Exam 2 Flashcards
(181 cards)
1
Q
what ions are higher in concentration intracellularly?
A
potassium, negatively charged organic molecules
2
Q
what ions are higher in concentration extracellularly?
A
sodium
3
Q
what is the charge of a neuron?
A
none, they are electrically neutral
4
Q
depolarization
A
potential difference is reduced. intracellular environment becomes more positive
5
Q
repolarization
A
return to resting membrane potential. intracellular become more negative
6
Q
hyperpolarization
A
intracellular more negative than resting membrane potential
7
Q
what is resting membrane potential?
A
-55mV
8
Q
what is another name for resting membrane potential?
A
threshold value
9
Q
what causes an action potential?
A
the influx of sodium
10
Q
what type of transport does depolarization and repolarization occur via?
A
diffusion
11
Q
what occurs after action potential?
A
Na+/K+ pump (ATPase pump)
12
Q
what is the most positive the amplitude during depolarization will get?
A
30-40mV
13
Q
absolute refractory period
A
axon membrane is incapable of producing another action potential
14
Q
relative refractory period
A
axon membrane can produce another action potential, but requires stronger stimulus
15
Q
what channel opens during absolute refractory period?
A
Na+
16
Q
what channel opens during relative refractory period?
A
K+
17
Q
low frequency action potential will yield what kind of stimulus?
A
a weaker stimulus
18
Q
high frequency action potential will yield what kind of stimulus?
A
a stronger stimulus
19
Q
recruitment
A
when stronger stimuli activate more axons with a higher threshold
20
Q
saltatory conduction
A
the process where electrical impulses jump between nodes of ranvier along a myelinated axon. fast rate of conduction
21
Q
synapse
A
functional connection between a neuron and another neuron or effector cell
22
Q
electrical synapse
A
broad effect. impulses can be regenerated w/o interruption in adjacent cells
23
Q
electrical synapse gap junctions
A
adjacent cells electrically coupled through a channel
24
Q
chemical synapse
A
specific effect. neurotransmitters are released within axon causing synaptic vesicles to fuse w/axon membrane + release NTs to cleft by exocytosis
25
excitatory postsynaptic potential (EPSP)
NT w/excitatory effects
26
example of an EPSP
glutamate, acetylcholine
27
inhibitory postsynaptic potential (IPSP)
NT w/inhibitory effects. inhibits reciprocal muscles from firing
28
example of IPSP
GABA
29
what electrical effect occurs during EPSP?
depolarization
30
what electrical effect occurs during IPSP?
hyperpolarization
31
lateral ventricles
paired c-shaped chambers in each hemisphere
32
what separates the anterior horns of the lateral ventricles?
the septum pellucidum
33
what is the roof of the anterior horn of lateral ventricles?
corpus callosum
34
what is the floor of the anterior horn of lateral ventricles?
superior thalamus + caudate nucleus (basal ganglia)
35
what is the floor of the inferior horn of the lateral ventricles?
hippocampus
36
what are the 3 horns in the lateral ventricles?
anterior (frontal), posterior (occipital), + inferior (temporal)
37
what is the atrium of the lateral ventricles?
triangular cavity where the body, posterior, and inferior horns communicate
38
what is another name for the atrium?
trigone
39
what allows communication and flow of CSF between the lateral ventricles and 3rd ventricle?
intraventricular foramen of monro
40
where is the 3rd ventricle located?
middle space between the thalamus + hypothalamus
41
superior border of the 3rd ventricle?
fornix
42
anterior border of the 3rd ventricle?
lamina terminalis + anterior commissure
43
floor of the 3rd ventricle?
infundibulum + optic chiasm
44
posterior wall of the 3rd ventricle?
pineal wall
45
lateral border of the 3rd ventricle?
medial nuclei of thalami
46
what are the 3rd ventricle recesses?
infundibular, supraoptic, pineal, suprapineal
47
what connects the 3rd to the 4th ventricle?
cerebral or mesencephalic aqueduct
48
what is another name for the cerebral aqueduct?
aqueduct of sylvius
49
what is the inferior portion of the 4th ventricle called?
obex
50
what does the obex connect?
the central canal of the spinal cord and the 4th ventricle
51
anterior border of the 4th ventricle?
rhomboid fossa
52
posterior border of the 4th ventricle?
cerebellar peduncles + superior/inferior medullary velum
53
lateral walls of the 4th ventricle?
cerebellar peduncles
54
how does the 4th ventricle communicate with the subarachnoid spaces?
medial foramen of magendie + lateral foramen of luschka
55
ependyma
thin, neuroepithelial lining of the ventricles and central canal of the spinal cord
56
choroid plexus
produces CSF + barrier between blood and CSF
57
function of CSF
provide cushion to protect the brain, drainage of cerebral metabolites, + regulate cerebral blood flow
58
CSF volume
150mL
59
CSF components
99.13% water + .87% organic/inorganic substances
60
flow of CSF
lateral ventricles > interventricular foramen > 3rd ventricle > cerebral aqueduct > 4th ventricle > subarachnoid space > cisterna magna > arachnoid villi > dural venous sinuses
61
where does CSF drain into?
subarachnoid space
62
where is the subarachnoid cistern located?
