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USMLE COMPREHENSIVE REVIEW > D201-400 > Flashcards

D201-400 Flashcards

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USMLE® Step 1 flashcards
1
Q

What lower extremity nerve is described by the following motor loss? • Loss of adduction of the thigh

A

Obturator nerve

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2
Q

What nerve lesion presents with ape or simian hand as its sign?

A

Median nerve lesion

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3
Q

What muscle acts in all ranges of motion of the arm?

A

Deltoid

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4
Q

What is the first branch of the abdominal artery?

A

Inferior phrenic artery

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5
Q

What vessel does the right gonadal vein drain into?

A

The right gonadal vein drains into the inferior vena cava directly, and the left gonadal vein drains into the left renal vein.

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6
Q

What two muscles do you test to see whether CN XI is intact?

A

Trapezius and sternocleidomastoid

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7
Q

What two CNs are responsible for the carotid body and sinus reflexes?

A

CN IX and X

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8
Q

At what vertebral level does the trachea bifurcate?

A

T4 vertebral level posteriorly and anteriorly at the sternal angle (angle of Louis).

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9
Q

What is the function of the arachnoid granulations?

A

Resorb CSF into the blood

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10
Q

Damage to what nerve will give you winged scapula?

A

Long thoracic nerve. To avoid confusing long thoracic nerve and lateral thoracic artery: long has an n for nerve; lateral has an a for artery.

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11
Q

What portion of the intervertebral disk is a remnant of the notochord?

A

Nucleus pulposus

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12
Q

What component of the pelvic diaphragm forms the rectal sling (muscle of continence)?

A

Puborectalis

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13
Q

What are the five branches of the median cord of the brachial plexus?

A

Four Ms and a U 1. Median 2. Medial antebrachial 3. Medial pectoral 4. Medial brachial cutaneus 5. Ulnar

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14
Q

What bone houses the ulnar groove?

A

Humerus (between the medial epicondyle and the trochlea)

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15
Q

What CN is associated with the sensory innervation of • Nasopharynx?

A

Maxillary division of CN V and glossopharyngeal nerves

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16
Q

What CN is associated with the sensory innervation of • Oropharynx?

A

Glossopharyngeal nerve

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17
Q

What CN is associated with the sensory innervation of • Laryngopharynx?

A

Vagus nerve

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18
Q

What protective covering adheres to the spinal cord and CNS tissue?

A

Pia mater

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19
Q

What is the name of the urinary bladder where the ureters enter and the urethra exits?

A

Urinary trigone

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20
Q

What is the term when the brachial artery is compressed, resulting in ischemic contracture of the hand?

A

Volkmann’s contracture

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21
Q

What attaches the cusps of the valves to the papillary muscles in the heart?

A

Chordae tendineae

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22
Q

What is the lymphatic drainage of the pelvic organs?

A

Internal iliac nodes

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23
Q

What bursa is inflamed in clergyman’s knee?

A

Infrapatellar bursa

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24
Q

What muscle is the chief flexor of the hip?

A

Psoas major

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25
Q

What component of the ANS, when stimulated, results in bronchoconstriction?

A

Parasympathetic stimulation, via the vagus nerve, results in bronchoconstriction, whereas sympathetic stimulation results in bronchodilation.

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26
Q

What muscles in the hand adduct the fingers?

A

The Palmar interosseus ADducts, whereas the Dorsal interosseus ABducts (PAD and DAB)

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27
Q

What type of cerebral bleed is due to a rupture of a berry aneurysm in the circle of Willis?

A

Subarachnoid hematoma

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28
Q

What are the five terminal branches of the facial nerve?

A
  1. Temporal 2. Zygomatic 3. Buccal 4. Mandibular 5. Cervical (Two Zebras Bit My Clavicle.)
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29
Q

What structure of the knee is described thus? • C-shaped shock absorber; aids in attachment of the tibia to the femur via the medial collateral ligament

A

Medial meniscus

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30
Q

What structure of the knee is described thus? • Prevents posterior displacement and has medial-to-lateral attachment on the tibia

A

Posterior cruciate ligament

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31
Q

What structure of the knee is described thus? • Prevents adduction

A

Lateral collateral ligament

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32
Q

What structure of the knee is described thus? • Prevents anterior displacement and has lateral-to-medial attachment on the tibia

A

ACL

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33
Q

What structure of the knee is described thus? • Prevents abduction

A

Medial collateral ligament

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34
Q

What branches of CN X are the sensory and motor components of the cough reflex? Be specific.

