Embryology (Part 3) Flashcards Preview

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Flashcards in Embryology (Part 3) Deck (148)
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1
Q

Does cranial nerve V3 provide innervation to region (A), (B), or (C)? Does it provide sensation or taste?

A

(C) anterior two thirds of the tongue; sensation

2
Q

Does cranial nerve VII provide innervation to region (A), (B), or (C)? Does it provide sensation or taste?

A

(C) anterior two thirds of the tongue; taste

3
Q

Does cranial nerve IX provide innervation to region (A), (B), or (C)? Does it provide sensation or taste?

A

(B) posterior one third of the tongue; both

4
Q

Does cranial nerve X provide innervation to region (A), (B), or (C)? Does it provide sensation or taste?

A

(A) extreme posterior two thirds of the tongue; both

5
Q

The malleus of the ear is formed from what fetal structure?

A

Branchial arch 1

6
Q

The incus of the ear is formed from what fetal structure?

A

Branchial arch 1

7
Q

The stapes of the ear is formed from what fetal structure?

A

Branchial arch 2

8
Q

The tensor tympani muscle in the ear is derived from what fetal structure?

A

Branchial arch 1

9
Q

The tensor tympani muscle in the ear is innervated by what nerve?

A

Cranial nerve V3

10
Q

The stapedius muscle in the ear is derived from what fetal structure?

A

Branchial arch 2

11
Q

The stapedius muscle in the ear is innervated by what nerve?

A

Cranial nerve VII

12
Q

The external auditory meatus is derived from what fetal structure?

A

Branchial cleft 1

13
Q

The tympanic membrane is derived from what fetal structure?

A

The first branchial membrane

14
Q

The eustacian tube, middle ear cavity, and mastoid air cells are derived from what fetal structure?

A

The first brancial pouch

15
Q

The anterior two thirds of the tongue are derived from which branchial arch?

A

Branchial arch 1

16
Q

Sensation in the anterior two thirds of the tongue is mediated by which cranial nerve?

A

V3

17
Q

Taste in the anterior two thirds of the tongue is mediated by which cranial nerve?

A

VII

18
Q

The posterior third of the tongue is derived from which branchial arches?

A

Branchial arches 3 and 4

19
Q

Sensation in the posterior third of the tongue is mediated by which cranial nerve?

A

IX; as well as taste

20
Q

Taste in the posterior third of the tongue is mainly mediated by which cranial nerve?

A

IX; as well as sensation

21
Q

Taste in the extreme posterior of the tongue is mediated by which cranial nerve?

A

X

22
Q

True or False: Taste and sensation in the anterior two-thirds of the tongue are mediated by the same cranial nerve.

A

False; cranial nerve VII mediates taste, while sensation is mediated by CN V3

23
Q

Taste in the anterior two thirds of the tongue is mediated by cranial nerve _____, whereas taste in the posterior third of the tongue is mediated by cranial nerve _____.

A

VII; IX

24
Q

Sensation in the anterior two thirds of the tongue is mediated by cranial nerve _____, whereas sensation in the posterior third of the tongue is mediated by cranial nerve _____.

A

V3; IX

25
Q

Which cranial nerve supplies motor innervation to the tongue?

A

XII

26
Q

Which cranial nerves mediate the sense of taste?

A

VII, IX, and X

27
Q

Cranial nerves that mediate the sense of taste project to the ______ nucleus.

A

Solitary

28
Q

Which cranial nerves mediate the sense of pain in the tongue?

A

V3, IX, and X

29
Q

True or False: The muscles of the tongue are derived from occipital myotomes.

A

TRUE

30
Q

Which cranial nerve mediates taste and sensation in the extreme posterior portion of the tongue?

A

CN X

31
Q

Which cranial nerve mediates taste and sensation in most of the posterior third of the tongue, except for the extreme posterior portion?

A

CN IX

32
Q

Which cranial nerve mediates taste in the anterior two thirds of the tongue?

A

CN VII

33
Q

Which cranial nerve mediates sensation in the anterior two thirds of the tongue?

A

CN V3

34
Q

True or False: The thyroid gland develops as a diverticulum of the gastrointestinal tract.

A

True; it arises from the floor of the primitive pharynx

35
Q

What is the name of the structure that connects the thyroid gland with the tongue?

A

The thyroglossal duct

36
Q

True or False: The thyroglossal duct usually persists into adulthood.

A

False; it normally disappears

37
Q

The thyroglossal duct normally disappears during development, but it may persist as the ______ lobe of the thyroid.

A

Pyramidal

38
Q

What is the name of the normal remnant of the thyroglossal duct?

A

The foramen cecum

39
Q

What is the most common site of ectopic thyroid tissue?

A

The tongue

40
Q

A thyroglossal duct cyst is commonly found and felt where?

