Msk Final Flashcards

(289 cards)

1
Q

Autoimmune disorder attaching schwann cells causing demyelination in the peripheral nervous system

A

Guillian barre

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2
Q

hypaxial/ Extrinsic back muscles are innervated by who

A

CN11 and brachial plexus branches

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3
Q

epaxial/ intrinsic back muscles are innervated by who

A

dorsal rami of spinal nerves

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4
Q

what muscles make up the erector spinae group of intrinsic back muscles? They extend and laterally flex vertebral column.

A

spinalis, longissimus, iliocostalis

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5
Q

what muscles make up the transversospinalis group of intrinsic back muslces

A

rotatores, multifidus, semispinalis

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6
Q

what modalities are carried by dorsal root fibers

A

sensory

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7
Q

what modalities are carried by dorsal ramus of spinal nerve

A

sensory and motor

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8
Q

what modalities are carried by ventral root fibers

A

motor

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9
Q

what modalities are carried by ventral ramus of spinal nerve

A

sensory and motor

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10
Q

insertion, action, and innervation of splenius cervicis (originates at nuchal ligament)

A

transverse process of C-3
extend head/ neck, lateral flexion and rotation of neck
dorsal rami of spinal nerves

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11
Q

insertion, action, and innervation of splenius capitis

A

lateral part of mastoid process
extend head/ neck, lateral flexion and rotation of neck
dorsal rami of spinal nerves

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12
Q

action, blood supply, and innervation of iliocostalis (runs from iliac crest to lumbar, thoracic, and cervical transverse processes)

A

extend and laterally flex vertebral column
posterior intercostal and lumbar aa.
dorsal rami of spinal nerves

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13
Q

action, blood supply, and innervation of longissimus

A

extend/ lateral flex vertebral column
posterior intercostal aa. for thoracis and cervicis portions
occipital a. for capitis portion
nerve: dorsal rami

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14
Q

action, blood supply, and innervation of spinalis m. (thoracis, cervicis, capitis portions)

A

extend and lateral flex vertebral column
posterior intercostal aa.
dorsal rami

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15
Q

blood supply and innervation for semispinalis

A

cervicis and capitis: deep cervical a.
thoracis: posterior intercostal aa.
all are innervated by dorsal rami

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16
Q

muscle running from transverse process of one vertebra to spinous process of the vertebra superiorly

A

multifidus (attach to tip of spinous process)

rotatores (2 bellies attach at base of spinous process)

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17
Q

blood supply, innervation, and action of multifidus

A

posterior lumbar arteries
dorsal rami
stabilize vertebra during localized movement

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18
Q

blood supply, innervation, and action of rotatores

A

posterior intercostal arteries
dorsal rami
extend head and spine and rotate contralaterally

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19
Q

what is the only intrinsic back muscle that receives BOTH ventral and dorsal contribution from spinal nerves

A

intertransversari m.

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20
Q

blood supply to interspinales

A

vertebra, occipital, posterior intercostal aa.

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21
Q

blood supply to intertransversari

A

deep cervical, vertebral, posterior intercostal aa.

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22
Q

blood supply to legator costarum

A

posterior intercostal a.