A

The sensory component is through the superior laryngeal nerve, and the motor limb is via the recurrent laryngeal nerve.

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35
Q

What nerves provide sensory innervation above the vocal cords? Below the vocal cords?

A

The internal laryngeal nerve supplies sensory information from above the vocal cords while the recurrent laryngeal nerve supplies sensory information below.

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36
Q

From what pharyngeal groove is the external auditory meatus derived?

A

First pharyngeal groove; all others degenerate.

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37
Q

What embryonic structure forms the adult male structure? • Corpus cavernosus, corpus spongiosum, and glans and body of the penis

A

Phallus

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38
Q

What embryonic structure forms the adult male structure? • Scrotum

A

Labioscrotal swelling

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39
Q

What embryonic structure forms the adult male structure? • Urinary bladder, urethra, prostate gland, bulbourethral gland

A

Urogenital sinus

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40
Q

What embryonic structure forms the adult male structure? • Testes, seminiferous tubules, and rete testes

A

Gonads

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41
Q

What embryonic structure forms the adult male structure? • Ventral part of the penis

A

Urogenital folds

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42
Q

What embryonic structure forms the adult male structure? • Gubernaculum testes

A

Gubernaculum

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43
Q

What embryonic structure forms the adult male structure? • Epididymis, ductus deferens, seminal vesicle, and ejaculatory duct

A

Mesonephric duct

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44
Q

Which PG is associated with maintaining a PDA?

A

PGE and intrauterine or neonatal asphyxia maintain patency of the ductus arteriosus. Indomethacin, ACh, and catecholamines promote closure of the ductus arteriosus.

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45
Q

When does the primitive gut herniate out of the embryo? When does it go back into the embryo?

A

6 weeks 10 weeks

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46
Q

What results when the palatine prominences fail to fuse with the other side?

A

Cleft palate

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47
Q

What is the term for a direct connection between the intestine and the external environment through the umbilicus because the vitelline duct persists?

A

Vitelline fistula

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48
Q

Where do the primordial germ cells arise?

A

From the wall of the yolk sac

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49
Q

What disorder is due to a 5–reductase deficiency, resulting in testicular tissue and stunted male external genitalia?

A

Male pseudo-intersexuality (hermaphrodite); these individuals are 46XY.

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50
Q

Does the zygote divide mitotically or meiotically?

A

The zygote divides mitotically; only germ cells divide meiotically.

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51
Q

During what embryonic week does the intraembryonic coelom form?

A

Third week

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52
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Cerebral hemispheres

A

Proencephalon

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53
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Midbrain

A

Mesencephalon

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54
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Cerebellum

A

Rhombencephalon

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55
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Medulla

A

Rhombencephalon

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56
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Diencephalon

A

Proencephalon

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57
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Metencephalon

A

Rhombencephalon

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58
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Telencephalon

A

Proencephalon

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59
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Thalamus

A

Proencephalon

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60
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Eye

A

Proencephalon* *diencephalon derivative

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61
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Pons

A

Rhombencephalon

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62
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Myelencephalon

A

Rhombencephalon

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63
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Pineal gland

A

Proencephalon* *diencephalon derivative

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64
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Cerebral aqueduct

A

Mesencephalon

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65
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Neurohypophysis

A

Proencephalon* *diencephalon derivative

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66
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Third ventricle

A

Proencephalon

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67
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Hypothalamus

A

Proencephalon* *diencephalon derivative

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68
Q

Name the primary vesicle the following structures are derived from (proencephalon, mesencephalon, or rhombencephalon). • Lateral ventricles

A

Proencephalon

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69
Q

What malignant tumor of the trophoblast causes high levels of hCG and may occur after a hydatidiform mole, abortion, or normal pregnancy?

