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118 Cards in this Set
- Front
- Back
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What are the 8 main functions of endocrine glands?
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1. Metabolism and tissue maturation
2. Ion regulation 3. Water Balance 4. Immune System Regulation 5. Heart Rate / Blood Pressure 6. Blood glucose levels / nutrients 7. Reproductive functions 8. Uterine contractions and lactation |
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Where is the pituitary gland located and how many major hormones does it manage?
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In the sella turcica of the sphenoid bonej
9 hormones |
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What is the main connection between the nervous system and the endocrine system?
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Hypothalamus (it regulates the pituitary gland)
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Describe the structure of the pituitary?
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Posterior= neurohypophysis
continuous with the brain secretes neurohormones because posterior pituitary is really an extension of nervous system Anterior = adenohypophysis pars tuberalis pars distalis pars intermedia Anterior pituitary secretes hormones |
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What is a portal system?
What portal system are we interested in with regard to the endocrine system? |
blood vessels that begin in a primary capillary network, extend some distance and end in a secondary capillary network.
hypothalamohypophysial portal system |
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Where does the hypothalamohypophysial portal system go?
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From the hypothalamus to the anterior pituitary
It is supplied by arteries that supply the hypothalamus |
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Describe what happens when utilizing the hypothalamohypophysial portal system.
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1. hypothalamus sends out neurohormones through the primary capillary network of the hypothalamohypophysial portal system which prompts the Anterior pituitary to either:
release hormones or inhibit hormones. If the anterior pituitary is prompted to release hormones, it does so into the secondary capillary network where it goes into circulation to reach target tissue |
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HORMONE
GHRH STRUCTURE TARGET TISSUE RESPONSE |
Growth hormone-releasing hormone
peptide Anterior pituitary Tells Ant. pit. to secrete more GH |
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HORMONE
GHIH STRUCTURE TARGET TISSUE RESPONSE |
Growth hormone-inhibitating hormone (somatostatin)
small peptide ant. pit. tells ant. pit. to decrease secretion of GH |
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HORMONE
TRH STRUCTURE TARGET TISSUE RESPONSE |
Thyrotropine-releasing hormone
small peptide ant. pit. tells ant. pit. to secrete more TSH |
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HORMONE
CRH STRUCTURE TARGET TISSUE RESPONSE |
Corticotropin-releasing hormone
peptide ant. pit. tells ant. pit. to increase secretion of adrenocorticotropic hormone |
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HORMONE
PIH STRUCTURE TARGET TISSUE RESPONSE |
Prolactin-inhibiting hormone
unknown ant. pit tells ant. pit. to decrease secretion of prolactin |
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HORMONE
GnRH STRUCTURE TARGET TISSUE RESPONSE |
Gonadotropin-releasing hormone
small peptide ant. pit. tells ant. pit. to increase secretion of LH and FSH |
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HORMONE
PRH STRUCTURE TARGET TISSUE RESPONSE |
Prolactin releasing hormone
unknown ant. pit. tells ant. pit. to increase the secretion of prolactin |
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How do neurohormones from the hypothalamus get to the posterior pituitary?
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neurosecretory cells in the hypothalamus extend their axons thru the hypothalamohypophysial tract.
