Neuro Anatomy review Flashcards
1
Q
What is part of the CNS?
A
Brain
Spinal Cord
2
Q
What is part of the PNS?
A
CN and branches
Spinal nerve and branches
3
Q
What are extensions off of the soma, whose role is to basically receive any and all information coming that neuron’s way?
A
Dendrites
4
Q
How do dendrites receive signals from other neurons?
A
by binding to neurotransmitters released from neighboring neurons
5
Q
The signals received by the binding of neurotransmitters are interpreted where?
A
Soma (cell body)
6
Q
Soma sends the now organized signal inputs straight to where, which is at the start of the neuron’s axon?
A
Axon hillock
7
Q
What acts both as an insulator but most importantly as a conductor, it significantly increases the speed at which the action potential runs down the axon?
A
myelon sheath
8
Q
With myelin present, how does that AP travel down the axon terminal?
A
AP jumps down the axon via the nodes of Ranvier
9
Q
Role of oligodendrocytes?
A
production and maintenance of myelin
10
Q
PNS equivalent to oligodendrocytes?
A
Schwann Cells
11
Q
1 schwann cell creates how many myelin?
A
one area on one axon
12
Q
1 oligodendrocytes creates how many myelin?
A
produce dozens of myelin internodes on multiple axons
13
Q
Role of astrocytes? (3)
A
- Support cells
1. repair damage
2. regulate communication between neurons
3. maintenance of our blood brain barrier, which keeps toxic substances that may be circulating the blood stream from entering our brain
14
Q
Role of ependymal cells?
A
- Line ventricle walls
2. Produce CSF
15
Q
Role of microglia?
A
“Macrophages of the CNS” - remove foreign bodies
16
Q
normal resting potential -
A
-70mV
17
Q
Graded potential -
A
up to 15 mV
18
Q
Depolarization -
A
positive charge = excites
19
Q
Hyperpolarization -
A
negative charge = inhibits
20
Q
Where is the electrical signal (graded potential) created in the neuron?
A
Axon hillock
21
Q
T/F 1 Graded potential is not enough to do anything.
A
True, little potentials start adding up
22
Q
What is the threshold for a neuron?
A
-55mV - Hit that threshold, and an action potential is formed that travels down the axon
23
Q
Signal conduction if dependent on what 3 things?
A
- Fiber diameter (bigger the axon the more it can hold)
- Presence of myelin
- Thickness of myelin
24
Q
How are axons graded by conduction velocity?
A
Type A, B, C from fastest to slowest
25
How are axons graded by fiber diameter?
Type I, II, III, IV from biggest to smallest
26
A/Ia =
- proprioception, stretch
- primary muscle spindle afferents
- motor efferents to extrafusal muscle
27
A/Ib =
Golgi tendon organ afferents - contractile tension
28
Ab/II =
- Mechanoreceptors: discriminative touch, pressure, joint rotation
- Secondary muscle spindle afferents (static muscle length)
29
Ay/II =
- Motor efferents to muscle spindle intrafusal fibers
30
Ad/III =
- Mechanoreception: touch
| - Nociception: discriminative pain
31
B =
Autonomic preganglionic axons
32
C/IV =
- Nociception: inflammatory/visceral pain, thermal
| - Autonomic postganglionic axons
33
Somatic nervous system -
- Voluntary movement
| - spinal and CN
34
Autonomic NS -
- Involuntary control or autonomic processes
| - Sympathetic and para
35
How many pairs of spinal nerves?
31:
| 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal
36
Glutamate is what type of NT?
Excitatory
37
Gaba is what type of NT?
Inhibitory
38
Driving NT at the neuromuscular junction (NMJ)?
ACh
39
Motor unit -
motor neuron and the skeletal muscle fibers innervated by that motor neuron's axonal terminals.
40
What is the postsynaptic target at the NMJ?
Motor end plate (muscle spindle)
41
Physical response during sympathetic (fight or flight) response?
Pupil dilation
Increased HR and BP
Blood vessel constriction to non-essential organs
Blood vessel dilation to essential organs
Stimulate liver glycogenolysis, and adipose lipolysis
Inhibit non essential body functions
42
Physical response during parasympathetic (rest and digest) response?