A

Gestational trophoblastic neoplasia (GTN or choriocarcinoma)

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70
Q

What syndrome is due to a deficiency of surfactant?

A

Respiratory distress syndrome; treatment with cortisol and thyroxine can increase production of surfactant.

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71
Q

How many oogonia are present at birth?

A

None; they are not formed until a girl reaches puberty.

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72
Q

What right-to-left shunt occurs when the aorta opens into the right ventricle and the pulmonary trunk opens into the left ventricle?

A

Transposition of the great vessels arises from a failure of the aorticopulmonary septum to grow in a spiral.

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73
Q

What are the adult remnants of the following structures? • Left umbilical vein

A

Ligament teres

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74
Q

What are the adult remnants of the following structures? • Foramen ovale

A

Fossa ovale

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75
Q

What are the adult remnants of the following structures? • Right and left umbilical arteries

A

Medial umbilical ligaments

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76
Q

What are the adult remnants of the following structures? • Ductus arteriosus

A

Ligamentum arteriosum

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77
Q

What are the adult remnants of the following structures? • Ductus venosus

A

Ligamentum venosum

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78
Q

Mandibular hypoplasia, down-slanted palpebral fissures, colobomas, malformed ears, and zygomatic hypoplasia are commonly seen in what pharyngeal arch 1 abnormality?

A

Treacher Collins syndrome

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79
Q

What is the tetrad of tetralogy of Fallot?

A

SHIP: Shifting of the aorta, Hypertrophy of the right ventricle, Interventricular septal defect, Pulmonary stenosis

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80
Q

What is the term for the external urethra opening onto the ventral surface of the penis?

A

Hypospadia

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81
Q

What CN is associated with the • First pharyngeal arch?

A

CN V

82
Q

What CN is associated with the • Second pharyngeal arch?

A

CN VII

83
Q

What CN is associated with the • Third pharyngeal arch?

A

CN IX

84
Q

What CN is associated with the • Fourth pharyngeal arch?

A

CN X

85
Q

What CN is associated with the • Fifth pharyngeal arch?

A

None; it degenerates.

86
Q

What CN is associated with the • Sixth pharyngeal arch?

A

CN X

87
Q

What disease results in a failure of neural crest cells to migrate to the myenteric plexus of the sigmoid colon and rectum?

A

Hirschsprung’s disease (colonic gangliosus)

88
Q

What immunologic syndrome is due to a pharyngeal pouch 3 and 4 failure?

A

DiGeorge’s syndrome

89
Q

What embryonic structure, around day 19, tells the ectoderm above it to differentiate into neural tissue?

A

The notochord

90
Q

What is the term for failure of the testes to descend into the scrotum?

A

Cryptorchidism; normally the testes descend into the scrotum within 3 months of birth.

91
Q

Is a membranous septal defect more commonly interventricular or interatrial?

A

Membranous septal defects are interventricular; a persistent patent ovale results in an interatrial septal defect.

92
Q

What pharyngeal pouch and groove persist when a pharyngeal fistula is formed?

A

The second pharyngeal pouch and groove

93
Q

How early can a pregnancy be detected by hCG assays in the blood? In urine?

A

hCG can be detected in the blood by day 8 and in the urine by day 10.

94
Q

From what pharyngeal pouch is the following structure derived? • Middle ear

A

First M PITS for pharyngeal pouch derivatives

95
Q

From what pharyngeal pouch is the following structure derived? • Superior parathyroid gland and ultimobranchial body of the thyroid

A

Fourth M PITS for pharyngeal pouch derivatives

96
Q

From what pharyngeal pouch is the following structure derived? • Inferior parathyroid gland and thymus

A

Third M PITS for pharyngeal pouch derivatives

97
Q

From what pharyngeal pouch is the following structure derived? • Palatine tonsil

A

Second M PITS for pharyngeal pouch derivatives

98
Q

What is the term for the external urethra opening onto the dorsal surface of the penis?

A

Epispadia

99
Q

True or false? In females, meiosis II is incomplete unless fertilization takes place.

A

True. The elimination of the unfertilized egg is menses.

100
Q

What adult structures are derived from preotic somites?

