Term
Endocrine system - overview |
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Definition
body's means by which it influence metabolic activities of cells by means of hormones |
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Term
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Definition
pituitary, thyroid, parathyroid, adrenal, pineal, and thymus |
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Term
The pancreas and gonads also produce what other product? |
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Definition
Produce both hormones and exocrine |
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Term
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Definition
chemicals that exert effect on the same cells that secrete them |
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Term
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Definition
locally acting chemicals that affect cells other than those that secrete them |
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Term
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Definition
chemical substances secreted by cells into the extracellular fluids |
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Term
What are characteristics of hormones? |
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Definition
Regulate the metabolic functions of other cells, have lag times ranging from seconds to hours, tend to have prolonged effects, are classified as amino acid-based hormones, or steroid |
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Term
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Definition
biologically active lipids with local hormone-like activity |
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Term
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Definition
Amino acid based, steroid, Eicosanoids |
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Term
Amino-acid based hormone types |
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Definition
Amines, thyroxine, peptide, and protein hormones |
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Term
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Definition
gonadal and adrenocortical hormones |
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Term
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Definition
leukotrienes and prostaglandins |
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Term
Target Cell Specificity: Overview |
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Definition
Hormones circulate to all tissue but only activate target cells. Target cells must have specific receptors to which the hormone binds. The receptors may be intracellular or located on the plasma membrane |
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Term
Three types of hormone interactions |
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Definition
Permissiveness, Synergism, Antagonism |
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Term
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Definition
one hormone cannot exert its effects without another hormone being present |
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Term
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Definition
more than one hormone produces the same effects on a target cell (multiply) |
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Term
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Definition
one or more hormones opposes the action of another hormone (blocking) |
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Term
How is the release of hormone controlled? |
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Definition
Through a negative feedback system that varies with a narrow desirable rage based on blood levels |
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Term
What are hormones synthesized and released in response to? |
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Definition
Humoral stimuli, Neural stimuli, Hormonal stimuli |
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Term
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Definition
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Term
How many lobes does the pituitary gland contain? |
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Definition
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Term
How many major hormones does the pituitary gland secrete? |
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Definition
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Term
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Definition
Posterior lobe and the infundibulum |
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Term
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Definition
connecting stalk between hypothalamus and posterior lobe of pituitary |
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Term
What is the functiom of the neurohypophysis? |
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Definition
Receives, stores, and releases hormones from the hypothalamus |
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Term
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Definition
anterior lobe, made up of glandular tissue |
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Term
Function of the Adenohypophysis |
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Definition
Synthesizes and secretes a number of hormones |
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Term
Pituitary-Hypothalamic Relationships: Posterior Lobe - General info |
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Definition
Posterior lobe is a down growth of hypothalamic neural tissue. Has a neural connection with the hypothalamus (hypothalamic-hypophyseal tract) |
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Term
What does the nuclei of the hypothalamus synthesize? |
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Definition
Oxytocin and antidiuretic hormone (ADH) |
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Term
What happens to the hormones synthesized by the nuclei of the hypothalamus? |
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Definition
Transported to the pituitary |
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Term
What is the anterior lobe of the pituitary an out-pocketing of? |
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Definition
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Term
Is there direct neural contact with the hypothalamus and the anterior lobe of the pituitary gland? |
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Definition
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Term
Hypophyseal portal system |
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Definition
the vascular connection between the anterior pituitary and the hypothalamus |
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Term
What does the hypophyseal portal system consist of? |
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Definition
Primary capillary plexus, Hyophyseal portal veins, secondary capillary plexus |
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Term
The hypothalamus sends a chemical stimulus to the anterior pituitary: Release |
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Definition
Releasing hormones stimulate the synthesis and release of hormones |
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Term
The hypothalamus sends a chemical stimulus to the anterior pituitary: Inhibiting |
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Definition
Inhibiting hormones shut off the synthesis and release of hormones |
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Term
What are tropic hormones? |
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Definition
Hormones that produce indirect effects at organs |
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Term
Tropic hormones released by the Anterior Lobe of the Pituitary Gland |
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Definition
Growth Hormone (GH), Thyroid-stimulating hormone (TSH), Adrenocorticotropic hormone (ACTH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Prolactin (PRL) |
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Term
Function of the Tropic Hormones |
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Definition
Regulate the activity of other endocrine glands |
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Term
What is the posterior pituitary lobe made up of? |
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Definition
made of axons of hypothalamic neurons |
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Term
What does the posterior pituitary lobe store? |
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Definition
antidiuretic hormone (ADH, vasopressin) and oxytocin |
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Term
What does Antidiuretic hormone influence? |
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Definition
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Term
What does oxytocin stimulate? |
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Definition
Smooth muscle contraction in breasts and uterus |
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Term
What does thyroid hormone consist of? |
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Definition
Two related iodine-containing compounds. T4 and T3 |
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Term
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Definition
