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16 Cards in this Set
- Front
- Back
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What is an endocrine gland?
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An endocrine gland is a group of cells that secrete a chemical messenger into the bloodstream that affects a target cell. The endocrine glands are ductless.
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Differentiate between classic endocrine, paracrine, autocrine.
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Classic Endocrine: hormone secreted into the bloodstream
Paracrine: secretes hormones that affects the cells beside it Autocrine: affects itself |
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What is an Amine Hormone? Catecholamine?
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An amine hormone (thyroid hormones, epinephrine, norepinephrine) is derived from the amino acid tyrosine. Catecholamines are secreted my the adrenal medulla and affect the sympathetic nervous system.
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What is a Peptide Hormone?
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A peptide hormone (Insulin and Glucagon) involves prohormone production. Prohormones are packaged in the ER and Golgi body.
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What is a steroid hormone?
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A steroid hormone (testosterone, estrogen) are produced by the adrenal cortex and the gonads. Sex hormones are involved in stress and kidney funtion. Cholesterol is their precursor. Steroid Hormones are not stored in an endocrine gland.
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What hormones are lipid soluble and water soluble? Where are there receptors?
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Thyroid hormones and steroid hormones are lipid soluble , whereas Catecholamines and peptide hormones are water soluble. Steroid & Thyroid hormone receptors are located in the nucleus. Catecholamines and Peptide Hormone receptors are found in the plasma membrane.
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Explain up-regulation and down-regulation.
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Up-regulation refers to a cells ability to increase the sensitivity to a chemical. I.E. insulin up-regulation involves adding more insulin receptors cause insulin concentrations are low. Down-regulation occurs when a chemical is high in concentration, therefore, less receptors are needed and they are down-regulated.
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What are 4 factors that control hormone secretion?
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1) Ions or Nutrients
2) Neurotransmitters 3) Hormones 4) Tropic Hormones |
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What is Hyper/hyposecretion? Hyper/hyporesponsiveness?
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Hypersecretion: too much secreted (increased cortisol due to damaged adrenal medulla)
Hyposecretion: not enough secretion (Decreased thyroid hormone production due to insufficient iodine) Hyperresponsiveness: up-regulation of receptors Hyporesponsiveness: Diabetes Mellitus, not enough or abnormal receptors. |
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What is hypoglycemia and hyperglycemia? Symptoms?
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Hypoglycemia is low blood glucose concentration. Symptoms: weakness, nausea, confusion, hallucinations, coma
Hyperglycemia: too much blood glucose. Symptoms: polyuria, polydipsia, diabetes, hypotension, cardiac arrythmias |
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What hormones do beta cells, alpha cells, delta cells release? what percentage of these cells make up the pancreas?
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Beta cells (80%) - insulin (decreases plasma glucose levels)
Alpha cells (15%)- Glucagon (increases plasma glucose levels) Delta cells (5%) - Somatostatin - inhibits growth hormone. |
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How does insulin promote glucose uptake?
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Insulin promotes translocation of glucose transporters to the cell membrane allowing more glucose to enter the cell.
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Increases blood glucose levels promotes clustering and endocytosis of insulin receptors. T/F.
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True.
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What is the effect of epinephrine on exercise?
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Epinephrine is released from the adrenal medulla and uses a 2nd messenger to stimulate breakdown of muscle glycogen to provide energy for muscle cells.
In the pancreas, epinephrine inhibits insulin release. |
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How do kinases activate and inactivate proteins?
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Kinase phosphorylates and activates a protein. Phosphotase removes a phosphate and inactivates a protein.
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Explain how epinephrine activates glycogen phosphorylase, and deactivates glycogen synthase.
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1)Epinephrine interacts with a g-protein receptor
2)A g-protein activates adenylyl cyclase 3)Adenylyl cyclase hyrdolyzes ATP forming cAMP 4)cAMP activates a cAMP dependent protein kinase! 5) Protein kinase activates glycogen phosphorylase and deactivates glycogen synthase. |
