Anatomy Review Questions (ES)

The following statements concerning the hypothalamohypophyseal tract are correct except which? A. Oxytocin inhibits the contraction of the smooth muscle of the uterus. B. The nerve cells of the supraoptic and paraventricular nuclei produce the hormones vasopressin and oxytocin. C. The hormones travel in the axons of the tract. D. Vasopressin stimulates the distal convoluted tubules and collecting tubules of the kidney, causing increased absorption of water from the urine. E. The hormones leave the axons and are absorbed into the bloodstream in the capillaries of the posterior lobe of the pituitary gland.

A Oxytocin stimulates contraction of the smooth muscle fibers of the uterus.

An 8-year-old boy is found to have a mid-line tumor of the thymus gland that is impinging posteriorly on a blood vessel. The affected vessel is most likely the: A. left brachiocephalic vein B. left pulmonary vein C. left bronchial vein D. right pulmonary artery E. right superior intercostal vein

A Remember--the thymus is a very superficial structure found in the anterior mediastinum. The left brachiocephalic vein courses through the mediastinum to join the right brachiocephalic vein and form the superior vena cava on the right side of the thorax. Since the left brachiocephalic vein is fairly superficial, it travels just deep to the thymus. So, it might be compressed by the tumor. See Netter Plate 206 for a picture of the thymus and the left brachiocephalic vein. The left pulmonary vein, left bronchial vein, and right pulmonary arteries are deep structures that enter and exit the lung at its root--they are not near the thymus. The right superior intercostal vein drains intercostal spaces 2-4. It drains into the arch of the azygos vein and is not associated with the thymus.

The middle cervical sympathetic ganglion, recurrent laryngeal nerve, and parathyroid glands are all closely related with which blood vessel? A. Inferior thyroid artery B. Inferior thyroid vein C. Superior thyroid artery D. Superior thyroid vein

A The inferior thyroid artery branches from the thyrocervical trunk to provide blood to the lower poles of the thyroid gland. This artery approaches the posterior side of the thyroid gland, crossing the recurrent laryngeal nerve and coming near the middle cervical sympathetic ganglion. This artery also supplies blood to the parathyroid glands, which are on the posterior surface of the thyroid. The inferior thyroid veins are associated with the lower parts of the gland--however, these veins are on the anterior side of the thyroid and are not as closely associated with these structures found deep to the gland. The superior thyroid artery and vein are associated with the superior pole of the thyroid. Remember--the important relationship here is that the superior thyroid artery travels with the external branch of the superior laryngeal nerve.

The suprarenal gland receives its arterial supply from which of the following? A. Aorta, inferior phrenic, and renal arteries B. Lumbar arteries C. Superior phrenic artery D. Testicular (ovarian) artery E. Subcostal artery

A The suprarenal gland receives its arterial supply from the aorta and inferior phrenic and renal arteries.

The nerve that innervates the cells of the suprarenal medulla consists of fibers of the: A. Greater thoracic splanchnic nerve B. Lesser thoracic splanchnic nerve C. Least thoracic splanchnic nerve D. Anterior vagal trunk EE. Posterior vagal trunk

A The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic nerve. These fibers synapse on the cells in the adrenal medulla, causing a systemic sympathetic response. Other preganglionic fibers from the greater thoracic nerve synapse in the celiac ganglion; the postganglionic fibers from this ganglion distribute along branches of the celiac trunk. The preganglionic fibers from the lesser thoracic splanchnic nerve synapse in the aorticorenal ganglion--postganglionic processes from this ganglion supply vascular smooth muscle of branches of the renal artery and suprarenal arteries. The preganglionic fibers of the least thoracic splanchnic nerve synapse in the renal plexus. The anterior vagal trunk has a gastric and hepatic branch, supplying parasympathetic fibers to the stomach and liver. The posterior vagal trunk supplies some parasympathetic fibers to the stomach, but it also sends a celiac branch to the celiac plexus. The fibers from the posterior vagal trunk which pass to the celiac plexus eventually distribute to the organs of the abdomen, all the way to the last third of transverse colon.

During surgical procedures of the neck, structures within the carotid sheath can be retracted (pulled aside) as a unit. Which of the following structures would remain in place when the carotid sheath is retracted? A. common carotid artery B. cervical sympathetic trunk C. internal jugular vein D. internal carotid artery E. vagus nerve

B The cervical sympathetic trunk lies in front of the prevertebral muscles in the prevertebral fascia. It is not part of the carotid sheath. All of the other structures listed are in the carotid sheath. The carotid sheath contains 3 vessels: internal carotid, common carotid, and internal jugular vein. It also contains 2 nerves: vagus and the superior ramus of ansa cervicalis.

