Neuroanatomy Flashcards
1
Q
Components of CNS
A
Brain and spinal cord
2
Q
Components of PNS
A
Cranial nerves - 31 pairs
Ganglia outside of the CNS
3
Q
Somatic
A
Proving sensation to the body wall
4
Q
When do additional vesicles appear in the primary vesicle?
A
Around 6-8 weeks
4
Q
Autonomic
A
Not present outside and maintains the internal environment of the body
5
Q
3 swellings of primary vesicle
A
Prosencephalon, Mesencephalon and Rhombencephalon
6
Q
What does the prosencephalon develop into?
A
Telencephalon and Diencephalon
7
Q
What does the mesencephalon develop into?
A
It remains as the mesencephalon
8
Q
What does the rhombencephalon develop into?
A
Metancpehalon and mylencephalon
9
Q
Embryological division of cerebral hemispheres
A
Telencephalon
10
Q
Embryological division of thalamus and hypothalamus
A
Diencephalon
11
Q
Embryological division of midbrian
A
Mesencephalon
12
Q
Embryological division of pons and cerebellum
A
Metancephalon
13
Q
Embryological division of medulla oblongata
A
Myelencephalon
14
Q
What makes up the brain stem?
A
Midbrain, pons and medulla
15
Q
Descibe the horizontal plane
A
Superior and inferior portions of the brain
16
Q
Describe the coronal plane of the brain
A
Anterior and posterior portions of the brain
17
Q
Describe the sagittal plane of the brain
A
Right and left portions of the brain
18
Q
Functional divisions of the nervous system
A
Sensory - afferent division
Motor - efferent division
19
Q
Sensory afferent division of NS
A
Carries sensory information to the CNS
20
Q
Motor efferent division of NS
A
Carries motor commands from the CNS to muscles and glands
21
Q
Major structures and regions of the CNS
A
Brain: Cerebrum, cerebellum and brain stem
Spinal cord: Cervical, Thoracic, Lumbar, Sacral and Coccygeal segments
22
Q
Commissural tracts
A
Connect corresponding regions of the two cerebral hemispheres
23
Q
Association tracts
A
Connect different regions within the same cerebral hemisphere
24
Projection white matter tract
Connects the cortex with the spinal cord and brain stem
25
Cranial Nerve I
oLFACTORY
26
CNII
Optic
27
CNIII
Oculomotor
28
CNIV
Trochlear
29
CNV
Trigeminal
30
CNVI
Abducens
31
CNVII
Facial
32
CNVIII
Vestibulocochlear
33
CNIX
Glossopharyngeal
34
CNX
Vagus
35
CNXI
Accessory
36
CNXII
Hypoglossal
37
Acquiring neuroanatomical understanding
Reading current literature, dissections, reviewing radiological images
38
Grey matter
Outer part of cerebral hemisphere, large number of neurons, cell processes, synapses and supporting cells (microglia)
39
White matter
Inner part of the cerebral hemispheres, axons are myelinated
40
Myelinated cells in the CNS
Myelin sheath fromed by oligodendrocytes
41
Myelinated cells in PNS
Myelin sheath formed by Schwann cells
42
What do sulci and gyri do in the brain in terms of surface area?
Increase
43
Lobes of cerebral hemisphere
Frontal, Occipital, Parietal and Temporal
44
Blood supply in cranial cavity
Arterial and venous
45
Arterial supply in cranial cavity
Circle of Willis
46
Circle of Willis
R. and L. vertebral arteries join to create basilar artery and then the posterior cerebral artery.
Basilar artery forms the R. and L. posterior cerebral arteries which will form the R. and L. internal carotid arteries. They maintain contact via the posterior communicating artery.
R. and L. internal carotid go on to become the R. and L. anterior cerebral arteries respectively. These arteries communicate via the anterior communicating artery.
47
Cortical branches
Supplying arterial blood to the cortex
48
Central branches
Supplying arterial blood to the deep surfaces of the brain
49
Venous supply to the brain
Does not contain valves
They are called sinuses.
Present in two layers of dura mater - endosteal and meningeal
50
Dural venous sinuses
meningeal layer appears through gaps in the endosteal layer forming small gaps
51
Confluence of sinus
Present in the posterior part of the skull in cranial cavity. This is the area where the sinuses meet and drain into the internal jugular vein
52
Pathway of sinuses into internal jugular
Transverse sinus drains into sigmoid sinus drains into internal jugular vein
53
Types of veins
Superficial and deep
54
Superficial veins
Superior cerebral vein, superficial middle cerebral vein and inferior cerebral vein
55
Deep veins
Thalmostriate vein and choroidal vein which unite to create the internal cerebral vein and the great cerebral vein
56
Meninges - 3 layers
Dura mater
Arachnoid mater
Pi mater
57
Dura mater
Outer tough layer of CT
58
Arachnoid mater
relatively thin later that is usually apposed to the dura mater. Thin wispy cords of CT connect this layer to the pia
59
Pia mater
Very thin inner layer that is opposed to the surface of the brain. A layer of pia mater accompanies arteries penetrating into the brain
60
CSF
Cerebrospinal fluid
61
Where is CSF produced?
