Brain Basics Flashcards
1
Q
anterior
A
in front
2
Q
posterior
A
behind
3
Q
superior
A
top
4
Q
inferior
A
below
5
Q
dorsal
A
back
6
Q
ventral
A
front
7
Q
caudal
A
tail
8
Q
rostral
A
beak
9
Q
number of neurons in brain
A
86 billion
10
Q
number of neurons in entire NS
A
100 billion
11
Q
structure of an axon
A
every neuron has an input area with multiple branches called dendrites
the cell body contains the nucleus
there is an axon (long projection) in which neural impulses travel down
synapses are where neurons form junctions with each other
12
Q
2 broad categories of neurons
A
sensory (afferent)
motor (efferent)
13
Q
afferent
A
sensory
14
Q
efferent
A
motor
15
Q
what are sensory neurons connected to and where do they travel?
A
connected to sensory cell or organ and travel towards the CNS
16
Q
what are motor neurons connected to and where do they travel?
A
innervate and synapse with muscles and travel away from CNS
17
Q
2 major branches of the NS
A
peripheral and central nervous system
18
Q
what is the CNS?
A
neural tissue in the brain, brainstem and spinal cord
19
Q
what is the PNS
A
outside the brain and spinal cord including the spinal and cranial nerves
20
Q
bundles of neurons in the PNS
A
nerves
21
Q
definition of nerve
A
bundles of neurons in the PNS
22
Q
definition of tracts
A
bundles of neurons in CNS
23
Q
bundles of neurons in CNS
A
tracts
24
Q
grey matter
A
neuronal cell bodies and neurones nuclei
25
white matter
myelinated axons
26
what is myelin and its function?
lipid rich tissue with a pale appearance that insulates the axon to allow electrical signals to travel larger distances without diminishing
27
where is white matter often found?
connecting areas of grey matter to target tissue or organ, or connecting areas of the brain
28
how is myelin produced in the PNS?
by Schwann cells
29
how is myelin produced in the CNS
by oligodendrocytes
30
white and grey matter areas in the brain
outer cortex is grey matter with central areas containing large amounts of connecting white matter tracts
31
white and grey matter areas in the spinal cord
central grey matter areas where synapses and connections take place on a horizontal plane
white matter tracts in outer parts of the cord
32
role of white matter tracts in the spinal cord
info travels up and down spinal cord in white mater tracts
33
collection of neuronal cell bodies in the CNS
ganglion
34
collection of neuronal cell bodies outside the CNS
nuclei
35
definition of nuclei
collection of neuronal cell bodies outside the CNS
36
definition of ganglion
collection of neuronal cell bodies in the CNS
37
what is the basal ganglia? what does it include?
several interconnected parts located deep in the brain
includes: caudate nucleus, putamen, globus pallidus, substantia nigra, nucleus accumbent, subthalamic nucleus
38
what do the parts of the basal ganglia rely on to function correctly to create coordinated smooth movements?
dopamine from the substantia nigra
39
role of basal ganglia
to create coordinated smooth movements
40
putamen and globus pallidus make up the...
lenticular nucleus (lentiform)
41
lenticular nucleus (lentiform)
putamen and globus pallidus
42
caudate nucleus and putamen make up the...
dorsal striatum
43
what makes up the dorsal striatum?
caudate nucleus and putamen
44
nucleus accumbens and olfactory tubicle make up the...
ventral stiatum
45
what makes up the ventral striatum?
nucleus accumbens and olfactory tubicle
46
why is the substantia nigra dark?
melanin
47
damage to the basal ganglia results in what?
○ Problems with initiating and control of movements
○ Tremors, posture difficulties, etc
○ Parkinson's (reduction in number of neurons of substantia nigra in midbrain - dopamine) and Huntingdon's (loss of neurons in caudate nucleus)
48
divisions of the autonomic NS
sympathetic and parasympathetic
49
role of ANS
self-regulates without conscious thought with its own autonomy
50
sympathetic NS actions
fight or flight
increase HR, breathing rate
51
parasympathetic NS actions
rest and digest
pupils constrict to accomodate near vision
52
where is the sympathetic NS?
exits the spinal cord at the thoracolumbar region using a chain of paravertebral ganglia to transverse the full length of the body - sympathetic chains
53
where is the parasympathetic NS?