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HORMONE
ADH STRUCTURE TARGET TISSUE RESPONSE |
Antidiuretic hormone
posterior pituitary--small peptide kidney increased water reabsorption (less water in urine) |
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HORMONE
Oxytocin STRUCTURE TARGET TISSUE RESPONSE |
posterior pituitary=small peptide
Uterus; mammory glands increased uterine contractions; increased milk expulsion in females |
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HORMONE
GH STRUCTURE TARGET TISSUE RESPONSE |
Growth Hormone
Ant. Pit = Protein Most tissues Increased growth in tissues increased amino acid uptake and protein synthesis increased breakdown of lipids and release of fatty acids from cells increased glycogen sythesis and increased blood glucose levels increased somatomedin production |
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HORMONE
TSH STRUCTURE TARGET TISSUE RESPONSE |
Thyroid Stimulating Hormone
ant. pit. = glycoprotein Thyroid gland Increased thyroid hormone secretion |
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HORMONE
ACTH STRUCTURE TARGET TISSUE RESPONSE |
Adrenocorticotropic hormone
ant. pit = peptide Adrenal cortex increased glucocorticoid hormone secretion |
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HORMONE
Lipotropins STRUCTURE TARGET TISSUE RESPONSE |
ant. pit. = peptides
fat tissues Increased fat breakdown |
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HORMONE
B Endorphins STRUCTURE TARGET TISSUE RESPONSE |
ant. pit. = peptides
Brain plus ?others? Analgesia in the brain inhibition of gonadotropin-releasing hormone secretion |
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HORMONE
MSH STRUCTURE TARGET TISSUE RESPONSE |
Melanocyte-Stimulating Hormone
ant. pit. = peptide Melanocytes in the skin Increased melanin production in melanocytes to make the skin darker in color |
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HORMONE
LH STRUCTURE TARGET TISSUE RESPONSE |
Luteinizing hormone
ant. pit. = glycoprotein ovaries in females testes in males Ovulation and progesterone production in ovaries testosterone synthesis and sperm cell support in testes |
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HORMONE
FSH STRUCTURE TARGET TISSUE RESPONSE |
Follicle Stimulating hormone
ant. pit. = glycoprotein Follicles in ovaries of females seminiferous tubes in males follicle maturation and estrogen secretion in ovaries sperm cell production in testes |
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HORMONE
Prolactin STRUCTURE TARGET TISSUE RESPONSE |
ant. pit = protein
ovaries and mammary glands in females milk production increased response of follicle to LH and FSH not too sure about what it does in men? |
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Describe what happens when levels of ADH increase.
What regulates ADH? |
Urine volume decreases (vasopresin)j
Blood osmolality decreases Blood volume increases ADH is regulated by osmoreceptors which monitor blood osmolality and blood volume |
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Describe how oxytocin works
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sensory neurons detect:
stretch in the uterus stimulation of cervix nipple stimulation and send a.p.'s to hypothalamus which then releases oxytocin from axons in posterior pituitary |
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What is a somatomedin?
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Peptide synthesized in the liver capable of stimulating certain anabolic processes in bone and cartilage, such as synthesis of DNA, RNA and protein
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What regulates GH?
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hypothalamus releases GHRH or GHIH in response to stress, blood glucose levels, and amino acids in the blood:
stress = GH go low blood suger= GH go high blood sugar = GH stop More amino acids in blood= GH go |
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How is TSH regulated and what does it do in the Thyroid?
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Regulated by TRH from hypothalamus which binds to membrane of ant. pit.
activating a G protein and releasing TSH. In Thyroid it makes and secretes thyroid hormones. |
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What other hormones are associated with ACTH ?
How does ACTH work on it's target tissues? |
ACTH is derived from precursor protein proopiomelanocortin and is related to:
--lipotropins --B endorphins --MSH ACTH is secreted from ant. pit and binds to membrane bound receptors, activates G protein, increases cAMP and therefore increases secretion of hormones (CORTISOL) from the adrenal cortex and works with MSH on skin for pigmentation |
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What are the 3 gonadotropins?
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LH
FSH Prolactin |
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How are gonadotropins regulated?
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hypothalamic hormones GnRH or LHRH
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What is th isthmus?
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connection between two lobes of thyroid
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Describe the thyroid gland
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1. just below larynxj
2. highly vascular and large for an endocrine gland 3. follicles filled with thyroglobulin 4. parafollicular cells secrete calcitonin |
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What does calcitonin do?
