 54

What is developmental disorder of the eye characterized by small eye(s)?

Back 54

Microphthalmia

literally means small eye (micros = small; ophthalmos = eye)

The major causes for this disorder are genetic but environmental factors have also been implicated such as exposure to radiation, chemicals, or viruses.

Front 55

Absence of eye as a result of exposure of the mother to toxic chemicals during pregnancy

Back 55

Anopthalamia

Front 56

Cloudiness of lens

Back 56

Congenital cataract

Front 57

Somites develop from?

They form what structures?

Back 57

paraxial mesoderm - this is mesoderm that forms on each side of neural tube

vertebrae or backbone (not the spinal cord itself) and ribs, as well as musculature of back, ribs and limbs, but don't need to know all this for the final

Front 58

______ induces the formation of the neural plate, which gives rise to the entire nervous system

Back 58

notochord

Front 59

The closure of the tube begins in _____and then ______.

Back 59

1. cervical region
2. extends cranially and caudally.

Front 60

Encephalon (developing brain) begins to form when the neural tube swells and subdivides, first into the three primary vesicle: what are they?

Back 60

prosencephalon, mesencephalon and rhombencephalon

Front 61

five secondary vesicles

Back 61

five secondary vesicles (the telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon).

Front 62

What happens to neurohypophysis after it (as the infundibulum) fuses with Rathke's pouch?

Back 62

- Retains connection with hypthalmus and forms the PARS NERVOSA
(this is structure that makes up bulk of neurohypophysis)

Front 63

cervical flexure

cranial flexure

Back 63

between dev. brain and spinal cord

midbrain flexure

Front 64

The cavity of the neural tube becomes the ______ of the spinal cord. When formation of neuroepithelium ceases, it forms the ________.

Back 64

The cavity of the neural tube becomes the CENTRAL CANAL of the spinal cord. When formation of neuroepithelium ceases, it forms the EPENDYMA (thin epithelial membrane lining ventricles of brain and spinal cord. 1 of 4 neuroglia cells of CNS; involved in production of CSF)

Front 65

What cavity develops in myelencephalon?

Cranial nerves?

Back 65

fourth ventricle

cranial nerves 6-12

Front 66

What does the bony labyrinth of the internal ear develop from?

Back 66

The chondrification and ossification of the surrounding mesoderm