Development of Central Nervous System Flashcards
1
Q
gastrulation -
A
primitive streak stage
2
Q
Cranial part of the ___ presage the establishment of the brain and spinal cord
A
neural tube
3
Q
Neural crest cells give rise to the ___ and ___
A
peripheral nervous system (PNS)
autonomic nervous system (ANS)
4
Q
- Pseudostratified epithelium
- Progenitor cells of the nervous system
- is divided into (from lumen outward) ependymal, mantle, and marginal layer
A
Wall of Neural Tube
5
Q
Wall is divided into (from lumen outward)
?
A
ependymal, mantle, and marginal layer
6
Q
- Closest to the lumen of the neural tube
- Remaining cells differentiate to become ependymal of the central canal and ventricular system of the brain
A
Ventricular/ Ependymal Neuroepithelial Layer
7
Q
- Middle layer, immediately surrounds the ventricular zone
- Contains cell bodies of post-mitotic neuroblasts and presumptive glial cells
- Becomes the grey matter which is H or butterfly shaped
A
Intermediate/ Mantle Layer
8
Q
- Peripheral layer
- Contains neuronal processes but not neural cell bodies
- Forms the white matter, it is white because it contains myelinated neuronal process (myelin is white)
A
Marginal Layer
9
Q
- ___ becomes the dorsal sensory horn of the spinal cord
A
Alar plate
10
Q
- ___ becomes the ventral motor
horn
A
Basal plate
11
Q
- ____ becomes the dorsal median septum
A
Roof plate
12
Q
- ___ becomes the ventral fissure
A
Floor plate
13
Q
longitudinal groove separating the alar and basal plates of the developing spinal cord
A
Sulcus limitans-
14
Q
becomes a circular central canal
A
Longitudinal groove
15
Q
Ventral thickenings that form the ventral horn of the spinal cord containing motor neurons (general somatic effect efferent) and autonomic neurons (visceral efferent) The two are connected by the floor plate ventral to the central canal.
A
BASAL PLATES
16
Q
Dorsal thickenings Form dorsal horn containing the sensory neurons receiving input from the skin, joints and muscles (general somatic afferent), from the pharynx (special visceral afferent) and from
the viscera and heart (general visceral afferent) The left and right are connected dorsally over the central canal by the roof plate.
A
ALAR PLATES
17
Q
- Arise from mitosis of the neuroepithelial cells
- Progenitor of nerve cells or neurons
- Once formed, they lose their ability to divide
- Neurogenic cells in the ventral part of the spinal cord and the hindbrain are usually the first to stop dividing
- Cortical neurons in the cerebrum and the cerebellum are the last population to be formed
A
NEUROBLASTS
18
Q
- Give rise to astrocytes, which are present both in the mantle and marginal layers and oligodendrocytes which mainly populates the marginal layer.
A
SPONGIOBLASTS/
GLIOBLASTS
19
Q
The cranial part of the neural tube form neuromeres/ vesicles that forms the ____ and the portion of the neural tube with fading neuromeres becomes the _____.
A
BRAIN
SPINAL CORD
20
Q
At 1st, there are ____ primary brain vesicles, then ____ vesicles from which adult parts of the brain arise
A
three
five
21
Q
- Divides into telencephalon and diencephalon
- Optic vesicle grow out as evaginations from each side of the prosencephalon
A
PROSENCEPHALON
22
Q
- Forms the cerebral hemispheres and olfactory bulbs
A
TELENCEPHALON
23
Q
Cavities in the telencephalon form the ____
A
lateral ventricles
24
Q
consists of genicular gyrus, supracallosal gyrus, parahippocampal gyrus as well as the hippocampal gyrus and dentate gyrus
A
Archicortex-
25
comprises the olfactory bulbs, olfactory tracts, olfactory tubercle and piriform lobe
Paleocortex-
26
makes up most of the cerebral cortex
Neocortex-
27
Cerebrum evolutionarily subdivided into:
Allocortex
Neocortex-
28
Surface of the cerebral hemispheres
become folded and develop the sulci
(grooves) and gyri (elevations)
CEREBRUM
29
those that synapse with neurons of the
same hemisphere
Association neurons-
30
those with axons that connect corresponding regions of the two hemispheres
Commissural neurons-
31
those with axons that connect the cortex with deeper region of the CNS
Projection neurons-
32
* Gives rise to the epithalamus including the epiphysis, thalamus, metathalamus and hypothalamus as well as the neurohypophysis and the optic cups
DIENCEPHALON
33
Cavity within the diencephalon is the ____
third ventricle
34
* Master regulatory center, master’s gland
* Controls many basic homeostatic functions such as sleep, body temperature, hunger, fluid and electrolyte balance, emotional behavior and activity of the pituitary gland
HYPOTHALAMUS
35
* Acts as an important centre for relaying sensory impulses (auditory, visual, and tactile)
THALAMUS
36
* Pineal gland formed by the migration of neuroepithelial cells dorso-caudally from the roof of the diencephalon
* Cells differentiate into two types
of cells, pinealocytes and glial cells
* Involves in the circadian rhythm
EPIPHYSIS
37
Develop into two primordia:
*Adenohypophysis
* Neurohypophysis
HYPOPHYSIS
38
Rathke’s pouch-ectodermal outpocketing of the stomodeum
Adenohypophysis
39
Infundibulum-ventraldowngrowth of the diencephalon
Neurohypophysis
40
Remains structurally relatively simple, do not subdivide
MESENCEPHALON
41
The neural cavity of the midbrain becomes
mesencephalic aqueduct: (2)
* Tectum- dorsal
* Tegmentum- ventral
42
refers to the Four aggregations of the nuclei
CORPORA QUADRIGEMINA
43
integral part of the visual system
Rostral colliculi-
44
auditory functions
Caudal colliculi-
45
Divides into metencephalon and myelencephalon.
