Midterm Exam Weeks 1-3 Flashcards
(351 cards)
1
Q
bones of the skull
A
- neurocranium
- viscerocranium
- skull foramina
- skull fossae
2
Q
accessory bones of the skull
A
- ossicles
- hyoid bones
3
Q
neurocranium (braincase)
A
- frontal (1)
- parietal (2)
- occipital (1)
- temporal (2)
- ethmoid (1)
- sphenoid (1)
***8 bones total
4
Q
viscerocranium (facial skeleton)
A
- maxillae (2)
- palatine bones (2)
- nasal bones (2)
- inferior nasal conchae (2)
- zygomatic bones (2)
- lacrimal bones (2)
- vomer (1)
- mandible (1)
***14 bones total
5
Q
how many bones total in the skull
A
22 bones
6
Q
functions of the neurocranium
A
- surround and protect the brain
- articulates with the vertebral column
7
Q
functions of the viscerocranium
A
- supports and protects the entrances to digestive and respiratory tracts
8
Q
functions of the accessory bones of the skull
A
7 bones used for hearing and muscle attachment
9
Q
external features of the neurocranium
A
- external acoustic meatus
- mastoid process
- styloid process
- zygomatic process
10
Q
external acoustic meatus
A
opening in ear canal (entrance)
11
Q
mastoid process
A
attachment site for neck muscles
12
Q
zygomatic process
A
forms cheek bones
13
Q
anterior view of the neurocranium
A
- frontal bone
- parietal bones (2)
- sphenoid bone
- temporal bones (2)
- ethmoid bone
14
Q
lateral view of the neurocranium
A
- frontal bone
- parietal bones (2)
- occipital bone
- sphenoid bone
- temporal bones (2)
- ethmoid bone
- external acoustic meatus
- mastoid process
- styloid process
- zygomatic process
15
Q
superior view of the neurocranium
A
- frontal bone
- parietal bones (2)
- occipital bone
- temporal bones (2)
16
Q
inferior view of the neurocranium
A
- sphenoid bone
- temporal bone
- zygomatic process
- styloid process
- mastoid process
- mandibular fossa
- occipital bone
17
Q
mandibular fossa
A
articulates with the mandible
- joins the mandible to the skull
18
Q
features of the occipital bone
A
- foramen magnum (passage of the spinal cords)
- occipital condyle (articulation with atlas C1)
19
Q
ethmoid bone
A
unpaired bone that forms part of the orbital wall, nasal cavity/septum
20
Q
perpendicular plate
A
extends down into the nasal cavity and divides the nasal cavity into left/right
21
Q
features of the ethmoid
A
- crista galli
- superior nasal concha
- middle nasal concha
- cribriform plate
22
Q
crista galli
A
perpendicular projection of the ethmoid bone
- acts as an anchoring point for the meninges
23
Q
cribriform plate
A
rough base beside the crista galli
- branches of CN1 pass through it
24
Q
sphenoid bone
A
unpaired bone that forms part of the eye orbit and base of skull
***looks like owl
25
features of the sphenoid bone
1. greater wing
2. lesser wing
3. body
4. pterygoid process (attachment for muscles of mastication)
5. sella turcica
26
lesser wings vs greater wings
lesser wings are smaller and superior to the greater wings
27
sella turcica
fossa within the sphenoid bone
- holds pituitary glands
28
skull foramina
allows for passage of nerves and blood vessels
29
sphenoid bone - skull foramina
1. optic canal (CN II)
2. superior orbital fissure (CN III, IV, V1, VI)
3. inferior orbital fissure
4. foramen rotundum (CN V2)
5. foramen ovale (CN V3)
6. foramen spinosum
7. foramen lacerum
30
temporal bone - skull foramina
1. carotid canal (internal carotid artery)
2. internal acoustic meatus (CN VIII)
30
other features of the skull foramina
1. hypoglossal canal (occipital bone)
- CN XII
2. jugular foramen (occipital + temporal)
- CN IX, X, XI
31
sutures
boundaries between skull bones
- fibrous, immovable joints
1. sagittal
2. squamous
3. coronal
4. lamboid
32
sagittal suture
separates the two parietal bones
33
squamous suture
separates temporal bones from others
34
coronal suture
separates frontal bones from parietal
35
lamboid suture
separates the occipital from parietal
36
cranial fossae
floor of the cranial cavity divided into 3 fossae
1. anterior
2. middle
3. posterior
37
anterior cranial fossa
frontal lobe of brain
- contains the frontal, ethmoid, & sphenoid bones
38
middle cranial fossa
temporal lobes of the brain
- contains the sphenoid & temporal bones
39
posterior cranial fossa
cerebellum
- contains the occipital & temporal bones
40
bones in orbit
1. zygomatic
2. sphenoid
3. maxillae
4. ethmoid
5. frontal
6. lacrimal
7. palatine
41
maxilla vs. mandible
maxilla: upper jaw
mandible: lower jaw
42
features of the mandible
1. ramus
2. body
3. angle
4. condylar process (articulation with skull)
5. coronoid process
43
temporomandibular joint (TMJ)
only moveable joint of skull that has articulation between:
1. condylar process
2. mandibular fossa
44
inferior view of the facial skeleton
1. zygomatic bones (2)
2. zygomatic arch
3. maxillae (2)
4. incisive foramen (transmits nerves to the mouth)
5. palatine bones (2)
6. vomer
45
the hard palate
1. palatine process of the maxilla
2. palatine bones
46
palatine bones
extend up to make wall of the nasal cavity
47
vomer
sits on top of maxilla and palatine bones
