Musculo - Anatomy & Physiology Flashcards Preview

USMLE (S1) Musculoskeletal > Musculo - Anatomy & Physiology > Flashcards

Flashcards in Musculo - Anatomy & Physiology Deck (177)
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1
Q

What layer is found directly below the epidermis?

A

Dermis

2
Q

How many layers are found in the epidermis?

A

Five

3
Q

What is the name of the most superficial layer of the epidermis?

A

Stratum corneum

4
Q

What is the name of the deepest layer of the epidermis?

A

Stratum basalis

5
Q

What layer of the epidermis is found just superficial to the stratum basalis?

A

Stratum spinosum

6
Q

What layer of the epidermis is found just deep to the stratum corneum?

A

Stratum lucidum

7
Q

What layer of the epidermis is found between the stratum spinosum and the stratum lucidum?

A

Stratum granulosum

8
Q

Name the layers of the epidermis from the surface to the base.

A

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basalis (remember: Californians Like Girls in String Bikinis)

9
Q

Which epithelial cell junction prevents diffusion across the paracellular space?

A

Zona occludens

10
Q

What is another name for the zona occludens?

A

Tight junctions

11
Q

Which epithelial cell junction surrounds the perimeter just below the zona occludens?

A

Zona adherens

12
Q

Cadherins depend on what ion for their function?

A

Calcium

13
Q

Which epithelial cell junctions are small, discrete sites of attachment?

A

Macula adherens

14
Q

Which epithelial cell junctions allow adjacent cells to communicate for electric and metabolic functions?

A

Gap junctions

15
Q

Which epithelial cell junction connects cells with the underlying extracellular matrix?

A

Hemidesmosome

16
Q

The zona occludens is composed of what two substances?

A

Occludins and claudins

17
Q

The zona adherens contains which kind of filaments?

A

Actin filaments

18
Q

In the zona adherens, _____ molecules attach to _____ molecules in the cell to form a perimeter just below the zona occludens.

A

Cadherins; actin

19
Q

Which protein anchors macula adherens within the epithelial cell?

A

Keratin

20
Q

What is another name for zona adherens?

A

Intermediate junction

21
Q

What is another name for the macula adherens?

A

Desmosome

22
Q

Gap junctions are formed from ______ that have a central channel that allow adjacent cells to communicate for electric and metabolic functions.

A

Connexons

23
Q

A hemidesmosome is formed from ______ in the cell binding to ______ in the basement membrane to keep cells connected to the underlying extracellular matrix.

A

Integrin; lamin

24
Q

The medial collateral, medial meniscus, and anterior cruciate ligaments are commonly injured when a person plays which sport?

A

Football

25
Q

The terms anterior and posterior with regard to the cruciate ligaments refer to the sites of ______ attachment.

A

Tibial

26
Q

The positive anterior drawer sign is an indication of the tearing of which knee ligament?

A

Anterior cruciate ligament

27
Q

Abnormal passive abduction of the knee indicates that what ligament is torn?

A

Medial collateral ligament

28
Q

What ligament attaches the lateral condyle of the femur to the anterior aspect of the tibia?

A

Anterior cruciate ligament

29
Q

What ligament attaches the medial condyle of the femur to the posterior aspect of the tibia?

A

Posterior cruciate ligament

30
Q

What ligament attaches the medial condyle of the femur to the medial aspect of the tibia?

A

Medial collateral ligament

31
Q

What ligament attaches the lateral condyle of the femur to the lateral aspect of the tibia and fibula?

A

Lateral collateral ligament

32
Q

Name the cartilage that cushions the area between the medial condyle of the femur and the medial aspect of the tibia.

A

Medial meniscus

33
Q

Name the cartilage that cushions the area between the lateral condyle of the femur and the lateral aspect of the tibia.

A

Lateral meniscus

34
Q

Sensation from which nerve can be blocked by injection of local anesthetic near the ischial spine?