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23
Q

which ligament surrounds the dens holding it in place

A

transverse ligament of the atlas

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24
Q

ligament holding atlas and axis together posteriorly

A

deep: cruciate ligament
superficial: tectorial membrane

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25
the mm. of the sub occipital region are all innervated by dorsal rami of which spinal nerve?
C1: sub occipital nerve
26
rectus capitis posterior major and minor, obliquus capitis superior and inferior are postural muscles that aid extension and rotation at which joint
atlantoaxial joint (they are sub occipital muslces)
27
what are the borders and contents of sub occipital triangle
boarders: obliquus capités superior and inferior and rectus capitis major contents: suboccipital n. and vertebral a.
28
which vertebrae have foramina in their transverse process
cervical
29
which vertebrae have bifid spinous process
cervical
30
which vertebrae have facets for ribs
thoracic
31
which vertebrae have greatest ROM
cervical
32
which vertebrae have greatest strain
lumbar (dispace energy to pelvis)
33
where does ligamentum flavum run
just anteriorly to the spinous process of vertebra
34
what structure surrounds nucleus pulpous to help maintain intervertebral joints
annulus fibrosus
35
what supplies blood to the vertebra
cervical- vertebral/ cervical aa thoracic- posterior intercostal as lumbar- subcostal and lumbar aa sacral- iliolumbar/ sacral aa
36
what are the 2 enlargements of the spinal cord
cervical, lumbar
37
what is the outermost meningeal covering of the spinal cord
dura mater
38
which layer of spinal cord meningeal covering contains circulating CSF
arachnoid mater (middle layer)
39
what is the innermost layer of meningeal covering for the spinal cord and what connects it to the spinal cord
pia mater | denticulate ligaments
40
spinal nerve roots are partially covered by which meningeal layer
dura mater
41
which ribs are considered false ribs since they articulate with the sternum via cartilage rather than bone
8-10
42
which ribs are considered floating since they do not have their own cartilaginous or bony attachment to the sternum
11 and 12
43
what are the 3 components of the sternum
manubrium, body, xiphoid
44
which rib inserts to the xiphosternal joint?
7th
45
which rib inserts to the manubrosternal joint
2
46
mammary glands are classified as what
modified sweat glands
47
the breast rests on what superficial structure
pectoral fascia
48
name the potential space between breast and pectoral fascia
retromammary space
49
breast is innervated by what
intercostal nn 4-6
50
mammary gland lobules condense and drain into what structure before converging on the nipple
lactiferous ducts then sinuses
51
mammary gland lobules are separated by what named structure that also attaches to dermis of overlaying skin
suspensory ligament (Cooper's ligament)
52
arterial supply to breast tissue comes from where
axillary a. (via mammary branches) | internal thoracic a.
53
what causes rapid metastasis of breast cancer
lots of lymph drainage to axillary nodes
54
lymph from nipple, aerola, and lactiferous lobules drains to what
subareolar lymph nodes
55
75% of breast lymph drains to what
axillary nodes (pectoral, central, apical)
56
what innervates breast tissue
supraclavicular nn. | intercostal nn 4-6 (mammary branches)
57
deltopectoral (clavipectoral) triangle borders
deltoid, pec major, middle 1/3 of clavicle
58
deltopectoral (clavipectoral) triangle contents
cephalic vein deltopectoral lymph nodes deltoid branch of thoracoacromial a. (from axillary a)
59
what kind of fascia encloses the pec major
pectoral fascia
60
what kind of fascia encloses the subclavius and pec minor
clavipectoral fascia
61
contents of clavipectoral triangle pierce which layer of fascia
clavipectoral fascia
62
the clavipectoral fascia becomes what inferior to the pec minor
suspensory ligament of the axilla
63
innervation and blood supply to pec major
pectoral branch of thoracoacromial arterial trunk | lateral and medial pectoral nn. (C5-T1)
64
innervation and blood supply to pec minor
pectoral branch of thoracoacromial arterial trunk | medial pectoral n (C8-T1)... this also pierces the muscle
65
innervation and blood supply to subclavius
clavicular branches of thoracoacromial trunk | nerve to subclavius (C5-6)
66
innervation and blood supply to serratus anterior
lateral thoracic a | long thoracic n. (C5,6,7)
67
peau d'orange (skin resembling orange peel) of the breast indicates what
blockage of cutaneous lymph vessels
68
