NBDE: ANATOMICAL SCIENCES: Nervous System Flashcards Preview

NBDE PART 1 BIOCHEM/PHYSIOLOGY > NBDE: ANATOMICAL SCIENCES: Nervous System > Flashcards

Flashcards in NBDE: ANATOMICAL SCIENCES: Nervous System Deck (271):
1

which tract is responsible for coordinating eye and head movements?
a. tectospinal
b. rubrospinal
c. vestibulospinal
d. reticulospinal

a. tectospinal

2

Tracts __ to the spinal cord are concerned with voluntary motor function, muscle tone, reflexes and equilibrium, visceral innervation and modulation of ascending sensory signals.

descending

3

the single most important tract concerned with skilled voluntary activity is the

corticospinal tract

4

corticospinal tract originates in the

premotor, primary motor and primary sensory cortex

5

which spinal tract function is mainly inhibitory influence on motor neurons to skeletal muscles

medial reticulospinal

6

which spinal tract function is mainly coordination of body movement and posture

rubrospinal

7

which spinal tract function is mainly coordination of head, neck and eye movements

tectospinal tract aka colliculospinal

8

which spinal tract origin is the red nucleus of the midbrain

rubrospinal

9

which spinal tract function is mainly voluntary movement of the same side as location in the cord

anterior corticospinal (aka direct pyramidal)

10

which spinal tract function is mainly voluntary movement of the opposite side as location in the cord

lateral corticospinal (aka crossed pyramidal)

11

fasciculus gracilis and cuneatus are ascending (sensory) or descending (motor) tracts

ascending (sensory)

12

pt w/ type II diabetes comes in to ER with painful blistering skin rash on his forehead. the localized area of skin with sensory innervation from a single nerve root of the spinal cord is called?
a. fasciculus
b. dermatome
c. spindle
d. bundle

b. dermatome

13

dermatomes are areas of skin supplied by a _ nerve

single SPINAL NERVE

14

each of the 31 segments of the spinal cord gives rise to a pair of spinal nerves which carry messages into and out of the CNS. All the nerves end up innervating a different region of the skin called a dermatome EXCEPT WHICH SPINAL NERVE

spinal nerve C1 - does not play a role in dermatomes

15

the pattern of distribution of peripheral nerve is different from the dermatome pattern. T/f

true

16

cranial nerve dermatomes do not overlap (not innervated by more than one nerve) whereas the spinal nerve dermatomes _

do overlap each other by 50% as insurance against anesthesia of a dermatome

17

which dermatome is on your cheek

C2

18

which dermatome is on your neck

C3

19

which dermatome is on your clavicle

C4

20

which dermatomes are in your hand

C6 = thumb and radius
C7 = index and middle finger
C8 = pinky and ring finger up to elbow (ulna)

21

C7 and C8 are where

on your back and hands

22

S2 and S3 are where

pubic region front and back of legs is S1 and S2

23

S3, S4, S5 are

on your anus but area (S5 in the core)

24

Wernicke's area is in which cerebral lobe

temporal

25

the largest part of our brain is the

cerebrum aka cortex = outer layer of gray matter = associated with higher brain function such as thought and action

26

the limbic system is found buried in the

cerebrum

27

emotional brain is which lobe

temporal

28

basal nuclei are _ matter (white/gray) deep structures within each cerebral hemisphere that help control _ activity

grey
skeletal muscle

29

name the 3 areas in your temporal lobe

Wernicke's - interprets words as heard and written
auditory area- detects auditory signal
short- term memory storage

30

mnemonic for temporal lobe

temporal = WAS (Tempora-ry)
Wernicke
Auditory
Short term memory (temporary memory)

to remember auditory is here just remember that your acoustic meatus (ear is here)

31

the visual area (detects visual signals) is in what lobe

occipital (think you have eyes in the back of your head)

32

the somesthic area is what lobe

somesthic (somatosensory = temperature, pain, sensations of body) = parietal lobe

33

which lobe controls motor function: the thin muscles of body ex mouth, feet, eye, fingers

frontal (think your motor is in the front of your car/brain)

34

which lobe coordinates movemente

frontal

35

the prefrontal area of the frontal lobe controls

elaborate thinking process
planning of complex movements

36

what lobe controls speech (articulation of words)

frontal (motor area).

