Endocrine Glands and Structures

Adrenal Cortex

area of the adrenal glands that lies between the capsule and adrenal medulla and is comprised of three zones: zona glomerulosa, zona fasciculata, and zona reticularis. Cells in this area synthesize more than 25 different corticosteroids. (A & F)

Chromaffin Cells

cells in the adrenal medulla that are innervated by the splanchnic nerve and secrete epinephrine (adrenaline) and norepinephrine (noradrenaline).

chief cells

cells within the parathyroid glands that are the source of parathyroid hormone which is released in response to decreased blood calcium to return blood calcium within normal homeostatic levels. These cells are more numerous within the parathyroid and stain dark purple.

Oxyphil Cells

cells within the parathyroid hormone whose role is unknown. Their cytoplasms stain light pink/orange.

Pancreatic acini

clusters of cells within the pancreas that are involved in exocrine function and produce an alkaline pancreatic juice that is secreted to the small intestine.

Posterior pituitary gland

composed of a rounded lobe called the pars nervosa and the infundibulum, axons from the hypothalamus extend into this gland. Oxytocin and antidiuretic hormone are synthesized in the hypothalamus and then travel via the infundibulum to this gland.

Anterior pituitary gland

controlled by the hypothalamus, this gland secretes six major hormones, five of which are tropic hormones.

Pancreatic islets

endocrine cells within the pancreas composed primarily of two types of cells, alpha cells that secrete glucagon and beta cells that produce insulin. (aka islets of Langerhahns)

Corpus luteum

essentially a temporary endocrine gland, it is the remnants of the vesicular follicle after it expels the oocyte. This structure is formed under the presence of luteinizing hormone and secretes the sex hormones progesterone and estrogen which inhibit the hypothalamus and anterior pituitary. (6)

Ovarian follicles

located within the ovarian cortex and consisting of an oocyte surrounded by a follicle cells. There are six types of these structures, each representing a different stage of development. FSH and LH stimulate their development.

Zona fasciculata

the middle layer and largest region of the adrenal cortex, comprised of lipid-rich cells that synthesize glucocorticoids, principally cortisol and corticosterone. (D)

Ovarian cortex

the outer area of the ovaries deep to the tunica albuginea, containing thousands of ovarian follicles. (A)

Testicular germ cells

the product of spermatogenesis, these are gametes produced by the stimulation of the testes by high levels of FSH and LH.

Adenohypophysis

name for anterior pituitary (tealia's)

Neurohypophysis

name for posterior pituitary (tealia's)

ADH and OT

name the hormones stored within the posterior pituitary in alphabetic order, abbreviated.

Parafollicular Cells

neuroendocrine cells in the thyroid which primary function is to secrete calcitonin, a hormone that participates in the regulation of calcium metabolism. They are located adjacent to the thyroid follicles and reside in the connective tissue. (C)

Sustentacular cells

non-dividing support cells within the testes that provide a protective and nourishing environment for the developing sperm. These cells release inhibin hormone when sperm count is high, inhibiting FSH secretion from the anterior pituitary. (10)

Colloid

protein-rich fluid contained within the follicle lumen. Iodine molecules combine with thyroglobulin (TGB) in this fluid to produce thyroid hormone (TH).

Follicular Cells

(1) simple cuboidal epithelial cells that surround the follicle lumen and produce thyroid hormone (TH) by first producing thyroglobulin (TGB) and secreting it into the colloid fluid within the follicle lumen

Hypothalamus

(3) Located superior to the pituitary gland, this region of the brain has direct control over the release of hormones from the pituitary gland and has indirect control over the release of hormones from the thyroid gland, adrenal gland, liver, testes, and ovaries.

glucagon

Alpha cells within the pancreatic islets produce:

insulin

Beta cells within the pancreatic islets produce:

growth hormone-inhibiting hormone

Delta cells within the pancreatic islets produce:

Parathyroid Glands

Four (usually) glands located on the posterior surface of the thyroid gland. Contain chief cells and oxyphil cells

ACTH, FSH, GH, LH, PRL, and TSH

Name the six hormones secreted by the anterior pituitary in alphabetic order, abbreviated:

Zona reticularis

The innermost layer of the adrenal cortex, cells here produce gonadocorticoids, principally the sex hormone, androstenedione. (E)

