Stanford University MD SURG 203 Anatomy
(Macroscopic, Embryology and Histology) –
Stanford Medical School Anatomy Study Guide,
Original Practice Questions & Answers, SURG 203
Exam Preparation, Comprehensive Clinical
Anatomy Review, Gross Anatomy, Macroscopic
Anatomy, Embryology, Histology, Developmental
Anatomy, Medical Imaging, Dissection, Thorax,
Abdomen, Pelvis, Back, Upper & Lower Limbs, Head
& Neck & Clinical Applications
Question 1: Which of the following embryological structures is primarily
responsible for the formation of the adult central tendon of the diaphragm?
A. Septum transversum
B. Pleuroperitoneal folds
C. Cervical myotomes
D. Dorsal mesentery of the esophagus
CORRECT ANSWER: A. Septum transversum
Rationale: The septum transversum is a thick plate of mesodermal tissue that forms the
initial central tendon of the diaphragm. While the pleuroperitoneal folds and cervical
myotomes contribute to the muscular portions and closure of the diaphragm, the
septum transversum specifically gives rise to the tendinous center.
Question 2: In the adult male, the tunica vaginalis is a remnant of which
embryological structure?
A. Gubernaculum
B. Processus vaginalis
C. Mullerian duct
D. Mesonephric duct
CORRECT ANSWER: B. Processus vaginalis
Rationale: The processus vaginalis is an evagination of the peritoneum that precedes
the testis into the scrotum. The proximal part normally obliterates, while the distal part
remains as the tunica vaginalis, a serous covering of the testis. The gubernaculum aids
in testicular descent but does not form the tunica vaginalis.
Question 3: A tumor compressing the infundibulum of the pituitary gland would
most directly affect the hypothalamic-hypophyseal portal system, thereby
impairing the release of which of the following?
A. Oxytocin
B. Antidiuretic hormone (ADH)
,C. Adrenocorticotropic hormone (ACTH)
D. Vasopressin
CORRECT ANSWER: C. Adrenocorticotropic hormone (ACTH)
Rationale: The hypothalamic-hypophyseal portal system carries releasing and inhibiting
hormones from the hypothalamus to the anterior pituitary. ACTH is an anterior pituitary
hormone whose release is controlled by this portal system. Oxytocin and ADH are
synthesized in the hypothalamus and transported to the posterior pituitary via the
hypothalamic-hypophyseal tract, not the portal system.
Question 4: Which of the following structures is derived from the second
pharyngeal arch?
A. Malleus
B. Stapes
C. Incus
D. Mandible
CORRECT ANSWER: B. Stapes
Rationale: The second pharyngeal arch (Reichert's cartilage) gives rise to the stapes, the
styloid process, the stylohyoid ligament, and the lesser horn and upper body of the
hyoid bone. The malleus and incus are derived from the first pharyngeal arch (Meckel's
cartilage). The mandible is also derived from the first arch.
Question 5: Histologically, the zona glomerulosa of the adrenal cortex is
characterized by cells arranged in which pattern, and what is its primary secretory
product?
A. Clusters; aldosterone
B. Cords; cortisol
C. Nests; androgens
D. Fascicles; epinephrine
CORRECT ANSWER: A. Clusters; aldosterone
Rationale: The zona glomerulosa is the outermost layer of the adrenal cortex and
consists of cells arranged in rounded clusters or arches. Its primary function is the
secretion of mineralocorticoids, mainly aldosterone, which regulates sodium and
potassium balance. Cortisol is secreted by the zona fasciculata, and androgens by the
zona reticularis.
Question 6: During development of the male reproductive system, the Sertoli cells
secrete which factor that causes regression of the paramesonephric (Mullerian)
ducts?
A. Testosterone
B. Dihydrotestosterone (DHT)
,C. Anti-Mullerian hormone (AMH)
D. Androgen-binding protein (ABP)
CORRECT ANSWER: C. Anti-Mullerian hormone (AMH)
Rationale: Sertoli cells of the fetal testis secrete AMH, also known as Mullerian
inhibiting substance (MIS), which causes the paramesonephric ducts to regress.
Testosterone, secreted by Leydig cells, stabilizes the mesonephric ducts. DHT is a
derivative of testosterone that is important for external genitalia development.
Question 7: The foramen ovale in the fetal heart allows blood to bypass which of
the following structures?
A. Left ventricle
B. Pulmonary circulation
C. Ductus arteriosus
D. Right ventricle
CORRECT ANSWER: B. Pulmonary circulation
Rationale: The foramen ovale is an opening in the interatrial septum that allows
oxygenated blood from the placenta to pass from the right atrium to the left atrium,
thereby bypassing the non-functional fetal pulmonary circulation. The ductus arteriosus
shunts blood from the pulmonary trunk to the aorta.
Question 8: A 45-year-old patient presents with a loss of fine touch and
proprioception in the right lower limb. A lesion in which of the following spinal cord
regions is most likely?