37

1. Forming words/articulation = _lobe
2. understanding speech =

1. frontal
2. temporal ( Wernicke's speech area)

38

understanding of written and spoken language is

Wernicke's speech area

39

where specifically is Wernicke's speech area

temporal lobe: brodmann area 22
superior temporal gyrus (STG) in the dominant cerebral hemisphere (which is the left hemisphere in 95% of people)

40

Aphasia

is a disturbance of the comprehension and expression of language caused by dysfunction in the brain

41

which lobe is Broca's area and what is it responsible for

frontal of one hemisphere (usually the left), speech production. (think broken words). inferior frontal gyrus

42

name the 2 types of nervous tissue

neurons and neuroglial cells (glial cells)

43

__ transmit nerve impulses

neurons

44

do neuroglial cells (glial cells) conduct nerve impulses? function?

no. Glial cells are non conducting nervous tissue. they are "support cells"

45

name 3 types of neuroglial cells

astrocytes, microglial cells, and ciliated ependymal cells

46

__ are glial cells attached to the outside of a capillary blood vessel in the brain

astrocytes

47

phagocytes of the nervous system

microglial cells

48

ependymal cells in nervous system

form a sheath that lines fluid cavities in the ventricular system of the brain

49

perikaryon is aka

cell body (soma) aka cyton

50

cell body (perkaryon/cyton/soma) contain the nucleus and most of the cytoplasm.
1. They are located in the CNS as clusters called _
2. In the peripheral nervous system the groups of somas are called

1. nuclei = nuclei in CNS are a bunch of cell bodies
2. ganglia = groups of cell bodies in the peripheral

51

neuronal processes that send the impulse toward the cell body.

dendrites

52

Do all neurons have dendrites?

no some lack them

53

a nerve fiber is aka

axon

54

neurons classified according to structure can be bipolar, unipolar, or multipolar based on how many processes extend from the cell body. the most common type is

multipolar

55

neurons can be classified according to their function:
a. efferent = _
b. afferent = _
c. bw sensory and motor neurons ONLY inside CNS

a. motor
b. sensory
c. interneurons

56

whether or not someone feels different stimuli (pain, temperature, pressure) is determined by the

which nerve fiber type is stimulated

57

the principal glia of the peripheral nervous system

Schwann cells = nutritive, supportive

58

oligodendrocytes are only found in CNS/PNS?

CNS = create the myelin sheath

59

purkinje cell, pyramidal neurons and motor neurons are __(unipolar/bipolar/multipolar/anaxonic neurons)

multipolar

60

retinal and olfactory neurons are __(unipolar/bipolar/multipolar/anaxonic neurons)

bipolar

61

touch and pain sensory neurons are __(unipolar/bipolar/multipolar/anaxonic neurons)

unipolar

62

the amacrine cell is __(unipolar/bipolar/multipolar/anaxonic neurons)

anaxonic
Amacrine cells are interneurons in the retina

63

Café au lait spots

pigmented birthmarks.

64

Lisch nodules

Lisch nodule is a pigmented hamartomatous nodular aggregate of dendritic melanocytes affecting the iris

65

hamartomas

benign, focal malformation that resembles a neoplasm in the tissue of its origin

66

neurilemmomas are a neoplasm of myelin producing cells in the peripheral nervous system known as

schwann cells

67

neurolemmocyte
or neurolemma cell

schwann cells aka

68

are there schwann cells (neruolemmocytes) in the CNS

no! they are oligodendrocytes in the CNS

69

leptomeninges

The arachnoid and pia mater together, are sometimes called the leptomeninges, literally thin meninges