48
accessory bones of the skull
1. ossicles
2. hyoid bone
49
ossicles
small bones involved in hearing, housed in the temporal bone
- 3 in each middle ear
1. malleus
2. incus
3. stapes
50
hyoid bone
"floating bone" located in the neck
- has important attachment site for tongue and muscles involved in swallowing
51
features of the hyoid bone
1. lesser horn (cornu)
2. greater horn (cornu)
3. body
52
what are the two cell types the NS is comprised of
1. neurons
2. neuroglia
53
major components of the NS
1. brain
2. spinal cord
3. cranial nerves (off brain)
4. spinal nerves (off spinal cord)
5. ganglia
6. sensory receptors
54
central nervous system
brain and spinal cord
55
peripheral nervous system
1. cranial nerves and spinal nerves
2. ganglia and sensory receptors
56
nerve
bundle of axons located outside the brain and spinal cord
57
cranial nerves
- 12 pairs of nerves (I-XII)
- emerge from base of the brain
58
spinal nerves
- 31 pairs of nerves
- emerge from the spinal cord
59
ganglia
- clusters of neuron cell bodies
- located outside the CNS
***communication
60
sensory receptors
- monitor changes in the environment
- skin, eyes, nose, muscles, etc.
***detect changes
61
sensory function of the NS (input)
- sensory receptors detect internal and external stimuli
- sensory (afferent) neurons transmit information to the CNS (through a ganglion)
62
integrative function of the NS (control)
- perception (conscious awareness) of stimuli
- interneurons analyze and integrate sensory information
63
motor function of the NS (output)
- initiate actions in effector organs (muscles, glands)
- motor (efferent) neurons respond to integration
64
neurons in the somatic nervous system
1. somatic sensory neurons
2. somatic motor neurons
65
somatic sensory neurons
1. convey information TO the CNS FROM sensory receptors
for integration
66
somatic motor neurons
1. convey information FROM the CNS TO skeletal muscles muscular contraction
67
somatic nervous system
regulates voluntary control of skeletal muscles
68
autonomic nervous system
regulates involuntary control
1. sympathetic NS
2. parasympathetic NS
69
sympathetic nervous system (SNS)
1. INCREASE in activity and metabolic rate
2. fight-or-flight response
Ex. increase HR, dilate pupils
70
parasympathetic nervous system (PNS)
1. DECREASE in activity and metabolic rate
2. rest-or-digest response
Ex. decrease HR, constrict pupils
71
neurons
1. form complex processing networks
2. transfer and process information
72
neuroglia
1. smaller and more abundant than neurons
2. support, nourish, and protect neurons
3. do not participate in transfer of information
***create homeostatic environment
73
cerebrum (telencephalon)
initiates and manages conscious thoughts and actions
- located at the front of the brain
- consists of 2 hemispheres separated by a fissure
actions: read, write, & speak
74
encephalon (cerebrum)
the largest and more anterior part of the brain
75
structures of the cerebrum
1. white matter
2. gray matter
3. cerebral hemispheres
4. gyrus
5. sulcus
76
cerebral cortex
1. outer layer
2. covers cerebrum
77
white matter vs gray matter
white: internal
gray: external, comprises the cerebral cortex
78
gyrus vs sulcus
gyrus: ridges
sulcus: lines
79
features of the cerebrum
1. longitudinal fissure
2. corpus callosum
80
longitudinal fissure
separates right and left cerebral hemispheres
- stops at the corpus callosum
81
corpus callosum
connects right and left cerebral hemispheres
82
frontal lobe
largest lobe, anterior
1. planning
2. decision making
3. mood
83
temporal lobe
inferior
1. hearing and speaking
84
parietal lobe
supero-posterior
1. responding to stimuli from environment
2. proprioception
85
occipital lobe
posterior
1. vision
86
insular lobe (insula)
autonomic responses
- under parietal
87
fossae of the brain
1. anterior fossa - frontal lobe
2. middle fossa - temporal lobe
3. posterior fossa - brainstem and cerebellum
88
lobe divisions of the cerebrum
1. central sulcus
2. parieto-occipital sulcus
3. lateral sulcus
89
central sulcus
frontal and parietal
- travels transversely, middle of cerebrum
90
parieto-occipital sulcus
parietal and occipital
91
lateral sulcus
frontal and temporal
***thumb of glove
92
cerebellum features
1. folia (gray matter)
2. arbor vitae (white matter)
93
cerebellum functions
1. coordinates voluntary movements
2. regulates posture and balance
94
cerebellum structure
1. cerebellar hemispheres
2. cerebellar peduncles (information highway)
3. vermis (connects hemispheres)
95
cerebellum orientation
1. falx cerebri
2. falx cerebelli
3. tentorium cerebelli
4. transverse fissure
96
cerebellar ataxia
uncoordinated movements due to lesion/damage to cerebellum
97
SCALP
S: skin
C: connective tissue
A: aponeurosis
L: loose connective tissue
P: periosteum
98
scalp proper
3 superficial layers:
1. skin
2. connective tissue
3. aponeurosis
***all connected, they move together
99
aponeurosis
1. frontalis (raise eyebrows)
2. epicranial aponeurosis
3. occipitofrontalis
4. occipitalis (retract skull)