either hitchhike along cranial nerves or exit the CNS at the sacral region to innervate the viscera of the pelvis - craniosacral
54
divisions of the brain
cerebrum - forebrain
cerebellum - little brain (hindbrain)
brainstem - (hindbrain)
55
cerebrum - explain the make up/divisions
2 hemispheres separated by longitudinal fissure
outer region is the neocortex for higher order functioning
internal white matter of forebrain.
hemispheres connected by corpus callous and anterior and posterior commissures
56
anterior commisure
nub at front of fornix
57
nub at front of fornix
anterior commisure
58
posterior commisure
nub in front of pineal gland
59
nub in front of pineal gland
posterior commisure
60
parts of the corpus callosum
- Genu is the knee (front bend)
- Body (middle part)
- Splendium/bandage (back bulb)
61
septum pellucidum
Between corpus callosum and fornix is the septum pellucidum
- Thin membrane separating lateral ventricles from each other and midbrain
62
what is between the fornix and corpus callosum?
septum pellucidum
63
Thalamus role
- Sensory filter in diencephalon
64
sensory info and the thalamus
- Sensory info through eyes to lateral geniculate nucleus through thalamus
- Inferior colliculi
○ Auditory info pass through medial geniculate nucleus of thalamus
- Not olfactory info
- Trigeminal nerve, cranial nerve go to thalamus
- Also connected to cerebellum, basal ganglia, limbic system, etc
65
diencephalon
made up of the thalamus, hypothalamus and epithalamus (inc. pineal gland)
part of the forebrain
relay station for sensory info towards brain (not olfactory)
66
role of brainstem
links spinal cord to cerebellum and cerebrum
all motor and sensory signals pass through the brainstem to reach their destinations
67
divisions of the brainstem
midbrain
pons
medulla oblongata
68
role of midbrain
reflexive or involuntary movements of the eyes, head, and body towards the direction of visual and auditory stimuli.
reticular formation
69
role of pons
filled with tracts passing up and down the CNS
nuclei for cranial nerves 5 6 and 7 are in dorsal part of pons
70
role of medulla oblongata
ventral part contains tracts (corticospinal tracts on ventral surface form the longitudinal ridges of the medullary pyramids)
tracts cross in the pyramids from one side of the body to the other
nuclei for cranial nerves 8, 9, 10, 11, and 12 are found in the dorsal parts
71
role of cerebellum
balance, proprioception, coordination
72
where is the cerebellum?
posterior cranial fossa of the skull
73
Corpora quadrigemina
2 nubs in front of each hemisphere of cerebellum (in the midbrain)
- 2 superior colliculi (visual system and movements)
- 2 inferior colliculi (auditory system and vestibular system)
74
how is the cerebellum connected to the brainstem?
- 3 pairs of peduncles (white matter) connect cerebellum to brainstem
○ Superior - midbrain
○ Middle - pons
○ Inferior - medulla oblongata
75
what surrounds the cerebellum?
dura mater
76
what separates the cereberum and cerebellum?
- Tentorium cerebelli
○ 2 sheets of dura mater separating from cerebrum
77
divisions of the cerebellum
- From mid to outside: vermis, medial and lateral zones
- Anterior, posterior and folloculo lobes
○ Anterior and posterior separated by primary fissure
○ Postero-lateral fissure separates body (A and P) and folloculo lobe
78
blood supply to the cerebellum
- 3 pairs of arteries supplying blood to cerebellum
○ Posterior, inferior cerebellar arteries - branch from vertebral arteries. Before basilar artery
○ Anterior, inferior cerebellar arteries - from basilar artery (labyrinthe artery branches from internal auditory)
○ Superior cerebellar arteries - from basilar artery just before the end - right next to posterior cerebral arteries
79
olive
medulla oblongata
Olive --> olivary nuclei (movement, auditory)
80
central sulcus
- Central sulcus separates frontal and parietal lobes
81
lateral sulcus
- Lateral sulcus separates parietal and temporal and temporal and frontal lobes
82
Pareto-occipital sulcus
- Parieto-occipital sulcus separates the parietal and occipital lobes
83
sulcus between frontal and parietal
central
84
sulcus between parietal and occipital
parieto-occipital
85
sulcu between parietal and temporal and temporal and frontal lobes
lateral
86
cortex anterior of central sulcus
premotor cortex
87
premotor cortex location
cortex anterior of central sulcus
88
cortex posterior of central sulcus
somatosensory cortex
89
somatosensory cortex location
cortex posterior of central sulcus
90
lobes of the brain
frontal
parietal
occipital
temporal
limbic lobe - central lobe where limbic system is
91
gyri
ridges
92
sulci
depressions
93
role of frontal lobe
movement
decision making
emotions
94
role of parietal lobe
sensation
95
role of occipital lobe
vision
96
role of temporal lobe
memory
language
hearing
97
spinal cord length and location
continuation of the medulla oblongata through the foramen magnum in the occipital bone to the L1 or L2 vertebra ending in the conus medullaris
42-45cm long
98
spinal cord forms what after the L1/L2 region?