A

Muscles of the internal eye

101
Q

What disorder is associated with jaundice, white stools, and dark urine due to biliary duct occlusion secondary to incomplete recanalization?

A

Extrahepatic biliary atresia

102
Q

What hormone, produced by the syncytiotrophoblast, stimulates the production of progesterone by the corpus luteum?

A

hCG

103
Q

How many mature sperm are produced by one type B spermatogonium?

A

Four

104
Q

All primary oocytes in females are formed by what age?

A

They are all formed by the fifth month of fetal life.

105
Q

From what embryonic structure are the following structures derived? • The ascending aorta and the pulmonary trunk

A

Truncus arteriosus

106
Q

From what embryonic structure are the following structures derived? • The sinus venarum, coronary sinus, and the oblique vein of the left atrium

A

Sinus venosus

107
Q

From what embryonic structure are the following structures derived? • The right and left ventricles

A

Primitive ventricle

108
Q

From what embryonic structure are the following structures derived? • The aortic vestibule and the conus arteriosus

A

Bulbus cordis

109
Q

From what embryonic structure are the following structures derived? • The right and left atria

A

Primitive atrium

110
Q

After a longstanding left-to-right shunt reverses, causing cyanosis, and becomes a right-to-left shunt, what is it termed?

A

Eisenmenger’s syndrome

111
Q

True or false? The thyroid gland is an embryologic foregut derivative.

A

True. The thyroid gland, the lungs, and the pharyngeal pouches are foregut derivatives that are not a component of the gastrointestinal system.

112
Q

What embryonic structure forms the following adult structures? • Collecting ducts, calyces, renal pelvis, and ureter

A

Mesonephric duct (ureteric bud)

113
Q

What embryonic structure forms the following adult structures? • Urinary bladder and urethra

A

Urogenital sinus

114
Q

What embryonic structure forms the following adult structures? • External genitalia

A

Phallus, urogenital folds, and labioscrotal swellings

115
Q

What embryonic structure forms the following adult structures? • Nephrons, kidney

A

Metanephros

116
Q

What embryonic structure forms the following adult structures? • Median umbilical ligament

A

Urachus

117
Q

True or false? The epithelial lining of the urinary bladder and the urethra are embryologic hindgut derivatives.

A

TRUE

118
Q

Name the four ventral mesentery derivatives.

A
  1. The lesser omentum (consisting of the hepatoduodenal and hepatogastric ligaments) 2. Falciform ligament 3. Coronary ligament of the liver 4. Triangular ligament of the liver Liver is ventral; all other ligaments are dorsal mesentery derivatives.
119
Q

Projectile nonbilious vomiting and a small knot at the right costal margin (olive sign) are hallmarks of what embryonic disorder?

A

Hypertrophic pyloric stenosis due to hypertrophy of the muscularis externa, resulting in a narrowed pyloric outlet

120
Q

The separation of 46 homologous chromosomes without splitting of the centromeres occurs during what phase of meiosis?

A

Meiosis I; disjunction with centromere splitting occurs during meiosis II.

121
Q

Blood and its vessels form during what embryonic week?

A

Third week; they are derived from the wall of the yolk sac.

122
Q

What embryonic structure forms the adult female structures? • Glans clitoris, corpus cavernosus, and spongiosum

A

Phallus

123
Q

What embryonic structure forms the adult female structures? • Gartner’s duct

A

Mesonephric duct

124
Q

What embryonic structure forms the adult female structures? • Ovary, follicles, rete ovarii

A

Gonads

125
Q

What embryonic structure forms the adult female structures? • Uterine tube, uterus, cervix, and upper third of the vagina

A

Paramesonephric ducts

126
Q

What embryonic structure forms the adult female structures? • Labia majora

A

Labioscrotal swelling

127
Q

What embryonic structure forms the adult female structures? • Labia minora

A

Urogenital folds

128
Q

What embryonic structure forms the adult female structures? • Ovarian and round ligaments

A

Gubernaculum

129
Q

What embryonic structure forms the adult female structures? • Urinary bladder, urethra, greater vestibular glands, vagina

A

Urogenital sinus

130
Q

What direction does the primitive gut rotate? What is its axis of rotation?

