Endocrine System Flashcards
Exocrine glands
Secrete substances into ducts.
Endocrine glands
Secrete hormones directly into the bloodstream.
Organs which have endocrine qualities
Hypothalamus, thalamus, kidneys, GI mucosa, heart, placenta
Hormone
Internal secretion that functions as a chemical messenger in the endocrine system.
Hormonal regulation methods
Hormonal control, feedback systems and neural control
Hormonal control
One hormone controls another.
Feedback systems
The gland is turned on or off in response to the concentration of the hormone or end product.
Neural control
Glands are stimulated directly by the nervous system.
Pituitary gland
Small, grapelike gland attached to the hypothalamus. Sits in the sella turcica of the sphenoid bone.
Adrenohypophysis
Anterior lobe of the pituitary gland. Produces 7 hormones.
Neurohypophysis
Posterior lobe of the pituitary gland. Stores 2 hormones which are produced by the hypothalamus.
Anterior pituitary hormones
ACTH, GH, TSH, FSH, LH, PRL, MSH
Adrenocorticotropic hormone
Anterior pituitary hormone; regulates the adrenal cortex. ACTH.
Growth hormone
Anterior pituitary hormone; stimulates muscle and bone growth.
Thyroid-stimulating hormone
Anterior pituitary hormone; stimulates the thyroid to produce hormones. TSH.
Follicle stimulating hormone
Anterior pituitary hormone; stimulates the gonads to produce gametes. FSH.
Luteinizing hormone
Anterior pituitary hormone; stimulates ovulation and hormone production by the gonads.
Prolactin
Anterior pituitary hormone; stimulate milk production in the mammary glands.
Melanocyte-stimulating hormone
Anterior pituitary hormone; Increases skin pigmentation via the distribution of melanin granules.
Posterior pituitary hormones
Antidiuretic hormone and oxytocin.
Antidiuretic hormone
Posterior pituitary hormone; stimulates the kidneys to retain water. ADH.
Oxytocin
Posterior pituitary hormone; stimulates uterine contractions and causes milk expression.
Hypothalamus
Part of the diencephalon. Produces hormones that inhibit or stimulate the anterior pituitary.
Pineal gland
Pinecone shaped gland directly posterior to the pituitary. Secretes melatonin.
Melatonin
Involved in the control of the circadian rhythm.
Thyroid gland
Butterfly shaped gland found anterior to the trachea. Connected by the central isthmus. Secretes thyroid hormones and calcitonin.
Thyroid hormone
T3 and T4. COnsist of an iodized amino acid. Increase metabolic rate.
Calcitonin
Decrease blood calcium by stimulating osteoblasts.
Parathyroid glands
4 tiny glands on the posterolateral surface of the thyroid. Release parathyroid hormone.
Parathyroid hormone
Raises blood calcium levels by stimulating osteoclasts.
Adrenal glands
Found above the kidneys and divided into cortex and medulla.
Corticosteroids
The collective name for hormones released from the adrenal cortex.
Mineralocorticoids
Corticosteroids which maintain electrolyte and water balance. Primarily aldosterone.
Glucocorticoids
Corticosteroids which promote sugar metabolism, anti-stress and anti-inflammatory processes. Primarily cortisol.
Gonadocorticoids
Sex hormones produced by the adrenal glands.
Aldosterone
Adrenal cortex hormone that stimulates water and sodium retention by the kidneys.
Cortisol
Adrenal cortex hormone that affects metabolism and produces an anti-inflammatory response.
Adrenal medulla hormones
Epinephrine and norepinephrine. Enhance and prolong the function of the sympathetic nervous system.
Epinephrine and norepinephrine ratio
80% epinephrine, 20% norepinephrine.
Pancreas
Organ found inferior to the stomach. Has endocrine and exocrine functions.
Insulin
Hormone secreted by the beta cells of the pancreas. Reduces blood glucose by stimulating body cells to take up glucose.
Portio of the pancreas that secretes hormones
The pancreatic islets, also called islets of Langerhans.
Glucagon
Secreted by alpha cells of the pancreas. Increases blood glucose by stimulating the breakdown of glycogen.
Estrogen
Secreted by follicle cells of the ovaries. Controls female secondary sex characteristics and the menstrual cycle.
Ovaries
Female gonads found in the pelvic cavity. Controlled by LH and FSH. Secrete estrogen, progesterone and relaxin.
Progesterone
Secreted by the corpus luteum of the ovaries. Prepares the endometrium for pregnancy.
Relaxin
Softens the connective tissue in pregnant women.
Testes
Male gonads, found in the scrotum. Interstitial cells of Leydig produce androgens.
Testosterone
Increases male secondary sex characteristics, libido and sperm production.
Human chorionic gonadotropin
Produced by the placenta and stimulates secretion of estrogen and progesterone. Decreases lymphocyte activation.
Thyms
Bilobed gland found behind the sternum. Produces thymis hormones.
Thymic hormones
Thymosin and thymopoietin. Assist in the growth and development of the immune system.
Gastrin
Secreted by that gastric mucosa. Stimulates bile, pancreatic enzymes and gastric juices.
Cholecystokinin
Secreted by the intestinal mucosa. Stimulates the gallbladder and pancreas.
Secretin
Secreted by the intestinal mucosa. Stimulates the pancreas.
Ghrelin
Secreted by the GI mucosa. Stimulates appetite.
GIP
Secreted by the GI mucosa. Inhibits gastric secretion and potentiates insulin release.
Hormones released by adipocytes
Leptin and resistin.
Leptin
Hormone released by adipocytes. Inhibits hunger and is opposed by ghrelin.
Resistin
Hormone released by adipocytes. Increases blood sugar by causing body cells to be less sensitive to insulin.
Atrial natriuretic hormone
Hormone secreted by the heart. Increases urine production to decrease blood pressure.
Diabetes insipidus
Disorder caused by the posterior pituitary gland and insufficient ADH. Causes polyuria and subsequent polydipsia.
Polyuria
Increased urine production.
Polydipsia
Increased thirst.
Diabetes mellitus
A group of disorders leading to hyperglycemia.
Graves disease
Overproduction of thyroid hormone.
Hashimoto disease
Underproduction of thyroid hormone.