Any manipulation of the superior thyroid artery must be undertaken with care not to damage its small companion nerve, the: A. Cervical sympathetic trunk B. External branch of the superior laryngeal C. Inferior root of the ansa cervicalis D. Internal branch of the superior laryngeal E. Recurrent laryngeal

B The external branch of the superior laryngeal nerve runs with the superior thyroid artery--this artery and nerve might be damaged when removing the superior pole of the thyroid. If this nerve was damaged, the cricothyroid muscle would be paralyzed, and a patient would be unable to tense the vocal cords. The internal branch of the superior laryngeal nerve runs with the superior laryngeal artery and provides sensory innervation to the mucous membrane of the larynx, superior to the vocal fold. The recurrent laryngeal nerve crosses the inferior thyroid artery, near the lower pole of the thyroid. This means that the recurrent laryngeal nerve would be at risk in any surgery involving the inferior thyroid artery or the inferior poles of the thyroid. The recurrent laryngeal innervates all the muscles of the larynx with the exception of cricothyroid. So, an injury to the recurrent laryngeal nerve might lead to hoarseness and dificulty breathing. The cervical sympathetic trunk lies in front of the prevertebral muscles in the prevertebral fascia--it would not be near the structures involved with thyroid surgery. The inferior root of ansa cervicalis is a branch of the cervical plexus. It innervates the strap muscles. Ansa cervicalis hangs in a loop over the carotid vessels; it is not associated with the thyroid gland.

Following surgery on the upper pole of the right lobe of the thyroid gland, a patient complains of hoarseness and weakness of voice. What nerve may have been injured? A. Ansa cervicalis B. External branch of the superior laryngeal C. Inferior laryngeal D. Internal branch of the superior laryngeal E. Recurrent laryngeal

B The external branch of the superior laryngeal nerve travels with the superior thyroid artery toward the superior pole of the thyroid. So, it's in the right place to be injured by surgery on the upper pole of the gland. The external branch of the superior laryngeal nerve innervates cricothyroid, the muscle responsible for elongating the vocal cords. The patient's symptoms of horseness and a weak voice would fit with an injury to this nerve and the denervation of this muscle. The inferior laryngeal and recurrent laryngeal nerves are one in the same--the recurrent laryngeal changes its name to the inferior laryngeal at the inferior border of cricopharyngeus. This nerve innervates all of the other muscles of the larynx, besides cricothyroid. It runs with the inferior thyroid artery to the inferior poles of the thyroid--it could be injured in any surgery involving the inferior thyroid artery or inferior aspects of the gland. The internal branch of the superior laryngeal nerve pierces the thyrohyoid membrane along with the superior laryngeal artery--it is a sensory nerve only. It supplies sensory innervation to the mucosa of the larynx, superior to the vocal folds.

The following statements concerning the pineal gland are correct except which? A. It is small and cone shaped. B. It projects from the posterior end of the pons of the brain. C. Its activities can influence the functions of the suprarenals and the gonads. D. It does not possess a blood-brain barrier. E. It produces melatonin, which inhibits the release of the gonadotropic hormone.

B The pineal gland projects from the posterior end of the roof of the third ventricle.

Which statement is true of the internal jugular vein? A. It drains all of the thyroid gland on that side of the body B. It drains into the external jugular vein C. It is accompanied by the deep cervical chain of lymph nodes D. It lies deep to the prevertebral fascia E. It passes superficial to the sternocleidomastoid muscle

C The deep cervical chain of lymph nodes runs closely with the internal jugular vein. The internal jugular vein does not drain all of the thyroid gland--the superior and middle thyroid veins drain into the internal jugular vein, but the inferior thyroid veins drain directly into the brachiocephalic veins. The internal jugular vein does not drain into the external jugular vein. The external jugular vein is a smaller vein on the lateral neck which drains into the subclavian vein. The internal jugular vein meets the subclavian vein, and the two vessels join to form the brachiocephalic vein. The prevertebral fascia is found deep in the neck, over the vertebrae and the prevertebral muscles. So, the internal jugular vein is very superficial to this fascia. Finally, the sternocleidomastoid muscle crosses over the internal jugular vein.