breast elevates when woman places hands on hips and lesses elbows foreword indicates what is happening
invasion of pec major by the cancer
69
finger sized dimple in superiolateral quadrant of breast indicates what condition
shortening of suspensory ligaments by cancer in axillary tail of breast
70
action of pec major
adduct, medial rotate, flex, extend humerus anterior and inferior movement of scapula
71
action of pec minor
stabilize scapula
72
action of subclavius
depress and anchor scapula
73
action of serratus anterior
protraction and upward rotation of scapula
74
thoracoacromial trunk of axillary artery has what branches
acromial, deltoid, pectoral
75
what muscle is responsible for splitting the axillary artery into its 3 major regions in the clavipectoral region
pec minor
76
what major branch is given off of the axillary artery in part 1 (proximal to p minor)
superior thoracic a
77
what major branch is given off of the axillary artery in part 2 (posterior to p minor)
thoracoacromial trunk
78
what major branch is given off of the axillary artery in part 3 (distal to p minor)
subscapular a (circumflex scapular and thoracodorsal branches) anterior circumflex humeral posterior circumflex humoral
79
what are the anastomosing arterial branches of the scapula
suprascapular, dorsal scapular, posterior intercostal aa, circumflex scapular, thoracodorsal a
80
what are the 2 superficial venous contributions to axillary vein in the pectoral region
cephalic v | basilic v
81
what are the boundaries of axilla
anterior: pec major and minor posterior: scapula and subscapularis lateral: humerus (intertubercular sulcus and biceps tendon)
82
what all is contained in the axillary sheath
axillary v axillary a brachial plexus
83
shoulder joints are held together by which ligaments
coracoclavicular (trapezoid and conoid) coracoacromial glenohumeral (superior, middle, inferior)
84
what are the rotator cuff muscles of the shoulder
subscapularis supraspinatus infraspinatus teres minor
85
long thoracic n (C5, 6, 7) innervates which muscle
serratus anterior
86
blood supply and innervation to deltoid
deltoid branch of thoracoacromial arterial trunk | axillary n
87
blood supply and innervation to trees major
circumflex scapular a | lower sub scapular n
88
the transverse ligament of the humerus wraps around what holding it in the inter tubercular groove of the humerus
biceps tendon
89
what articulates with the greater tubercle of the humerus
supraspinatus, infraspinatus, teres minor
90
what articulates with the lesser tubercle of the humerus
subscapularis
91
blood supply and innervation to supraspinatus
suprascapular a | suprascapular n
92
blood supply and innervation to subscapularis
subscapular a | upper and lower subscapular nn
93
largest and strongest rotator cuff muscle
subscapularis
94
injuries to which rotator cuff muscle can lead to occipital tendon instability and biceps tendonitis
subscapularis
95
blood supply and innervation to infraspinatus
``` suprascapular a suprascapular n (C5-6) ```
96
blood supply and innervation to trees minor
circumflex scapular a | axillary n
97
what arterial branches come from the subclavian artery medial to the anterior scalene m
internal thoracic a vertebral a thyrocervical arterial trunk
98
what are the 4 branches of the thyrocervical arterial trunk
transverse cervical a inferior thyroid a ascending cervical a suprascapular a
99
what arterial branches come from the subclavian artery posterior to the anterior scalene m
costocervical arterial trunk (supreme intercostal and deep cervical artery)
100
this special artery can arise from subclavian artery or from the transverse cervical artery (30% of the time)
dorsal scapular a (always runs along vertebral border of scapula
101
the most superficial "space" of the posterior shoulder
triangle of auscultation
102
trees major, trees minor, and the long and lateral heads of triceps brachii all converge at the posterior shoulder to make what 3 spaces
``` triangular space (circumflex scapular a) quadrangular space (axillary n, post circumflex humeral a) triangular interval (deep brachial a, radial n) ```
103
first long bone to completely ossify (can present as congenital pseudoarthrosis or poorly healed fracture if ossification fails)
clavicle
104
what muscles abduct humerus
deltoid | supraspinatus
105
what muscles adduct humerus
teres major
106
what muscles flex humerus
deltoid
107
what muscles extend humerus
deltoid
108
what muscles lateral rotate humerus
infraspinatus, teres minor, deltoid
109
what muscles medial rotate humerus
trees major, subscapularis, deltoid
110
what muscles protract scapula
serratus anterior
111
what muscles depress scapula
serratus anterior