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Term
What is Thyroxine made up of? |
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Definition
Two tyrosine molecules plus four bound iodine atoms |
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Term
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Definition
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Term
What is triiodothyronine made up of? |
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Definition
two tyrosines, and three bound iodine atoms |
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Term
What is Thyroid Hormone concerned with? |
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Definition
Glucose oxidation, Increasing metabolic rate, Heat production |
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Term
What does thyroid hormone play a role in? |
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Definition
Maintaining blood pressure, regulating tissue growth, developing skeletal and nervous systems, maturation and reproductive capabilities |
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Term
Synthesis of Thyroid Hormone: Step 1 |
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Definition
Thyroglobulin is synthesized and discharged into the lumen of the follicle |
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Term
Synthesis of Thyroid Hormone: Step 2 |
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Definition
Iodides (I-) are actively taken into the cell, oxidized to iodine (I2), and released into the lumen |
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Term
Synthesis of Thyroid Hormone: Step 3 |
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Definition
Iodine attaches to tyrosine, mediated by peroxidase enzymes, forming T1 (monoiodotyrosine, or MIT) and T2 (diiodotyrosine, or DIT) |
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Term
Synthesis of Thyroid Hormone: Step 4 |
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Definition
Iodinated tyrosines link together to form T3 or T4 |
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Term
Synthesis of Thyroid Hormone: Step 5 |
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Definition
Colloid is then endocytosed and combined with a lysosome where T3 and T4 are cleaved from thryoglobulin and diffuse into the bloodstream |
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Term
Which "T" is there generally more of? |
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Definition
More T2 than T1, more T4 than T3 |
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Term
What produces Calcitonin? |
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Definition
The parafollicular cells of the thyroid |
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Term
What does calcitonin target? |
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Definition
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Term
What is Calcitonin's function? |
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Definition
Inhibits osteoclast activity and release of calcium from the bone matrix. Stimulates calcium uptake and incorporation into the bone matrix |
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Term
How is calcitonin regulated? |
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Definition
A humoral (calcium ion concentration in the blood) negative feedback mechanism |
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Term
How are the cells of the parathyroid glands arranged? |
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Definition
In cords containing oxyphil and chielf cells |
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Term
What do the Chief (principal) cells secrete? |
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Definition
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Term
What is Parathormone's (PTH) function? |
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Definition
Regulates caclium balance in the blood |
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Term
What does PTH release do, basic? |
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Definition
Increases Ca2+ in the blood |
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Term
What does PTH release do, whole story> |
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Definition
Stimulates osteoclasts to digest bone matrix, enhances the reabsorption of Ca2+ and the secretion of phosphate by the kidneys, Increases absorption of Ca2+ by intestinal mucosa |
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Term
How is PTH release inhibited? |
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Definition
By rising Ca2+ levels in the blood |
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Term
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Definition
paired, pyramid-shaped organs atop the kidneys |
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Term
Structurally and functionally the Adrenal Glands is what two glands in one? |
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Definition
Adrenal medulla and Adrenal cortex |
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Term
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Definition
neural tissue that acts as part of the sympathetic nervous system |
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Term
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Definition
glandular tissue derived from embryonic mesoderm |
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Term
What does the adrenal cortex synthesize and release? |
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Definition
Steroid hormones called corticosteroids |
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Term
What are the three layers of the adrenal cortex? |
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Definition
Zona glomerulosa, Zona fasciculata, Zona reticularis |
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Term
Smooth muscle contraction in breasts and uterus through oxytocin stimulation is a result of what mechanism? |
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Definition
PIP-calcium second messenger |
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Term
What does the Zona gomerulosa produce? |
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Definition
Mineralcorticoids, chiefly aldosterone |
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Term
What does the Zona fasciculata produce? |
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Definition
Glucocorticoids, chiefly cortisol |
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Term
What does the Zona reticularis produce? |
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Definition
Gonadocorticoids, chiefly androgens |
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Term
What is the role of a Mineralocorticoids? |
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Definition
Regulation of electrolytes in extracellular fluids. |
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Term
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Definition
most important mineralocorticoid |
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Term
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Definition
Maintains Na+ balance by reducing excretion of sodium from the body. Stimulates reabsorbtion of Na+ by the kidneys |
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Term
Aldosterone secretion is stimulated by: |
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Definition
Rising blood levels of K+, Low blood Na+, decreasing blood volume pressure |
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Term
Glucocorticoids (Cortisol): Helps the body resist stress by |
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Definition
Keeping blood sugar levels relatively constant. Maintaining blood volume and preventing water shift into the tissue |
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Term
Glucocorticoids (Cortisol): Cortisol provokes |
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Definition
Gluconeogenesis (formation of glucose from noncarbohyrdates), rises in blood glucose, fatty acids, and amino acids |
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Term
Excessive levels of glucocorticoids |
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Definition
Depress cartilage and bone formation, inhibit inflammation, depress the immune system, promote changes in cardiovascular, neural, and gastrointestinal function |
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Term
Gonadocorticoids (Sex hormones): Most secreted |
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Definition
Androgens, most important one is testosterone |
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Term
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Definition
The onset of puberty. The appearance of secondary sex characteristics, sex drive in females |
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Term
After menopause what can androgens be converted into? |
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Definition
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Term
Adrenal Medulla is made up of what cells? |
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Definition
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Term
What do Chromaffin eclls secrete? |
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Definition
Epinephrine and norepinephrine |