100
function of aponeurosis
helps prevent stretching of the scalp
101
deep scalp
1. loose connective tissue
2. periosteum
102
loose connective tissue
emissary veins in loose connective tissue provide a infection pathway into the cranial vault
103
periosteum
metabolically supportive layer
104
meninges
3 layers of tissue to provide protection and support to CNS
1. dura mater
2. arachnoid mater
3. pia mater
***superficial to deep
105
dura mater
- thick layer of meninges deep to calvarium (skull cap)
- encloses dural venous sinuses
106
dural venous sinuses
major structures that drain the cranial vault
107
three invaginations of the dura mater within the cranial vault
1. falx cerebri (midsaggital)
2. falx cerebelli (midsaggital)
3. tentorium cerebelli (transverse)
108
falx cerebri
on longitudinal fissure
109
tentorium cerebelli
separates cerebrum from inferior cerebellum
110
2 layers of dura mater
1. periosteal layer (superficial)
2. meningeal layer (deeper)
***these layers split to help form the dural venous sinuses
111
2 spaces of dura mater
1. epidural space
2. subdural space
***potential spaces
112
epidural space of the scalp
between skull and dura mater
113
subdural space of the scalp
between dura mater and underlying arachnoid mater
114
arachnoid mater
- sits deep to the dura, on dura mater
- contains subarachnoid space
115
subarachnoid space of the scalp
between the arachnoid and pia mater
- contains CSF
***very real space
116
cerebrospinal fluid (CSF)
helps metabolically and physically support brain
117
metabolic support of the CSF
exchanges medium (electrolytes and metabolites)
118
physical support of the CSF
buoyancy and cushion (so brain floats)
119
arachnoid granulations
drain CSF through the dura mater into the dural venous sinuses
120
arachnoid trabeculae
gives support to the arachnoid mater
121
pia mater
closely covers cortical sulci and gyri
- contains subpial space
122
subpial space
exists between pia and cortex
***potential space
123
spinal meninges
3 layers of tissue providing protection and support to spinal cord
1. dura mater
2. arachnoid mater
3. pia mater
124
dura meninges and archanoid meninges
cover the spinal nerve roots
125
denticulate ligaments (from pia mater)
connect to the dura for cord stability
(very thin ligaments)
126
epidural space of the spinal menginges
contains fat and venous plexuses
*** real space
127
subarachnoid space of the spinal menginges
contains CSF
128
subdural and subpial spaces of the spinal menginges
potential spaces
129
ventricles
4 cavities within the brain responsible for deep CSF flow
- 2 lateral ventricles
- third ventricle
- fourth ventricle
130
3 major horns of the lateral ventricles
1. anterior horns
2. inferior horns
3. posterior horns
131
other features of the lateral ventricle
1. body
2. atrium
3. interventricular foramen
132
atrium of the lateral ventricle
connects inferior and posterior horn with the anterior
133
interventricular foramen of the lateral ventricle
communication foramen that carries CSF
134
lateral ventricles
associated with the telencephalon
135
third ventricle
associated with the thalamus and hypothalamus (diencephalon)
136
features of the third ventricle
1. roof
2. anterior wall
3. lateral walls x2
4. posterior wall
5. floor
6. interthalamic adhesion
137
interthalamic adhesion
band of tissue passing directly through the third ventricle
- connects the bilateral masses of the thalamus
138
cerebral aqueduct
connects the third and fourth ventricles, passing through the midbrain into the pons
- moves fluid
139
fourth ventricle
associated with the pons (myelencephalon)
3 apertures:
- 2 lateral and 1 medial
140
lateral aperatures
foramina of luschka
141
medial aperatures
foramina of magendie
142
central canal
continues all the way down the spinal cord
- provides metabolic support (nourishment) to the deep spinal cord
143
hydrocephalus
abnormal enlargement of the ventricles caused by a buildup of CSF
144
choroid plexus
collection of ependymal cells found on the walls of all 4 ventricles
- produces cerebrospinal fluid, which flows into the ventricles
145
ventricular flow
1. lateral ventricle
2. interventricular foramen
3. third ventricle
4. cerebral aqueduct
5. fourth ventricle
3 pathways after the fourth ventricle:
1. foramina of luschka
2. central canal
3. foramen of magendie
146
cisterns (small subarachanoid spaces)
CSF flows into these and then along the outer corticies of the cerebrum and cerebellum (providing nutrients)
147
cranial CSF flows
1. choroid plexus
2. lateral ventricle
3. interventricular foramen
4. third ventricle
5. cerebral aqueduct
6. fourth ventricle
7. median/lateral aperatures
8. subarachnoid cisterns
9. bathes superficial brain
10. arachnoid granulations
11. dural venous sinuses
***or stop at 6 and go to central canal
148
three branches off the aorta
1. brachiocephalic trunk (right side)
2. left common carotid artery (ascend to brain)
3. left subclavian artery (under clavicle)
149
brachiocephalic trunk
bifurcates into...