112
what muscles upward rotate scapula
serratus anterior
113
impingement syndrome in the shoulder can involve what two structures
subacromial bursitis | supraspintaus tendonitis
114
which tendon likely tears in a "rotator cuff tear"
supraspinatus tendon
115
size of quadrangular space is reduced compressing what structure
axillary n (or posterior circumflex humeral artery)
116
what nerve supplies the skin over the forearm
lateral and medial antebrachial cutaneous n
117
the main arterial supply for the superficial palmar arch comes from what a
ulnar a
118
the main arterial supply for the deep palmar arch comes from what a
radial a
119
superficial muscles of the forearm (lateral to medial)
pronator teres flexor carpi radialis palmaris longus flexor carpi ulnaris
120
intermediate (layer 2) muscles of the forearm (lateral to medial)
flexor digitorum superficialis
121
deep muscles of the forearm (lateral to medial)
flexor pollicis longus, flexor digitorum profundus, pronator quadratus
122
blood supply and innervation for pronator teres
anterior ulnar recurrent a | median n
123
blood supply and innervation for flexor carpi radialis
ulnar a | median n
124
blood supply and innervation for palmaris longus
ulnar a | median n
125
blood supply and innervation for flexor carpi ulnaris
ulnar a | ulnar n
126
blood supply and innervation for flexor digitorum superficialis
ulnar a | median n
127
blood supply and innervation for flexor digitorum profundus
anterior interosseous a | median and ulnar nn
128
blood supply and innervation for flexor pollicis longus
anterior interosseous a | median n via anterior interosseous n
129
blood supply and innervation for pronator quadratus
anterior interosseous a | median n via anterior interosseous n
130
which nerve runs just superficial to the medial epicondyle of the humerus before supplying intrinsic hand mm
ulnar nerve
131
the median n pierces which forearm m
pronator teres
132
which nerve runs through the carpal tunnel making it susceptible to compression during carpal tunnel syndrome
median n
133
the anterior interosseous n and a run just deep to what muscle
pronator quadratus
134
What cutaneous innervations of the dorsum of the hand contain?
Ulnar nerve- lateral 2.5 fingers and lateral metatarsals/carpals Radial nerve- thumb, index, and half. Of middle finger and skin proximal to those fingers Median nerve- index and middle fingers distal to PIP joint
135
What muscles make up the radialis group
Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis
136
Which muscles make up the superficial layer of the posterior forearm
extensor carpi ulnaris Extensor digiti minimi Extensor digitorum
137
Which muscles make up the deep layer of the posterior forearm
``` Extensor indicus Extensor pollicis longus Extensor pollicis brevis Adductor pollicis longus Supinator ```
138
What is the common extensor origin of the forearm
Lateral epicondyle of humerus
139
All muscles of the posterior forearm are innervated by who
Radial nerve (deep branch or posterior interosseous n)
140
Superficial branch of the radial nerve does what
Cutaneous innervation in lateral hand
141
Blood supply and innervation to brachioradialis
Radial collateral and recurrent radial aa | Radial n
142
What is the action of brachioradialis
Flex forearm when pronated
143
Blood supply and innervation to extensor carpi radialis longus
Radial collateral, radial recurrent, radial interosseous aa | Radial n
144
Blood supply and innervation to extensor carpi radialis brevis
Radial collateral, radial recurrent, recurrent interosseous aa Deep branch of radial n
145
Blood supply and innervation to extensor digitorum
Posterior interosseous, recurrent interosseous, perforating branches aa Posterior interosseous n
146
Blood supply and innervation to extensor digiti minimi
Posterior interosseous, recurrent interosseous, perforating branches aa Posterior interosseous n
147
When extensor digitorum contracts it. Pulls what structure causing IP joints to extend?
Extensor expansion (extensor hood mechanism)
148
Blood supply and innervation to extensor carpi ulnaris
Radial collateral, radial recurrent, recurrent interosseous aa Posterior interosseous n
149
Blood supply and innervation to supinator
Radial, posterior interosseous, radial recurrent aa Deep branch of radial n
150
Blood supply and innervation to extensor indicus
Posterior interosseous and perforating branch aa | Posterior interosseous n
151
Blood supply and innervation to adductor pollicis longus
Posterior interosseous a | Posterior interosseous n
152
Blood supply and innervation to extensor pollicis brevis
Posterior interosseous and perforating branch aa | Posterior interosseous n