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Term
Secretion of epinephrine and norepinephrine causes: |
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Definition
Blood glucose levels to rise, Blood vessels to constrict, the heart to beat faster, blood to be diverted to the brain, heart, and skeletal muscle |
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Term
What role does epinephrine play with the heart? |
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Definition
The more potent stimulator of the heart and metabolic activities |
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Term
What is norepinephrine's more influential role? |
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Definition
Peripheral vasoconstriction and blood pressure |
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Term
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Definition
products are hormones, glandular, diffuses into blood stream |
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Term
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Definition
not hormones, leave through duct cells |
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Term
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Definition
triangular gland, with both exocrine and endcorine cells, located behind the stomach |
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Term
exocrine product of the pancreas |
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Definition
acinar cells produce an enzyme-rich juice used for digestion |
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Term
What are the pancreatic islets made up of? |
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Definition
Alpha cells and Beta cells |
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Term
What do the alpha cells of the pancreatic islets produce? |
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Definition
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Term
What do the beta cells of the pancreatic islets produce? |
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Definition
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Term
Are the products produced by the pancreatic islets endocrinic or exocrinic? |
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Definition
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Term
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Definition
A 29 amino acid polypeptide hormone that is a potent hyperglycemic agent |
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Term
What is glucagon's major target? |
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Definition
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Term
What does glucagon promote? |
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Definition
Glycogenolysis, gluconeogenesis, release of glucose to the blood form liver cells? |
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Term
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Definition
breakdown of glycogen to glucose |
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Term
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Definition
synthesis of glucose from lactic acid and noncarbohydrates |
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Term
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Definition
a 51-amino acid protein consisting of two amino acid chains linked by disulfide bonds |
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Term
What is insulin first synthesized as? |
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Definition
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Term
How do we get insulin from proinsulin? |
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Definition
Proinsulin is excised by enzymes, releasing functional insulin |
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Term
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Definition
Lowers blood glucose levels, enhances transport of glucose into body cells, counters metabolic activity that would enhance blood glucose levels |
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Term
Regulation of Blood Glucose Levels: Rising blood glucose level: Step 1 |
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Definition
Pancreas releases insulin |
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Term
Regulation of Blood Glucose Levels: Rising blood glucose level: Step 2 |
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Definition
Insulin stimulates glucose uptake by cells and stimulates glycogen formulation in the liver |
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Term
Regulation of Blood Glucose Levels: Rising blood glucose level: Step 3 |
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Definition
Blood Glucose returns to normal range |
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Term
Regulation of Blood Glucose Levels: Declining blood glucose level: Step 1 |
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Definition
Pancreas releases glucagon |
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Term
Regulation of Blood Glucose Levels: Declining blood glucose level: Step 2 |
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Definition
Glucagon stimulates glycogen breakdown in the liver |
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Term
Regulation of Blood Glucose Levels: Declining blood glucose level: Step 3 |
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Definition
Blood glucose rises to normal range |
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Term
Diabetes mellitus results from... |
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Definition
hyposecretion or hypoactivity of insulin |
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Term
What are the three cardinal signs of Diabetes? |
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Definition
Polyuria, Polydipsia, Polyphagia |
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Term
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Definition
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Term
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Definition
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Term
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Definition
excessive hunger and food consumption |
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Term
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Definition
excessive insulin secretion, resulting in hypoglycemia |
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Term
What are the female gonads? |
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Definition
Paired ovaries in the abdominopelvic cavity |
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Term
What hormones do the ovaries produce? |
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Definition
Estrogens and progesterone |
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Term
What are the female gonads responsible for? |
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Definition
Maturation of the reproductive organs, appearance of secondary sexual characteristics, breast development and cyclic changes in the uterine mucosa |
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Term
What are the male gonads? |
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Definition
Testes located in an extraabdominal sac (scrotum) |
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Term
What hormones do the male gonads produce? |
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Definition
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Term
What is the role of testosterone? |
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Definition
Initiates maturation of male reproductive organs. Causes appearance of secondary sexual characteristics and sex drive, is necessary for sperm production. maintains sex organs in their functional state |
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Term
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Definition
Small gland hanging from the roof of the third ventricle of the brain |
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Term
What hormone does the pineal gland secrete? |
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Definition
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Term
What is melatonin involved with? |
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Definition
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Term
At what point are melatonin levels highest? |
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Definition
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Term
What physiological processes does melatonin affect? |
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Definition
ones that show rhythmic variations )decrease body temperature, induce sleep, suppress appetite) |
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Term
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Definition
Lobulated gland located deep to the sternum |
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Term
What are the major hormonal products of the thymus? |
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Definition
Thymopoietins and thymosins |
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Term
What are thymopoietens and thymosins essential for? |
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Definition
The development of T lymphocytes (T Cells) of the immune system |
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