A. Left dorsal column
B. Right dorsal column
C. Left lateral corticospinal tract
D. Right spinothalamic tract
CORRECT ANSWER: A. Left dorsal column
Rationale: The dorsal columns carry ipsilateral fine touch, vibration, and
proprioception. A lesion in the left dorsal column would affect these sensations on the
left side. For the right lower limb to be affected by a dorsal column lesion, the lesion
must be on the right side. However, the question states loss in the right lower limb,
indicating a right-sided lesion. The correct answer is B. Right dorsal column.
CORRECT ANSWER: B. Right dorsal column
Rationale: The dorsal columns carry fine touch, vibration, and proprioception
ipsilaterally. Therefore, a lesion of the right dorsal column at an appropriate spinal level
will result in the loss of these modalities in the right lower limb.
Question 9: The epithelial lining of the fallopian tube is best described
histologically as which of the following?
, A. Simple squamous epithelium
B. Pseudostratified ciliated columnar epithelium
C. Stratified squamous epithelium
D. Simple cuboidal epithelium
CORRECT ANSWER: B. Pseudostratified ciliated columnar epithelium
Rationale: The fallopian tube is lined by a mucosa composed of a pseudostratified
ciliated columnar epithelium. It contains both ciliated cells (which aid in moving the
ovum) and secretory (peg) cells. The other epithelial types are found in different
locations (e.g., simple squamous in the parietal layer of Bowman's capsule, stratified
squamous in the vagina).
Question 10: Fusion of the neural folds during neurulation is initiated at which
vertebral level and proceeds in which direction?
A. Cervical region, cranially and caudally
B. Lumbar region, caudally only
C. Thoracic region, cranially only
D. Midbrain region, caudally only
CORRECT ANSWER: A. Cervical region, cranially and caudally
Rationale: Neurulation begins at the cervical region, which is the future level of the
hindbrain and upper spinal cord. Fusion of the neural folds then proceeds both cranially
(forming the brain vesicles) and caudally (forming the spinal cord). The caudal end
closes at approximately day 26, and the cranial end closes at day 25.
Question 11: Which of the following is a derivative of the ectoderm?
A. Splanchnic mesoderm
B. Cardiac muscle
C. Adrenal medulla
D. Sclerotome
CORRECT ANSWER: C. Adrenal medulla
Rationale: The adrenal medulla is derived from neural crest cells, which originate from
the ectoderm. The adrenal cortex is derived from mesoderm. Cardiac muscle and
sclerotome are also derived from mesoderm.
Question 12: The posterior interventricular artery, a branch of the right coronary
artery, supplies which of the following structures?
A. Anterior wall of left ventricle
B. Posterior third of the interventricular septum
C. Sinoatrial node
D. Right atrium
CORRECT ANSWER: B. Posterior third of the interventricular septum
(Macroscopic, Embryology and Histology) –
Stanford Medical School Anatomy Study Guide,
Original Practice Questions & Answers, SURG 203
Exam Preparation, Comprehensive Clinical
Anatomy Review, Gross Anatomy, Macroscopic
Anatomy, Embryology, Histology, Developmental
Anatomy, Medical Imaging, Dissection, Thorax,
Abdomen, Pelvis, Back, Upper & Lower Limbs, Head
& Neck & Clinical Applications
Question 1: Which of the following embryological structures is primarily
responsible for the formation of the adult central tendon of the diaphragm?
A. Septum transversum
B. Pleuroperitoneal folds
C. Cervical myotomes
D. Dorsal mesentery of the esophagus
CORRECT ANSWER: A. Septum transversum
Rationale: The septum transversum is a thick plate of mesodermal tissue that forms the
initial central tendon of the diaphragm. While the pleuroperitoneal folds and cervical
myotomes contribute to the muscular portions and closure of the diaphragm, the
septum transversum specifically gives rise to the tendinous center.
Question 2: In the adult male, the tunica vaginalis is a remnant of which
embryological structure?
A. Gubernaculum
B. Processus vaginalis
C. Mullerian duct
D. Mesonephric duct
CORRECT ANSWER: B. Processus vaginalis
Rationale: The processus vaginalis is an evagination of the peritoneum that precedes
the testis into the scrotum. The proximal part normally obliterates, while the distal part
remains as the tunica vaginalis, a serous covering of the testis. The gubernaculum aids
in testicular descent but does not form the tunica vaginalis.
Question 3: A tumor compressing the infundibulum of the pituitary gland would
most directly affect the hypothalamic-hypophyseal portal system, thereby
impairing the release of which of the following?
A. Oxytocin
B. Antidiuretic hormone (ADH)
,C. Adrenocorticotropic hormone (ACTH)
D. Vasopressin
CORRECT ANSWER: C. Adrenocorticotropic hormone (ACTH)
Rationale: The hypothalamic-hypophyseal portal system carries releasing and inhibiting
hormones from the hypothalamus to the anterior pituitary. ACTH is an anterior pituitary
hormone whose release is controlled by this portal system. Oxytocin and ADH are
synthesized in the hypothalamus and transported to the posterior pituitary via the
hypothalamic-hypophyseal tract, not the portal system.
Question 4: Which of the following structures is derived from the second
pharyngeal arch?