A

In the midline neck

41
Q

What happens to a thyroglossal duct cyst with swallowing?

A

It will move with swallowing, unlike a branchial cleft cyst

42
Q

A persistent cervical sinus, leading to a branchial cyst, is commonly found and felt where?

A

In the lateral neck

43
Q

A branchial cyst is commonly found in the _____ (lateral/midline) neck, while a thyroglossal duct cyst is commonly found in the _____ (lateral/midline) neck.

A

Lateral; midline

44
Q

A _____ cyst is commonly found in the lateral neck, while a _____ cyst is commonly found in the midline neck.

A

Branchial; thyroglossal duct

45
Q

Cleft lip results from the failure of which structures to fuse?

A

Maxillary nasal process and medial nasal process

46
Q

Cleft palate results from failure of which structures to fuse?

A

The lateral palatine process, the nasal septum and the median palatine process

47
Q

Cleft lip is a defect in the formation of the _____ (primary/secondary) palate, and cleft palate is a defect in the formation of the _____ (primary/secondary) palate.

A

Primary; secondary

48
Q

What four structures contribute to the diaphragm?

A

The Septum transversum, the Pleuroperitoneal folds, the Body wall, and the Dorsal mesentery of the esophagus (remember: Several Parts Build Diaphragm)

49
Q

True or False: The septum transversum contributes to the diaphragm.

A

TRUE

50
Q

True or False: The body wall does not contribute to the formation of the diaphragm.

A

False; the body wall does contribute to the diaphragm

51
Q

What nerves innervate the diaphragm?

A

C3, C4, and C5 (remember: C3, 4, 5 keeps the diaphragm alive)

52
Q

Does the diaphragm ascend, descend, or form in situ during development?

A

It descends from its original formation to its final location in the body

53
Q

A neonate has an x-ray of the chest that shows abdominal contents in the chest cavity. This defect is likely the result of the incomplete development of the _____, resulting in a congenital _____ _____.

A

Diaphragm; diaphragmatic hernia

54
Q

True or False: A diaphragmatic hernia can lead to hypoplasia of thoracic organs due to space compression.

A

TRUE

55
Q

What does the septum transversum become in the mature diaphragm?

A

The central tendon

56
Q

What does the dorsal mesentery become in the mature diaphragm?

A

The diaphragmatic crura

57
Q

Name 3 findings seen with a congenital diaphragmatic hernia.

A

Hypoplasia of thoracic organs, scaphoid abdomen, and cyanosis

58
Q

In embryologic terms, what part of the gastrointestinal tract is derived from the foregut?

A

The pharynx to the duodenum

59
Q

In embryologic terms, what part of the gastrointestinal tract is derived from the midgut?

A

The duodenum to the transverse colon

60
Q

In embryologic terms, what part of the gastrointestinal tract is derived from the hindgut?

A

The distal transverse colon to the rectum

61
Q

In embryologic terms, from what part of the gastrointestinal tract is the area between the pharynx and the duodenum derived?

A

The foregut

62
Q

In embryologic terms, from what part of the gastrointestinal tract is the area between the duodenum and the transverse colon derived?

A

The midgut

63
Q

In embryologic terms, from what part of the gastrointestinal tract is the area between the distal transverse colon and the rectum derived?

A

The hindgut

64
Q

In fetal development, _____ is due to the failure of lateral body folds to fuse and the extrusion of abdominal contents outside the body wall.

A

Gastroschisis

65
Q

True or False: Gastroschisis results in extrusion of abdominal contents though abdominal folds.

A

TRUE

66
Q

True or False: Gastroschisis is a failure of midline fusion.

A

TRUE

67
Q

An _____ is the persistence of herniated abdominal contents into the umbilical cord.

A

Omphalocele

68
Q

Omphalocele is the persistence of herniated abdominal contents into the _____.

A

Umbilical cord

69
Q

True or False: Tracheoesophageal fistulas are abnormal connections between the esophagus and trachea.

A

TRUE

70
Q

What is the most common subtype of tracheoesophageal fistula?

A

A blind pouch upper esophagus with the lower esophagus connected to the trachea

71
Q

What are some symptoms seen with the most common subtype of tracheoesophageal fistula?

A

Cyanosis, choking and vomiting with feeding, air bubble on x-ray of the chest, and polyhydramnios

72
Q

A newborn is noted to choke and vomit with routine feedings; the mother had polyhydramnios during pregnancy; what is the most likely diagnosis?

A

Tracheoesophageal fistula

73
Q

In what disease is there hypertrophy of the pylorus?

A

Congenital pyloric stenosis

74
Q

In congenital pyloric stenosis, hypertrophy of the pylorus leads to what problem?

A

Obstruction

75
Q

What are the two classic findings in an infant with congenital pyloric stenosis?