1. right common carotid artery
2. right subclavian artery
150
4 major arteries to the brain
1. common carotid artery splits into the internal carotid artery
2. subclavian artery splits into vertebral artery
151
vertebral artery
runs through the vertebral foramina of the cervical vertebrae
152
arteries coming through the skull
1. internal carotid artery passes through the carotid canal
2. vertebral artery passes through the anterior foramen magnum
153
basilar artery
1. joined by an anastomose of the right and left vertebral arteries
2. sits in basilar groove of pons
3. gives off pontine arteries to supply the pons
154
posterior cerebral arteries
x2 (supply their respected hemisphere - left/right)
formed by bifurcation of the basilar artery at superior border of pon
- supply the posterior cerebral cortex
155
circle of willis
anastomosis of arteries providing major cerebral blood supply
156
circle of willis - the flows
1. basilar artery
2. posterior cerebral arteries
3. posterior communicating arteries
4. internal carotid arteries
5. middle cerebral arteries
6. anterior cerebral arteries
7. anterior communicating artery
157
posterior communicating artery
connects internal carotid artery with posterior cerebral artery
158
steps of the circle of willis
1. basilar artery bifurcates into posterior cerebral arteries
2. internal carotid gives off anterior cerebral and middle cerebral arteries
3. also ICA gives off posterior communicating artery
4. anterior cerebral arteries are connected by anterior communicating artery
159
purpose of the circle of willis
maintains cerebral blood flow through the brain in case of a clot or something
160
venous drainage
consists of dural venous sinuses that drain the inner structures of the cranial vault
161
superior sagittal sinus
lies along mid-sagittal plane, in falx cerebri
162
confluence of sinuses
1. superior sagittal sinus
2. confluence of sinuses
3. 2 transverse sinuses
163
transverse sinuses
sit in the tentorium cerebelli
- becomes sigmoid sinus when exiting tentorium cerebelli
164
sigmoid sinus
drains into the internal jugular vein via jugular foramen
165
cavernous sinus
venous plexus sitting lateral to body of the sphenoid bone
- drains the eye, parts of the cerebral cortex, and pituitary gland
166
what is the cavernous sinus pierced by?
internal carotid artery
***only venous sinus that is pierced by another artery (CS)
167
3 parts of the diencephalon
1. epithalamus (above)
2. thalamus
3. hypothalamus (below)
168
thalamus
major relay centre of senses except for smell
- autonomic activities
169
parts of the thalamus
1. interthalamic adhesion
2. third ventricle
3. internal capsule
170
interthalamic adhesion
joins left and right halves of the thalamus
171
hypothalamus
- controls body activities
- produces hormones and regulates homeostasis
- regulates emotions & circadian rhythms
172
infundibulum
connects pituitary gland to the hypothalamus
173
parts of the epithalamus
1. habenular nuclei
2. pineal gland
174
habenular nuclei
sense of smell and emotional response to odors
175
pineal gland
secretes melatonin
- on third ventricle
176
3 structures on the brainstem
1. midbrain
2. pons
3. medulla oblongata
177
medulla oblongata
1. continuation of superior spinal cord
2. forms inferior brainstem
3. contains sensory (ascending) and motor (descending) tract that connects spinal cord to brain
178
pyramids on the medulla
anterior aspect of white matter
- 90% of axons cross to opposite side = decussation of pyramids
- this allows for contralateral control
179
pons
superior to medulla, and anterior to cerebellum
- contains a control centre for respiration
180
midbrain
1. extends upward from pons to diencephalon
2. involved in the auditory and visual pathway
***connects the 3rd and 4th ventricles
181
features on the midbrain
1. superior colliculi
2. inferior colliculi
182
superior colliculi
vision
183
inferior colliculi
audition
184
what system are the cranial nerves a part of
peripheral nervous system
185
12 cranial nerves
I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
186
sensory cranial nerves
contain axons of sensory neurons