Where is it secreted from? |
Regulates Ca levels in body fluid
Parafollicular cells in Thyroid |
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Describe the 6 step process of T3 and T4 synthesis
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1. Iodide transported into follicle cells
2. thyroglobulin is made in follicle cells 3. thyroglobulin gets together with Tyrosine amino acids (iodinated) 4. T3 & T4 made 5. endocytosis of T3 &T4 6. Thyroglobulin stays and T3 and T4 go to circulatory system |
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What mineral is very important for the production of T3 & T4?
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Iodine
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Is the half life short or long for T3 & T4?
Why? |
Long half life because T3 & T4 bind to Thyroixne binding globulin and create large resevoirs of Thryroid hormones in blood.
Level of these hormones is fairly consistant. |
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What do T3 and T4 do?
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Similar to steroids on its target tissues.
Diffuses into cell to make DNA and synthesize proteins. Effects ALOT of tissues for: metabolism / growth / maturation Body temperature |
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How does T3 & T4 help with metabolism?
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Speeds up the metabolization of glucose, protein and fat
gives off heat as a byproduct of this increased metabolism for body temp Helps K+ and Na+ pumps Alters the # of mitochondria for increased ATP production |
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What are some effects of hypothyroidism?
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1. decreased metabolic rate (low body temp and intolerance to cold)
2. Weight gain but reduced appetite 3. dry and cold skin, coarse hair (reduced activity of sweat and sebaceous glands) 4. Reduced heart rate, low blood pressure, dialated and enlarged heart 5. Weak, flabby skeletal muscles, sluggish movements 6. Constipation 7. Myxedeme (facial and body swelling) 8. Apathy 9. Decreased iodide uptake 10. possible goiter |
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What are some effects of hyperthyroidism?
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1. Increased metabolic rate, high body temp, heat intolerance
2. Weight loss but increased appetite 3. Copious sweating, warm and flushed skin 4. Rapid heart rate, high blood pressure, abnormal electrocardiogram 5. Weak skeletal muscles that exhibit tremors, exaggerated reflexes 6. Diarrhea 7. Exophthalmos (protruding of the eyes) 8. Hyperactivity, insomnia, restlessness, irratability, short attention span 9. Increased iodide uptake 10. Almost always a goiter |
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What is a goiter?
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abnormal enlargement of the thyroid gland
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What does cretinism arise from?
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very low T3 & T4 during development
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What regulates T3 & T4?
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TRH goes from hypothalamus via hypothalamohypophysial portal system to ant. pit.
Ant. pit. secretes TSH which acts on Thyroid to secrete T3 & T4 T3 & T4 act on target tissues and also inhibit TRH from Hypothalamus |
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Iodine Deficiency
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Causes Hypothyroidism
Not enough T3 & T4 are made so there is elevated TSH secretion which causes a goiter |
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Goiterogenic substances
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hypothyroidism
found in some drugs and plants like cabbage inhibits T3 & T4 synthesis |
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Lack of Thyroid gland
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hypothyroidism
partial or complete surgical removal as treatment for Grave's Disease |
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Pituitary insufficiency
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hypothyroidism
lack of TSH secretion and associated with inadequate secretions of other ant. pit. hormones |
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Hashimoto Disease
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hypothyroidism
autoimmune normal or depressed thyroid hormone secretion |
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Graves Disease
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Hyperthyroidism
goiter and exophthalamos autoimmune patients have TSH like immunoglobulin in their plasma |
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Tumors
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hyperthyroidism
result in either normal or hyper secretion of thyroid hormones |
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Thyroiditis
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hyperthyroidism
painful swelling of the thyroid gland with normal or slightly increased T3 & T4 production |
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Elevated TSH levels
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hyperthyroidism
result from a pituitary tumor |
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Thyroid storm
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hyperthyroidism
sudden release of a large amount of T3 &T4, caused by surgery, stress, infections and unknown reasons |
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Calcitonin
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increased Ca levels in blood stimulates parafollicular cells to secrete calcitonin
acts on bones to decrease osteoclast activity and lengthens lives of osteoblasts so more Ca goes in Bone deposition calcitonin may also decrease appetite to slow food intake |
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What does the parathyroid secrete and what are the target tissues?