A

Pudendal nerve

35
Q

Pudendal nerve blocks are used to relieve pain in what clinical situation?

A

Childbirth

36
Q

Describe the location of McBurneys point.

A

Two thirds of the way from the umbilicus to the anterior superior iliac spine

37
Q

What is located at McBurneys point?

A

Pain due to appendicitis localizes to McBurneys point

38
Q

Where is the needle inserted during a lumbar puncture?

A

Between vertebrae at the level of the iliac crest

39
Q

Name the muscles that make up the rotator cuff.

A

Supraspinatus, infraspinatus, teres minor, subscapularis (remember: SItS; small t is for teres minor)

40
Q

Which rotator cuff muscle helps the deltoid abduct the arm?

A

Supraspinatus

41
Q

Which rotator cuff muscle laterally rotates the arm?

A

Infraspinatus

42
Q

Which rotator cuff muscle adducts and laterally rotates the arm?

A

Teres minor

43
Q

Which rotator cuff muscle medially rotates and adducts the arm?

A

Subscapularis

44
Q

Which muscles insert on the posterior aspect of the humerus?

A

Infraspinatus and teres minor

45
Q

Which muscle of the rotator cuff is found on the anterior aspect of the humerus?

A

Subscapularis

46
Q

Which muscle of the rotator cuff is found on the superior aspect of the humerus?

A

Supraspinatus

47
Q

Fracture of the surgical neck or dislocation of the humerus can traumatize which nerve?

A

Axillary nerve

48
Q

Midshaft fracture of the humerus damages what nerve?

A

Radial nerve

49
Q

Sublaxation of the radius causes trauma to which nerve?

A

Deep branch of the radial nerve

50
Q

The recurrent branch of the medial nerve can be damaged by a superficial laceration to what surface?

A

The palm of the hand

51
Q

What nerve root is commonly compressed by a cervical disk lesion?

A

C7

52
Q

A Pancoasts tumor can compress what trunk of the brachial plexus?

A

Lower trunk

53
Q

Compression of the lower trunk of the brachial plexus can lead to nerve injury known as what?

A

Klumpkes palsy

54
Q

Improper use of crutches can compress what nerve?

A

Radial nerve

55
Q

Supracondylar fracture of humerus can compress what nerve causing what syndrome?

A

Median nerve; pronator teres syndrome

56
Q

Fracture of what specific part of the humerus can cause ulnar nerve trauma?

A

Medial epicondyle

57
Q

The anterior interosseous nerve is at risk for compression where?

A

The deep forearm

58
Q

Name the nerve compressed in carpal tunnel syndrome.

A

Median nerve

59
Q

A dislocated lunate will affect which nerve?

A

Median nerve

60
Q

Trauma to the heel of the hand can cause damage to which nerve?

A

Ulnar nerve

61
Q

Fracture of hook of hamate can disrupt which nerve?

A

Ulnar nerve

62
Q

A patient presents with a waiters tip deformity after being thrown from a motorcycle. What cervical roots have been injured?

A

C5 and C6

63
Q

A lesion of the lower trunk of the brachial plexus would cause what notable sign on physical exam?

A

A total claw hand (Klumpkes palsy)

64
Q

A lesion at what cord of the brachial plexus would cause damage to the axillary and radial nerves?

A

Posterior cord

65
Q

Injury to the posterior cord of the brachial plexus would produce what sign on physical exam?

A

Wrist drop

66
Q

A patient presents with a winged scapula. What nerve has been injured?

A

Long thoracic nerve

67
Q

Deltoid paralysis is caused by injury to what nerve?

A

Axillary nerve

68
Q

A patient presents with Saturday night palsy, which consists of a wrist drop. What nerve was most likely injured?

A

Radial nerve

69
Q

A solitary lesion of what nerve within the brachial plexus might make it difficult to flex the elbow?

