Structural Neuroanatomy Flashcards
1
Q
what are the 3 parts of NEUROANATOMY?
A
- layout & directions (nervous system)
- divisions of the brain
- cells & neurotransmitters
2
Q
what are the 2 VERTEBRATE nervous systems?
A
- peripheral nervous sytem (PNS)
- central nervous system (CNS)
3
Q
what are the 2 divisions of the PERIPHERAL NS (PNS)?
A
- somatic NS
- autonomic NS
4
Q
what is the SOMATIC NS (SNS)?
A
- interacts w/ external environment
- afferent nerves, carry sensory signals from skin, muscles, eyes, ears, etc to CNS
- efferent nerves carry motor signals from CNS to muscles (perform actions)
5
Q
what is the AUTONOMIC NS (ANS)?
A
- regulation of internal environment
- afferent nerves, carry sensory signals from internal organs to CNS
- efferent nerves carry motor signals from CNS to internal organs
6
Q
what are the 2 systems the AUTONOMIC NS (ANS) can be split into?
A
- Sympathetic NS
- Parasympathetic NS
7
Q
what does the SYMPATHETIC NS do?
A
mobilize energy in threatening situation (ie. via adrenal glands, inc heart rate)
8
Q
what does the PARASYMPATHETIC NS do?
A
act to conserve energy or “rest & digest” (ie. stimulate gut motility, slow heart rate)
9
Q
describe the spinal cord structure
A
centre H-shaped core of grey matter (cell bodies & unmyelinated axons) & surrounding white matter (myelinated axons)
10
Q
in CNS, what is a cluster of cell bodies called?
A
nucleus
11
Q
in CNS, what is a bundle of axons called?
A
tract
12
Q
in PNS, what is a cluster of cell bodies called?
A
ganglion
13
Q
in PNS, what is a bundle of axons called?
A
nerve fibres
14
Q
what is gray matter made up of?
A
cell bodies & capillary blood vessels (outer surface of brain)
15
Q
what is white matter made up of?
A
myelinated axons (inner layer of brain)
16
Q
point to DORSAL direction of brain
A
top of head
17
Q
point to DORSAL direction of spine
A
towards back
18
Q
point to VENTRAL direction of brain
A
chin
19
Q
point to VENTRAL direction of spine
A
chest
20
Q
point to ROSTRAL/ANTERIOR direction of brain
A
forehead
21
Q
point to CAUDAL/POSTERIOR direction of brain
A
back of head
22
Q
point to ROSTRAL direction of spine
A
up the spine towards head
23
Q
point to CAUDAL direction of spine
A
down spine towards “tail”
24
Q
point to MEDIAL and move LATERAL
A
start at centre of head & move outwards
25
draw the HORIZONTAL plane of a head scan
slice horizontally from nose to back of head
26
draw CORONAL plane of head scan
slice from top of head to chin from the side
27
draw SAGITTAL plane of head scan
slice vertically from nose to side of head
28
what is unilateral?
on 1 side
29
what is bilateral?
on both sides
30
what is ipsilateral?
on the same side (injury on right side, paralysis on right side)
31
what is contralateral?
on opposite sides (injury on right side, paralysis on left side)
32
what are the 3 divisions of the brain present in a 18-21 day old human embryo?
forebrain, midbrain, hindbrain
33
what are the 5 structures in the brainstem?
Telencephalon, Diencephalon, Mesencephalon, Metencephalon, Myelencephalon
34
what is the myelencephalon (aka medulla)?
composed of tracts carrying signals b/w rest of brain & body, has lots of myelin helps transmit info quickly
35
what is the metencephalon?
made up of pons & cerebellum
36
what is pons?
houses many fibre tracts, part of reticular formation
37
what is cerebellum?
50% of all neurons in the brain, connected to cortex, involved in movement & timing
38
what is mesencephalon?
composed of the tectum (roof) & tegmentum (floor)
39
what is the tectum?
mesencephalon, "roof" contains nuclei that receive & relay visual info (superior colliculi) and auditory info (inferior colliculi)
40
what is the tegmentum?
mesencephalon, "floor' contains nuclei related to motor function (substantia nigra & red nucleus) & pain (periaqueductal grey)
41
what is reticular formation?
in midbrain & hindbrain, many nuclei that plays role in arousal, attention, cardiac/respiratory reflexes & other jobs
42
what is the dejerine syndrome (disorder midbrain & hindbrain)?
bilateral medial medullary stroke
- respiratory failure
- paralysis of all 4 limbs
- tongue dysfunction
43
what is the chiari malformation (disorder midbrain & hindbrain)?
compression & distortion of cerebellum due to skull shape
- headache
- neck pain
- coordination issues
- swallowing issues
44
what is pontine tegmental cap dysplasia (disorder midbrain & hindbrain)?
rare genetic disorder of pons & cerebellum formation due to developmental error in axon growth & guidance
- abnormal gaze, swallowing, facial movements
45
what is the diencephalon composed of?
thalamus & hypothalamus
46
what is the thalamus?