- I, II, VIII
187
motor cranial nerves
contain axons of motor neurons
- III, IV, VI, XI, XII
188
mixed cranial nerves
axons of sensory and motor neurons
- V, VII, IX, X
189
I Olfactory Nerve (S) - Function
olfaction/smell
190
I Olfactory Nerve (S) - Skull Exit
cribriform plate
191
II Optic Nerve (S) - Function
vision/sight
192
II Optic Nerve (S) - Skull Exit
optic canal
193
III Oculomotor Nerve (M) - Function
movement of the eyeballs
194
III Oculomotor Nerve (M) - Skull Exit
superior orbital fissure
195
IV Trochlear Nerve (M) - Function
movement of the eyeballs
196
IV Trochlear Nerve (M) - Skull Exit
optic canal
197
V Trigeminal Nerve (S&M) - Function
Sensory: innervation to the face
Motor: innervation to muscles of mastication
198
V Trigeminal Nerve (S&M) - Skull Exits
1. ophthalmic branch (V1) exits at superior orbital fissure
2. maxillary branch (V2) exits at foramen rotundum
3. mandibular branch (V3) exits at foramen ovale
199
VI Abducens Nerve (M) - Function
movement of the eyeballs
200
VI Abducens Nerve (M) - Skull Exit
superior orbital fissure
201
what are the 3 cranial nerves that move the eyeballs
1. III Oculomotor Nerve
2. IV Trochlear Nerve
3. VI Abducens Nerve
202
VII Facial Nerve (S&M) - Function
Sensory: taste for anterior 2/3 of tongue
Motor: control muscles of facial expression
203
VII Facial Nerve (S&M) - Skull Exit
stylomastoid foramen (between mastoid and styloid process on temporal bones)
204
VIII Vestibulocochlear Nerve (S) - Function
hearing and equilibrium
205
VIII Vestibulocochlear Nerve (S) - Skull Exit
internal acoustic meatus
206
X Vagus Nerve (S&M) - Function
autonomic regulation (HR, digestion, breathing)
207
X Vagus Nerve (S&M) - Skull Exit
jugular foramen
208
XI Accessory Nerve (M) - Function
innervation of trapezius and sternocleidomastoid muscles
209
XI Accessory Nerve (M) - Skull Exit
foramen magnum
210
XII Hypoglossal Nerve (M) - Function
1. speech
2. manipulation of food
3. swallowing
211
XII Hypoglossal Nerve (M) - Skull Exit
hypoglossal foramen
212
Mnemonic to remember S&M
Some
Say
Money
Matters
But
My
Brother
Says
Big
Brains
Matter
More
213
protective structures of the spinal cord
1. vertebral column
2. spinal meninges
3. CSF (shock absorbing tissue)
214
vertebral column
surrounds spinal cord
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 fused sacral
- 4 fused coccygeal
215
spinal meninges
1. dura mater (outermost)
2. arachnoid mater (middle)
3. pia mater (innermost)
***all continuous with their corresponding cranial mater
216
structures in the spinal meninges
1. epidural space
2. subdural space
3. subarachnoid space
4. denticulate ligaments
217
epidural space of the spinal cords
between vertebral canal and dura mater
- cushion of fat & CT for protection
218
subdural space
between dura and arachnoid mater
219
subarachnoid space
between arachnoid and pia mater
- contains shock absorbing CSF
220
denticulate ligaments
suspend spinal cord in dural sheath
- triangle shaped membranes
- anchor the spinal cords
221
cervical enlargement
1. C4-T1
2. supplies upper extremities
222
lumbosacral enlargement
1. T9-T12
2. supplies lower extremities
223
spinal cord external anatomy
1. conus medullaris
2. filum terminale
3. cauda equina
224
conus medullaris
located between L1-L2
- determines the termination of the spinal cord
225
filum terminale
- extension of the pia mater
- attaches the spinal cord to the coccyx
226
cauda equina
- lumbar, sacral and coccygeal spinal nerves
- "horses tail"
227
lumbar puncture
samples CSF
228
internal structure of the spinal cord
1. posterior median sulcus (narrow groove)
2. anterior median fissure (wider groove)
3. central canal
4. grey matter (surrounded by the white matter)
5. white matter
229
central canal
extends entire length of spinal cord and contains CSF
230
grey matter of spinal cord
1. posterior horn (sensory)
2. lateral horn
3. anterior horn (motor)
231
white matter of spinal cord
1. posterior funiculus
2. lateral funiculus
3. anterior funiculus
232
sensory vs motor
sensory= ascending
motor= descending
233
which part of the brainstem surrounds the cerebral aqueduct?