A

Musculocutaneous nerve

70
Q

A patient is unable to move his thumb. Physical exam reveals a Popes blessing sign. If the cause is nerve damage, what is the principal nerve that is involved?

A

Ulnar nerve

71
Q

What muscle protects the brachial plexus during a clavicle fracture?

A

Subclavius muscle

72
Q

A waiters tip results from lesions at what two nerve roots?

A

C5 and C6

73
Q

Name the order in which the brachial plexus divides.

A

The order is Roots, Trunks, Divisions, Cords, and Branches (remember: Randy Travis Drinks Cold Beer)

74
Q

A patient with a fractured surgical neck of the humerus could demonstrate what sensory and motor deficits?

A

Inability to abduct the arm at the shoulder, lack of sensation over the deltoid muscle

75
Q

A patient presents with a flattened deltoid. Name the two injuries that could result in this finding.

A

Fractured surgical neck of the humerus and dislocation of the humeral head resulting in axillary nerve injury

76
Q

A patient suffers a midshaft humerus fracture damaging the extensor compartment. He has a wrist drop. What sensory deficit is expected?

A

Deficit over the posterior arm and dorsal hand

77
Q

What is the cause of Saturday night palsy?

A

Extended compression of the axilla by the back of a chair or crutches resulting in radial nerve injury

78
Q

A patient presents with inability to extend his wrist, fingers (at the metacarpophalangeal joint), and thumb. What nerve is damaged?

A

Radial nerve

79
Q

Injury to the radial nerve may result in what sign on physical exam?

A

Wrist drop

80
Q

A patient presents with a loss of sensation over the lateral palm, the thumb, and the radial two and one half fingers. What fracture may have caused the deficit?

A

Supracondylar fracture of the humerus

81
Q

A patient has a supracondylar fracture of the humerus that affects the flexors of the hand. What sensory deficit is expected?

A

Decreased sensation in the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger

82
Q

A patient has carpal tunnel syndrome involving swelling of the wrist that affects the flexors of the hand. What motor deficit is expected on physical exam of the hand? Of the thumb?

A

Cannot flex fingers; cannot abduct/oppose thumb

83
Q

A patient has carpal tunnel syndrome involving swelling of the wrist that affects the flexors of the hand. What sensory deficit is expected?

A

Decreased sensation in the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger

84
Q

A patient has a fracture at the medial condyle of the humerus that affects the flexors of the hand. What motor deficits are expected on physical exam?

A

Cannot adduct thumb or abduct or adduct fingers; claw hand

85
Q

A patient has a fracture at the medial condyle of the humerus that affects the flexors of the hand. What sensory deficit is expected on physical exam?

A

Decreased sensation in palmar and dorsal sides of fifth digit and half of fourth digit

86
Q

A patient presents with Popes blessing/hand of benediction. What physical injury causes this finding?

A

Fracture of the hook of hamate, likely from falling onto an outstretched hand, affecting the ulnar nerve

87
Q

Name the two muscle groups affected in a patient with ulnar claw hand.

A

Interossei and lumbricals

88
Q

A patient presents with decreased sensation over the lateral forearm and an inability to flex the arm at the elbow. What nerve is damaged?

A

Musculocutaneous nerve

89
Q

Name six causes of mononeuropathy.

A

Compression, trauma, diabetes, vasculitis, radiation, and inflammation

90
Q

The loss of innervation in what muscle causes pronation of the forearm in Erb palsy?

A

Biceps

91
Q

Erb-Duchenne palsy is caused by the traction/tear of what two nerve roots?

A

C5 and C6

92
Q

A patient presents with his left arm hanging to the side, medially rotated, with pronation of the forearm. What type of palsy does he have?

A

Erb-Duchenne palsy

93
Q

Name the four components of thoracic outlet syndrome.

A
  1. Atrophy of the thenar and hypothenar eminences; 2. Atrophy of the interosseous muscles; 3. Sensory deficits on the medial side of the forearm and hand; 4. Disappearance of the radial pulse upon moving the head toward the opposite side
94
Q

Thoracic outlet syndrome results from compression of the _____ artery and the _____ trunk of the brachial plexus by a cervical rib.

