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87 Cards in this Set
- Front
- Back
What is the general function of the Endocrine system?
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The endocrine system releases hormones to control body activities and help maintain homeostasis.
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Hormone
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A hormone is a molecule that is released in one part of the body but regulates the activity of cells in other parts of the body.
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How does the response time of the endocrine system compare to that of the nervous system?
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Nervous system is rapid response (instantaneous). The endocrine system responses are slower and more sustained.
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Secretions from an _____________ ______________ enter ducts that carry the secretions to body surfaces or into cavities.
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exocrine gland
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Endocrine glands...
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secrete hormones into interstitial fluid to diffuse into capillaries and circulate in the blood to target tissues.
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The endocrine system comprises...
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all the endocrine glands and hormone-secreting cells.
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Target cells
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have specific receptors for a hormone to bind to and affect cell activities.
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What are the two classes of hormones?
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lipid-soluble and water-soluble
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Describe the difference in how water-soluble hormones and lipid-soluble hormones circulate.
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Water-soluble hormones circulate in blood plasma unattached to plasma proteins; most lipid-soluble hormones circulate attached to transport proteins.
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Transport proteins: (3 functions)
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1) increase blood solubility of lipid-soluble hormones
2) prevent loss of small hormone molecules to urine 3) provide a ready reserve of hormones in the blood |
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4 functions of Hormones
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1) Help regulate. Chemical composition, Metabolism
2) Control growth and development 3) Regulate operation of reproductive systems. 4) Help establish circadian rhythms |
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What are 3 factors that influence the responsiveness of a target cell to a hormone?
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1) the hormone's concentration,
2) abundance of target cell receptors 3) influences exerted by other hormones. |
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Hormone secretion is regulated by what 3 things?
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1) nervous system signals
2) chemical changes in the blood 3) other hormones. |
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Steroid hormones are derived from ____________.
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cholesterol
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What are the two Thyroid hormones?
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T3 (Triiodothyronine)
T4 (Thyroxine) |
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Where are transport proteins for hormones synthesized?
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The liver
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Where do lipid soluble hormones bind to target cells? water soluble?
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Receptors within the cell. Receptor on exterior of plasma membrane.
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The major integrating link between the nervous and endocrine system is the _____________.
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Hypothalamus
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_______________ is controlled by the hypothalamus although it secretes several hormones that control endocrine glands.
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Pituitary gland
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The ___________ sits in the _________ of the sphenoid bone. Pea shaped structure.
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pituitary gland; sella turcica
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Infundibulum
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stalk that attaches the pituitary gland and hypothalamus
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Another name for pituitary gland?
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hypophysis
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What are the 2 distinct regions of pituitary gland?
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Anterior pituitary
Posterior pituitary |
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The _________ ___________ secretes hormones when stimulated by __________ hormones and stops secreting hormones when inhibited by _______ hormones.
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anterior pituitary; releasing; inhibiting
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Hypophyseal portal system
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links the hypothalamus and the anterior pituitary. Blood flows without passing through the heart.
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_______ hormones are hormones that influence the secretion of other endocrine glands.
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tropic hormones....also known as tropins
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Thyroid stimulating hormone stimulates the thyroid gland to secrete _______________ (T3) and ______________ (T4)
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triiodothyronine; thyroxine
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hGH promotes synthesis and secretion of protein hormones called _________ _______ _______ that stimulate body growth and repair.
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insulinlike growth factors
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What is the difference between a stimulating hormone and a releasing hormone?
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Stimulating hormone stimulates a second endocrine gland to release a hormone. (releasing hormone)
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_______-_______ hormone targets the ovaries for monthy development of several ovarian follicles that surround a developing oocyte.
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Follicle-stimulating hormone
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______-______ hormone from the hypothalamus stimulates Follicle Stimulating Hormone (FSH) release by the anterior pituitary.
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Gonadotropin-releasing hormone (GnRH)
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_______________ hormone triggers ovulation.Stimulates secretion of estrogens by ovaries and testoterone by the testes.
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Luteinizing hormone (LH)
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______________ initiates milk secretion by mammary glands.
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Prolactin (PRL)
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Corticotropin-releasing hormone is released by the hypothalamus and stimulates the release of _____________-releasing hormone from the anterior pituitary, which causes secretion of glucocorticoids such as cortisol from the adrenal cortex.
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Adrenocorticotropic hormone (ACTH)
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Low blood sugar levels of glucocorticoids stimulate neurosecretory cells in the hypothalamus to release Corticotropin releasing hormone which then stimulates secretion of _____________ hormone from the _______ _________.
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Adrenocorticotropic hormone;
anterior pituitary |
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There is little circulating __________-________ hormone in humans. It's exact role in humans is unkown.
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Melanocyte-stimulating Hormone
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The posterior pituitary is also known as?
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neurohypophysis
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What are the two hypothalamic hormones released and stored by the posterior pituitary?
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Oxytocin
and Antidiuretic hormone (Vasopressin) |
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Blood is supplied to the posterior pituitary by the _________ ________ arteries.
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inferior hypophyseal
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hormone that is responsible for uterin contractions
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Oxytocin
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Hormone that decreases urine production
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Antidiuretic hormone (Vasopressin)
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Where are the hormones secreted by the posterior pituitary produced? How do they get to posterior pituitary?