Choroid plexus in ventricles produces CSF
62
Journey of CSF
Circulates around the brain and spinal cord from the 4 ventricle to the subarachnoid space
63
Absorption of CSF
Reabsorbed into the dural venous sinuses by specialised structures called arachnoid granulations
64
Function of CSF
Cushions the brain both internally and externally
65
Cells of the nervous system and their roles
Neurons and glial cells
66
Neurons
transmit electrical signals
67
Glial cells
support and nourish neurons, maintain homeostasis and provide insulation
68
Cytoarchitecture of the cerebral and cerebellar cortices
Cerebral cortex - 6 layers
Cerebellar cortex - 3 layers
69
Layers of cerebral cortex
Molecular (plexiform) layer
External granular layer
External pyramidal layer
Internal granular layer
Internal pyramidal layer
Multiform (fusiform) layer
Diverse cell types which are organised into gyri and sulci
70
Layers of cerebellar cortex
Molecular layer
Purkinje cell layer
Granular layer
Highly folded structures
71
Basic development of nervous system
Neurulation - results in the formation of the neural tube from the ectoderm of the trilaminar germ disc.
Differentiation - neuroepithelial cells give rise to neurons and glial cells
Migration - neurons migrate to their final destinations
Synaptogenesis- formation of synapses between neurons
Myelination- glial cells wrap axons with myelin sheaths which will enhance signal transmission
72
Singalling factors acting as ligands
GDF
73
Groups of GDF
Fibroblast growth factors (FGF)
WNT
hedgehog
Transforming growth factor-b (TGF-b)
74
Mammals have 3 hedgehog genes - what are the names?
Desert
Indian
Sonic
75
WNT gene properties
15 different genes that are related to the segment polarity gene. The receptors of these genes are members of the frizzled family of proteins
76
TGF-b protein properties
More than 30 members, the mone morphogenetic proteins (BMP), the Mullerian inhibiting factor (MIF, anti-Mullerian hormone)
77
BMP inhibitory or non-inhibitory signal?
Inhibitory
78
BMP role
Critical molecules for preventing neural induction
79
Presence of BMP
inhibits the formation of neural tissue
80
Absence of MBP
allows for the formation of neural tissue
81
Cells closely packed together will form....
the epidermis
82
Cells disassociated and not closely packed together will...
not form epidermis but form neural tissue
83
Does presence of BMP allow the epidermis to form?
Yes
84
Mesoderm dorsal to the blastopore....
secretes moelciles that inhibits BMPs located in overlying ectoderm and will convert it to neuroderm
85
Types of BMP receptors
Type I and Type II
86
How do BMP molecules bind do a receptor?
They form a dimer and interact with the receptor which leads to the formation of 2 pathways
87
Pathways of bound BMP to receptor
SMAD and MAPK
88
Activation of the pathways after BMP has reacted with the receptor leads to
Phosphorylation.
89
Types of SMAD pathways which are a result of phosphorylation.
SMAD 1,5 and 8 which will combine to form complexes with SMAD4 and enter the nucleus to regulate the transcription of specific target cells
90
Fibroblast growth factor (FGF) will react with tyrosine kinase which leads to...
Activation of MAPK pathway.
91
Wnt proteins binds to only
proteins in the frizzled family, this occurs within the cell membrane and will activate another reaction in the cytoplasm
92
Interaction of Wnt with frizzled family protein leads to
Activation of dishevelled family proteins which inhibits a complex of proteins including axin, glycogen synthase kinase 3 (GSK-3) and adenomatous polyposis coli (APC)
93
Result of absence of Wnt singalling
Lead to phosphorylation of Beta-catenin which is degraded proteolytically.
94
Adding Wnt to the medial part of epiblast in experiment will
inhibit the formation of neural tisse
95
Adding Wnt to the lateral part of the epiblast will
no markers found
96
Addition of FGF to the medial explant
overrides the Wnt signalling and inhibts the formation of the neural tissue allowing the epidermis to continue to form
97
Addition of FGF to the lateral explant
no formation of neural tissue but the epidermis will develop
98
BMP inhibitor
Inhibits the formation of neural tissue
99
Neuroectoderm
Sheet that consists of neural cells. Cranial part of the ectoderm will form from the neural tube and form the brain and the spinal cord
100
Factors to consider when looking at neural patterning
Positional information and morphogens
101
Regionalisation...
involves long-range signalling that provides cells with information about their location in the neural epithelium. This information is known as positional information
102
Cells close to the source of cell
Very high levels of cell signalling
103
Cells far away from the source of cell
Very low levels of cell signalling
104
Signal that provokes more than one cellular response
Morphogen
105