A. Malleus
B. Stapes
C. Incus
D. Mandible
CORRECT ANSWER: B. Stapes
Rationale: The second pharyngeal arch (Reichert's cartilage) gives rise to the stapes, the
styloid process, the stylohyoid ligament, and the lesser horn and upper body of the
hyoid bone. The malleus and incus are derived from the first pharyngeal arch (Meckel's
cartilage). The mandible is also derived from the first arch.
Question 5: Histologically, the zona glomerulosa of the adrenal cortex is
characterized by cells arranged in which pattern, and what is its primary secretory
product?
A. Clusters; aldosterone
B. Cords; cortisol
C. Nests; androgens
D. Fascicles; epinephrine
CORRECT ANSWER: A. Clusters; aldosterone
Rationale: The zona glomerulosa is the outermost layer of the adrenal cortex and
consists of cells arranged in rounded clusters or arches. Its primary function is the
secretion of mineralocorticoids, mainly aldosterone, which regulates sodium and
potassium balance. Cortisol is secreted by the zona fasciculata, and androgens by the
zona reticularis.
Question 6: During development of the male reproductive system, the Sertoli cells
secrete which factor that causes regression of the paramesonephric (Mullerian)
ducts?
A. Testosterone
B. Dihydrotestosterone (DHT)
,C. Anti-Mullerian hormone (AMH)
D. Androgen-binding protein (ABP)
CORRECT ANSWER: C. Anti-Mullerian hormone (AMH)
Rationale: Sertoli cells of the fetal testis secrete AMH, also known as Mullerian
inhibiting substance (MIS), which causes the paramesonephric ducts to regress.
Testosterone, secreted by Leydig cells, stabilizes the mesonephric ducts. DHT is a
derivative of testosterone that is important for external genitalia development.
Question 7: The foramen ovale in the fetal heart allows blood to bypass which of
the following structures?
A. Left ventricle
B. Pulmonary circulation
C. Ductus arteriosus
D. Right ventricle
CORRECT ANSWER: B. Pulmonary circulation
Rationale: The foramen ovale is an opening in the interatrial septum that allows
oxygenated blood from the placenta to pass from the right atrium to the left atrium,
thereby bypassing the non-functional fetal pulmonary circulation. The ductus arteriosus
shunts blood from the pulmonary trunk to the aorta.
Question 8: A 45-year-old patient presents with a loss of fine touch and
proprioception in the right lower limb. A lesion in which of the following spinal cord
regions is most likely?
A. Left dorsal column
B. Right dorsal column
C. Left lateral corticospinal tract
D. Right spinothalamic tract
CORRECT ANSWER: A. Left dorsal column
Rationale: The dorsal columns carry ipsilateral fine touch, vibration, and
proprioception. A lesion in the left dorsal column would affect these sensations on the
left side. For the right lower limb to be affected by a dorsal column lesion, the lesion
must be on the right side. However, the question states loss in the right lower limb,
indicating a right-sided lesion. The correct answer is B. Right dorsal column.
CORRECT ANSWER: B. Right dorsal column
Rationale: The dorsal columns carry fine touch, vibration, and proprioception
ipsilaterally. Therefore, a lesion of the right dorsal column at an appropriate spinal level
will result in the loss of these modalities in the right lower limb.
Question 9: The epithelial lining of the fallopian tube is best described
histologically as which of the following?
, A. Simple squamous epithelium
B. Pseudostratified ciliated columnar epithelium
C. Stratified squamous epithelium
D. Simple cuboidal epithelium
CORRECT ANSWER: B. Pseudostratified ciliated columnar epithelium
Rationale: The fallopian tube is lined by a mucosa composed of a pseudostratified
ciliated columnar epithelium. It contains both ciliated cells (which aid in moving the
ovum) and secretory (peg) cells. The other epithelial types are found in different
locations (e.g., simple squamous in the parietal layer of Bowman's capsule, stratified
squamous in the vagina).
Question 10: Fusion of the neural folds during neurulation is initiated at which
vertebral level and proceeds in which direction?
A. Cervical region, cranially and caudally
B. Lumbar region, caudally only
C. Thoracic region, cranially only
D. Midbrain region, caudally only
CORRECT ANSWER: A. Cervical region, cranially and caudally
Rationale: Neurulation begins at the cervical region, which is the future level of the
hindbrain and upper spinal cord. Fusion of the neural folds then proceeds both cranially
(forming the brain vesicles) and caudally (forming the spinal cord). The caudal end
closes at approximately day 26, and the cranial end closes at day 25.
Question 11: Which of the following is a derivative of the ectoderm?
A. Splanchnic mesoderm
B. Cardiac muscle
C. Adrenal medulla
D. Sclerotome
CORRECT ANSWER: C. Adrenal medulla
Rationale: The adrenal medulla is derived from neural crest cells, which originate from
the ectoderm. The adrenal cortex is derived from mesoderm. Cardiac muscle and
sclerotome are also derived from mesoderm.
Question 12: The posterior interventricular artery, a branch of the right coronary
artery, supplies which of the following structures?
A. Anterior wall of left ventricle
B. Posterior third of the interventricular septum
C. Sinoatrial node
D. Right atrium
CORRECT ANSWER: B. Posterior third of the interventricular septum