A

The gut rotates clockwise around the superior mesenteric artery.

131
Q

What syndrome occurs when a 46XY fetus develops testes and female external genitalia?

A

Testicular feminization syndrome (Dude looks like a lady!)

132
Q

Preeclampsia in the first trimester, hCG levels above 100, 00 mIU/mL, and an enlarged bleeding uterus are clinical signs of what?

A

Hydatidiform mole

133
Q

True or false? The foramen ovale closes just prior to birth.

A

False. It closes just after birth because the change in pulmonary circulation causes increased left atrial pressure.

134
Q

At ovulation, in what stage of meiosis II is the secondary oocyte arrested?

A

Metaphase II

135
Q

What is the name for failed recanalization of the duodenum resulting in polyhydramnios, bile-containing vomitus, and a distended stomach?

A

Duodenal atresia

136
Q

What remains patent in a hydrocele of the testis, allowing peritoneal fluid to form into a cyst?

A

A patent processus vaginalis

137
Q

True or false? The respiratory system is derived from the ventral wall of the foregut.

A

True. The laryngotracheal (respiratory) diverticulum is divided from the foregut by the tracheoesophageal septum. ——————————————————————————–

138
Q

What is the name for failure of the allantois to close, resulting in a urachal fistula or sinus?

A

Patent urachus

139
Q

What structure is derived from the prochordal plate?

A

The mouth

140
Q

What is the only organ supplied by the foregut artery that is of mesodermal origin?

A

Spleen

141
Q

What tumor is derived from primitive streak remnants and often contains bone, hair, or other tissue types?

A

Sacrococcygeal teratoma

142
Q

What two pathologic conditions occur when the gut does not return to the embryo?

A

Omphalocele and gastroschisis

143
Q

True or false? For implantation to occur the zona pellucida must degenerate.

A

True. Remember, it degenerates 4 to 5 days post fertilization, and implantation occurs 7 days post fertilization!

144
Q

What results when the maxillary prominence fails to fuse with the medial nasal prominence?

A

Cleft lip

145
Q

What is the direction of growth for the primitive streak, caudal to rostral or rostral to caudal?

A

The primitive streak grows caudal to rostral.

146
Q

During what embryonic week do somites begin to form?

A

Third week

147
Q

In men, at what embryonic week do the primordial germ cells migrate to the indifferent gonad?

A

Week four, and they remain dormant there until puberty.

148
Q

What embryonic week sees the formation of the notochord and the neural tube?

A

Third week

149
Q

What right-to-left shunt occurs when only one vessel receives blood from both the right and left ventricles?

A

Persistent truncus arteriosus

150
Q

What three embryonic cell layers form the chorion?

A
  1. Cytotrophoblast 2. Syncytiotrophoblast 3. Extraembryonic mesoderm
151
Q

Where are the preganglionic neuron cell bodies, the CNS or the PNS?

A

They are in the grey matter of the CNS.

152
Q

Which three CNs send sensory information to the solitary nucleus?

A

CN VII, IX, and X; taste and general sensation for the tongue is sent to the solitary nucleus.

153
Q

What syndrome is associated with the following brainstem lesions? • Vertebral artery or anterior spinal artery occlusion, resulting in contralateral corticospinal tract and medial lemniscus tract deficits and an ipsilateral CN XII lesion

A

Medial medullary syndrome

154
Q

What syndrome is associated with the following brainstem lesions? • Contralateral corticospinal and medial lemniscus tract deficits and an ipsilatera medial strabismus secondary to a lesion in CN VI

A

Medial pontine syndrome

155
Q

What syndrome is associated with the following brainstem lesions? • Slow-growing acoustic neuroma producing CN VII deficiencies

A

Pontocerebellar angle syndrome

156
Q

What syndrome is associated with the following brainstem lesions? • Occlusion of the PICA, resulting in ipsilateral limb ataxia, ipsilateral facial pain and temperature loss, contralateral pain and body temperature loss, ipsilateral Horner’s syndrome, and ipsilateral paralysis of the vocal cords, palate droop, dysphagia, nystagmus, vomiting, and vertigo