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PTH
bone, kidneys, intestines |
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What does PTH do to bone?
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binds to membrane bound receptor on osteoblast and stromal cells , activates G protein, increases cAMP
increases osteoclast activity, makes more osteoclasts to breakdown bone which releases more calcium and phosphate |
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What does PTH do in the kidneys?
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induces Ca reabsorption in kidneys so that less Ca leaves body in urine
increases production of Vit D increases the excretion of Phosphate |
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What does PTH do in the intestines?
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It makes more Vit D (in kidneys) which in turn makes the gut absorb more Ca.
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What is PTH regulated by?
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low Ca blood levels kick PTH in motion
low Ca can open Na channels and you have tetany (constant depolarization) |
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What are the physical characteristics of the Adrenal Glands?
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located on superior poles of kidneys
surrounded by adipose, retroperitoneal and connective tissue capsule well vascularized medulla and cortex |
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What are the 3 specialized layers of the Adrenal Cortex?
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zona glomerulosa
zona fasciculata (thickest) zona reticularis |
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What are the hormones of the Adrenal Medulla?
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Epi
Norepi neurohormones that interact with adrenergic receptors on target tissues |
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Describe an a adrenergic receptor
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Ca gates open
release Ca from endoplasmic reticulum open K channels decrease cAMP synthesis stimulate protaglandins |
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Describe a B andrenergic receptor
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increases cAMP synthesis
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Describe how Epinephrine increases blood glucose levels
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1. binds to membrane bound receptors in liver
2. cAMP activates enzymes that catalyze the breakdown of glycogen to glucose and prompts liver cells to release glucose into blood. |
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What are the metabolic functions of epinephrine?
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converts glycogen to glucose in liver
breaks down glycogen in muscles increases fat breakdown in adipose tissue which releases fatty acids into the blood |
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How does Epi prepare the body for activity?
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increases metabolic break down of glycogen
increases heart rate and force of contraction constricts blood vessels in skin, kidneys and gastro tract dilates blood vessels in skeletal muscles and cardiac muscles |
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What regulates epinephrine?
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released in response to stimulation of sympathetic neurons because adrenal medulla is a specialized part of ANS
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What are the hormones of the Adrenal Cortex?
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mineralocorticoids
glucocorticoids androgens |
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What type of hormone are mineralcorticoids, glucocorticoids and androgens?
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Steroids--lipids derived from cholesterol
lipid soluable (bind to intracellular receptors) released upon synthesis |
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What is the main Mineralcorticoid and what does it do?
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aldesterone
from the zona glomerulosa increases rate of Na reabsorption in kidneys, thereby increasing blood Na levels (more Na causes H2O reabsorption by kidneys and increase in blood volume) increased K excretion into urine by kidneys increased H excretion |
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What is the main glucocorticoid and what does it do?
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cortisol
from zona fasciculata metabolic --increase fat catabolism --decrease glucose and amino acid uptake in skeletal muscles --increase gluconeogenesis in liver --degrades more protein and fats for energy for cells Development --maturation of tissues (fetal lungs) --developes receptor cells for epi and norepi on its target tissues Anti-Inflammatory --suppresses immune system |
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What regulates the adrenal cortex?
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ACTH is vital
CRH is released from hypothalamus which prompts the ant. pit. to secrete ACTH zona fasciculata is very sensitive to ACTH and responds by increasing cortisol secretion. ACTH, in higher concentrations, also acts on zona glomerulosa to increase the secretion of aldosterone. ACTH also tells hypothalamus to stop sending CRH |
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What happens with stress or hypoglycemia with regards to adrenal cortex?
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hypothalamus secretes CRH to ant. pit.
Ant. pit. secretes ACTH zona fasciculata secretes cortisol zona glomerulosa secretes aldosterone |
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What do the adrenal androgens do?