A

Subclavian; inferior

95
Q

What nerve of the upper extremity is known as the great extensor nerve?

A

Radial nerve

96
Q

Name the muscles innervated by the radial nerve.

A

Brachioradialis, Extensors of the wrist and fingers, Supinator, and Triceps (remember: radial nerve innervates the BEST)

97
Q

After supination, is the palm or dorsum of the hand facing up?

A

Palm (remember: to supinate is to move as if carrying a bowl of soup)

98
Q

What three muscles compose the thenar eminence?

A

The opponens pollicis, the abductor pollicis, and the flexor pollicis brevis, remember: Oppose, Abduct, and Flex (OAF)

99
Q

What three muscles compose the hypothenar eminence?

A

The opponens digiti minimi, the abductor digiti minimi, and the flexor digiti minimi (remember: Oppose, Abduct, and Flex (OAF))

100
Q

What muscle group in the hand adducts the fingers?

A

Palmar interosseous muscles (remember: PAD = Palmars ADduct)

101
Q

What muscle group in the hand abducts the fingers?

A

Dorsal interosseous muscles (remember: DAB = Dorsals ABduct)

102
Q

What muscle group in the hand flexes the fingers at the metacarpophalangeal joint?

A

Lumbrical muscles

103
Q

Name two specific injuries caused by repetitive elbow trauma.

A

Lateral epicondylitis (tennis elbow), medial epicondylitis (golf elbow)

104
Q

A patient has an anterior hip dislocation and can no longer adduct the thigh. She has a sensory deficit along the medial thigh. What nerve has been damaged?

A

Obturator nerve

105
Q

A patient has a pelvic fracture. He can no longer flex his thigh or extend his leg. He has a sensory deficit along the anterior thigh and medial leg. What nerve has been damaged?

A

Femoral nerve

106
Q

A patient experiences trauma to his lateral leg and can no longer evert or dorsiflex his foot, nor can he extend his toes. What nerve has been injured?

A

Common peroneal nerve, causing foot drop

107
Q

A patient has a fibula neck fracture and can no longer evert or dorsiflex his foot, nor can he extend his toes. What nerve has been injured, and what sign is evident on physical exam?

A

The common peroneal nerve; foot drop (remember: PED = Peroneal Everts and Dorsiflexes; if injured, foot dropPED)

108
Q

A patient has had trauma to his knee and can no longer invert or plantar flex his foot, nor can he flex his toes. He has decreased sensation in the sole of his foot. What nerve has been damaged?

A

Tibial nerve

109
Q

A patient has had trauma to his knee and damaged his tibial nerve. What motor deficits would be expected on physical exam?

A

Cannot invert foot, cannot plantar flex foot, and cannot flex toes (remember: TIP = Tibial Inverts and Plantarflexes; if injured, cant stand on TIPtoes)

110
Q

A patient has a posterior hip dislocation. He has a positive Trendelenburg sign. What motor deficit is present?

A

Inability to abduct thigh

111
Q

A patient has a posterior hip dislocation and cannot abduct his thigh (positive Trendelenburg sign). What nerve has been damaged?

A

Superior gluteal nerve

112
Q

A patient has a posterior hip dislocation. She cannot jump, climb stairs, or rise from a seated position. What nerve has been damaged?

A

Inferior gluteal nerve

113
Q

What two nerves may be damaged if a patient sustains a posterior hip dislocation?

A

Inferior gluteal nerve and superior gluteal nerve

114
Q

Loss of foot eversion is due to damage of the _____ nerve, while loss of foot inversion is due to damage of the _____ nerve.

A

Common peroneal; tibial

115
Q

Loss of dorsiflexion of the foot is due to damage of the _____ nerve, while loss of plantar flexion of the foot is due to damage of the _____ nerve.

