ENDOCRINE SYSTEM Flashcards
Group of ductless Glands, secrete hormones directly into the blood stream and influence widely divergent structures
Endocrine System
Chemical messengers that “regulates” various types of reactions in the body. Secreted into blood and binds to target cells.
Hormones
biological catalysts the speed up chemical reactions. regulation is controlled by the cell’s DNA
ENZYMES
Loop system wherein the system responds to a perturbation in the opposite direction, regulation of hormone synthesis, blood glucose and body temperature regulation are examples.
Negative feedback mechanism
Loop system wherein the system responds to a perturbation in the same direction
Positive feedback mechanism
responsible for the secretion of melatonin and serotonin. a median unpaired organ inferior to the corpus callosum, under the roof of the 3rd ventricle.
PINEAL GLAND “Epiphysis Cerebri”
- Largest in early childhood, involutes at puberty.
- Regulates daily rhythms of bodily activities.
Pineal Gland is contained within the
PIA MATER
Functions as a neurotransmitter in the CNS and as a hormone in the periphery.
It mediates happiness, satisfaction and optimism.
Serotonin
- precursor of melatonin
- Happy hormone
- derived from tryptophan
Inhibits the onset of puberty, inhibitory to hypothalamic gonadotropin releasing hormone
MELATONIN
Center or a plethora of physiological processes like thermoregulation, osmoregulation and hormonal regulation
HYPOTHALAMUS
- supplied by anterior and posterior branches of Circle of Willis and superior hypophyseal artery.
Thermoregulation by sympathetic nervous system, allows heat conservation result to body heating
Posterior Nuclei
Involved in thermoregulation by stimulation of the parasympathetic nervous system, allows heat loss resulting to body cooling.
Anterior nuclei
found in the hypophyseal fossa of the sphenoid bone, protected by the sella turcica.
Pituitary Gland
Origin of anterior pituitary gland
Rathke’s pouch
development of rathke’s pouch
3rd week
Contains endocrine cells. primary source of hormones
PARS DISTALIS
May play a role in the synthesis and secretion of melanocyte stimulating hormone
Pars Intermedia
also contains endocrine cells but does not contribute so much in hormone release. Surrounds the infundibulum, carries portal veins of the hypophyseal portal system.
Pars Tuberalis
Hypersecretion of GH in childhood before the fusion or closure of the epihyseal plates.
Gigantism
- may result to diabetes mellitus and visual disturbances due to compression of the optic chiasma
Hypersecretion of GH in adult after the fusion or closure of the epiphyseal plates.
Acromegaly
Responsible for milk production and breast development.
PROLACTIN
What is the effect of DOPAMINE on your PROLACTIN
Dopamine and Prolactin is involved in negative feedback mechanism.
Hypersecretion of ACTH, caused by a tumor or excessive growth of the pituitary gland
Cushing’s Disease
hormone that initiates ovulation
Leutinizing Hormone
Connects the pars nervosa to the hypothalamus, a stalk that carries the axons of the neurosecretory cells.
Infundibulum
Produces contraction of the myoepithelial cells in mammary small ducts responsible for milk ejection from the lactating breast and rhythmic contraction of uterine smooth muscle during labor.
OXYTOCIN
- synthesized by the neurosecretory cells of the paraventricular nuclei
Regulates body fluid osmolarity through V2 receptor., synthesized by the neurosecretory cells of the supraoptic nuclei
VASOPRESSIN (ADH)
a form of Diabetes Insipidus that has a failure of ADH to be secreted
Central Dia. Ins.
form of Diabetes insipidus that has a Failure of the renal duct cells to respond to ADH
Nephrogenic Dia. Ins.
“love hormone” is known as
Oxytocin
Largest endocrine gland, located anterior to the trachea at the level of the cricoid cartilage.
Thyroid Gland
Enlargement of the thyroid gland, associated with deficient, normal, or excessive hormone production. Related to iodine deficiency and diminished production of thyroid hormone.
GOITER
Caused by excess secretion of thyroid hormones.
Hyperthyroidism
Exophthalmic or diffused goiter, autoimmune condition wherein thyroid stimulating antibodies are produces
Grave’s Disease
- act like TSH and activate thyroid follicular cells
affects children characterized by stunted growth, total failure of the gland development.