midbrain
234
central nervous system (CNS)
1. brain
2. brainstem
3. spinal cord
235
peripheral nervous system (PNS)
nerves and ganglia outside the CNS
*** cranial and spinal nerves
236
somatic nervous system
- includes both sensory and motor neurons
- voluntary
237
somatic sensory neurons (afferent)
convey input from
1. receptors for somatic senses
2. receptors for special senses
***information from the outside to brain
238
somatic motor neurons (efferent)
innervate skeletal muscles
***information from the brain to outside
239
autonomic nervous system
involuntary
1. regulates cardiac & smooth muscle, and glandular tissue
240
autonomic motor neurons
regulate visceral activities by exciting or inhibiting activities in effector tissues
241
somatic sensory vs. visceral sensory
somatic: carries signals from receptors in skin, muscles, bones and joints (DIRECT)
visceral: carries signals mainly from organs in the thoracic and abdominal cavities (PRE AND POST)
242
which sensory response is not a part of the somatic sensory division?
taste
243
the 3 general sensory receptors
1. free nerve endings
2. encapsulated
3. proprioceptors
244
free nerve endings of sensory neurons (functional class)
1. nociceptors (pain)
2. thermoreceptors (heat and cold)
3. mechanoreceptors (pressure)
4. chemoreceptors (chemical change)
245
free nerve endings of sensory neurons (body location)
most body tissues; most dense in connective tissue
246
modified free nerve endings - Merkel discs (functional class)
mechanoreceptors (light pressure)
247
modified free nerve endings - Merkel discs (body location)
deepest layer of epidermis (most superficial layer of the skin)
248
hair follicle receptors (functional class)
mechanoreceptors (hair deflection)
249
hair follicle receptors (body location)
in and surrounding hair follicles
250
tactile (meissner's) corpuscles (functional class)
mechanoreceptors (light pressure, discriminative touch, vibration of low frequency)
251
tactile (meissner's) corpuscles (body location)
1. hairless skin
2. particularly nipples
3. external genitalia
4. fingertips
5. eyelids
252
lamellar (pacinian) corpuscles (functional class)
mechanoreceptors (deep pressure, stretch, vibration of high frequency)
253
lamellar (pacinian) corpuscles (body location)
1. dermis and hypodermis
2.fingers
3. soles of feet
4. external genitalia
5. nipples
254
ruffini corpuscles (functional class)
mechanoreceptors (deep stretch and stretch of tendons)
255
ruffini corpuscles (body location)
1. deep in dermis
2. hypodermis
3. joint capsules
256
muscle spindles (functional class)
mechanoreceptors (muscle stretch)
257
muscle spindles (body location)
skeletal muscles - particularly those of the extremities
258
tendon organs (functional class)
mechanoreceptors (tendon stretch)
259
tendon organs (body location)
tendons
260
free nerve endings
1. free nerve endings of sensory neurons
2. modified free nerve endings (merkel discs)
3. hair follicle receptors
261
encapsulated sensory receptors
1. tactile (meissner's) corpuscles
2. lamellar (pacinian) corpuscles
3. ruffini corpuscles
262
proprioceptors sensory receptors
1. muscle spindles
2. tendon organs
263
features of the spinal cord
1. posterior horn (thoracic)
2. anterior horn (upper lumbar)
3. lateral horn (sacral)
4. central canal
5. white matter
264
purpose of spinal nerves
1. communication system between brain and various body parts
2. essential for voluntary and involuntary actions
3. highway for sensory and motor integrations
4. important for rapid automatic responses through reflexes
265
anatomy of the spinal cord
1. epineurium (outermost and superficial)
2. perineurium (surround axons)
3. endoneurium
***all provide structural support, protection, and organization to the nerves
266
how many pairs of spinal nerves are there?
31 pairs
267
segments of the 31 spinal nerves
- 8 pairs of cervical nerves
- 12 pairs of thoracic nerves
- 5 pairs of lumbar nerves
- 5 pairs of sacral nerves
- 1 pair of coccygeal nerves
268
what pairs of nerves leave the spinal cord above their vertebrae level?
pairs 1-7
269
dorsal root
connects the spinal nerves to the spinal cord
- contains axonal processes of sensory neurons arising from the POSTERIOR horn
- contains the dorsal root ganglion
270
dorsal root ganglion
- enlargement of the dorsal root
- cluster of cell bodies of sensory neurons
- functions as sensory relay stations by processing and modulating sensory signal before reaching the CNS
271
where do the spinal nerve and DRG lie within?
the intervertebral foramina
272
ventral root
- contains axonal processes of motor neurons whose cell bodies are located in ANTERIOR horn
273
what does each spinal nerve branch into?
