B6: Path Exam 1 (1-9) (I'm so sorry this is so long)

steroid and thyroid hormones

what type of hormones are hydrophobic, with the ability to penetrate the membrane and target cytoplasmic receptors?

juxtacrine signaling

What type of hormone signaling:

-signaling molecule remains on secreting cell surface or ECM

-requires cell contact

anterior

parts of the _____ pituitary:

-pars tuberalis

-pars intermedia

-pars distalis

posterior

parts of the anterior pituitary:

-infundibular stalk

-pars nervosa

sella turcica on the sphenoid bone

where is the pituitary gland found?

neurohypophysis

origin of __________:

-bud grows down from the diencephalon as a stalk

adenohypophysis

origin of __________:

-hypophyseal (rathke) pouch from ectoderm growing cranially

neurohypophysis

posterior pituitary is aka:

adenohypophysis

anterior pituitary is aka:

anterior pituitary

ID dark-stained tissue

posterior pituitary

ID light-stained tissue

-derived from neural tissue (hypothalamus)

paraventricular (oxytocin) and supraoptic (ADH)

axons from the ______ and _______ nuclei of the hypothalamus extend through the infubdibulum into the posterior pituitary

-then released into capillaries from the posterior pituitary

superior hypophyseal artery

delivers blood to the capillary network in the median eminence and infundibular stalk

inferior hypophyseal artery

blood supply to the neurohypophysis

hypothalamic/hypophyseal portal system

function of ________________ ______ ________:

-Carries neuropeptides from median eminence to neurohypophysis where they can stimulate or inhibit hormone release

LH and FSH

gonadotropin releasing hormone (GnRH) stimulates the release of ______ and ________

somatostatin

inhibits release of somatotropin (GH) and TSSH

dopamine

hormone that inhibits the release of prolactin

pars distalis

what part of anterior pituitary?

chromophils (acidophils/basophils) & chromophobes

what cells compose the pars distalis?

chromophils

secretory cells in which hormone is stored in cytoplasmic granules

acidophils

darkly staining pink granule cells in pars distails

somatotrophs (growth hormone)

lactotrophs (PRL)

cells/hormones released from acidophils in pars distalis (2):

acidophils

ID A

basophils

ID B

chromaphobes

ID C

corticotrophs (ACTH)

gonadotrophs (FSH / LH)

thyrotrophs (TSH)

cells/hormones released from basophils in pars distalis

pro-piomelanocortin (gets cleaved to make ACTH)

what do corticotrophs secrete?

chromophobes

function of ________ in pars distalis:

include stem and undifferentiated progenitor cells or any degranulated cells

FSH and LH

these hormones act on gonads to stimulate development of gametes (sperm and oocyte)

ACTH (adrenocorticotropic hormone)

acts on the adrenal cortex to cause release of corticosteroids (cortisol)

pars intermedia

What part of the pituitary:

-posterior portion of the anterior pituitary

-in contact with neural tissue

-most active during fetal development

basophils, chromophobes, and colloid filled cysts (remnants of embryonic hypophyseal pouch)

components of pars intermedia

pars tuberalis

What part of the pituitary:

-part of anterior pituitary that wraps around the infundibulum

-composed of epithelial tissue within a thin wrapping of connective tissue

pituitary adenomas

tumors producing excessive numbers of functional acidophils or basophils

gigantism

adenomas involving somatotropic cells in children

acromegaly

adenomas involving somatotropic cells in adults

posterior pituitary

this part of pituitary does not contain the cells that synthesize its hormones

-ADH and oxytocin come from nuclei from hypothalamus

ADH and oxytocin

hormones released from posterior pituitary

pars nervosa

What part of the pituitary:

made up of modified glial cells and axons that have descended from the hypothalamus

herring bodies

eosinophilic neurosecretory bodies in the terminal ends of axons in the pars nervosa

-contain granules of ADH or oxytocin bound to neurophysin I or II proteins--> protein cleaved when stimulated

neurosecretory (herring) bodies and pituicytes

what makes up the pars nervosa?

foregut endoderm

origin of the thyroid gland

Thyroxine/tetraiodothyronine (T4) , tri-iodothyronine (T3), and calcitonin

hormones synthesized by the thyroid gland

thyroid gland

What structure:

-parenchyma composed of rounded follicles line by simple cuboidal/columnar epithelium , containing gelatinous acidophilic colloid

Thyroglobulin

colloid in thyroid glands contain this, a precursor for active thyroid hormones

thyroid gland

Only endocrine gland in which a significant portion of secretory product is stored (outside of cells)

TSH from the anterior pituitary

what stimulates thyrocytes?

parafollicular C cells

What structure:

-cells in the thyroid gland found within the basal lamina of follicular epithelium or as clusters; stains less strongly than follicular cells

-secrete calcitonin

calcitonin

function of _______:

-inhibit osteoclast activity when triggered by high calcium

iodine

_____ deficiency inhibits thyroid hormone production, causing excess TSH----> excessive growth of thyroid follicles causing goiter

glycoprotein thyroglobulin, precursors for T3 and T4

colloid within thyroid gland contains

iodine

______ is essential for the production of thyroid hormone, as iodination of tyrosol residues allows formation of pre T3 and T4

Graves disease

autoimmune disorder in which antibodies produce chronic stimulation of the follicular cells and release of thyroid hormones (hyperthyroidism)

thyroiditis

inflammation of the thyroid gland resutling in hypothyroidism

Hyperthyroidism

Symptoms of _______:

-Nervousness, weight loss despite increased appetite, excessive sweating and heat intolerance, palpitations, frequent bowel movements, muscular weakness of the proximal type and tremor

hypothyroidism

Symptoms of _______:

Fatigue, lethargy. Modest weight gain with anorexia. Dry, coarse skin and cold intolerance. Swelling of face, hands, and legs. Constipation. Weakness, muscle cramps, arthralgias, paresthesias, impaired memory and hearing.

inferior thyroid arteries

vasculature of parathyroid glands arise from

4th pouch

origin of superior parathyroid glands

3rd pouch

origin of inferior parathyroid glands

chief cells release PTH which increases serum calcium levels

function of parathyroid glands

parathyroid glands

What structure:

histology: thin capsule with trabeculae that divide parenchyma into lobules

-lots of capillaries

principal (chief) cells

oxyphil cells

cell types of parathyroid glands

principal chief cells

What cell of the parathyroid gland:

-most abundant

-small, light staining pale cytoplasm and central nuclei

oxyphil cellls

What cell of the parathyroid gland:

-larger

-have abundant eosinophilic cytoplasm, contain many mitochondria

-unknown function, more abundant in old people

1. Osteoblasts produce osteoclast-stimulating factor to increase osteoclasts and Ca+

2. Distal convoluted tubules: Stimulates CA reabsorption and inhibits phosphate reabsorption

3. Increases Ca absorption in small intestine by stimulating vitamin D activation

targets of PTH

hypoparathyroidism

In cases of ___________:

-bone become more mineralized and denser and striated muscle exhibits abnormal contractions due to inadequate calcium

-tetany, weakness, HA, prolonged QT

hyperparathyroidism

In cases of ___________:

-stimulates osteoclast number and activity, leading to increased levels of blood calcium

-renala stones, diseases of bones/bone pain, psychic moans, peptic ulcers

neural crest

embryonic origins of adrenal medulla

mesoderm

embryonic origins of adrenal cortex

Mineralocorticoids, Glucocorticoids, Weak androgens

adrenal cortex secretes:

NE and epinephrine

adrenal medulla secretes:

zona glomerulosa

What zone of the adrenal cortex:

-located immediately inside the capsule

-composed of columnar cells in spherical/ovoid groups

zona glomerulosa

What zone of the adrenal cortex:

-makes mineralcorticoids (aldosterone)

zona fasciculata

What zone of the adrenal cortex:

-middle layer

-composed of basophilic cells in parallel columns sepaarated by capillaries

zona fasciculata

What zone of the adrenal cortex:

-makes glucocorticoiods (cortisol)

-affects carbohydrate metabolism by stimulating gluconeogenesis and glycogen synthesis; suppresses immune function, controlled by ACTH

zona reticularis

What zone of the adrenal cortex:

-innermost layer of adrenal cortex

-composed of branching/anastomosing cords of darker staining small cells

zona reticularis

What zone of the adrenal cortex:

-makes weak androgens

-stimulated by ACTH

chromaffin cells

cells of the adrenal medulla

-secrete mostlyl epi, NE

norepinephrine

which catechholamine:

-Constricts vessels in GI system and skin, increases blood flow to heart, muscles and brain

-Elevates blood glucose

neuroectoderm (in the posterior wall of the 3rd ventricle)

origin of the pineal gland

pinealocytes

cells producing melatonin, low moleculaara weight tryptophan derivative

pituitary adenomas

-benign neoplasms of the anterior lobe of the pituitary gland

-extra-axial tumors (external to brain parenchyma)

pituitary adenomas

most frequent primary intracranial neoplasm

30-50 years

avg age of presentation of pituitary adenomas

Prolactinoma

most frequent type of pituitary adenoma

nonfunctioning adenoma

2nd most frequent type of pituitary adenoma

adenomas that secrete FSH, LH, and TSH

most rare pituitary adenomas

mass effect

effect of local _____ ______ of pituitary adenomas

-bitemporal heminaopsia

-cavernous sinus syndrome (LOF of eye muscles)

-elevated intracranial pressure

stalk section effect

effect of pituitary adenoma that distorts the pituitary stalk---> reduction in most pituitary hormones due to lack of communication with hypothalamus

reduce most of the pituitary hormones but will give rise to hyperprolactinemia secondary to lack of inhibition (decreased dopamine)

effect of stalk section effect

pituitary adenoma

gross pathology of _______ _________

-tan-to purple in color and creamy in texture

-macro or micro

pituitary adenoma

histology of _______ _________

-uniform, polygonal cells arranged in thin cords and ribbons; monotonous appearance of small round cells

-see acidophils, basophils, and chromophobes

GNAS1

gene associated with somatotroph adenoma

-codes for alpha subunit--->cAMP activated PKA----> excessive GH secretion

USP8

gene associated with corticotroph adenomas

Psammoma bodies

distinct histological finding of prolactinomas

prolactinomas

electron microscopy findings of _______:

-abundant rough ER, prominent golgi complel, but sparse secretory granules

amenorrhea, galactorrhea, and infertility

effects of prolactinoma in women:

loss of libido, erectile dysfunction

effects of prolactinoma in men

-densely granulated (acidophilic)

-sparsely granulated (chromophobe)

types of somatotroph adenoma