TBL 29

Question 1

Define Rathke’s pouch and infundibulum (embryologically) = (structure)

Answer 1

ectodermal outpocketing (aka Rathke’s pouch) from the roof of the mouth and a downward extension of neural ectoderm (aka infundibulum) form the pituitary gland.

Question 2

Discuss embryological tissue origin of anterior/posterior lobe of pituitary gland.

Answer 2

the anterior lobe (aka pars distalis) is oral ectoderm-derived and neural ectoderm forms the posterior lobe (aka pars nervosa).

Question 3

the pars TUBERALIS and pars INTERMEDIA have minimal/maximal function in adults/children.

Answer 3

the pars tuberalis and pars intermedia have minimal function in adults.

Question 4

the hypophyseal arteries branch from the (structure) to supply (2).

Answer 4

the hypophyseal arteries branch from the internal carotid arteries to supply the posterior lobe capillaries and the capillary plexus in the superior infundibulum (aka median eminence that unites with the hypothalamus of the brain).

Question 5

the capillary plexus of the superior infundibulum empties into (structure) which (discuss continuation and joining)

Answer 5

the capillary plexus of the superior infundibulum empties into the hypophyseal portal veins that descend the infundibulum to unite with the capillaries of the anterior lobe

Question 6

the capillaries of the anterior and posterior lobes drain into (Structure).

Answer 6

the capillaries of the anterior and posterior lobes drain into intracranial veins

Question 7

secretory cells of the anterior lobe produce (7) and function.

Answer 7

• growth hormone to stimulate growth of the bones, muscles, and viscera
• prolactin to stimulate milk production in the mammary glands during pregnancy
• ACTH to activate the synthesis and release of cortisol from the adrenal gland
• TSH to activate synthesis, storage, and release of the thyroid hormones
• FSH and LH to regulate the menstrual cycle and ovulation
• LH to activate the synthesis of testosterone in the testes

Question 8

What forms the form the hypothalamohypophyseal tract (3). Discuss the distention route of the hypothalamohypohyseal tract.

Answer 8

clusters of secretory neurons form the paraventricular and supraoptic nuclei in the hypothalamus, and axons of the secretory neurons collectively form the hypothalamohypophyseal tract that descends the infundibulum into the posterior lobe.

Question 9

ADH is discharged mainly from where and goes where?

Answer 9

ADH is discharged mainly from axon terminals of the supraoptic neurons into capillaries of the posterior lobe.

Question 10

ADH acts on (structure and function of ADH).

Answer 10

ADH acts on the collecting ducts of the kidney to concentrate urine.

Question 11

What MAKES AND DISCHARGES OXYTOCIN? Function of oxytocin (2).

Answer 11

the paraventricular neurons mainly synthesize and discharge oxytocin that stimulates uterine contraction during childbirth and milk ejection during nursing.

Question 12

Discuss primitive nipples and what happens to them?

Answer 12

bilateral epidermal thickenings (primitive nipples) appear in the early embryo but only one pair remaining in the pectoral region invaginates into the dermis (i.e., the breasts are modified sweat glands).

Question 13

how many rudimentary lactiferous ducts occupy the breasts in childhood?

The ducts open onto (location).

Answer 13

15-25 rudimentary lactiferous ducts occupy the breasts in childhood.

the ducts open onto the surface of the nipple.

Question 14

at puberty, (substances-2) induce budding of (structure) from the lactiferous ducts.

The substances also induce (substance) accumulation between the terminal ducts.

Answer 14

at puberty, OVARIAN estrogen and progesterone induce budding of small terminal ducts from the lactiferous ducts

the ovarian hormones also induce fat accumulation between the terminal ducts.

Question 15

during pregnancy, the ovarian hormones and PROLACTIN from the (structure) stimulate the formation of (structures).

What else do the hormones do?

Answer 15

during pregnancy, the ovarian hormones and prolactin from the pituitary gland stimulate the formation of secretory acini at the ends of the terminal ducts.

milk secretion into the acinar lumens is also the activated by the hormones during lactation.

Question 16

What muscles underlie the breasts?

Answer 16

the pectoralis major and serratus anterior underlie the breasts

Question 17

Discuss function of suspensory ligaments.

Answer 17

suspensory ligaments attach the breasts to the dermis of the skin.

Question 18

Discuss lymph drainage from LATERAL QUADRATES of the BREASTS. Said drainage structure is a constituent group of the (structure).

Answer 18

lymph from the lateral quadrates of the breasts drains initially into the pectoral lymph nodes, a constituent group of the axillary nodes.

Question 19

lymph from the MEDIAL quadrants of the breasts drains where and compare.

Answer 19

lymph from the medial quadrants of the breasts drains into the parasternal lymph nodes that like the axillary nodes drain mainly into the supraclavicular lymph nodes.

Question 20

Discuss the embryological origin of the thyroid gland.

Answer 20

the thyroid gland originates as an endodermal bud (the thyroglossal duct) at the foramen cecum in the posterior tongue.

Question 21

Discuss the embryological origin of the thyroid and what occurs to it subsequently.