1. dorsal ramus
2. ventral ramus
274
properties of both the dorsal and ventral rami
1. contain both sensory and motor fibres
2. exit the vertebral column through intervertebral foramina
3. supply the entire somatic region of the body
275
dorsal rami
supplies dorsum of neck and back
276
ventral rami
1. supplies anterior and lateral regions of neck and trunk
2. supplies all regions of the limbs
***much thicker than the dorsal rami
277
nerve plexuses
formed by the ventral rami when they do not travel directly to their target tissues and instead branch out to form these complex networks
278
4 primary nerve plexuses function
travel to specific target tissues, such as muscles, skin, and organs, to facilitate motor control and sensory perception
279
the 4 primary nerve plexuses from ventral rami
1. cervical plexus
2. brachial plexus
3. lumbar plexus
4. sacral plexus
280
cervical plexus spinal nerves
C1-C4
281
cervical plexus supplies:
sensory and motor innervation to:
- neck
- portions of the head
282
brachial plexus spinal nerves
C5-T1
283
brachial plexus supplies:
sensory and motor innervation to:
- shoulder
- upper limbs
284
lumbar plexus spinal nerves
L1-L4
285
lumbar plexus supplies:
nerves to the:
- lower back
- abdominal wall
- part of the lower limb
286
sacral plexus spinal nerves
L4-S5
287
sacral plexus innervation:
1. buttocks
2. pelvic structures
3. remainder of lower limb
288
the path from the spinal cord
1. nerves originate from the spinal cord through 2 roots
1. dorsal roots
2. ventral roots
2. dorsal and ventral roots unite outside the spinal cord to form a spinal nerve (motor/sensory fibres)
3. the spinal nerve branches into 2 rami
1. dorsal rami
2. ventral rami
289
dorsal roots
carrying sensory information into the spinal cord
290
ventral roots
carrying motor information away from the spinal cord
291
dorsal rami
branches that supply the dorsal parts of the body, including the skin and muscles
292
ventral rami
larger branches that supply the ventral parts of the body and form complex nerve plexuses
***has both motor and sensory information
293
dermatomes
1. sections of skin innervated by a single spinal nerve
2. motor and sensory innervation for those specific areas
294
important dermatomes
1. T4 nipples
2. T10 umbillicus (belly button)
295
motor reflex arc
1. neural pathway that mediates rapid involuntary actions
2. integrates sensory inputs and motor inputs
3. physiological & neural response against potential harmful stimuli
296
anatomy of the motor reflex arc
1. sensory receptor
2. sensory neuron (afferent)
3. dorsal root ganglion
4. dorsal root
5. posterior horn
6. interneurons
7. anterior horn
8. motor neuron
9. effector muscle
297
autonomic nervous system (ANS)
involuntary (unconscious) motor (efferent) branch of NS that innervates smooth and cardiac muscle, viscera and glands
298
other word for ANS
visceral motor system
299
examples of unconscious processes from ANS
1. heart rate
2. respiration
3. sweating
300
sympathetic vs. parasympathetic
sympathetic: increases HR; active in times of stress
parasympathetic: decreases HR; active in relaxed conditions
301
functions of sympathetic NS
1. increases HR
2. stimulates metabolism
3. downregulates digestive activity
4. dilates blood vessels in skeletal muscle
302
functions of parasympathetic NS
1. decreases HR
2. promotes relaxation
3. stimulates digestive secretions and increase gut motility
4. dilates blood vessels in GI tract
303
neurons
highly specialized cells that carry electrical signals
304
myelin sheath
lipid-rich sheath that surrounds some nerve cell axons
- acts as an insulating layer (increases velocity of the signals)
305
somatic NS
1. voluntary control
2. one neuron between CNS and target to innervate skeletal muscle
306
autonomic NS
1. involuntary control
2. two neuron chain between CNS and target
- preganglionic neuron synapses to the postsynaptic neuron
307
location of preganglionic neuronal cell bodies
brainstem or spinal cord
308
location of postganglionic neuronal cell bodies
autonomic ganglion
309
preganglionic vs postganglionic
preganglionic: myelinated
postganglionic: unmyelinated
310
ganglion
collection of neuronal cell bodies found in the PNS
DRG: sensory ganglion in SNS
311
autonomic ganglia
function as relay stations between preganglionic and postganglionic neurons of the ANS
312
autonomic outflow of sympathetic
thoracolumbar (T1-L2)
313
autonomic outflow of parasympathetic
cranio-sacral
cranial nerves:
- CN III - oculomotor
- CN VII - facial
- CN IX - glossopharyngeal
- CN X - vagus
***carry sympathetic information
sacral regions: S2-S4
314
sympathetic ganglia
1. preganglionic: short because they need a fast response (ForF)
2. postganglionic: long
315
rami communicans
connection between the spinal nerve and sympathetic truck
- dorsal and ventral root form spinal nerve
- white + grey ramus communicans
316
sympathetic outflow
1. originates in lateral horn on SC, from segments T1-T12
2. pregang neuron exit SC via ventral horn and root to enter spinal nerve