A

A palpable epigastric olive-sized mass and projectile vomiting

76
Q

Where is the "olive" mass typically palpated in a patient with congenital pyloric stenosis?

A

In the epigastric region

77
Q

If inspected, the vomit from a patient with congenital pyloric stenosis is noted as lacking what substance?

A

Bile

78
Q

At about what age do infants with congenital pyloric stenosis typically start projectile vomiting?

A

2 weeks

79
Q

What is the treatment for congenital pyloric stenosis?

A

Surgical incision (a pyloromyotomy)

80
Q

What is the approximate incidence of congenital pyloric stenosis?

A

1:600 live births

81
Q

Congenital pyloric stenosis often occurs in what demographic group?

A

Male first-born infants

82
Q

Is the pancreas derived from the foregut, the midgut, or the hindgut?

A

The foregut

83
Q

Is the head of the pancreas derived from the ventral or dorsal pancreatic bud?

A

The ventral pancreatic bud

84
Q

Is the main duct of the pancreas derived from the ventral or dorsal pancreatic bud?

A

The ventral pancreatic bud

85
Q

Is the body of the pancreas derived from the ventral or dorsal pancreatic bud?

A

The dorsal pancreatic bud

86
Q

Is the tail of the pancreas derived from the ventral or dorsal pancreatic bud?

A

The dorsal pancreatic bud

87
Q

Is the accessory pancreatic duct derived from the ventral or dorsal pancreatic bud?

A

The dorsal pancreatic bud

88
Q

The head of the pancreas is derived from the _____ (ventral/dorsal) pancreatic bud, the body is derived from the _____ (ventral/dorsal) pancreatic bud, and the tail is derived from the _____ (ventral/dorsal) pancreatic bud.

A

Ventral; dorsal; dorsal

89
Q

The main pancreatic duct is derived from the _____ (ventral/dorsal) pancreatic bud, whereas the accessory pancreatic duct is derived from the _____ (ventral/dorsal) pancreatic bud.

A

ventral; dorsal

90
Q

True or False: The spleen arises as a diverticulum off of the gastrointestinal tract.

A

False; the spleen arises from the dorsal mesentery and is mesodermal

91
Q

True or False: The spleen receives its blood supply from the foregut, although it is not derived from the foregut.

A

True; it is supplied via the celiac artery

92
Q

A patient has a congenital malformation of the pancreas in which the ventral bud abnormally encircles the second part of the duodenum and forms a ring of tissue; what is the name of this abnormality?

A

Annular pancreas

93
Q

An annular pancreas may lead to the narrowing of what structure?

A

The duodenum

94
Q

What portion of the duodenum is affected by an annular pancreas?

A

The 2nd part of the duodenum

95
Q

With regard to the embryologic development of the kidney, when does the pronephros develop?

A

During week 4

96
Q

After week 4, what happens to the pronephros?

A

The pronephros degenerates

97
Q

During which trimester of fetal development does the mesonephros arise?

A

During the first trimester

98
Q

What fetal structure functions as the interim kidney for the first trimester?

A

Mesonephros

99
Q

Of the following fetal structures, which ultimately contributes to the male genital system: the pronephros, mesonephros, or metanephros?

A

The mesonephros

100
Q

The _____ develops into the bladder, urethra, and allantois.

A

urogenital sinus

101
Q

The urogenital sinus develops into what three structures?

A

Bladder, urethra, and allantois

102
Q

Which of the three fetal kidney structures develops into the adult kidney?

A

Metanephros

103
Q

From what part of the developing kidney is the ureteric bud derived?

A

The mesonephros

104
Q

What adult structures in the urinary tract are derived from the mesonephros?

A

The collecting ducts, calyces, pelves, and ureter

105
Q

What adult structures in the urinary tract are derived from the metanephros?

A

The kidney from the glomerulus to the distal convoluted tubule

106
Q

What syndrome results from bilateral renal agenesis?

A

Potter's syndrome

107
Q

In Potter's syndrome, what pathophysiologic consequence of bilateral renal agenesis leads to the hallmark features of limb deformities, facial deformities, and pulmonary hypoplasia?

A

Oligohydramnios (remember: babies with Potter's can't !Pee" in utero)

108
Q

What embryonic structure is malformed in patients with Potter's syndrome?

A

The ureteric bud

109
Q

What is the name of the anatomic abnormality resulting from the fusion of the inferior poles of the kidneys?

A

Horseshoe kidney

110
Q

Horseshoe kidneys remain low in the abdomen because, during fetal development, they get trapped under the what artery?

A

The inferior mesenteric artery

111
Q

Are horseshoe kidneys formed by the fusion of the two kidneys' inferior or superior poles?