70

__ cells are the resident immune cells of the CNS. function resembles that of tissue macrophages

microglial

71

which ascending tract carries pain and temperature sensory to thalamus

lateral spinothalmic

72

lateral spinothalmic cord carries pain, temperature, and crude touch to which side

opposite side

73

anterior spinothalmic carries

crude touch and pressure

74

which tract caries discriminating touch and pressure sensations

fasciculus gracilis and cuneatus

75

which tract carries unconscious kinesthesia

anterior and posterior spinocerebellar

76

tracts whose names begin with a part of the brain are motor/sensory

motor tracts

77

which spinal nerve structure is only composed of sensory fibers:
ventral root/dorsal root/ventral rami/dorsal rami

dorsal root

78

the spinal cord begins at the brainstem and ends at which vertebrae

the 2nd lumbar

79

at 31 places along the spinal cord, the dorsal and ventral roots come together to form spinal nerves. = contain both sensory and motor fibers as do most nerves. how many spinal nerves (name)

8 Cervical
12 Thoracic
5 Lumbar
5 Sacral (S1-S5)
1 coccygeal nerve

80

C1 nerve is bw

the cranium and the atlas (1st cervical vertebra)

81

spinal nerves divide into branches called

rami

82

ventral primary rami exit _ and dorsal primary rami exit

anteriorly
posteriorly

83

a nerve plexus is a

network of adjacent spinal nerves that join together

84

head, neck, shoulders, diaphragm = _ plexus

cervical

85

the upper limbs, some neck and shoulder muscles = _ plexus

brachial plexus

86

part of abdominal wall, lower limbs and external male genitalia = _ plexus

lumbar

87

perineum, buttocks, and most of the lower limbs = _ plexus

sacral

88

external female genitalia = _ plexus

pudendal

89

motor neuron pathways are of two types: 1. somatic =
2. autonomic =

1. skeletal
2. smooth muscle, cardiac muscle and glands

90

the PNS = structures outside the CNS (brain and spinal cord). are the cranial nerves and spinal nerves PNS or CNS

PNS

91

the afferent division of PNS includes _ sensory neurons which carry impulses to the CNS from the skin, fascia, and joints along with _ sensory neurons from viscera of body (blood pressure, hunger pangs)

somatic
visceral

92

the __ division of PNS includes somatic (voluntary) and autonomic (involuntary) nervous system.

efferent

93

what are the 2 divisions of the diencephalon

hypothalamus and thalamus

94

which of the following separates the occipital lobe and the cerebellum:
falx cerebri
falx cerebelli
tentorium cerebelli
corpus callosum

tentorium cerebelli

95

the __ are 3 concentric protective membranes surrounding the brain and spinal cord (the CNS)

meninges

96

the outermost tough fibrous layer that lines the skull and forms the folds, reflections, that descend into the brain fissures and provide stability

dura mater

97

the 3 dural folds are

falx cerebri
falx cerebelli
tentorium cerebelli

98

which dura mater fold lies in the longitudinal fissure and separates the cerebral hemispheres

falx cerebri

99

which dura mater fold separates the two lobes of the cerebellum

falx cerebelli

100

which dura mater fold separates the occipital lobe of cerebrum from cerebellum

tentorium cerebelli

101

which layer of meninges is a fragile network of collagen and elastin fibers with a cobbweb like appearance.

arachnoid mater

102

name the order of meninges from scalp to brain

dura mater
arachnoid mater
pia mater (DAP)

103

the innermost membrane of the meninges, extremely thin, made of collagen and elastic fibers and contains many blood vessels. adheres closely to the brain and spinal cord

pia mater

104

which layer of meninges is most vascular?

pia mater (arachnoid is moderately vascular)

105

the structures involved in meningitis are the

meninges (DAP)

106

if inflammation of the meninges (meningitis) becomes severe enough it could become

encephalitis (brain inflammation)

107

bw what layers of the meninges can you find cerebrospinal fluid (CSF)

subarachnoid layer (between the arachnoid and pia layer)

108

name the two potential spaces in the meningeal area

epidural space and subdural space

109

where is the potential epidural space

over the dura mater. potential = means that normally it does not exist

110

when could the epidural space become a real space rather than a potential space

pathology ie accumulation of blood from a torn meningeal artery (epidural hematoma)

111

the subdural space is a closed space bw the

dura mater and arachnoid membrane -

112

often site of hemorrhage after head trauma

subdural space

113

in ventricles of the brain, the pia mater and ependymal cells contribute to form the _ plexus

choroid

114

the choroid plexus regulates the

intraventricular pressure by secretion of CSF

115

if you have an epidural hemorrhage what vessel associated with it?

middle meningeal

116

if you have an subdural hemorrhage what vessel associated with it?

bridging vein

117

if you have an subarachnoid hemorrhage what vessel associated with it?

circle of willis (berry aneurism)

118

mnemonic to remember what vessel responsible for hemorrhage?