A 35 year old woman was diagnosed with an adenoma of the thyroid gland. This required excision of the lower pole (left lobe) of the gland and ligation of the artery supplying that region. Which of the following nerves accompanying the artery is most likely to be damaged if the surgeon is not careful? A. External branch of the superior laryngeal B. Internal branch of the superior laryngeal C. Recurrent laryngeal D. Vagus proper E. Sympathetic trunk

C The inferior thyroid artery supplies the lower lobes of the thyroid. It is a branch of the thyrocervical trunk. Branches of this artery cross the recurrent laryngeal nerve, so this is the nerve that might be damaged during the surgery. The external branch of the superior laryngeal nerve runs with the superior thyroid artery--this artery and nerve might be damaged when removing the superior lobes of the thyroid. The internal branch of the superior laryngeal nerve runs with the superior laryngeal artery, piercing the thyrohyoid membrane. The vagus nerve proper runs with the common carotid artery, in the carotid sheath. It gives off the recurrent laryngeal nerve, but it does not come as close to the inferior thyroid artery. Finally, the sympathetic trunk is in the deep neck, near the vertebral bodies. It should not be damaged in thyroid surgery.

Following thyroid surgery, it was noted that a patient frequently aspirated fluid into her lungs. Upon examination it was determined that the area of the piriform recess above the vocal fold of the larynx was numb. What nerve may have been injured? A. External branch of the superior pharyngeal B. Hypoglossal C. Internal branch of the superior laryngeal D. Lingual E. Recurrent laryngeal

C The internal branch of the superior laryngeal is a sensory nerve that pierces the thyrohyoid membrane along with the superior laryngeal artery. It supplies sensory fibers to the mucous membrane of the larynx, superior to the vocal folds. Since this area lost sensation, it appears that the internal branch of the superior laryngeal nerve must have been injured. The external branch of the superior laryngeal nerve is a motor nerve that innervates the cricothyroid muscle--it does not provide any sensory innervation to the larynx. The recurrent laryngeal nerve ascends from the thorax and provides motor innervation to the upper esophagus, lower pharynx, and all the laryngeal muscles except cricothyroideus. The hypoglossal nerve supplies motor innervation to the muscles of the tongue. The lingual nerve is a sensory nerve for the anterior 2/3 of the tongue. These nerves are not important for innervating the larynx.

The following statements concerning the pancreas are correct except which? A. The pancreas receives part of the arterial supply from the splenic artery. B. The main pancreatic duct opens into the secondary part of the duodenum. C. The islets of Langerhans are more numerous than in its body, neck, or tail. D. The bile duct (common bile duct) lies posterior to the head of the pancreas. E. The transverse mesocolon is attached to the anterior border of the pancreas.

C The islets of Langerhans are more numerous in the the tail of the pancreas than in its body, neck, or head.

You are attending an operation to remove a thymic tumor from the superior mediastinum. The surgeon asks, "What important nerve lying on and partly curving posteriorly around the arch of the aorta should we be careful of as we remove this mass?" You quickly answer, "The-- A. left phrenic B. left sympathetic trunk C. left vagus D. right phrenic E. right sympathetic trunk

C The left vagus nerve lies against the lateral surface of the arch of the aorta. The left recurrent laryngeal nerve is an especially important nerve from the vagus which loops around the aortic arch. This nerve innervates the muscles of the left larynx. If it is damaged, a patient may experience hoarseness after surgery. Care must be taken to preserve this nerve, especially during thyroid surgery. The left and right phrenic nerves, which innervate the diaphragm, are lateral to the vagus nerves and are not looping near the aortic arch. The left and right sympathetic trunks lie on the posterior chest wall and are not involved with the aortic arch.

With one exception, preganglionic sympathetic axons synapse upon postganglionic sympathetic dendrites or cell bodies. The exception to this general rule occurs within the: A. Kidney cortex B. Kidney medulla C. Suprarenal medulla D. Suprarenal cortex

C The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic splanchnic nerve. These preganglionic fibers synapse on the cells of the adrenal medulla, causing the cells in the adrenal medulla to release norepinephrine and/or epinephrine. The preganglionic fibers can synapse on these cells of the adrenal medulla because they are modified nervous tissue. The epinephrine and norepinepherine enters the blood stream to cause a systemic response.

The following statements concerning the thymus are correct except which? A. In the newborn, it reaches its largest size relative to the body. B. In the infant, it may extend from the anterior mediastinum into the superior mediastinum and even into the root of the neck. C. The thymus continues to grow into adult life and, in middle age, starts to involute. D. It is the site for the development of the T lymphocytes. E. It produces the hormone thymosin, which influences the maturation and function of the T lymphocytes.