Pupil constriction
Increase salivation, lacrimation, urination, digestion, defecation
Decreased HR and BP
Decrease airway diameter
43
Monosynaptic reflexes involve what type of connections?
direct connections between sensory neurons and motor neurons, without any need for neurons in between
ex: spinal reflexes
44
Spinal reflexes -
- Monosynaptic reflex (DTR)
- normal muscle tone and mediate a number of simple motor responses
- reflex arcs that occur at the level of the spinal cord, without any involvement of the brain
- The brain receives information about the movement after it has been initiated
45
Polysynaptic reflexes -
- use INTERNEURONS to pass signals from sensory to motor neurons, creating multiple synaptic connections
ex: withdrawal stimulus
46
withdrawal stimulus -
painful stimulus detected by nociceptors -> afferent to spinal cord:
1. excites a motor neuron that activates the flexors to pull the limb away
2. another to inhibit the extensors to let that happen
3. contralateral excitation to extensors to help the opposite limb brace for the withdrawal
4. inhibition of contralateral flexion
47
What occurs to reflex arc when we lose descending inhibition?
hyperreflexia
48
Protective layers of the cns:
```
epidural space
dura mater
subdural space
arachnoid mater
subarachnoid space
pia mater
```
49
The vertebral artery supplies circulation where (generally)?
posterior circulation
50
Common carotid (interior) supplies circulation where (generally)?
anterior circulation
51
Anterior blood supply includes these branches off internal carotid:
1. Ophthalmic
2. Anterior choroidal
3. Posterior communicating
4. Middle cerebral
- lenticulostriate
5. Anterior cerebral
- anterior communicating
52
Posterior blood supply includes these branches off the vertebral artery:
1. Anterior Spinal Arteries
2. Posterior Inferior Cerebellar Arteries
3. Posterior Spinal Arteries
53
Posterior blood supply includes these branches off the basilar artery:
1. Anterior Inferior Cerebellar Arteries
2. Labyrinthine Arteries
3. Pontine Arteries
4. Superior Cerebellar Arteries
5. Posterior Cerebral Arteries
54
Circle of willis includes what 4 arteries?
Anterior Communicating Artery
Anterior Cerebral Arteries
Posterior Communicating Arteries
Posterior Cerebral Arteries
55
Anterior cerebral artery travels along where in the brain and innervates what?
1. Longitudinal fissure above corpus callosum (connection between right and left hemi) -> medial aspect of frontal and parietal lobes (usually medial sensorimotor cortex
2. Deeper branches to basal nucleus & limbic regions
56
Middle cerebral artery innervates what parts of the brain?
1. Lateral frontal lobe
2. Lateral parietal lobe
3. Lateral occipital lobe
4. Medial and lateral temporal lobe
5. Insula
6. Subcortical structures (via lenticulostriate)
- Basal ganglia
- Internal capsule
- Limbic structures
57
Posterior cerebral artery innervates what parts of the brain?
1. Cortex
- Medial and inferior occipital lobe
- Inferior temporal lobe
2. Subcortical structures
- Midbrain
- Subthalamus
- Thalamus
58
The blood supply to brainstem structures arise from where?
Vertebrobasilar system
59
Ventral spinal cord supplied by what artery that arises from where?
1 Anterior spinal artery off vertebral arteries
60
Dorsal spinal cord supplied by what artery that arises from where?
2 Posterior spinal arteries off vertebral (or PICA, depending on level)
61
Cerebrospinal fluid created where by what type of cells?
created in choroid plexus by ependymal cells
62
Functions of CSF?
Buoyancy
Protection
Homeostasis
Waste clearance
63
Lateral ventricles are located where?
cerebral hemispheres
1. Anterior horn in frontal lobe
2. Posterior horn occipital
3. Inferior horn temporal
64
3rd ventricle is located where?
thalamus
65
4th ventricle is located where?
Within the pons, medulla and base of cerebrum
66
General function of frontal lobe?
- Higher executive functions including emotional regulation, planning, reasoning, attention, and problem solving
- Primary and Supplementary Motor Regions
- Supplementary Speech Regions (dominant)
67
General function of parietal lobe?
Primary and Supplementary Somatosensory Regions
Perceptual integration (non-dominant)
Visual processing regions (“Where?”)
Supplementary Speech Regions (dominant)
68
General function of temporal lobe?
Primary Auditory Center
Visual processing regions (“What?”)
Memory
69
General function of occipital lobe?
Primary visual center
70
Unimodal sensory association cortices -
receives its predominant input from the primary sensory cortex of a specific sensory modality and performs higher-order sensory processes for that modality
71
heteromodal association cortex -
BIDIRECTIONAL CONNECTIONS with BOTH motor and sensory association cortices for all modalities
- found in frontal lobes and at parieto-occipitotemporal junctions
72
Superior colliculi found where in brainstem? Role?
Midbrain
- receive information from the environment and then use that information to initiate a behavioral response appropriate to the current environmental context
73
Inferior colliculi found where in brainstem? Role?
Midbrain
- Hearing
- Largest nucleus of the auditory system
- All auditory pathways traveling through the brainstem converge
74
Red nucleus found where in brainstem? Role?
Midbrain
| - motor function and coordination.
75
Raphe nuclei found where in brainstem? Role?
midbrain
| - serotonin production
76
Ventral tegmentum area found where in brainstem? Role?
midbrain
| - dopamine production
77
T/F Most vertical tracts continue unchanged through the pons
True, except corticopontine and some corticobrainstem tracts synapse in pons.