Children are dwarfed, with underdeveloped mandible, overdeveloped maxilla, large tongue, delayed tooth eruption and mental retardation.
Cretinism
Hypothyroidism in adult characterized by generalized edematous appearance.
Retard mentation, physical activities and thickened tongue are common manifestations.
MYXEDEMA
autoimmune disease in which the thyroid gland is gradually destroyed. Also known as chronic lymphocytic thyroiditis.
Hashimoto’s Thyroiditis
- thyroid may enlarge forming a painless goiter
- TX: levothyroxine
a hormone that is involved in regulation of calcium and phosphate, suppresses bone resorption by decreasing calcium and phosphate release
CALCITONIN
- high calcium content in plasma, gastrin
increases serum calcium, decreases serum phosphate
Parathormone
Deficiency of PTH secretion caused by autoimmune disease, deficiency of receptors for PTH in target cells, parathyroidectomy
HYPOPARATHYROIDISM
-leads to hypocalcemia - tetany
Excessive secretion of PTH caused by tumor or hyperplasia of the parathyroid glands. Compensatory hypertrophy in response to hypocalcemia due to other pathological conditions:
Chronic renal failure, Vitamin D Def.
HYPERPARATHYROIDISM
- results to hypercalcemia
Increase in plasma calcium level of >12mg/dl
Hypercalcemia
results to neuromuscular hyperexcitability
characterized by painful muscular spasm or involuntary contraction of muscles.
TETANY
Spasm of the hand that develops 3 mins after arresting blood flow to the lower arm or hand
Trosseau’s Sign
Twitch of the facial muscles caused by gentle tap over the facial nerve in front of the ear.
Chvostek’s Sign
Located superior and medial to the upper pole of each kidney
ADRENAL GLANDS!
“SupraRenal”
Secretory cells are arranged in irregular, ovoid clumps, secretes mineralocorticoids (Mainly aldosterone)
Zona Glomerulosa
Life-saving hormone, maintains the osmolarity and volume extracellular fluid.
Aldosterone
Secretory cells are arranged in narrow cords, secretes glucocorticoids (Mainly cortisol)
Zona Fasiculata
Hypersecretion of Glucocorticoids
round-shouldered or buffa-hump appearance, mooning of the face, generalized obesity of the upper portion, diabetes mellitus. common in female
Cushing’s Syndrome
Secretory cells are arranged in irregular network as anastomosing cords and clumps. Secretes androgens, converted to testosterone and estrogen in tissues
Zona Reticularis
hypoadrenocorticism because of adrenal cortex insufficiency
Characterized by extreme weakness, low blood pressure and irregular melanin pigmentation described as “BRONZING”
Addison’s Disease
Adrenal medulla is derived from
Neuroectoderm (neural crest cells)
Adrenal Medulla
- consist of chromaffin cells
- secretes cetecholamines
Are modified postganglionic sympathetic neurons that synthesize, store, and secrete catecholamines.
Chromaffin Cells
Sympathetic effects depending on the receptor it occupies, alpha receptor, beta 1 receptor and beta 2 receptors
Epinephrine
Tumor arising from the adrenal medulla, secretes a large amount of norepinephrine, causes sustained or paroxysmal hypertension
Pheochromocytoma
Endocrine tissue (islets of Langerhans) can be found scattered throughout the exocrine pancreas, most numerous in the tail portion
Endocrine Pancreas
cell type that secretes Glucagon to increase blood glucose
Alpha Cells
cell type that secretes insulin to decrease blood glucose
Beta Cells
secretes somatostatin which inhibits the production of beta cells, alpha cells and growth hormone.
Delta Cells
cells that secrete pancreatic polypeptide (digestive enzyme)
F Cells
Single polypeptide synthesized as a prohormone from a cell of the islets of Langerhans cell.
Glucagon
building up of glycogen
glycogenesis
peptide consisting of two chains: alpha and beta chains.
regulates carbohydrate, protein and fat metabolism and blood sugar level.
Insulin
Insulin dependent diabetes mellitus
Due to insulin deficiency
TYPE 1 DM “JUVENILE” TYPE
Non-insulin dependent DM
due to absence or deficiency in insulin receptors. “Mature onset”
caused by hereditary disorders, other endocrine disorders.
TYPE II DM