C The thymus gland continues to grow until puberty but thereafter undergoes involution.

Which of the following is true of the inferior thyroid arteries? A. They arise from the external carotid arteries B. They cross over the superior cervical sympathetic ganglion C. They supply most of the anterior surface of the thyroid gland D. They often supply all four parathyroid glands

D The inferior thyroid arteries are branches of the thyrocervical trunk. (The superior thyroid arteries are branches of the external carotid artery.) The inferior thyroid arteries are closely associated with the middle cervical sympathetic ganglia and supply the inferior poles of the thyroid. They are found on the posterior surface of the thyroid gland, which is where the parathyroid glands are located. So, they are the primary source of blood for the four parathyroid glands.

The following statements concerning the parathyroid glands are correct except which? A. They are four in number. B. They are closely related to the posterior border of the thyroid gland within its fascial capsule. C. The arterial supply is from the superior and inferior thyroid arteries. D. The activity of the cells of the parathyroid glands reduces the calcium levels in the blood. E. The inferior parathyroid glands may reside in the superior mediastinum in the thorax.

D The parathyroid hormone produced by the chief cells of the parathyroid gland raises the calcium levels of the blood.

The following statements concerning the pituitary gland (hypophysis cerebri) are correct except which? A. It is separated from the optic chiasma by the diaphragma sellae. B. The sphenoid sinus is inferior to it. C. It receives its arterial supply from the internal carotid artery. D. It is suspended from the floor of the third ventricle by the pars anterior. E. It is deeply placed within the sella turcica of the skull.

D The pituitary gland is suspended from the floor of the third ventricle by the infundibulum.

In performing a thyroidectomy, caution should be exercised when ligating (tying) the inferior thyroid artery, as it lies in a very close relationship to which nerve? A. ansa cervicalis B. hypoglossal C. phrenic D. recurrent laryngeal E. vagus

D The recurrent laryngeal nerve crosses the inferior thyroid artery near the lower lobe of the thyroid. This means that the recurrent laryngeal nerve would be at risk in any surgery involving the inferior thyroid artery or the inferior poles of the thyroid. The recurrent laryngeal nerve becomes the inferior laryngeal nerve at the inferior border of cricopharyngeus, and this nerve continues on to innervate all the muscles of the larynx with the exception of cricothyroid. So, you really need to take care to protect the recurrent laryngeal nerve--injuring this structure could lead to hoarseness, permanent loss of voice, or even death due to a laryngeal spasm. None of the other listed nerves are related to the inferior thyroid artery. Ansa cervicalis is a branch of the cervical plexus which hangs in front of the internal jugular vein. It innervates the strap muscles. The hypoglossal nerve winds behind the internal jugular vein, then sweeps around lateral to the carotid vessels and into the floor of the mouth, where it innervates the tongue muscles. The phrenic nerve lies on top of the anterior scalene muscles--it then travels through the thorax to innervate the diaphragm. Finally, the vagus is found in the carotid sheath--it is associated with the common carotid and the internal carotid arteries.

Which of the following nerves might be injured when tying the inferior thyroid artery during operations on the thyroid gland. A. The sympathetic trunk B. The internal laryngeal nerve C. The descendens cervicalis D. The recurrent laryngeal nerve E. The superior laryngeal nerve

D The recurrent laryngeal nerve is closely related to the inferior thyroid artery and might be damaged when tying the artery during operations on the thyroid gland.

Which statement regarding the suprarenal glands is correct? A. Its entire arterial supply is directly from the abdominal aorta. B.Veins from both glands drain directly into the inferior vena cava. C. The glands are localized in the pararenal space. D. Cells that secrete epinephrine and norepinephrine are innervated by preganglionic fibers from the greater thoracic splanchnic nerve.

D The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic splanchnic nerve. These preganglionic fibers synapse on the cells of the adrenal medulla, causing the cells in the adrenal medulla to release norepinephrine and/or epinephrine. The preganglionic fibers can synapse on these cells of the adrenal medulla because they are modified nervous tissue. The epinephrine and norepinepherine enters the blood stream to cause a systemic response. The superior suprarenal arteries branch from the inferior phrenic, the middle suprarenal artery is a direct branch of the abdominal aorta, and the inferior suprarenal arteries are branches of the renal artery. Although the vein from the right gland drains into the inferior vena cava, the vein from the left suprarenal gland drains into the left renal vein. Finally, the pararenal space is the space outside the renal fascia, covered with the pararenal fat. The suprarenal gland is covered by the renal fascia, so it's in the perirenal space, not in the pararenal space.