A

Lateral medullary (Wallenberg’s) syndrome

157
Q

What syndrome is associated with the following brainstem lesions? • AICA or superior cerebellar artery occlusion, resulting in ipsilateral limb ataxia, ipsilateral facial pain and temperature loss, contralateral loss of pain and temperature to the body, ipsilateral Horner’s syndrome, ipsilateral facial paralysis, and hearing loss

A

Lateral pontine syndrome

158
Q

What syndrome is associated with the following brainstem lesions? • Posterior cerebral artery occlusion resulting in a contralateral corticospinal tract signs, contralateral corticobulbar signs to the lower face, and ipsilateral CN III palsy

A

Medial midbrain (Weber’s) syndrome

159
Q

What CNs are affected if there is a lesion in • The midbrain?

A

CN III and IV

160
Q

What CNs are affected if there is a lesion in • The upper medulla?

A

CN IX, X, and XII

161
Q

What CNs are affected if there is a lesion in • Pontomedullary junction?

A

CN VI, VII, and VIII

162
Q

What CNs are affected if there is a lesion in • The upper pons?

A

CN V

163
Q

What is the only CN nucleus found in the cervical spinal cord?

A

Accessory nucleus

164
Q

What component of the trigeminal nuclei • Supplies the muscles of mastication?

A

Motor nucleus of CN V

165
Q

What component of the trigeminal nuclei • Receives sensory input (all but pain and temperature) from the face, scalp, dura, and the oral and nasal cavities?

A

Spinal trigeminal nucleus

166
Q

What component of the trigeminal nuclei • Forms the sensory component of the jaw jerk reflex?

A

Mesencephalic nucleus

167
Q

What deep cerebellar nuclei receive Purkinje cell projections in • The flocculonodular lobe?

A

The lateral vestibular nucleus

168
Q

What deep cerebellar nuclei receive Purkinje cell projections in • The vermis?

A

The fastigial nucleus

169
Q

What deep cerebellar nuclei receive Purkinje cell projections in • The lateral cerebellar hemispheres?

A

The interposed nucleus

170
Q

What deep cerebellar nuclei receive Purkinje cell projections in • The intermediate hemispheres?

A

The dentate nucleus

171
Q

What is the only excitatory neuron in the cerebellar cortex, and what is its neurotransmitter?

A

The granule cell is the only excitatory neuron in the cerebellar cortex, and it uses glutamate as its neurotransmitter. All the other cells in the cerebellum are inhibitory neurons, and they use GABA as their neurotransmitter.

172
Q

What three CNs are associated with conjugate eye movements?

A

CN III, IV, and VI

173
Q

What is the term to describe the soft, flabby feel and diminished reflexes seen in patients with acute cerebellar injury to the deep cerebellar nuclei?

A

Hypotonia (rag doll appearance)

174
Q

What bedside test is used to differentiate a dorsal column lesion from a lesion in the vermis of the cerebral cortex?

A

The Romberg sign is present if the patient sways or loses balance when standing with eyes open. In a dorsal column lesion, patients sway with eyes closed. (Don’t forget this one.)

175
Q

Which one of the cerebellar peduncles is mainly responsible for outgoing (efferent) information?

A

Superior cerebellar peduncle; the inferior and the middle consist mainly of incoming (afferent) tracts and fibers.

176
Q

What tract carries unconscious proprioceptive information from the Golgi tendon organs and muscle spindles to the cerebellum, helping monitor and modulate muscle movements?

A

Lower extremity and lower trunk information travels in the dorsal spinocerebellar tract. The upper trunk and extremity information travels in the cuneocerebellar tract. (Cuneocerebellar and fasciculus cuneatus both apply to upper extremities.)

177
Q

What reflex, seen in lesions of the corticospinal tract, is an extension of the great toe with fanning the of remaining toes?

A

The Babinski reflex is present in UMN lesions. Muscle atrophy due to disuse, hyperreflexia, spastic paralysis, increased muscle tone, and weakness are commonly seen in UMN lesions.

178
Q

What is the triad of Horner’s syndrome?