1. epiDural = miDDle meningeal artery
2. suBdural = Bridging vein
3. subaraChnoid = Circle of willis

119

a rupture of middle meningeal artery will probably cause a _hemorrhage

epiDural

120

a rupture of bridging vein will probably cause a _hemorrhage

suBdural

121

a rupture of circle of willis (berry aneurism) will probably cause a _hemorrhage

subaraChnoid

122

the periosteal layer and meningeal layer =

dura mater

123

the falx cerebri seperates the 2 hemispheres of the brain. what does it attach to in front and back

It is narrow in front, where it is attached to the crista galli of the ethmoid; and broad behind, where it is connected with the upper surface of the tentorium cerebelli.

124

what 2 sinuses are contained in the falx cerebri

it contains the superior sagittal sinus and inferior sagittal sinus

125

which cranial nerves arise in the pons

V, VI, VII

126

which CN arises in the inner ear and goes to the pons

VIII

127

what CN's are attached to the medulla oblangata

CN IX, X, XI, XII

128

what CN's are located in the anterior portion of the brain

I, II, III, IV

129

brainstem made up of

midbrain, pons, medulla oblongata, and

130

centers in the brainstem regulate

vital functions: heartbeat, respiration, blood pressure

131

substantia nigra is in which part of brainstem

midbrain

132

substantia nigra help to control

movement

133

lesions to substantia nigra lead to

Parkinson's disease

134

the _ connects the cerebellum with the cerebrum

pons

135

one of the respiratory centers of the brain is in which part of the brainstem

pons

136

which cranial nerve exits thru the pons

V

137

the pons is involved with _ activity

motor

138

the medulla oblongata is the most inferior portion of the brainstem and is a small cone shaped structure that joins the spinal cord at the level of the

foramen magnum

139

what area in brainstem controls reflexes such as coughing, gagging, swallowing and vomiting

medulla oblangata

140

the reticular formation is grey matter in the _ that regulates

medulla oblongata
sleep, arousal (reticular activating center), pain perception, and includes the vital centers that regulate breathing and heart activity

141

what meningeal structure is a ring=shaped fold that allows the passage of the infundibulum of the pituitary gland?

diaphragm sellae

142

the dura mater is composed of how many layers

1

143

dura mater layers
1. _ layer adheres tightly to the inner surface of the cranium
2. the _ layer forms partitions (folds or reflections) into the brain's fissures and provide stability

1. periosteal
2. meningeal

144

the two vertical folds of the dura mater are the

falx cerebri and falx cerebelli

145

the falx cerebelli separates the two lobes of the ___ and contains the _ sinus

cerebellum
occipital

146

falx cerebri = longitudinal fissure that separates the _ and contains _ sinus

cerebral hemispheres
inferior and superior sagittal sinus

147

the horizontal fold of the dura mater is called the

tentorium cerebelli

148

tentorium cerebelli separates the _ and contains what sinuses

cerebrum from cerebellum
straight, transverse, and superior petrosal sinuses

149

the dural venous sinuses lay bw the _ layers of dura

periosteal and meningeal layers

150

the sinuses in ur cranium contain __blood that originates from the

venous
brain and cranial cavity

151

the sinuses contain an endothelial lining that is continuous into the veins that are connected to the sinuses. most of the venous blood in the sinuses drains from cranium via the

internal jugular vein

152

the diaphragm sellae is a ring shaped fold of dura mater that covers the _ and contains an aperature for the passage of the _