63
cisterns
compartments within the subarachnoid space where the pia mater + arachnoid membrane are not close
64
arachnoid villi function
return CSF to venous circulation through the dural venous sinus
65
dural venous sinuses
large valveless venous channels that drain venous blood from cranial cavity
66
where are dural venous sinuses located?
periosteal dura + meningeal dura
67
function of dural venous sinuses
maintain systemic circulation by collectively returning deoxygenated blood from the cranial vault
68
cerebral + cerebellar veins
cross subdural space to drain into the superior sagittal vein
69
emissary veins
venous structures that allow communication between intracranial + extracranial vessels
70
diploic veins
intraosseous venous vessels that drain blood between the inner + outer layer flat bones of the skull
71
meningeal veins
collect blood from the meninges + drain
72
arachnoid granulations
CSF returning to the venous circulation
73
superior sagittal sinus location
base of the falx cerebri + runs from the foramen cecum to occipital protuberance
74
what is the superior sagittal sinus function?
main location for CSF return after passing arachnoid granulations
75
inferior sagittal sinus location
free margin of the falx cerebri
76
inferior sagittal sinus function
collects blood from the falx + medial surfaces of brain hemispheres
77
where does the inferior sagittal sinus drain?
straight sinus
78
straight sinus location
within the posterior end of falx cerebri + middle of tentorium cerebelli
79
straight sinus function
drains the cerebellum, thalamus, + basal ganglia
80
confluence of sinuses
site of union for the superior sagittal sinus, straight sinus, occipital sinus, + transverse sinus
81
transverse sinus
paired. drains the blood from the veins of the cerebellum + inferior surface of brain
82
where does the transverse sinus receive blood from?
superior petrosal sinus
83
where does the sigmoid sinus drain into?
paired. drains into the internal jugular vein
84
where does the sigmoid sinus begin?
after the tentorium cerebelli ends
85
cavernous sinus function
drains the anterior/inferior surface of the brain
86
cavernous sinus location
either side of the sella turcica + body of the sphenoid bone
87
contents of cavernous sinus
oculomotor n (CN III), troclear n (CN IV), abducens n (CN VI), trigeminal ophthalmic branch, trigeminal maxillary branch, internal carotid artery
88
what can cause cavernous sinus syndrome?
mass effect from tumor, infection, or thrombus
89
pituitary adenoma
most common benign brain tumor in adults (10%)
90
superior petrosal sinus location
petrous part of the temporal bone in the base of tentorium cerebelloi
91
superior petrosal sinus function
drains the venous blood from the brainstem, temporal lobe of cerebrum, cerebellum, middle + inner ear
92
what is CN I?
olfactory
93
what is CN II?
optic
94
what is CN III?
oculomotor
95
what is CN IV?
trochlear
96
what is CN V?
trigeminal
97
what is CN VI?
abducens
98
what is CN VII?
facial
99
what is CN VIII?
vestibulocochlear
100
what is CN IX?
glossopharyngeal
101
what is CN X?
vagus
102
what is CN XI?
accessory
103
what is CN XII?
hypoglossal
104
CN I functional classification
sensory
105
CN II functional classification
sensory
106
CN III functional classification
motor
107
CN IV functional classification
motor
108
CN V functional classification
both sensory + motor
109
CN VI functional classification
motor
110
CN VII functional classification
both sensory + motor
111
CN VIII functional classification
sensory
112
CN IX functional classification
both sensory + motor
113
CN X functional classification
both sensory + motor
114
CN XI functional classification
motor
115
CN XII functional classification
motor
116
what nerves have parasympathetic functions?
CN III, VII, IX, X
117
what nerves are special somatic afferent?
CN II (optic) + CN VIII (vestibulocochlear)
118
what nerves are general somatic afferent?
CN V (trigeminal). small amount of fibers from CN VII (facial), CN IX (glossopharyngeal), and CN X (vagus)
119
what nerves are special visceral afferent?
CN VII (facial), CN IX (glossopharyngeal), CN I (olfactory)
120
what nerves are general visceral afferent?
CN IX (glossopharyngeal), CN X (vagus)
121
what nerves are general visceral efferent?