A

Ptosis (eyelid drooping), miosis (pupillary constriction), and anhydrosis (lack of sweating) occur when the preganglionic sympathetic fibers from T1-to T4 are obstructed.

179
Q

What component of the inner ear • Contains perilymph and responds to angular acceleration and deceleration of the head?

A

Semicircular canal

180
Q

What component of the inner ear • Contains endolymph and responds to head turning and movement?

A

Semicircular duct

181
Q

What component of the inner ear • Contains endolymph and gravity receptors monitoring linear acceleration and deceleration of the head, noting changes in head position?

A

Utricle and saccule

182
Q

What is the name of demyelination of the corticospinal tract and the dorsal column in the spinal cord due most commonly to a vitamin B12 deficiency?

A

Subacute combined degeneration, which is bilateral below the level of the lesion.

183
Q

What encephalopathy causes ocular palsies, confusion, and gait abnormalities related to a lesion in the mammillary bodies and/or the dorsomedial nuclei of the thalamus?

A

Wernicke’s encephalopathy

184
Q

Which thalamic nucleus receives auditory input from the inferior colliculus?

A

MGB

185
Q

Where are the postganglionic neuron cell bodies, the CNS or the PNS?

A

They are in ganglia in the PNS.

186
Q

What disease is a cavitation of the spinal cord causing bilateral loss of pain and temperature at the level of the lesion?

A

Syringomyelia

187
Q

What nucleus of the hypothalamus receives visual input from the retina and helps set the circadian rhythm?

A

Suprachiasmatic nucleus

188
Q

Are white rami preganglionic or postganglionic fibers?

A

White rami are preganglionic fibers, whereas grey rami are postganglionic fibers.

189
Q

What area of the hypothalamus is responsible for recognizing a decrease in body temperature and mediates the response to conserve heat?

A

Posterior hypothalamic zones; lesions here result in poikilothermy (environmental control of one’s body temperature).

190
Q

What CN transmits sensory information from the cornea?

A

CN V1, the occulomotor division of the trigeminal nerve, is the sensory component of the corneal reflex.

191
Q

What preganglionic sympathetic fibers are responsible for innervating the smooth muscle and glands of the pelvis and the hindgut?

A

Lumbar splanchnics

192
Q

Where are the cell bodies for the DCML and spinothalamic sensory systems?

A

The first sensory neuron is in the dorsal root ganglia. It carries ascending sensory information in the dorsal root of a spinal nerve, eventually synapsing with second sensory neuron. In the brainstem (DCML) and the spinal cord (spinothalamic) the second neuron cell body sends its axons to synapse in the thalamus. The third sensory neuron cell body is a thalamic nuclei that sends its fibers to the primary somatosensory cortex.

193
Q

What term describes the reflex that increases the curvature of the lens, allowing near vision?

A

Accommodation

194
Q

What CN carries preganglionic parasympathetic fibers that innervate the viscera of the neck, thorax, foregut, and midgut?

A

CN X (Remember, the vagus nerve supplies the parasympathetic information from the tip of the pharynx to the end of the midgut and all between.)

195
Q

What area of the hypothalamus is responsible for recognizing an increase in body temperature and mediates the response to dissipate heat?

A

Anterior hypothalamic zone; lesions here result in hyperthermia.

196
Q

What excitatory fibers arise from the inferior olivary nuclei on the contralateral side of the body?

A

Climbing fibers;, they are monosynaptic input on Purkinje cells. Mossy fibers, also excitatory, are axons of all other sources and synapse on granule cells.

197
Q

What four CN carry preganglionic parasympathetic fibers?

A

CN III, VII, IX, and X

198
Q

Name the form of spina bifida. • Meninges and spinal cord project through a vertebral defect

A

Meningomyelocele All except occulta cause elevated-fetoprotein levels.

199
Q

Name the form of spina bifida. • Meninges project through a vertebral defect

A

Meningocele All except occulta cause elevated-fetoprotein levels.

200
Q

Name the form of spina bifida. • An open neural tube lying on the surface of the back

A

Myeloschisis All except occulta cause elevated-fetoprotein levels.

USMLE COMPREHENSIVE REVIEW (8 decks)

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