2 lobed structure, many different types of nuclei (some process & relay info b/w receptors & cortex)
- nuclei may be specific to 1 sense or non-specific & involved in multimodal integration
47
what does abnormal synchronization in thalamo-cortical network cause?
absense seizures (thalamus involved w/ consciousness)
48
what is the hypothalamus?
role in feeding, sex, sleeping, temperature, emotion, movement
- act upon body's endocrine (hormone) system via pituitary gland
49
what is the telencephalon?
largest division of the brain (wrinkly area)
- basal ganglia
- limbic system
- cerebral cortex
50
what is the basal ganglia (telencephalon)?
collection of nuclei highly connected to cortex, thalamus & midbrain
- involved movement & learning
51
what is the limbic system (telencephalon)?
includes hippocampus (spatial memory) & amygdala (emotion)
52
what is the cortex?
highly folded/convoluted to inc surface area while fit inside skull
53
what are fissures?
sulci (bottom of fold) deep enough to indent the ventricles
- gyrus (top of fold)
54
__ % of human cerebral cortex is ISOCORTEX = 6-layered
90
55
__ % of human cerebral cortex is ALLOCORTEX <6 layers
10
56
what is lissencephaly (disorder in cerebral cortex)?
when cells don't migrate normally during develpment, folding is interrupted
- seizures, muscle spasms, developmental delays, difficulty swallowing/eating
- most don't live past 10yo
57
what are cerebral commissures & what is the largest?
tracts that connect the cerebral hemispheres, corpus callosum
58
what are the 4 cortical lobes?
frontal lobe, parietal lobe, temporal lobe, occipital lobe
59
what is the longitudinal fissure?
divides the left & right hemisphere of the brain
60
what is the central sulcus fissure?
divides frontal & parietal lobe
61
what is the lateral sulcus fissure?
divides frontal & temporal lobe
62
what fluid to ventricles contain?
cerebrospinal fluid
63
what are the 3 purposes of cerebrospinal fluid (CSF)?
1. buoyancy (brain floats in fluid, reducing weight)
2. protection (prevents brain hitting skull)
3. chemical stability (bring in nutrience & remove waste, maintain hormone & pH level)
64
do we only use 10% of our brains?
no
65
what are the 2 broad categories of cells in nervous system?
neurons & glia
66
what are the parts of a neuron?
nucleus, cell body, dendrites, axon
67
what is the difference b/w dendrites & axons?
dendrites are contacted by other neurons, axons contact other cells
68
what is unipolar (processes = axons + dendrites)?
1 process leaves cell body
69
what is bipolar (processes = axons + dendrites)?
2 processes leave cell body
70
what is multipolar (processes = axons + dendrites)?
3+ processes extend from cell body
71
what is interneuron (processes = axons + dendrites)?
no axon/short axon
72
molecules & ions cross into/out of neurons via...
1. passive diffusion (fat soluble molecules)
2. facilitated diffusion through channels
3. active transport, requires energy, through pumps
73
what is the resting membrane potential (voltage) of a healthy neuron?
-60mV to -80mV (change as Na+ and K+ move in/out of cell)
74
how many sodium/potassium move in/out to maintain resting potential?
3 Na+ out = 2 K+ in
75
if charge in membrane exceeds ___ mV, neuron fires a ____
-55mV, action potential
76
why does charge across membrane change to begin with?
stimulus in sensory cell OR neurotransmitters communicating b/w neurons
77
what is the synapse?
small, active gap b/w 2 neurons
78
what is the presynaptic neuron?
the neuron sending the signal
79
what is the postsynaptic neuron?
the neuron receiving the signal
80
neurotransmitters can be...
1. excitatory (make receiving more likely to fire action potential)
2. inhibitory (make receiving less likely to fire action potential)
3. modulatory (trigger other changes)
81
what are drugs as an agonist?
turning on receptor & activating its effects (ie. methadone - stimulates opioid receptors)
82
what are drugs as an antagonist?
blocking receptor from being turned on (ie. narcan - prevents overdose)
83
how do neurotransmitters "clean up"/ remove neurotransmitters from synapse?
1. diffuse away
2. broken down by enzymes
3. reuptake (by presynaptic neuron, by glia)
84
serotonin & norepinphrine are _____ used to treat ___,___,____
neurotransmitters, depression, anxiety, pain
85
what is glia?
sticky, 10x more numerous than neurons (10glia = 1 neuron)
86
what is oligodendroglia?
glia cell, wrap around axons of neurons in CNS, forming MANY myelin sheaths per cell
87
what is schwann cells?
glia cell, wrap around axons of neurons in PNS, forming ONE myelin sheath per cell
88
what is microglia?
glia cell, respond to injury & disease, triggering immune response, only CNS
89
what is astroglia?
largest glial cell
- support blood brain barrier
- maintain ion balance in CNS
- repair after injury
- communicate w/ neurons & glia
- control & maintain synapses
- only CNS
90
what is the blood-brain barrier?
protect brain by filtering blood, active transport for large molecules
91
glia likely play an ______ role in many neurological conditions given their ____ & ____ roles
underestimated, immune, "clean-up"
92