Zona glomerulosa

The outermost layer of the adrenal cortex, cells in this zone synthesize mineralocorticoids, principally aldosterone, which regulates Na+ and K+ and body fluids. (C)

Hypothalamo-hypophyseal tract

The term identifying the route of unmyelinated axons extending from the hypothalamus travel through the infundibulum and their synaptic knobs located within the pars nervosa

Melatonin

a hormone that helps regulate the circadian rhythm and is produced in the pineal gland

Pineal Gland

a small, cone-shaped structure forming the posterior region of the epithalamus. It is the location for melatonin secretion.

Capsule

a thin fibrous connective tissue layer that surrounds the adrenal glands and contains a network of arteries that carry the blood supply. Thin strands of this layer enter the glands, carrying blood to them. (top most blue layer)

Pars tuberalis

a thin wrapping around the infundibulum (4)

Infundibulum

a very thin stalk by which the hypothalamus communicates the pituitary gland.

Ovaries

paired female reproductive organs located laterally to the uterus in which ova or eggs are produced

Adrenal glands

paired, pyramid-shaped endocrine glands located on the superior surface of the kidneys. The two regions of these glands, the cortex and the medulla, secrete different types of hormones.

pancreatic juice

pancreatic acini are not considered endocrine structures because they produce what?

Ovarian germ cells

primary or secondary oocytes, these are the cells in an ovary that may undergo meiotic division to form an ovum. (H, D, and E)

Hypothalamo-hypophyseal Portal System

the blood vessel network that provides a direct blood pathway between the hypothalamus and the anterior pituitary

Corpus albicans

the corpus luteum undergoes regression and turns into a white connective tissue scar

Ovarian medulla

the inner area of the ovaries, deep to the ovarian cortex, composed of areolar connective tissue and contains branches of the ovarian blood vessels, lymph vessels, and nerves. (H)

Adrenal Medulla

the inner core of the adrenal glands. has a pronounced red-brown color due to extensive vascularization. it releases norepinephrine and epinephrine in response to sympathetic nervous stimulation. (G & B)

Pars Distalis

the large rounded anterior portion of the anterior pituitary. (9)

Thyroid Gland

the largest endocrine gland in the body; the main hormone produced here increases metabolic rate and body temperature. This hormone is under control of the hypothalamus via the anterior pituitary.

Pars Nervosa

the rounded lobe that makes up this posterior pituitary with the infundibulum. (6)

Seminiferous tubules

the site of the germination, maturation, and transportation of the sperm cells within the male testes. Sustentacular cells located here are stimulated by follicle-stimulating hormone to produce adrogen-binding hormone, necessary for high testosterone levels.

Pituitary Gland

this gland is located inferior to the hypothalamus and rests within the sella turcica. It is divided into anterior and posterior lobes.

Pancreas

this gland/organ performs both exocrine and endocrine functions. Its endocrine function includes production of insulin, glucagon, somatostatin and pancreatic polypeptide. It is also a digestive organ, producing pancreatic juices containing digestive enzymes.

testes

two egg-shaped male reproductive organs located in the scrotum. They produce sperm and the male hormone, testosterone. (I)

Alpha cells

type of cell within pancreatic islets that produce glucagon.

Beta cells

type of cell within pancreatic islets that produce insulin.

Delta cells

type of cell within the pancreatic islets that produce growth hormone-inhibiting hormone.

rising sperm count levels

what causes sustentacular cells of the testes to produce inhibin? (hint: not a hormone)

inhibin

what do the sustentacular cells secrete in response to rising sperm count levels?

inhibin

what hormone do the follicles of the ovaries secrete which inhibits FSH production and thus prevents excessive ovarian follicle development and allows the current primary follicles to develop?

leutinizing hormone

what hormone do the interstitial cells of the testes respond to and causes their secretion of testosterone?

testosterone

what hormone do the interstitial cells of the testes secrete in response to LH?

estrogen, inhibin, and progesterone

what hormones does the corpus luteum of the ovaries secrete? The combination of these hormones inhibits both the hypothalamus and anterior pituitary and builds the uterine lining. (alphabetical order)

ovarian follicles

what structures of found within the cortex of the ovaries?