78
Medulla plays crucial role in what?
regulation of cardiovascular (baroreceptors) and respiratory functions (chemoreceptors)
79
Path of information about bp changes:
baroreceptors -> medulla -> nucleus of solitary tract -> bp changes
80
Path of information about O2/CO2 changes:
chemoreceptors -> medulla -> NST and NA (nucleus ambigous) -> change in respiration
81
Pyramidal decussation found where in brainstem? Role?
Medulla
| - 90% of corticospinal tracts cross here
82
Inferior olivary nuclei found where in brainstem? Role?
Medulla
| - connect to cerebellum and are involved in movement generation
83
Reticular formation -
- through entire length of brainstem
| - role in promoting arousal and consciousness
84
reticular activating system (RAS) associated with what NT?
acetylcholine and norepinephrine
85
T/F Nearly all afferent pathways that project to the cerebral cortex do so via synaptic relays in the thalamus
True
86
Thalamus acts as important relay and processing station for what type of information?
Major sensory relay station
Motor inputs from cerebellum and basal ganglia
Limbic inputs
Reticular inputs
87
Function of Lateral corticospinal tract -
Motor function of contralateral extremities
88
Function of anterior corticospinal tract -
Motor function of bilateral axial and girdle muscles
89
Rubrospinal tract originates where? describe pathway
red nucleus of midbrain -> decussates -> descend in lateral aspect of spinal cord
90
Function of rubrospinal tract -
Motor function and tone regulation of contralateral extremities, particularly flexor muscle groups*
91
Function of vestibulospinal tract -
Medial VST
Lateral VST
Medial VST - Positioning of head/neck
| Lateral VST - Trunk control/balance
92
Where does the reticulospinal tract originate?
reticular formation
93
Function of reticulospinal tract -
medial RST -
Lateral RST -
Automatic posture and gait-related movements
Medial RST: Axial and extensor motor neurons, postural support
Lateral RST: Flexor motor neurons
94
Structures of the basal ganglia:
1. striatum (made up of the caudate and putamen)
2. globus pallidus
3. substantia nigra
4. subthalamc nucleus
95
Basal ganglia role -
regulation of UMN circuits and facilitating movements
96
T/F Nearly all regions of the cerebral cortex project directly into the striatum, making the cortex the source of the largest input to the basal ganglia
True
97
Globus pallidus and substantia nigra role -
- main output centers of the BG
- send projections out from the BG back to the cerebral cortex, usually by way of the thalamus
- also send projections to nuclei in the brainstem
98
Role of basal ganglia in general:
1. INITIATION and EXECUTION of movement
2. Prevention of unwanted movement
as well as
3. Goal-directed behavior loop
4. Social behavior loop
5. Emotion loop
99
anterior (spinocerebellum) lobe of the cerebellum:
- receives spinal cord afferents
| - functions in controlling axial muscle tone; degree of flexion and extension
100
posterior (cerebrocerebellum) lobe of the cerebellum:
- input and output to the cerebral cortex
101
flocculonodular (vestibulocerebellum) lobe of the cerebellum:
- receives vestibular and visual information
| - it is involved with balance, vestibular reflexes, and eye movements
102
Roles of cerebellum in general:
1. Coordination - Limb, trunk, oculomotor
2. Movement planning, control & feedback
3. Motor learning
4. Postural Control/Balance
5. VOR Suppression (balance)
6. Muscle tone
103
Function of hypothalamus:
HEAL
1. Homeostasis
2. Endocrine control via pituitary gland
3. Autonomic Control
4. Limbic Mechanisms
104
Function of limbic system:
HOME
1. Homeostasis - hypothalamus
2. Olfaction - olfactory cortex
3. Memory - hippocampal formation
4. Emotions and drives - amygdala
105
Primary blood supply of limbic system?
ACA
106
Afferent input to limbic system (4):
1. special senses, olfaction, taste, vision, auditory via entorhinal cortex
2. reticular formation monoamine neuronal projections
3. hypothalamus feedback connections
4. thalamus
107
Efferent output to limbic system (4):
1. thalamus
2. hypothalamus: mammillary bodies, medial hypothalamus
3. cerebral cortex
4. periaquiductal gray
108
2 otolith organs:
1. utricle
| 2. saccule
109
3 semicircular canals:
Anterior
posterior
horizontal
110
Vestibular nuclei receive inputs from where?
from ipsilateral and contralateral vestibular nuclei, cerebellum, visual and somatic sensory inputs
111
VOR -
keeps eyes forward as the head moves around
112
VSR -
Anti-Gravity Muscles - mediating our postural adjustments
113
VCR -
Upper cervical muscles - control our Head & neck relationship in concern to the rest of the body