sella turcica
infundibulum of the pituitary gland

153

the diencephalon lies beneath the cerebral hemispheres and contains the

hypothalamus and thalamus

154

cell bodies in the CNS group together as_ matter

gray

155

axons/processes of neurons group together as _ matter

white

156

the 4 main parts of the brain are

cerebrum, diencephalon, brain stem, and cerebellum

157

how many lobes in the cerebrum

4 paired lobes

158

the cerebral hemispheres are connected by _ matter called

white
corpus collasum

159

80% of the brain is which part

cerebrum

160

two layers of cerebrum

cortex and medulla

161

the thalamus is grey/white matter

gray

162

the thalamus lies on either side of the

3rd ventricle

163

the ventricles are filled with

CSF

164

__ matter is mostly unmyelinated nerve cell bodies

gray

165

__ matter is mostly myelinated nerve cell bodies

white

166

support neurons in _ are Schwann cells and satellite cells

PNS

167

with the exception of microglia which derive from __ all neuroglia derive from __

microglia = mesoderm
neuroglia = ectoderm

168

main phagocytic cell and antigen presenting cells in the CNS are

microglia

169

ependymal cells

line most of the ventricles in the CNS

170

choroidal cells =

form the choroid plexus. SECRETE CEREBROSPINAL fluid

171

astrocytes

provide structural support in the CNS

172

besides the schwann cells and satellite cells all others are found in the

CNS

173

schwann cells are

flattened cells arranged in series around axons. form myelin in PNS

174

satellite cells

flattened cells support cell bodies in PNS

175

1. Schwann cells in the PNS myelinate _ axon
2. Oligodendrocytes in the CNS myelinate _ axons
(numbers)

1. ONE
2. many (50+)

176

cell bodies of preganglionic sympathetic fibers to the head are located in the

lateral gray horns of segments T1 to T4 of spinal cord

177

sympathetic division of ANS are derived from _ spinal nerves

T1-L2

178

1. which sympathetic neurons are myelinated and short
2. which are unmyelinated and long

1. preganglionic
2. post ganglionic

179

tone in most organs = PNS/SNS

parasympathetic

180

sympathetic tone is solely in the

BV, adrenal medulla, sweat glands, piloerector muscles of skin

181

septum pellucidum

how the lateral ventricles communicate with each other

182

the 4 ventricles of the brain connect with each other, the spinal cord, and the _ surrounding the brain and spinal cord

subarachnoid (remember this has the CSF and so do the ventricles)

183

the right and left ventricles are located

in the right and left cerebral hemispheres

184

interventricular foramen (foramen of Monro)

bw lateral ventricles and 3rd ventricle

185

the cerebral aqueduct connects (aqueduct of Sylvius)

3rd and 4th ventricle

186

the 4th ventricle is dorsal to _ and ventral to _

dorsal to brainstem and ventral to cerebellum

187

foramen of Magendie (median aperture) and foramina of Luschka (lateral aperatures) allow communication bw the subarachnoid space and the

4th ventricle

188

the only ventricles that are paired are the

lateral (2) + 3rd (1)+ 4th (1)

189

cerebrospinal fluid produced by what structure located in all the ventricles

choroid plexus

190

CSF gets absorbed into the bloodstream in which sinus

superior sagittal sinus

191

arachnoid granulations (arachnoid villi)

in superior saggital sinus = where csf is absorbed into bloodstream.

192

when will csf enter bloodstream?

when csf pressure is higher than venous pressure

193

arachnoid granulations (arachnoid villi) are one way valves which means

if csf pressure is less than venous pressure blood can't pass into the ventricles thru them

194

the spinal cord terminates at the:
central canal
cauda equine
arachnoid space
filum terminale
conus medullaris

conus medullaris

195

conus medullaris is where the spinal cord ends at what level?