153
Blood supply and innervation to extensor pollicis longus
Posterior interosseous a | Posterior interosseous n
154
What is the anastomosis in the hand
Radial artery contributes to both deep palmar arch and dorsal carpal arch
155
The deep branch of the radial nerve continues as the posterior interosseous nerve. After passing through what structure
Supinator m
156
Which artery and bone lie deep to the anatomical snuff box
Radial a | Scaphoid bone
157
Which structures are ruptured in a shoulder separation but not a shoulder dislocation
Acromioclavicular ligament (and sometimes other shoulder ligaments as well)
158
What nerve is most commonly injured with shoulder dislocation
Axillary n
159
When do upper limbs form? Lower limbs?
Day 26- arms | Day 27/28- Legs
160
What layer gives rise to limbs
Somatic layer of lateral plate mesoderm
161
Mesenchyme thickens at the surface to direct limb bud formation at what named structure
Apical ectodermal ridge
162
What signal causes mesenchyme to migrate and proliferate?
FGF8
163
What genes direct limb bud formation proximal to distal? What takes over as they get farther from the axial skeleton?
HOX genes until RA takes over (tells mesenchyme which bones to form from proximal) FGF8 signals at distal end
164
First cells to be exposed to RA become humerus and femur and are called what
Stylopod
165
cells that when exposed to RA become radius/ulna or tibia/fibula and are called what
Zeugopod
166
Last cells to be exposed to RA become carpels, metacarpals, tarsals, metatarsals, digits and are called what
Autopod
167
When do hand and foot plates appear along with chondrification centers appear in developing embryo?
Week 5
168
When do digital rays of hands appear in developing embryo? (Entire limb skeleton is cartilage)
Week 6
169
What occurs that removes webbing between our digits? When does this occur in developing embryo?
Apoptosis | Week 8
170
When do digital rays of feet form in developing embryo (and osteogenesis of long bones begins along with limb rotation)
Week 7
171
Limb musculature is derived from what
Dorsolateral cells of somites
172
During week 7, upper limbs rotate 90 degrees in which direction
Lateral rotation
173
During week 7, lower limbs rotate 90 degrees in which direction
Medial rotation
174
Cranial surface (preaxial/anterior) surface of the upper limb includes what features
Thumb and radius
175
Caudal surface (postaxial/posterior) surface of the upper limb includes what features
Ulna and little finger
176
Motor axons from spinal cord enter limb buds when during development
Week 5
177
What generates first motor or sensory axons?
Motor
178
Neural crest cells are doing what with the PNS during week 5 of development
Making sensory axons and schwann cells (myelination)
179
In the developing embryo what is the main blood. Supply. To the lower limb (before it gets taken over. By femoral a)
Deep femoral a (profunda femoris a)
180
Most common musculoskeletal defect: sole of foot turned medially and foot is inverted (more common in males) fixed usually by casting
Club foot
181
Musculoskeletal defect occurs more in females and involves under development of acetabulum of hip bone and joint laxity
Developmental hip dysplasia
182
Patterning and positioning of limbs along craniocaudal axis is regulated by what genes
HOX (also control type and shape of the bones in limbs)
183
Proximodistal growth and patterning of limbs occurs at what area and requires what type of signalling
Apical ectodermal ridge, FGF signalling
184
Dorso-ventral patterning helps us form flexor and extensor surfaces of limbs. The ventral surface is maintained by ___ signaling and dorsal is maintained by ___ signaling. These signals set up the apical ectodermal ridge
BMPS (ventral) | Wnt7 (dorsal)
185
Anterior posterior patterning of the limb is controlled by establishing what zone on posterior side of limb? What signal signals this posterior region?
Zone of polarizing activity | Shh and RA
186
Loss of ZPA (zone of polarizing activity) results in what
Loss of posterior elements (digits 3-5 or ulna) and you WILL have a thumb
187
Upregulation of ZPA (zone of polarizing activity) results in what
Polydactyly (extra digits) and you WILL have a thumb
188
Duplication of ZPA (zone of polarizing activity) results in what
Polydactyly::: Duplication of posterior elements (digits 3-5 mirrored on both sides of the "thumb" but may not have fingers with only 2 phalanges)
189
Which elements form first: posterior (little finger/ ulna) or anterior elements (thumb/ radius)
Posterior forms first! | Thus disruption of anteroposterior patterning= loss of anterior elements
190