3. pregan neuron enters sympathetic chain via white ramus communicans "on ramp"
317
3 main routes for pregang neurons upon entering sympathetic chain - sympathetic outflow
1. synapse within the chain at same level
2. change level within the chain and then synapse
3. formation of a splanchnic nerve
318
1st route for pregang entering sympathetic chain
pregang neuron synpases with postgang neuron at same level, and exits via grey ramus, travelling with spinal nerve to target
ex. sympathetic innervation of blood vessels and sweat glands of the body wall and limbs
319
white ramus communicans vs. grey ramus communicans
white: myelinated (on ramp)
grey: unmyelinated (off ramp)
320
same level upon entering sympathetic chain
- pregang neurons located between T1-T12
nerves target:
1. body wall
2. ab and thoracic viscera
3. limbs
321
dermatomes
strip of skin supplied by a spinal nerve
322
2nd route for pregang entering sympathetic chain
change level: pregang neuron fiber can ASCEND or DESCEND within the sympathetic chain
- runs from T1-L2
- occurs before synapse
323
change level: ascending nerves target
1. head/neck
2. thoracic viscera
3. upper limbs
324
change level: descending nerves target
1. abdominopelivic viscera
2. lower limbs
325
autonomic plexuses
network of intersecting fibres that supply organs
- postgang contributes to
1. cardiac plexus (heart)
2. pulmonary plexus (lungs)
326
3rd route for pregang entering sympathetic chain
formation of a splanchnic nerve
327
splanchnic nerves
associated with abdominoplevic viscera
- form when autonomic fibres do not re-join spinal nerve, instead they form a splanchnic nerve
328
how are splanchnic nerves formed
pregang fibres bypass the sympathetic chain completely and synapse in a peripheral (prevertebral) ganglion near target organ
329
where do splanchnic nerves originate
thoracic and lumbar vertebral levels
330
sets of paired splanchnic nerves
1. greater splanchnic (T5-T9)
2. lesser splanchnic (T10-T11)
3. least/lumbar splanchnic (T12-L2)
331
where does the greater splanchnic nerve synpase
celiac ganglion
332
where does the lesser splanchnic nerve synapse
superior mesenteric ganglion
333
where does the least/lumbar splanchnic nerve synapse
inferior mesenteric ganglion
334
sympathetic outflow pathways summary
1. pregang neuron synapses in sympathetic region, postgang axon exits to re-join spinal nerve at SAME LEVEL to innervate target
2. pregang neuron ASCENDS/DESCENDS within sympathetic chain before synapsing, postgang axon exits via spinal nerve above or below original spinal level
3. pregang neuron passes through sympathetic chain without synapsing, forming a splanchnic nerve, this synapses in prevertebral ganglion
335
parasympathetic nervous system targets
1. viscera of head and neck
2. ab and thoracic viscera
3. pelvic viscera
336
parasympathetic ganglia
preganglionic: long
postganglionic: short
337
cranial outflow- parasympathetic
pregang cell bodies synapse on ganglia in or near effector organ
- axons travel through cranial nerves III, VII, IX, X
338
cranial outflow - head and neck
pregang neurons leave brainstem from parasympathetic nuclei and synapse on postgang neuron within parasympathetic ganglia
- CN III, VII, IX - synapse on 4 different ganglia
339
example of cranial outflow - head and neck
parasympathetic innervation of salivary glands
- CN VII synapses at submandibular ganglion and innervates submandibular galnds
340
CN VII cranial outflow
1. synapses at submandibular ganglion and innervates submandibular and sublingual gland
2. synapses at pterygopalatine ganglion and innervates lacrimal gland
341
CN III cranial outflow
synapses at ciliary ganglion and innervates the eye
342
cranial outflow: thoracic and abdominal viscera
1. pregang neurons leave the brainstem vis CN X, which contribute to autonomic plexuses
2. pregang neurons synapse on ganglia within or close to target organ
343
CN X cranial outflow
synapses at intra-mural ganglion and innervates:
1. cardiac and pulmonary plexus
2. celiac plexus
3. superior hypogastric plexus
344
sacral outflow: distal GI tract and pelvic viscera
1. pregang neuronal cell bodies located in spinal segments S2-S4
2. axons travel via pelvic splanchnic nerves which contribute to autonomic plexuses
3. pregang nerves synapse within ganglia in or near effector organ to supply targets
345
pelvic splanchnic nerves supply
inferior hypogastric plexus
346
visceral afferent fibres
conduct sensory information from autonomic targets to the CNS
- are not considered sympathetic or parasympathetic
347
visceral reflex arcs
are the simplest functional units in the ANS
- consist of sensory nerve (visceral afferent) and visceral motor neurons
348
example of visceral reflexes
shinning a light in the eye triggers a visceral reflex that constricts the pupils
349
enteric nervous system
third division of the ANS
- network of neurons located in the walls of the digestive tract
- receives regulatory signals via sympathetic and parasympathetic divisions
350