A

Common peroneal; tibial

116
Q

If a patient has foot drop, his ______ nerve is damaged; but if a patient cannot stand on his tiptoes, then the _____ nerve is damaged.

A

Common peroneal; tibial

117
Q

During the conduction of an action potential to muscle, the action potential causes the opening of which voltage-gated channels in the nerve terminal?

A

Voltage-gated calcium channels, causing release of neurotransmitter

118
Q

During skeletal muscle signal conduction, postsynaptic ligand binding leads to the depolarization of which membrane?

A

The motor end plate of the muscle cell

119
Q

During skeletal muscle signal conduction, the action potential travels down into invaginations in the membrane that are called what?

A

T-tubules

120
Q

_____ receptors release calcium from the sarcoplasmic reticulum.

A

Ryanodine

121
Q

Name the specific receptors on the skeletal muscle cell membrane that are voltage sensitive.

A

Dihydropyridine

122
Q

What term describes the process by which calcium entering a muscle cell through voltage-gated calcium channels on the cell membrane is able to increase the intracellular calcium content of the muscle cell by releasing more calcium from the sarcoplasmic reticulum?

A

Calcium-induced calcium release

123
Q

During skeletal muscle contraction, released calcium binds to troponin C, thereby causing a conformational change to move tropomyosin out of what area of the actin filament?

A

The myosin-binding groove

124
Q

During skeletal muscle contraction, which bands of the sarcomere shorten in length?

A

H-band and I-band

125
Q

During skeletal muscle contraction, what band of the sarcomere remains the same length?

A

A-band (remember: A band is Always the same length; HIZ shrinkage)

126
Q

In the sarcomere, does the A-band correspond to the length of actin or myosin?

A

Myosin

127
Q

In the sarcomere, does the I- band correspond to the area that is only actin or only myosin?

A

Only actin

128
Q

In the sarcomere, does the H-band correspond to the area that is only actin or only myosin?

A

Only myosin

129
Q

In the sarcomere, is the Z line the site of actin or myosin attachment?

A

Actin

130
Q

In the sarcomere, is the M line the site of actin or myosin attachment?

A

Myosin

131
Q

A sarcomere is defined as the area between one ______ to the next ______.

A

Z line; Z line

132
Q

Type I muscle fibers are _____ (fast/slow) twitch.

A

Slow

133
Q

Type II muscle fibers are _____ (fast/slow) twitch.

A

Fast

134
Q

Type I muscle fibers are red secondary to what?

A

Increased mitochondria and myoglobin concentration

135
Q

Type II muscle fibers are white secondary to what?

A

Decreased mitochondria and myoglobin concentration

136
Q

In type I muscle fibers, there is a(n) _____ (increase;decrease) in oxidative phosphorylation.

A

Increase

137
Q

True or False? Type I muscle fibers create a sustained contraction.

A

True (remember: one slow red ox)

138
Q

Weight training results in hypertrophy of what type of muscle fibers?

A

Fast-twitch muscle fibers

139
Q

In type II muscle fibers, there is a(n) _____ (increase; decrease) in anaerobic glycolysis.

A

Increase

140
Q

In skeletal muscle contraction, ATP binds to what molecule?

A

Myosin head

141
Q

In skeletal muscle contraction, calcium binds to what substance, thereby causing a conformational change?

A

Troponin C

142
Q

What process causes cocking of the myosin head?

A

Hydrolysis of ATP

143
Q

The absence of ATP binding to the myosin head in skeletal muscle may cause what finding?

A

Rigor mortis

144
Q

The binding of ATP allows for what process in actin/myosin cross-bridging?

A

Release

145
Q

After a smooth muscle membrane is depolarized, voltage-gated _____ _____ will open.

A

Calcium channels

146
Q

In the process of smooth muscle cell contraction, calcium binds to what?

A

Calmodulin

147
Q

With the binding of calcium to calmodulin in smooth muscle contraction, the activation of _____ _____-_____ kinase takes place.