CN III (oculomotor), CN VII (facial), CN IX (glossopharyngeal), CN X (vagus)
122
what nerves are special visceral efferent?
CN V (trigeminal), CN VII (facial), CN IX (glossopharyngeal), CN X (vagus), CN XI (accessory)
123
what nerves are general somatic efferent?
CN III (oculomotor), CN IV (trochlear), CN VI (abducens)
124
CN III parasympathetic functions
pupil constriction. smooth muscle of inner eye
125
CN VII parasympathetic function
salivatory and lacrimal glands
126
CN IX parasympathetic function
parotid gland (salivation)
127
CN X parasympathetic function
muscles of heart, lung, and bowel that are involved in movement + secretion
128
special somatic afferent function
sensory info about vision, balance, + hearing
129
general somatic afferent function
sensory info from receptors in skin, muscle, + joints of head
130
special visceral afferent function
sensory info about taste and smell
131
general visceral afferent function
sensory info from viscera in the core (heart, vessels, lungs)
132
general visceral efferent function
preganglionic autonomic fibers to the core + periphery
133
special visceral efferent function
motor info to muscles of the jaw, face, larynx, pharynx from branchial arches
134
general somatic efferent function
motor info to skeletal muscles of the eye and tongue
135
CN I function
smell
136
CN II function
vision
137
CN III function
eye movements, pupillary constriction, upper eyelid
138
CN IV function
eye movement (intorsion - down + in)
139
olfactory receptors
bi-polar neurons
140
sustentacular cells
supporting cells of olfactory epithelium
141
what cranial nerve does NOT have to relay information to the thalamus?
CN I - olfactory
142
what is 80% of our reality based on?
vision
143
special somatic sensory pathway
retina > optic nerve > optic chiasm > optic tract > lateral geniculate nucleus > loop of meyer > calcarine sulcus
144
what is it called when there is a leison to the optic nerve?
bitemporal hemianopsia
145
associated field of defect with bitemporal hemianopsia
lateral field of vision, bilateral
146
LR6 SO4
3
meaning
lateral rectus m, CN 6. superior oblique m, CN 4. All other eye muscles, CN 3
147
what is the edinger-westphal nucleus?
nucleus of parasympathetic function for oculomotor n
148
pupillary constriction is mediated through which cranial n?
oculomotor n
149
what is the smallest cranial n in diameter?
trochlear n
150
what cranial nerve arises from posterior brainstem?
trochlear n
151
CN V function
somatic sense from, mouth, cornea. muscles of mastication
152
CN VI function
lateral eye movement
153
CN VII function
muscles of facial expression. taste to anterior 2/3 tongue
154
CN VIII function
hearing + sense of balance
155
trigeminal n branches
opthalmic, maxillary, and mandibular
156
what are the muscles of mastication innervated by the trigeminal n?
masseter, temporalis, medial and lateral pterygoid muscles
157
what extraocular muscles are innervated by abducens n?
lateral rectus
158
facial n motor function
muscles of facial expression
159
facial n parasympathetic function
salivary and lacrimal glands
160
facial n visceral function
taste for anterior 2/3 tongue
161
stapedius function
transmit vibration to sound in the ear
162
stroke vs bells palsy
163
vestibularcochlear n functions
balance/equilibrium and hearing
164
cochlear branch of CN VIII pathway
lateral lemniscus > inferior colliculus > medial genticulate nuclei > primary auditory cortex
165
CN IX function
sensory - posterior 1/3 of tongue and pharynx. taste - posterior 1/3. chemoreceptors + baroreceptors
166
CN X function
autonomic function of gut. cardiac inhibition. sensation from larynx + pharynx. muscles of vocal cords. swallowing
167
CN XI function
trapezius and sternocleidomastoid
168
CN XII function
movement of tongue
169
CN IX parasympathetic function
stimulation of parotid gland
170
CN IX taste function
posterior 1/3 of tongue, bitter taste
171
CN IX somatic sensory function
general sensation to posterior 1/3 tongue, pharynx, external ear, tympanic membrane
172
CN IX parasympathetic modality
general visceral efferent (GVE)
173
CN IX taste modality
special visceral afferent (SVA)
174
CN IX somatic sensory modality
general somatic afferent (GSA)
175
what cranial nerve is considered to be 75% parasympathetic functions?
CN X - vagus
176
CN X parasympathetic function
saliva production
177
what nucleus is associated with the parasympathetic function of vagus n?
dorsal motor nucleus
178
CN X somatic sensory somatic function
posterior meninges, skin on back of ear, external acoustic meatus, pharynx, larynx
179
what does CN XI innervate?
trapezius and sternocleidomastoid
180
CN XII function
tongue movements. speech and swallowing
181
CN XII modality for tongue movement function
GSE