L1 to L2

196

the dura and arachnoid continue past where the spinal cord ends to the level of _ where the arachnoid fuses with the _

S2 filum terminale

197

a needle inserted bw the spines at L3, L4, or L5 will enter what space?

subarachnoid space = filled with CSF = wont injure the spine

198

if you wanted to insert a needle into the spine it should be below

L2 (conus medullaris)

L3-L5

199

cauda equina

nerve bundles in spinal column below the spinal cord that serves the legs

200

CSF is colorless thin fluid found where

ventricles of brain, subarachnoid space, central canal of spinal cord

201

subarachnoid space goes how far down the vertebrae

S2 (think S for subarachnoid and S2)

202

the choroid plexus regulates the intraventricular pressure by secretion of

cerebrospinal fluid

203

ependymal cells line the membrane of ventricles and of central canal of spinal cord. they also are in the choroid plexus of the CNS and participate in the

production of CSF

204

the ciliary, pterygopalatine, submandibular, and otic ganglia are all
a. sympathetic ganglia
b. parasympathetic ganglia
c. both

b. parasympathetic ganglia

205

ciliary ganglion are which CN

CNIII oculomotor Parasympathetic ganglia

206

which muscle accommodates the lens: ciliary muscle or sphincter pupillae muscle

ciliary muscle
CN III

207

which muscle causes miosis: ciliary muscle or sphincter pupillae muscle

sphincter pupillae muscle
CN III

208

pterygopalatine ganglion = Parasympathetic ganglia of which CN

VII = lacrimal gland, oral and nasal mucosa

209

submandibular ganglion = Parasympathetic ganglia of which CN

CN VII = sublingual and submandibular salivary glands

210

Parasympathetic ganglia: otic ganglia = of which CN

CN IX = parotid salivary gland

211

S2-S4 = Parasympathetic ganglia that innervate

large intestine rectum genitalia, ureters, urinary bladder

212

what neurotransmitter is used in Parasympathetic ganglia of the CN's

both pre and post ganglionic synapses = AcH

213

sympathetic ganglia Nt

NE except on adrenal medulla where it is AcH

214

all sympathetic preganglionic neurons enter the paravertebral ganglion chain via the _ ramus

white (myelinated)

215

post ganglionic sympathetic nerves to peripheral organs are carried via the _ ramus

grey (unmelinated)

216

when does neurulation begin

3rd week

217

neurulation is the stage of organogenesis in vertebrae embryos, during which the neural tube is transformed into primitive structures that will develop into the

CNS

218

closure of the neural tube occurs in the middle and then moves anteriorly and posteriorly. failure to close the neural tube anteriorly causes

anencephaly = forebrain and skull degeneration = always fatal

219

failure to close the posterior neural tube =

spina bifida = in most severe form wont form the neural plate

220

dentist sticks paper into root canal to dry it out. Patient jumps up from pain. which type of primary afferent fiber carries info related to sharp pain and temperature
A-alpha fibers/A-beta fibers/A-delta fibers/C-nerve fibers

A-delta fibers

221

All the A fiber nerves (A-alpha fibers/A-beta fibers/A-delta fibers) are myelinated/unmyelinated

myelinated

222

the C-nerve fibers are myelinated/unmyelinated

unmyelinated

223

the thicker the nerve fiber, the _ the information travels in it

faster

224

__ nerve fiber carry info related to proprioception (muscle sense)

A-alpha

225

__ nerve fiber carry info related to touch

A-beta

226

_ nerve fiber carry info related to pain and temperature

A-delta

227

_ nerve fiber carry info related to pain, temperature and itch

C-nerve

228

mnemonic to remember the nerve fibers?

A-alPha = Proprioception
A-beTa = Touch
A-delTa = touch and pain
C- nerve = touch pain and itCh

229

all autonomic preganglionic synapses have _ as NT and _ receptors

AcH nicotinc

230

all postganglionic parasympathetic synapses have _ as NT and _ receptors

AcH
muscarinic

231

most postganglionic sympathetic synapses have _NT and _ receptor

NE adrenergic

232

most preganglionic sympathetic synapses at adrenal medulla have _NT and _ receptor

AcH nicotinic receptor and release E (80%) and NE (20%)

233

sympathetic postganglionic NT at sweat glands? receptor?

AcH muscarinic

234

the only excitatory cell in the cerebellum:
basket cells/stellate cells/granule cells/purkinje cells/Golgi cells

granule cells

235

Nystagmus

involuntary eye movement

236

dysmetria

altered range of motion (misjudge distance)

237

ataxia

altered voluntary movement
abnormal gait and uncoordinated movements

238

dysfunctions of cerebellum?