Congenital joint contractures of 1 or more joints possibly caused by neurologic defect, muscular abnormalities, fetal crowding
Arthrogryposis
191
Vascuature remodeling occurs in the forearm and most people lose this artery but it canremain in some people
Median a
192
Abnormal short digits due to week 6 malfunction
Bradydactyly
193
Fusion of digits because apoptosis fails in week 8
Syndactyly
194
Development of limbs close to the body is called __ and can occur after mama bear takes what med?
Phocomelia , Thalidomide
195
MOA for phocomelia
FGF does not signal AER correctly causing the short limbs
196
Absence of limbs
Amelia (wk 4 upper limbs, wk 5 lower)
197
Absence of part of limb and the two sub types
Meromelia (hemimelia is missing a bone like ulna, phocomelia is limb develop close to body)
198
Which stage of limb development is most affected in hemimelia
Zeugopod
199
what are the steps involved in neurotransmission at the neuromuscular junction
ACh synthesis, storage, release, destruction leads to muscle contraction
200
enzyme that combines acetyl coA and choline to form ACh
choline acetyltransferase (ChAT)
201
alzheimer patients have reduced cerebral production of what ACh forming enzyme?
ChAT
202
by what mechanism is ACh shuttled into storage vesicles after synthesis
ACh vesicular transporter + ATP
203
upon depolarization, what kind of voltage gated channels open?
Ca++ channels open and calcium flows in
204
what is the role of calcium in NMJ transmission
promotes vesicle fusion to the presynaptic membrane
205
what are the vesicular and plasma membrane proteins that initiate vesicle plasma membrane fusion to release ACh
VAMP and SNAP (they are SNAREs)
206
what is known to block the snare complex thus inhibiting release of ACh from the presynaptic neuron
botulinum toxin (BOTOX)
207
enzyme that cleaves ACh into cholineand acetate so that choline can go back to motor neuron for reuse
acetylcholinesterase
208
sodium potassium pumps in the presynaptic membrane of the NMJ create a sodium gradient that is used to bring what into the cell for recycling in making neurotransmitter
choline
209
what is the effect of an acetylcholinesterase inhibitors
increase ACh
210
what type of ACh receptor do you find in skeletal muscle
nicotinic
211
where do we often find muscarinic ACh-R's
smooth muscle mostly but also cardiac muscle
212
what type of channel is a nicotinic ACh-R?
ligand gated na+ channel
213
what type of channel is a muscarinic ACh-R?
GPCR
214
what lines the pore of the nicotinic ACh-R?
negatively charged AA side chains (Asp, Glu)
215
what are the 3 types of nAChRs?
skeletal, peripheral neuronal, central neuronal
216
what agonists bind to muscular nicotinic ACh receptors
nicotine ACh succinyl choline
217
what antagonists bind to muscular nicotinic ACh receptors
atracurium vecuronium d-tubocurarine pancuronium
218
how can drugs target only one subtype of nicotinic ACh receptors
each subtype is made up of different subunits and these are the target for drugs that allow us to target only one subtype
219
how many molecules of ACh have to bind in order to activate a nAChR and allow Na+, K+ or Ca++ to pass through down their concentration gradient
2
220
while the motor end plate cannot perform this action itself, if enough Na+ comes in the adjacent muscle membrane can do what
depolarize (gotta reach threshold)
221
the presence of an action potential in the neuron at the NMJ causes the opening of what type of channel
voltage gated Ca++ (the calcium helps with vesicle fusion)
222
Tetrodotoxin (puffer fish) can cause weakness, dizzy, paresthesia, reflex loss, hypotension, paralysis by what MOA?
inhibiting voltage gated Na+ channels thus blocking axonal conduction
223
Local anesthetics like lidocaine, bupivacaine, procaine are used to control pain during procedures by what MOA?
inhibiting Na+ channels to inhibit axonal conduction | especially sensory neurons
224
batrachotoxin (poison dart frog) is potent and causes paralysis by what MOA?
increased Na+ permeability (persistent depolarization)
225
Botulinum toxin causes flaccid paralysis by what MOA
cleave SNARE components so neuron cannot release ACh
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tetanus toxin causes muscle spasms and rigid paralysis by what MOA
cleave SNARE components to block vesicle fusion and travel up the spinal cord (retrograde movement)
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curare alkaloids (like d-tubocurarine) are used during anesthesia to relax muscles (flaccid paralysis) by inhibiting Ach binding to receptor. whats the MOA
compete with Ach for the receptor