A

Myosin light-chain

148
Q

Myosin light-chain kinase is an enzyme that adds a _____ group to the _____-_____ complex during _____ muscle contraction.

A

Phosphate, actin-myosin; smooth

149
Q

In smooth muscle contraction, dephosphorylation of the myosin-actin complex is carried out by what enzyme?

A

Myosin light-chain phosphatase

150
Q

Dephosphorylation of the myosin-actin complex leads to what response by smooth muscle?

A

Relaxation

151
Q

In bone formation, _____ (endochondral/membranous) ossification is responsible for longitudinal bone growth, while _____ (endochondral/membranous) ossification is responsible for flat bone growth.

A

Endochondral; membranous

152
Q

The skull, facial bones, and axial skeleton are examples of bones formed as a result of what type of ossification pattern?

A

Membranous ossification

153
Q

In endochondral ossification, what two type of cells replace the cartilaginous model with woven and later lamellar bone?

A

Osteoclasts and osteoblasts

154
Q

Osteoblasts are derived from _____ stem cells in the periosteum.

A

Mesenchymal

155
Q

_____ (Endochondral/Membranous) ossification involves the production a cartilaginous model that is remodeled into lamellar bone, while _____ (endochondral/membranous) ossification involves the direct production of woven bone that is remodeled into lamellar bone.

A

Endochondral; membranous

156
Q

C4 innervates what dermatome?

A

Shoulder

157
Q

The dermatome of the lateral aspect of the upper arm is innervated by what nerve root?

A

C5

158
Q

Which dermatome covers the thumb?

A

C6

159
Q

The C7 nerve root innervates which dermatome?

A

The middle finger

160
Q

The dermatome of the pinky is innervated by which nerve root?

A

C8

161
Q

The dermatome of the medial aspect of the forearm is innervated by what nerve root?

A

T1

162
Q

The dermatome of the axilla is innervated by what nerve root?

A

T2

163
Q

The palmar surface of the first three digits is innervated by what branch of the median nerve?

A

Cutaneous branches of the median nerve

164
Q

The interossei and adductor polliois muscles are innervated by what nerve?

A

Branches of the deep ulnar nerve

165
Q

The thenar muscles are innervated by what branch of the median nerve?

A

The recurrent branch of the median nerve

166
Q

The flexor retinaculum is anchored between what three bones?

A

Trapezium, hook of hamate, and scaphoid

167
Q

How many tendons run through the carpal tunnel?

A

Nine

168
Q

Tendons from which two muscles anchor on the pisiform bone?

A

Abductor digiti minimi and flexor carpi ulnaris

169
Q

Describe the dermatomal distribution of the ulnar nerve on the hand.

A

Medial palmar and dorsal surfaces of the hand

170
Q

The dermatome of the thumb is innervated by what nerve(s)?

A

Radial and median nerves

171
Q

Name the function of the lumbrical muscles of the hand.

A

The lumbricals flex the metacarpophalangeal joints and extend both the distal interphalangeal and proximal interphalangeal joints

172
Q

Ulnar claw or "Pope& blessing" is caused by a lesion of what nerve?

A

A distal lesion of the ulnar nerve

173
Q

What digits are affected in a distal ulnar nerve lesion?

A

Fourth and fifth digits

174
Q

Median claw is caused by a lesion of the distal median nerve. Specify the exact location of the lesion.

A

The lesion is located after the branch containing C5-C7 brances off to feed forearm flexors

175
Q

A proximal median nerve lesion causes loss of what muscle function?

A

It causes loss of opponens polliois muscle function

176
Q

How does a proximal median nerve lesion affect the thumb?

A

It causes an inability to abduct thumb, know as "ape hand"

177
Q

Klumpke& total claw hand is caused by a lesion of what trunk of the brachial plexus affecting what nerve roots?

A

Lower trunk and nerve roots C8, T1