"DIVA"
dysmetria, intention tremor (oscillating motion esp head during movement), vestibular signs (nystagmus, head tilt), ataxia

239

three layers of cerebellar cortex

molecular layer (most superficial)
purkinje layer (middle)
granular layer (deepest)

240

the _ layer of cerebellar cortex contains axons of granule, basket, and stellate cells

molecular

241

the Purkinje layer of cerebellum contains a single layer of large neuronal cell bodies =

purkinje cells

242

the granular layer of cerebellum contains

granule cells

243

the only output neuron from the cerebellar cortex are_ cells that utilize _

Purkinje cells = GABA to inhibit neurons in deep cerebellar nuclei

244

Granule cells use _ as an excitatory transmitter = excites Purkinje cells

granule cells

245

_ cells in cerebellar cortex are inhibitory interneurons that use GABA to inhibit Purkinje cells

Basket

246

behavior hearing speech vision and memory = _ lobe

temporal

247

balance and coordination

cerebellum

248

intelligence language reading and sensation = lobe?

parietal

249

behavior intelligence memory movement = _ lobe?

frontal lobe

250

t/f the dorsal root ganglion is a collection of cell bodies for afferent nerve fibers that exits just outside of the spinal cord

true

251

there is no ventral root ganglion t/f

true

252

there is no ventral root ganglion bc the motor efferent fibers have their cell bodies in the _

ventral horns of the spinal cord

253

the spinal cord extends from the base of the skull to about _ down the back

2/3

254

the spinal cord runs thru the

vertebral canal

255

In the developing NS, the __ is the region of the neural tube ventral to the sulcus limitans

basal plate

256

neurons found in the basal plate are mostly motor or sensory

motor

257

neurons found in the alar plate are mostly motor or sensory

sensory

258

afferent nerves are what type

pseudo-unipolar type = have an axon with 2 branches that act as a single axon

259

upper motor neurons UMN are motor neurons that originate in the

motor region of the cerebral cortex or brainstem

260

do UMN directly stimulate the target muscles?

no. the main effector neurons for voluntary movement lie with layer V of the primary motor cortex and are called BERTZ CELLS

261

Lower motor neurons are classified based on the type of muscle fiber they innervate:
name the two kinds of LMN's

alpha motor neuron and gamma motor neuron

262

1. ___ motor neurons innervate extrafusal muscle fibers - the most numerous type of muscle fiber and the one involved in muscle contraction.

alpha

263

gamma motor neurons innervate _ muscle fibers which together with sensory afferents compose muscle spindles. these are part of the system for sensing body position (proprioception)

intrafusal

264

__ muscle fibers are skeletal muscle fibers that serve as specialized sensory organs (proprioceptors) that detect the amount and rate of change in length of a muscle

Intrafusal

265

intrafusal muscle fibers constitute the muscle spindle and are innervated by two axons, one sensory and one motor. why are they called intrafusal?

Intrafusal muscle fibers are walled off from the rest of the muscle by a collagen sheath. This sheath has a spindle or "fusiform" shape, hence the name "intrafusal

266

__muscle fibers are the skeletal standard muscle fibers that are innervated by alpha motor neurons and generate tension by contracting, thereby allowing for skeletal movement. They make up large mass of skeletal (striated) muscle and are attached to bone by fibrous tissue extensions (tendons).

Extrafusal

267

in the peripheral nervous system, which fibers carry impulses to smooth and cardiac muscle as well as to glands: visceral efferent/afferent?

visceral efferent fibers

268

fibers of peripheral nervous system are either somatic/visceral and either sensory or motor. somatic sensory fibers (afferent) carry impulses from

cutaneous and proprioceptive receptors

269

visceral _ fibers carry impulses from the viscera

sensory(afferent)

270

_ fibers carry impulses to skeletal muscle

somatic motor fibers (efferent)
(from cortical levels to skeletal muscles and are all voluntary)

271

visceral motor (efferent fibers) carry impulses to

smooth and cardiac muscles and glands
(from hypothalamus and midbrain and are involuntary, but have input from the cortex and thalamus)