Answer 21

the thyroglossal duct, which remains attached to the tongue as the thyroid descends in the midline to the anterior surface of the trachea, subsequently disappears.

Question 22

Where do the aortic arches arise from and course through what?

Answer 22

the aortic arches arise from the aortic sac and course through the mesenchyme of the pharyngeal arches enroute to the dorsal aortae.

Question 23

PHARYNGEAL ARCHES contribute to the formation of the (2).

Answer 23

the pharyngeal arches contribute to the formation of the neck and face.

Question 24

What forms the PHARYNGEAL POUCHES.

Answer 24

endodermal outpocketings from the developing pharynx form the pharyngeal pouches.

Question 25

Embryologically what differentiates into parafollicular cells which become incorporated into the (structure).

Answer 25

neural crest cells that migrate into the endoderm of the 4th pharyngeal pouch differentiate into parafollicular cells, which become incorporated into the developing thyroid gland.

Question 26

Discuss the superior pair of parathyroid glands (embryologically and attachment).

Answer 26

the superior pair of parathyroid glands are endodermal derivatives of the 4th pharyngeal pouch and attach to the descending thyroid gland.

Question 27

Discuss the embryological origin of the thymus and INFERIOR PAIR of parathyroid glands. What occurs in relation to the descending thymus?

Answer 27

the thymus and inferior pair of parathyroid glands are endodermal derivatives of the 3rd pharyngeal pouch, and the descending thymus pulls the inferior pair of parathyroid glands to the thyroid gland.

Question 28

Discuss the spatial relation of the BI-Lobed thyroid gland.

Answer 28

the bi-lobed thyroid gland lies anterolateral to the trachea

Question 29

How and where are the lobes of the thyroid interconnected?

Answer 29

the lobes are interconnected across the 2nd and 3rd tracheal rings by the isthmus of the gland.

Question 30

Discuss what the thyroglobulin are filled into and what lies said (structure)?

Answer 30

spherical follicles filled with thyroglobulin and lined by simple cuboidal epithelium.

Question 31

Define thyroglobulin.

Answer 31

thyroglobulin is the iodinated glycoprotein precursor of the thyroid hormones, triiodothyronine (T3) and tetraiodothyronine (T4).

Question 32

What cells secrete CALCITONIN and discuss their arrangement (comment on location also).

Answer 32

the parafollicular cells, which secrete calcitonin, organize into small clusters in the stroma between the follicles.

Question 33

Discuss the pairs making up the parathyroid glands (comment on size) and grossly are found (location).

Answer 33

the superior and inferior pairs of parathyroid glands (each the size of an apple seed) are embedded in the posterior surface of the thyroid.

Question 34

Discuss function of PTH.

Answer 34

parathyroid hormone (PTH) stimulates osteoclasts to mobilize calcium from the bony matrix and parafollicular cell-derived calcitonin activates osteoblasts to utilize blood calcium for bony matrix formation.

Question 35

ID the outer cortex and central medulla of the adrenal glands.

Answer 35

Informational

Question 36

What embryological cell type forms the primitive adrenal cortex?

Answer 36

mesenchymal cells in the intermediate mesoderm proliferate to form the primitive adrenal cortex.

Question 37

(Cell type) infiltrate the paravertebral and prevertebral sympathetic ganglia.

Answer 37

neural crest cell-derived chromaffin cells infiltrate the paravertebral and prevertebral sympathetic ganglia.

Question 38

Discuss how the CENTRAL PORTION of the PRIMITIVE ADRENAL CORTEX is transformed and into what?

Answer 38

some of the chromaffin cells migrate into the primitive adrenal cortex and transform its central portion into the adrenal medulla.

Question 39

Discuss the staining of Epi/NE and the interpretation of the color.

Answer 39

oxidation of epinephrine and norepinephrine by potassium chromate (i.e., the chromaffin reaction) stains the catecholamines reddish brown; thus, cells that synthesize and store the catecholamines are designated chromaffin cells.

Question 40

What synapses with the medullary chromaffin cells?

Answer 40

some presynaptic sympathetic fibers of the least splanchnic nerve synapse with the medullary chromaffin cells.

Question 41

What results in catecholamine secretion into the medullary capillaries.

Answer 41

synaptic activation of the chromaffin cells results in catecholamine secretion into the medullary capillaries.

Question 42

arteries either supply the CORTICAL capillaries or do what?

Answer 42

arteries either supply the cortical capillaries or traverse the cortex to directly supply the medullary capillaries.

Question 43

the (structure-2) drain into the adrenal veins that reside solely in the (structure).

Answer 43

the cortical and medullary capillaries drain into the adrenal veins that reside solely in the medulla.

Question 44

Discuss the adrenal cortex ( role and composition-3)

Answer 44

the adrenal cortex, which is essential to life, consists of the thin zona glomerulosa beneath the capsule, the thick zona fasciculata, and the thin zona reticularis adjacent to the medulla.

Question 45

What released renin into the afferent/efferent arterioles?

Answer 45

recall activated JG cells release renin into the afferent arterioles

Question 46

circulating renin stimulates (location) to release (substance) in the (structure).