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from zona reticularis
cause secondary sex characteristics in male cause axillary and pubic hair growth in females |
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What does hyposecretion of aldosterone cause?
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1. hyponatremia (low blood levels Na)
2. hyperkalemia (high blood levels K) 3. Acidosis (pH value of body fluids below 7.35) 4. low blood pressure 5. tremors and tetany of skeletal muscles 6. Polyuria (excessive passage of urine) |
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What does hyposecretion of cortisol cause?
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1. Hypoglycemia (low blood glucose levels
2. Depressed immune system 3. Protein and fats from diet unused (weight loss) 4. Loss of appetite, nausea and vomiting 5. Increased skin pigmentation (if ACTH levels are high) |
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What does hyposecretion of androgens cause?
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reduction of axillary and pubic hair
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What does hypersecretion of aldosterone cause?
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1. slight hypernatremia
2. Hypokalemia 3. alkalosis (blood pH levels of 7.45 or higher) 4. High blood pressure 5. Weakness of skeletal muscles 6. Acidic urine |
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What does Hypersecretion of cortisol cause?
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1. Hyperglycemia--leads to diabetes mellitus)
2. depressed immune system 3. destruction of tissue prteins, causing muscle atrophy and weakness osteoporosis, easy bruising (weak capillaries), thin skin, impaired wound healing, fat redistribution to face, neck and abdomen 4. euphoria and depression |
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What is Addison's disease?
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low levels of aldosterone and cortisol
decreased blood pressure due to Na and H2O loss in kidneys |
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What is Aldosteronism?
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excess aldosterone production
adrenal cortex tumor reduces blood K levels, increases blood pH and increases blood pressure due to retention of Na and H2O in kidneys |
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What is Cushing Syndrome?
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Hypersecretion of cortisol and androgens
or excess secretion of ACTH from non-pituitary tumor causess muscle wasting and fat redeposition increased blood glucose levels early secondary sex characteristics or masculination of young females |
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Describe how the pancreas is both an exo and endo crine gland?
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Exo--
acini produce pancreatic juice and have a duct system which carries the juice to small intestine Endo-- pancreatic islets (islets of Langerhans) release hormones into circulatory system |
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Describe the cells of the pancreatic islets
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alpha cells secrete glucagon
beta cells secrete insulin delta cells secrete somatostatin |
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HORMONE
Insulin STRUCTURE TARGET TISSUE RESPONSE |
protein
liver, skeletal muscles, fat tissue Increased uptake and use of glucose and amino acids |
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HORMONE
Glucagon STRUCTURE TARGET TISSUE RESPONSE |
polypeptide
liver increased breakdown of glycogen release of glucose into the circulatory system |
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HORMONE
Somatostatin STRUCTURE TARGET TISSUE RESPONSE |
peptide
alpha and beta cells inhibition of insulin and glucagon |
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What effect does insulin have on skeletal muscles?
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increased glucose uptake and glycogen synthesis
increased uptake of certain amino acids |
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What effect does insulin have on the liver?
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Increased glycogen synthesis
increased use of glucose for energy |
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What effect does insulin have on adipose cells?
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Increased glucose uptake
increased glycogen synthesis increased fatty acid uptake increased glycolysis |
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What effect does insulin have on nervous system?
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increases glucose uptake in satiety center
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What effect does glucagon have on skeletal muscles?
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little effect
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What effect does glucagon have the liver?
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Rapid increase in the breakdown of glycogen to glucose and release of glucose into the blood
increased formation of glucose from amino acids and fats increased metabolism of fatty acids which causes increased ketones in the blood |
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What effect does glucagon have on adipose cells?
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high concentrations cause breakdown of fats
not too important |
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What effect does glucagon have the nervous system?
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no effect
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Describe how insulin works
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1. binds to membrane bound receptors, phosphorylate proteins
2. taken into cell via endocytosis 3. insulin is broken down and cell responds by increasing it's abiity to take up glucose and amino acids |
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What happens with low insulin levels?