A person develops a primary tumor of the thyroid gland and, among other symptoms, drooping of the eyelid and constriction of the pupil on the right side of the eye are noted. What nerve fibers have been interrupted by the tumor? A. postganglionic parasympathetic B. postganglionic sympathetic C. preganglionic parasympathetic D. the carotid nerve E. the cervical sympathetic trunk

E A tumor of the thyroid gland could disrupt the preganglionic fibers traveling in the cervical sympathetic trunk. The cervical sympathetic trunk lies in front of the preverterbral muscles in the preverterbral fascia--it is in the right location to be compressed by a thyroid tumor. Disrupting the cervical sympathetic trunk leads to Horner's syndrome, a disorder with a variety of characteristic symptoms. Sympathetic nerves innervate the dilator pupillae muscle, which allows the eye to dilate. If these sympathetic nerves are lost in a patient with Horner's syndrome, the pupil will contract due to unopposed parasympathetic action on sphincter pupillae. Ptosis (a droopy eyelid) is seen because the superior tarsal muscle, which raises the eyelid involuntarily, is innervated sympathetically. If this muscle is paralyzed, the eyelid droops. You might also observe enophthalmos (a sunken eye), possibly due to the paralysis of a smooth muscle in the floor of the orbit. Without the sympathetic nerve supply, the vasculature of the face cannot constrict. So, the arterioles in the patient's face are vasodilated, making the face red. Sympathetic nerves also innervate sweat glands; if these nerves are interrupted, the patient will not sweat and the face will appear very dry. These are all characteristic symptoms of Horner's syndrome, and you should be familiar with all of these! Parasympathetic fibers innervate the glands of the face, cause the pupil to constrict, and allow for accommodation of the eye for close vision; they are not involved with Horner's syndrome. The internal carotid nerve carries postsynaptic sympathetic fibers from the superior cervical ganglion to the nasal cavity. The thyroid gland is near the level of the middle cervical ganglion, not the superior cervical ganglion.

The following statements are correct concerning the hypophyseal portal system are correct except which? A. The portal system carries releasing hormones and release-inhibiting hormones to the secretory cells of the anterior lobe of the pituitary gland. B. The production of the releasing hormones and the release-inhibiting hormones can be influenced by the level of hormone produced by the target organ controlled by the pituitary gland. C. The blood vessels commence superiorly in the median eminence and end inferiorly in the vascular sinusoids of the anterior lobes of the pituitary gland. D. Afferent nerve fibers entering the hypothalamus influence the production of the releasing hormones by the nerve cells. E. The neuroglial cells of the hypothalamus are responsible for the production of the release-inhibiting hormones.

E The neurosecretory cells of the hypothalamus are responsible for the production of the releasing hormones and release-inhibitory hormones.

Since the puncture in the previous question was through the posterior wall of the esophagus, the doctors were also very concerned about possible damage to a thin-walled vessel just behind the esophagus and between the azygos vein and aorta, i.e., the: A. Hemiazygos vein B. Left bronchial vein C. Left pulmonary vein D. Superior vena cava E. Thoracic duct

E The thoracic duct is found directly behind the esophagus in the posterior mediastinum, with the aorta to its left and the azygos vein to its right. This relationship between these three vessels is an important one to keep in mind! The other vessels do not share the same relationship with the azygos and aorta.

The following facts concerning the development of the suprarenal glands are correct except which? A. The cortex is developed from the coelomic epithelium covering the posterior abdominal wall. B. The medulla is developed from the neural crest. C. Pre-ganglionic sympathetic nerve fibers grow into the medulla and influence the activity of the medullary cells. D. A fetal cortex is first formed that later degenerates and disappears. E. The final cortex grows between the fetal cortex and the medulla.

E The final cortex of the developing suprarenal gland covers the fetal cortex; the fetal cortex degenerates and disappears during the first few weeks of life.

The following statements concerning the left suprarenal gland are correct except which? A. The gland extends along the medial border of the left kidney from the upper pole to the hilus. B. The gland's vein drains into the left renal vein. C. The gland is separated from the left kidney by the peritoneum. D. The gland lied behind the lesser sac of peritoneum. E. The medulla is innervated by the postganglionic sympathetic nerve fibers.

E The medulla of the suprarenal gland is innervated by preganglionic sympathetic nerve fibers.