RHOMBENCEPHALON
46
Give rise to the pons and corpus trapezoideum ventrally and the cerebellum dorsally
METENCEPHALON
47
Transverse structure demarcating the anterior end of the medulla oblongata
Serves as pathway for the nerve fibers
Between the cerebral and cerebellar cortices
PONS
48
Coordination centre for the posture and movement
CEREBELLUM
49
are the primordia of the cerebellum.
Rhombic lips
50
Cortex shows three clearly separated layers:
outer molecular layer
Purkinje cell layer
inner granular layer
51
* Resembles the spinal cord structurally and functionally
* Forms the medulla oblongata
MYELENCEPHALON
52
Conduit for tracts between the spinal cord and higher regions of the brain
Contains important centres for the regulation of respiration and heart beat
MEDULLA OBLONGATA
53
Ventral cranial flexure which occurs the midbrain
CEPHALIC FLEXURE
54
A gradual ventral bend between the hindbrain and spinal cord
CERVICAL FLEXURE
55
A slight dorsal bending in the rhombencephalon
PONTINE FLEXURE
56
Brain Flexures
CEPHALIC FLEXURE
CERVICAL FLEXURE
PONTINE FLEXURE
57
Protective covering of the CNS
Meninges
58
derived from the axial mesoderm, forms
the dura mater
Outer ectomeninx-
59
derivative of neural crest cells, subdivides
into thin pia mater and middle arachnoidea
Inner endomeninx-
60
Cranial Nerves
Classified into three categories according to
their embryonic origin and their future
* Nerves with special sensory function
* Mixed nerves that innervate the pharyngeal arch derivatives
* Nerves with exclusively general somatic efferent fibers
61
Regulates many of the involuntary functions of the body
Autonomic NS
62
* Originates from the cranial and sacral regions
* The first and second neurons
utilize acetylcholine as the transmitter
Parasympathetic NS
63
* Originates from the thoracolumbar region
* Pre-ganglionic telodendria release acetylcholine whereas most sympathetic second neurons release norephinephrine.
Sympathetic NS
64
* Influence gastrointestinal motility and secretion
* Subdivided into two interconnected components:
* Auerbach plexus
* Meissner plexus
Enteric NS
65
Ganglia located circumfentially between the inner circular and outer longitudinal smooth muscle layers of the gut wall
Controls gastro-intestinal tract movement
AUERBACH/ MYENTERIC PLEXUS
66
Ganglia located in the submucosa of the gut
Controls the GI secretion and local blood flow
MEISSNER/ SUBMUCOSAL PLEXUS
67
General term for the malformation of the spinal cord
MYELODYSPLASIA
68
absence of the development of one or more segments of the spinal cord
APLASIA-
69
reduced development of segments of the spinal cord
HYPOPLASIA-
70
dilatation of the central canal due to an excess accumulation of cerebrospinal fluid
HYDROMYELIA-
71
abnormal cavitation of several segments of
the spinal cord, inherited in Weimaraner dogs and in tailless Manx cats
SYRINGOMYELIA-
72
abnormal accumulation of cerebrospinal
fluid within the ventricular system of the brain
HYDROCEPHALUS-
73
cerebral hemispheres are replaced by two
fluid sacs
- Most commonly caused by in utero viral infection (blue tongue virus in ruminants and panleukopenia in cats) or by an interruption of the blood supply to the telencephalon
HYDRAENCEPHALY-
74
abnormally small brain; caused may be genetic or a prenatal insult such as an infection or exposure to a teratogen
MICROCEPHALY-
75
characterized by caudal displacement of and herniation of cerebellar structures through the foramen magnum into the cranial cervical vertebral canal
ARNOLD-CHIARI MALFORMATION-
76
characterized by impaired or incomplete
midline division of the prosencephalon
HOLOPROSENCEPHALY-
77
extreme form of holoprosencephaly characterized by the failure of the prosencephalon to properly divide the orbits of the eye into two cavities
-CYCLOPIA-
78
a milder form of holoprosencephaly characterized by a monkey-like head with defective small flattened nose with a single
nostril or absent nostril
CEBOCEPHALY-
79
situation where an insufficiency of neurons
causes hypoplasia of the granular layer of the cerebellum; most commonly caused by prenatal or perinatal viral infections (feline
panleukopenia virus and bovine viral diarrhea virus)
CEREBELLAR HYPOPLASIA-
80
characterized by the degeneration of the
pukinje cells in the already formed cerebellar cortex
CEREBELLAR ABIOTROPHY-