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Hypothalamus; Neurosecretory cells
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What shape is the thyroid gland?
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butterfly shaped
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Mass of tissue that connects lobes of the thyroid gland
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isthmus
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Microscopic spherical sacs that make up most of the thyroid gland
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thyroid follicles
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Cells that surround the lumen of the follicle (Thyroid).
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follicular cells
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Follicular cells in the thyroid produce what two hormones?
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Triiodothyronine (T3)
Thyroxine (T4) |
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__________ cells lie between follicles in the thyroid.
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parafollicular cells
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Parafollicular cells produce the hormone ______________.
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Calcitonin
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this ion is trapped by Thyroid follicular cells.
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iodide
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a large glycoprotein secreted into the lumen of the follicle (Thyroid)
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thyroglobulin (TGB)
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The material that accumulates in the lumen of a thyroid follicle is called?
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colloid
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Droplets of colloid reenter follicular cells by ____________ and merge with lysosomes.
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pinocytosis
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Thyroid releasing hormone comes from the _____________. While Thyroid-stimulating hormone comes from the ____________.
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hypothalamus; anterior pituitary gland
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________ __________ __________ = The rate of oxygen consumption under standard conditions.
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Basal Metabolic Rate
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____________ ____________ causes the kidneys to return more water to the blood while decreasing urine volume.
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Antidiuretic Hormone
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lowers the blood levels of calcium ions (Ca2+) and promotes deposition of (Ca2+) into the bone matrix.
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Calcitonin:
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Symptoms of increased heart rate, more forceful heartbeats, and increased blood pressure, are all signs of _________________.
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hyperthyroidism
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What cells produce parathyroid hormone (PTH)
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chief cells
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Parathyroid glands are embedded in the....
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posterior surface of the thyroid gland.
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___________ hormone is the major regulator of the levels of calcium, magnesium, and phosphate ions in the blood.
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Parathyroid hormone from the Parathyroid glands
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What are the primary target tissues for Parathyroid hormone and calcitriol?
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Osteoclasts
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What are the 3 secretions out of the 3 zones of the Adrenal Cortex?
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(capsule)
Mineralocorticoids (outer zone) Glucocorticoids (middle zone) Androgens (inner zone) (adrenal medulla) |
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Major mineralocorticoid. Regulates homeostasis of sodium ions (Na+) and potassium ions (K+)
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Aldosterone
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Name the Glucocorticoid which regulates metabolism and resistance to stress. It's the most abundant, 95% of glucocorticoid activity.
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cortisol (hydrocortisone)
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What hormone of the hypothalamus is responsible for stimulating glucocorticoid secretion?
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corticotropin-releasing hormone.
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____________ increase protein breakdown, enhance glucose formation, break down triglycerides, inhibit inflammation, depress immune system responses.
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Glucocorticoids
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Androgens that stimulate growth of axillary and pubic hair, aid prepubertal growth spurts and contribute to libido in females are created in the __________ __________ of the _______ glands.
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Adrenal cortex; Adrenal glands
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Adrenal medulla secretes ___________ and ____________. These hormones augment the fight or flight response.
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epinephrine and norepinephrine
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The ____________ is both and endocrine and exocrine gland.
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pancreas
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The pancreatic endocrine tissue is referred to as _________ _____ or ________ _____________.
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pancreatic islets,
islets of Langerhans |
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Alpha cells of pancreas secrete the hormone ___________.
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glucagon
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Beta cells of pancreas secrete the hormone _____________.
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insulin
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Low blood surgar levels cause secretion of __________ which acts on cells to release glucose into the blood.
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glucagon
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High blood glucose levels cause secretion of ___________, which acts on cells to increase diffusion of glucose into those cells and increases protein and fatty acid synthesis.
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Insulin
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Ovaries produce ___________ and ____________ hormones. These hormones regulate the female reproductive cycle, maintain pregnancy, and prepare the mammary glands for lactation.
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estrogens and progesterone.
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Ovaries produce ___________, a hormone that inhibits Follicle stimulating hormone secretion.
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inhibin
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The hormone ___________, produced by the ovaries and placenta during pregnancy, increases the flexibility of the pubic symphysis and helps dialate the cervix.
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relaxin
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The testes produce _________ and _________.
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Testosterone; inhibin.
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What gland produces the hormone melatonin?
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Pineal gland
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During sleep, blood levels of ____________ rise.
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melatonin.
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99% of the pancreas consists of clusters of exocrine cells called ________ . These produce digestive enzymes.
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Acini
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Pancreatic islets are also called _______ of __________. And are found scattered amongst the _______ of the pancreas.
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islets of Langerhans;
acini |
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Where is the pancreas located?
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between the kidneys
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Where are the Adrenal glands located?
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one of each lies superior to each kidney.
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Glucocorticoids have the following 5 effects :
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Protein breakdown
Glucose formation Breakdown of triglycerides Resistance to stress Anti-inflammatory effects |
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A conversion of a substance other than glycogen or another monosaccharide into glucose is called ___________. Example: Liver may convert amino acids or lactic acid to glucose.
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gluconeogenesis
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