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this Ach agonist is used as an induction agent for anesthesia and acts by binding nAChRs causing first depolarization which continues until receptor blockade and paralysis
succinylcholine
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which of the Ach agonists is a depolarizing blocker? | which of the Ach agonists is a nondepolarizing blocker?
``` succinylcholine Curare alkaloids (non) ```
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whats the function of cholinesterase inhibitors and when do we use them?
they increase ACh at the NMJ | parkinson, alzheimer, myasthenia gravis, nerve gas, reverse neuromuscular blockade during anesthesia
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what drug inhibits ryanodine receptors in SR blocking release of ca++? when do we use it?
dantrolene | malignant hypothermia, upper motor nerve disorders
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Property of muscles : Capacity to respond to stimulus
Excitability
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Property of muscles : ability to shorten and generate pulling force
Contratility
234
Property of muscles : can strech back to original length
Extensibility
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Property of muscles : can recoil to original resting length after stretched
Elasticity
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Muscle fibers are surrounded by what structures that deliver oxygen and nutrients
Capillary beds
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Each skeletal muscle Fiber contains several nuclei. As well as what to maintain energy required for contraction
Lots of mitochondria, myoglobin
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How and when does the troponin-tropomyosin complex move to expose actins myosin binding site?
When calcium binds to troponin C, it causes the troponin-tropomyosin complex to release from the myosin binding site
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Which myofilament has ATPase activity
Myosin (thick filament)
240
If the. Power stroke. Generated by actin/myosin interaction is strong enough to move the load what type of muscle contraction results?
Isotonic (muscle shortens)
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If the. Power stroke. Generated by actin/myosin interaction is NOT strong enough to move the load what type of muscle contraction results?
Isometric (no shortening of muscle)
242
What type of Ach receptors. Do you. Find at the. Neuromuscular junction
Nicotinic
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Where. Does an action potential propagate to in a muscle cell
Through sarcolemma and down t tubules
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Voltage gated ca++ channels allow calcium out of the sarcoplasmic Reticulum and open in response to binding of what molecules
Ryanodine, DHPP
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Renal failure, blood. Clotting, and cardiac arrhythmias can result from leakage of ca++, K+, phosphate, urate, myoglobin, or lactate dehydrogenase into circulation as a result of what condition
Rhabdomyolysis (unaccustomed physical excersize)
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When bound to actin, myosin heads pull causing sarcomere to shorten. What "bands disappear" as the thin filament moves toward the center
H and I
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Which "band" in the sarcomere remains the same length during contraction
A band (myosin)
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During contraction myosin forms a bond with an actin molecule. What do we call this bond
Crossbridge
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Once a cross bridge is formed, myosin head bends and pulls itself along the actin filament. What is this motion called
Power stroke
250
What happens when ATP binds to myosin during power stroke
It releases from the actin
251
How do we. Restore calcium. Levels. After contraction
Active transport in the SR
252
After you die the cytosolic concentration of calcium rises because the muscle membrane is no longer active. calcium leaks out and moves troponin complex aside letting actin and myosin form cross bridges. Since no ATP is being generated, they cannot detach so dead muscles remain stiff. What do we call this?
Rigor Mortis
253
What mechanisms control strength of a muscle contraction
1. Motor unit recruitment | 2. Individual fiber contractility manipulation (frequency of stimulation)
254
What makes up a motor unit
1 neuron + all muscle fibers it supplies
255
What happens if two action potentials reach one muscle fiber at the same time