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1. glucose and amino acids can't move into cells
2. satiety center needs insulin to detect glucose in extracellular fluid, so it won't be able turn off the hunger bell--polyphagia. 3. Polyuria occurs and loss of water (osmosis due to glucose in kidney tubules) 4. Tienes sed |
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What happens with too much isulin?
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1. blood glucose levels fall dramatically
2. All the glucose is in cell so there is a deficit for the CNS and it can malfunction |
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What are the main hormones that make sure that the brain and the muscles have adequate energy sources?
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Insulin
GH Glucagon Epinephrine Cortisol |
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Describe how glucagon works on the liver
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1. binds to membrane bound receptor, activates a G protein, increases cAMP
2. causes breakdown of glycogen and increases synthesis of glucose 3. increases the breakdown of fats 4. liver spills glucose into blood upon secretion of glucagon |
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What 3 mechanisms regulate the pancreatic hormones?
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1. nutrient levels in the blood
2. neural stimulation 3. hormones |
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How do nutrient levels in blood regulate pancreatic hormones?
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1. hyperglycemia (elevated blood sugar levels)
--stimulates B cells and release of insulin after a meal insulin released 2. hypoglycemia (low blood sugar) --inhibits insulin release fasting inhibits insulin |
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How does the ANS regulate pancreatic hormones?
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Parasympathetic branch increases insulin as a result of eating
Sympathetic branch inhibits insulin to prevent large drop in blood glucose levels --also monitors levels during activity |
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How do hormones regulate pancreatic hormones?
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gastrointestinal hormones increase insulin secretion
somatostatin inhibits insulin--keeps it from over secreting |
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Describe what happens after a meal...
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1. decreased secretion of glucagon, cortisol, GH and epi
2. increase insulin via para symp. and blood nutrient levels 3. Increased uptake of glucose / amino acids / fats by target cells (tissues store excess) 4. Glucose changed into glycogen in liver / skeletal muscles to make fat in adipose tissues Later... 5. blood glucose levels decrease 6. Increased glucagon, cortisol, GH, epi 7. insulin decreases as glucose goes into target tissues |
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Describe what happens during exercise?
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1. epi secretion and glucagon secretion increase
2. liver changes more glycogen to glucose and blood glucose levels increase 3. insulin secretion decreases to allow for more energy in the blood for the activity 4. fat metabolism increases because of increased epi, GH, cortisol and glucagon |
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Describe how FSH and LH effect the male testes
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FSH and LH are secreted from ant. pit. and prompt the testes to release testosterone
testosterone prompts the production of sperm and development of male organs |
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What is inhibin?
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a hormone secreted by the male testes and female ovaries to inhibit the secretion of FSH from ant. pit.
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Describe how FSH and LH effect the female ovaries
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FSH and LH are secreted from ant. pit. prompting the ovaries to secrete estrogen and progesterone
(menses, pregnancy, lactation and female sex organs) |
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What is relaxin?
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secreted by the ovaries, it relaxes the connective tissues in preparation for childbirth
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What are the hormones of the pineal body and what do they do?
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melatonin and arginine vasotocin
inhibit hypothalamus or gonads melatonin decreases GnRH from hypothalamus inhibiting reproductive processes and making a sleep cycle arginine vasotocin regulates reproductive stuff |
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What is the importance of the photoperiod?
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increased light sends messages to brain to lower secretions from the pineal body
decreased light tells the brain to increase secretions from the pineal body |
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What are the effects of aging on the endocrine glands?
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It's not the same for all glands...
GH decreases (more severely for sedintary folks) so you lose lean body mass melatonin decreases to cause age related sleep changes Thyroid hormones decrease has implications for immune system kidneys have less renin and it's harder for them to regulate blood pressue Thymosin decreases and immune system function decreases making one more susceptible to cancer or infection |