Answer 46

circulating renin stimulates the zona glomerulosa to release aldosterone in the cortical capillaries.

Question 47

cells of the zona fasciculate release (substance) into (location). Function of substance and how does its product get transported?

Answer 47

cells of the zona fasciculata release cortisol into the bloodstream and circulating cortisol stimulates hepatocytes to synthesize glucose that is both stored as glycogen and released into the circulation.

Question 48

cells of the ZONA RETICULARIS mainly synthesize (substance and converts into-2).

Answer 48

cells of the zona reticularis mainly synthesize weak androgens that can be converted to testosterone and estrogen in other tissues.

Question 49

What makes up the endocrine pancreas?

Answer 49

the pancreatic islets (of Langerhans) comprise the endocrine pancreas.

Question 50

selective staining of insulin and glucagon respectively identifies the beta cells and alpha cells of the pancreatic islets.

Answer 50

Informational.

Question 51

how does insulin lower blood glucose?

Answer 51

insulin lowers blood glucose mainly by prompting glucose entry into hepatocytes, adipocytes, and the skeletal muscle fibers.

Question 52

How do the hypophyseal portal veins regulate secretory functions of the anterior lobe?

Answer 52

The superior hypophyseal arteries, from above, bring blood to the anterior lobe by first forming a primary capillary plexus made of vascular loops in the area of the median eminence and pars tuberalis. These vessels give rise to a network of portal venules—the hypophyseal
portal system—which crosses the ventral aspect of the pituitary stalk to drain into a secondary plexus of sinusoidal fenestrated capillaries in the anterior lobe.

This portal system is critical for control of the adenohypophysis by neurosecretions from hypothalamic
neurons that convey releasing and inhibiting hormones to
the primary plexus.

Question 53

What are the causes and symptoms of diabetes insipidus?

Answer 53

Damage to supraoptic and paraventricular nuclei of the hypothalamus or destruction of the hypothalamohypophyseal tract may interfere with ADH production and lead to the rare diabetes insipidus.

Question 54

Where do breast carcinomas typically arise and what is the most common site for metastasis?

Answer 54

Carcinomas of the breast are malignant tumors, usually adenocarcinomas (glandular cancer) arising from the epithelial cells of the lactiferous ducts in the mammary gland lobules.

Because most of lymphatic drainage of the breast is to the axillary lymph nodes, they are the most common site of metastasis from a breast cancer.

Question 55

How do thyroglossal duct cysts develop and where are they typically located?

Answer 55

During this relocation of the descending thyroid, the thyroid gland is attached to the foramen cecum by the thyroglossal duct.

This duct normally disappears but remnants of epithelium
may remain and form a thyroglossal duct cyst at any
point along the path of its descent

The cyst is usually in the neck, close or just inferior to the hyoid

Question 56

How are thyroglossal cysts and cancerous thyroid nodules distinguished?

Answer 56

Swallow the thyroglossal cyst will move.

The mass on the neck moves during swallowing or on protrusion of the tongue because of its attachment to the tongue via the tract of thyroid descent.

Question 57

What is a goiter? Why does hypertrophy of the follicular epithelium occur with Graves disease?

Answer 57

Chronic enlargement of the thyroid.

This autoimmune disorder is caused by antibodies
to the TSH receptor on follicular cells. Histologically, the
enlarged gland contains highly infolded follicles lined by high cuboidal epithelium.

Thyroid hormone production increases markedly, colloid volume is reduced, and TSH production by the adenohypophysis is suppressed. Lymphocyte infiltration of surrounding stroma accompanies lymphoid follicles with germinal centers.

Question 58

Why can thyroidectomy be fatal?

Answer 58

Postoperative hemorrhage after thyroid gland surgery may compress the trachea, making breathing diffi cult.

Atrophy or inadvertent surgical removal of all the parathyroid glands results in tetany, a severe neurologic syndrome characterized by muscle twitches and cramps. The generalized spasms are caused by decreased serum calcium levels. Because laryngeal and respiratory muscles are involved, failure to respond immediately with appropriate therapy can result in death.

Question 59

What is the consequence of a pheochromocytoma?

Answer 59

Pheochromocytoma is a neoplasm
that arises from catecholamine-producing cells. Ensuing elevated levels of epinephrine and norepinephrine released into the blood lead to sustained or intermittent hypertension.

Question 60

Why are the medullary arterioles essential during the autonomic “fight or flight” response?

Answer 60

Some arterioles from the capsule do not
supply the cortex but go directly into the medulla. There, they drain into sinusoidal fenestrated capillaries, which lead into collecting veins. The medulla thus has a dual blood supply.

More direct route to be perfused to release the Catecholamines.

Question 61

What is the usual cause of primary hyperparathyroidism and why do kidney stones result?

Answer 61

Primary hyperparathyroidism is usually due to an adenoma of one or more parathyroid glands.

Excessive production of PTH in this disorder leads
to hypercalcemia (high serum calcium levels) because of increased osteoclastic activity of bone. Enhanced reabsorption of calcium in renal tubules may lead to nephrolithiasis, or formation of renal stones,
rich in calcium oxalate and calcium phosphate.