Summation - tension of the two is added (more time is needed for ca++ to leave after and muscle to relax)
256
What do you call it when repeated stimulation to muscle results in a plateau of tension and the muscle stays there
Tetanus
257
A decline in muscles ability to maintain a constant force of crontraction in the face of long term repetitive stimulation
Fatigue
258
Type of periodic paralysis caused by decreased blood K+ during paralytic episodes
Hypokalemic periodic paralysis
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Type of periodic paralysis caused by normal or increased blood K+ during paralytic episodes
Hyperkalemic periodic paralysis
260
Which skeletal muscle type is comprised for slow twitch fibers (high blood flow, lots of mitochondria, fatigue resistant)
Type I
261
Which skeletal muscle type is comprised for fast twitch fibers that receive HIGH blood flow and HIGH mitochondrial content (relatively fatigue resistant)
Type IIa
262
Which skeletal muscle type is comprised for fast twitch fibers that receive LOW blood flow and LOW mitochondrial content (fatigue rapidly)
Type IIb
263
Disorder where patient creates autoantibodies against nicotinic acetylcholine receptors creating muscle weakness mostly in eyelids and mouth region is called what? What do we use to treat it?
Myasthenia gravis | Treat with acetylcholinesterase inhibitor
264
how are mtDNA inherited differently from nuclear DNA
we got it from our MAMA (also we have multiple copies per cell)
265
most common mitochondrial disease: subacute loss of vision in young adults (mostly men) due to mutation in gene encoding for complex I subunits
Leber's Hereditary Optic Neuropathy (LHON)
266
this disease can be caused by mutations in nuclear or mitochondrial DNA that code for complex I or IV presenting as developmental delay, respiratory abnormality, recurrent vomiting, nystagmus, ataxia, dystonia, early death
Leigh's Syndrome.... 90% of mtDNA contains mutation
267
multisystem mitochondrial disorder where brain, muscle, endocrine are involved leading to death in young adulthood. symptoms include stroke like episodes (infarct in temporal and occipital lobes). this is an angiopathy. Treat with L-arginine to decrease stokes.
mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes (MELAS)
268
mitochondrial disorder where mutations occur in tRNA for lysine. symptoms: cervical lipomas, myoclonus, epilepsy, COX negative
Myoclonus epilepsy and ragged red fibres (MERRF)
269
what are canonical features of mitochondrial OXPHOS disorders?
recessive inheritance, reduction in cellular oxygen consumption and ATP synthesis, increased resting lactic acid, overproduction of ROS, sometimes induce autoimmune response
270
all mtDNA is encoded to create what
OXPHOS system
271
who carrie sub threshold levels of potentially harmful mtDNA mutations
normal humans like you and me - we get more as we age
272
what type of mutation auses MELAS
A to G in gene for tRNA for leucine
273
what type of mutation auses MERRF
A to G in gene for tRNA Lys
274
what tissues are most likely to accumulate mtDNA mutations
postmitotic tissue (brain, heart, muscle)
275
what important cancer causing gene also regulates respiratory chain function and glycolysis via regulating transcription and making SCO2 (loss of this gene stimulates glycolysis and TCA cycle)
p53
276
whats the crabtree effect
p53 mutation causes cancer cells to prefer glycolysis and TCA cycle and suppress OXPHOS
277
Warburg hypothesis states that mutation in nDNA encoding which two TCA cycle intermediates can lead to cancer
succinate dehydrogenase, fumarase
278
a defect in the gene product of MELAS patients
tRNA for leucine or ND1
279
a defect in the gene product of MERRF patients
tRNA for lysine
280
a defect in the gene product of LHON patients
NADH ubiquinone oxidoreductase (N1)
281
how are transmitochondiral lines created for studying mitochondrial disease and mutation load of mitochondrial mutations
making cybrids: injecting mtDNA of sick pt into empty mitochondria
282
what is the phenotypic threshold value for mtDNA deletions? for mtDMA mutations?
60% for deletions | 90% for mutations
283
different tissues have different thresholds for phenotype of mtDNA mutations. which has a higher threshold: brain or heart tissue?
heart!
284
What medication do we give in emergent situation of malignant hypothermia?
Dantrolene (blocks Ryanodine receptor)
285
cox positive mt disease
melas
286
cox negative mt disease
merrf
287
mt disease that has the red ragged fibers
merrf
288
mt disease with strokes due to angiopathy
melas
289
complex I mutation mt disease leads to blindness
lhon