cauda equina
99
ventral/anterior horns - role/what leaves here
give rise to motor neurons leaving spinal cord in ventral roots
100
dorsal horns - role
receive sensory info from afferent neurons arriving in through dorsal root ganglion
101
dorsal and ventral roots/horns merge to form what?
the spinal nerve
102
rootlets
leave the spinal cord to form roots (form bilateral pairs of spinal nerves in a designated spinal cord segment)
103
once the rootlets join to form roots, the nerve divides to make what?
anterior and posterior rami (contain sensory and motor fibres)
104
how many layers of meninges?
3
105
layers of meninges
dura mater
arachnoid mater
pia mater
106
pia mater
thin direct covering of gyri and sulk (inner layer)
107
arachnoid mater
web like middle layer
108
space between arachnoid and Pia mater layers
subarachnoid space
109
what is contained in the subarachnoid space?
arteries and veins
CSF
110
dura mater
tough outer layer lining the bones of the cranial cavity
111
how many layers in dura mater?
2
112
sagittal fold between the hemispheres
falx cerebri
113
falx cerebri
sagittal fold between the hemispheres
114
inferior part of the falx cerebra between the two parts of the cerebellum
falx cerebelli
115
inferior part of the falx cerebra between the two parts of the cerebellum
falx cerebelli
116
horizontal fold between the cerebrum and the cerebellum
tentorium cerebelli
117
tentorium cerebelli
horizontal fold between the cerebrum and the cerebellum
118
- Diphragma sella
covers sella turcica with pituitary gland inside
119
infoldings of the dura contain...
dural venous sinuses
120
where are the venous sinuses
between the two layers of dura mater
121
role of venous sinuses
drain blood from brain
122
how does the blood drains by the venous sinuses return to circulation
via internal jugular vein
123
main venous sinuses
- Superior sagittal
- Inferior sagittal
- Straight sinus
- Transverse sinus
- Sigmoid sinus
- Cavernous sinus
- Superior and inferior petrosal sinus
124
divisions of the blood supply to the brain
anterior and posterior circulation
125
anterior circulation is provided via the...
internal carotid arteries
126
the internal carotid arteries supply what part of the circulation
anterior
127
route of posterior circulation
initially formed from left and right vertebral arteries which merge to form the basilar artery as they pass through the foramen magnum
circle of willis is formed as the posterior communicating arteries branch from each cerebral artery off the basilar artery. these connect to the middle cerebral artery and then the anterior communicating artery
referred to as the vertebrobasilar system
128
fucntion of anterior circulation
anterior communicating artery (disinhibition, aphasia, apraxia, legs)
middle communicating artery (face, limbs, speech)
129
function of posterior circulation
posterior communicating artery
occipital lobe (vision)
cerebella signs
brainstem signs
130
brain is surrounded by what?
CSF
131
where is CSF found?
between pia mater and arachnoid mater is subarachnoid space
132
what produces CSF?
ependymal cells of the choroid plexus produce CSF
133
where is CSF made?
mainly lateral ventricles
134
how many ventricles are there?
4
135
ventricles of the brain
2 lateral ventricles
3rd
4th
136
role of interventricular foramen
allows CSF to flow from lateral ventricles into 3rd ventricle
137
cerebral aqueduct
links 3rd and 4th centricles
138
where can CSF leave?
4th ventricle to arachnoids layer (via lateral and medial aperture to the cisterns)
139
where does CSF return to and how?
returns to the dural venous sinuses through arachnoid granulations
140
disruption to flow of CSF causes what?
hydrocephalus
141
hydrocephalus
result of disruption to flow of CSF
142
role of CSF
shock absorber, buoyancy, immune function etc.
143
production of CSF
Produced by choroid plexus (20ml an hour - 150ml in CNS)
144
2 layers of the dura mater
periostial layer = outer layer
meningial layer = inner layer
145
space below the fornix
third ventricle (in midline of the brain) below pineal gland
146
cistern
CSF filled space