A

Inferior

112
Q

During the embryologic development of the renal system, do the kidneys ascend or descend in the abdomen?

A

Ascend

113
Q

True or False: A horseshoe kidney functions normally.

A

TRUE

114
Q

The mesonephric duct is also known as what?

A

The Wolffian duct

115
Q

What four structures are derived from the mesonephric duct?

A

The Seminal vesicles, the Epididymis, the Ejaculatory duct, and the Ductus deferens (remember: SEED)

116
Q

The paramesonephric duct is also known as what?

A

The müllerian duct

117
Q

What three structures are derived from the paramesonephric duct?

A

The fallopian tubes, the uterus, and upper one-third of the vagina

118
Q

What hormone inhibits the development of the paramesonephric duct in males?

A

Müllerian-inhibiting substance

119
Q

What class of hormones promotes the development of the mesonephric ducts in males?

A

Androgens

120
Q

Is male or female development the default fetal development?

A

Female; in the absence of a Y chromosome, female reproductive organs will develop

121
Q

In female development, the _____ duct degenerates and the _____ duct develops.

A

mesonephric; paramesonephric

122
Q

In male development, the _____ gene on the _____ chromosome codes for testis-determining factor.

A

SRY; Y

123
Q

In male development, the mesonephric duct develops into all genitourinary internal structures except the _____.

A

Prostate

124
Q

Which embryologic structure of the genitals degenerates in the female?

A

Mesonephric duct

125
Q

Which cells produce müllerian-inhibiting substance in males?

A

Sertoli cells

126
Q

Which cells produce the androgens that promote development of the mesonephric ducts?

A

Leydig cells

127
Q

What structure becomes the lower two-thirds of the vagina?

A

The urogenital sinus

128
Q

What is the name of the congenital pathology that is associated with incomplete fusion of the paramesonephric ducts?

A

Bicornuate uterus

129
Q

What are 2 complications associated with a bicornuate uterus?

A

Bicornuate uterus is associated with urinary tract abnormalities and infertility

130
Q

True or False: Bicornuate uterus results from incomplete fusion of the mesonephric ducts.

A

False; bicornuate uterus results from the incomplete fusion of the paramesonephric ducts

131
Q

The genital tubercle forms what two structures under the influence of dihydrotestosterone?

A

The glans penis and the corpus spongiosum

132
Q

The genital tubercle forms what two structures under the influence of estrogen?

A

The glans clitoris and the vestibular bulbs

133
Q

The urogenital sinus forms what two structures under the influence of dihydrotestosterone in the male embryo?

A

The prostate and the bulbourethral glands

134
Q

Embryologically, the urogenital sinus forms what two structures under the influence of estrogen in the female embryo?

A

The greater vestibular glands (of Bartholin) and the urethral and paraurethral glands (of Skene)

135
Q

Embryologically, the urogenital folds develop into what structure under the influence of dihydrotestosterone in the male embryo?

A

The ventral shaft of the penis (penile urethra)

136
Q

Embryologically, he urogenital folds develop into what structure under the influence of estrogen in the female embryo?

A

The labia minora

137
Q

Embryologically, the labioscrotal swelling develops into what structure under the influence of dihydrotestosterone in the male embryo?

A

The scrotum

138
Q

Embryologically, the labioscrotal swelling develops into what structure under the influence of estrogen in the female embryo?

A

The labia majora

139
Q

Embryologically, the genital tubercle develops into what structure in the male and what structure in the female?

A

The glans penis in the male and the glans clitoris in the female

140
Q

Embryologically, the urogenital folds develop into what structure in the male and what structure in the female?

A

The ventral shaft of the penis in the male and the labia minora in the female

141
Q

Embryologically, the labioscrotal swellings develop into what structure in the male and what structure in the female

A

The scrotum in the male and the labia majora in the female

142
Q

What condition results from an abnormal opening of the penile urethra on the inferior (ventral) side of the penis as a result of the failure of urethral folds to close?

A

Hypospadias (remember: Hypo is below)

143
Q

What condition results from an abnormal opening of the penile urethra on the superior (dorsal) side of the penis as a result of the faulty positioning of the genital tubercle?

A

Epispadias (remember: when you have Epispadias you hit your Eye when you p,EE)

144
Q

What common complication is prevented by fixing hypospadias?

A

Urinary tract infections

145
Q

Which is a more common congenital penile abnormality: epispadias or hypospadias?

A

Hypospadias

146
Q

Which is associated with exstrophy of the bladder: epispadias or hypospadias?

A

Epispadias (remember: Exstrophy of the bladder is associated with Epispadias)

147
Q

Which congenital penile abnormality is associated with failure of the urethral folds to close?

A

Hypospadias

148
Q

Which congenital penile abnormality is associated with faulty positioning of the genital tubercle?

A

Epispadias