Endocrine histology Flashcards
The endocrine system is composed of _________ that secrete _______ into the ________. Secretion is controlled by ___________.
ductless glands
hormone
blood stream
feedback mechanisms
Three types of hormones, and an example of each + organs that produce them
Protein and peptide hormones
- insulin - pituitary, parathyroid, C-cell, islets of Langerhans
Amino acid derivatives
- epinephrine - adrenal medulla, thyroid
Steroid and fatty acid derivatives
- testosterone, progesterone - adrenal cortex
Two parts of the pituitary gland (hypophysis)
anterior (adenohypophysis)
posterior (neurohypophysis)
the adenohypophysis is derived from _______ (and the name for it)
it has two regions:
oral ectoderm (Rathke’s pouch)
pars distalis and pars intermedia
cells found in pars distalis of adenohypophysis and what they produce (2 cell types)
acidophils - GH, prolactin
basophils - FSH, LH, TSH, ACTH
the cells of the adenohypophysis are stimulated by releasing factors from the ______
hypothalamus
the neurohypophysis is derived from _______, a downgrowth from the _______
neuroectoderm
hypothalamus
region of the posterior pituitary
pars nervosa
what’s found in the neurohypophysis? (2) and what hormones are stored there?
axons from neurons in the hypothalamic nuclei
Herring bodies
- vasopressin (ADH) - oxytocin
expanded nerve fibers for hormone storage, but NOT production
Herring bodies
ADH is made in the _______ of the hypothalamus
Oxytocin is made in the ______ of the hypothalamus
Supraoptic nucleus
Paraventricular nucleus
Hormone source and target:
ACTH GH MSH TSH FSH, LH Prolactin Oxytocin ADH
ACTH - ant. pit.; adrenal cortex
GH - ant. pit; protein production (bones, muscle)
MSH - skin
TSH - ant. pit; thyroid
FSH, LH - ant. pit.; testes and ovaries
Prolactin - ant. pit,; breast (milk production)
oxytocin - post. pit; breast and muscle contraction
ADH - post. pit; kidney
Blood supply to pituitary gland is through the
hypophyseal portal system
hypophyseal portal system connects the ______ to the _______
primary capillary plexus to the secondary capillary plexus
primary capillary plexus drains_______ and carries releasing hormones to _______
secondary capillary plexus drains ________ and carries hormones to the ________ –> ________
hypothalamus; hypophysis
hypophysis; hypophyseal veins –> systemic circulation
which stains darker, and why?
anterior or posterior pituitary
anterior - chromophils
acromegaly is almost always caused by ________
pituitary adenomas
stored thyroid hormone
colloid
structure of thyroid
2 glands (bilobed) connected by isthmus
_______ composed of ________ cells form colloid bound to _______
Follicles
follicular cells
thyroglobulin
what is iodinated colloid
T3 and T4 (thyroxine) – active thyroid hormones
two types of cells in the thyroid gland and what they are for
follicular cells - secretes thyroglobulin which is then cleaved to release hormones
C-cells (parafollicular cells) - b/w follicles; secrete calcitonin (DECREASES serum calcium)
follicular cells in thyroid surround
colloid “cysts”
hyperplasia of thyroid follicular cells leading to hyperthyroidism
common symptom is exophthalmos
Graves’ disease
enlargement of thyroid gland as a result of iodine deficiency
Goiter
two types of cells found in parathyroid glands, and what they are for
Chief cells - secrete PTH (INCREASES calcium levels)
Oxyphil cells - inactive chief cells?
There are ___ adrenal glands and each has an outer ____ and inner _____
2
cortex; medulla
The adrenal cortex makes these ________ derived hormones (3)
cholesterol derived (steroids)
mineralocorticoids, glucocorticoids, androgens
the adrenal medulla makes these _______ derived hormones (3)
amino acid derived (catecholamines)
epinephrine, norepinephrine
Adrenal cortex is derived from ________
mesoderm
Three layers of adrenal cortex (superficial to deep) and what they produce
Gobstoppers For Rations
Zona glomerulosa
- mineralocorticoids: aldosterone (control fluid and electrolyte balance)
Zona fasiculata
- glucocorticoids: cortisol (control metabolism)
Zona reticularis
- androgens (weak masculinizing hormones)
decreased secretion of adrenocortical hormones and autoimmune destruction of the adrenal cortex
steroid treatment is required for survival
Addison’s disease
Small tumors on the anterior pituitary that cause an increase in ACTH and an overproduction of cortisol (resulting in moon face)
Cushing’s disease
adrenal medulla is derived from
neural crest cells
two types of cells in adrenal medulla and what they’re for
Chromaffin cells - contain epi and norepi in pre-formed granules
Ganglion cells - receive sympathetic stimuli and cause chromaffin cells to degranulate
aka “epithalamus”
controls circadian rhythm
pineal gland
cells found in pineal gland and what they’re for (2)
pinealocyte - synthesize and release melatonin at night; inhibit GH release
interstitial cells - neuroglial cells (astrocytes)
the endocrine portion of the pancreas
islets of Langerhans
cell types of islets of Langerhans (5) and what they’re for
All Good Boys Initially Do Something Foolish (Period) Gotta Go
alpha cells - glucagon to increase blood sugar
beta cells - insulin to decrease blood sugar
delta cells - somatostatin to inhibit both endocrine and exocrine pancreas secretions
F cells - pancreatic polypeptide to inhibit exocrine pancreas
G cells - gastrin to increase HCl secretion in stomach
Describe:
Type I diabetes
Type II diabetes
Type I: insulin dependent; beta cells are destroyed
Type II: non-insulin dependent; insulin antagonism with impaired secretion - islets are ultimately exhausted; may be reversed with lifestyle changes
