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29 Cards in this Set
- Front
- Back
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What are the 4 mechanisms 0f intercellular communication?
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1. Direct communication
2. Paracrine comm. 3. Endocrine comm. 4. Synaptic comm. |
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What is paracrine comm.?
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It is primarily limited to local area, where concentrations are relatively high.
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What are the 3 major hormone groups/
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1. Amino acid derivatives
2. Peptide hormones 3. Lipid derivatives |
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Name 4 hormonal substances that are derivatives of tyrosine?
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1. Thyroxine
2. Epinephrine These are 3. Norepinephrine all bio- 4. Dopamine genic- hormones. |
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Name a hormone that is derived from tryptophan?
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Melatonin.
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What are eicosanoids?
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They are small molecules with a 5 carbon ring at one end.
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The activated G protein activates the enzyme adenylate cyclase also called adenyl cyclase. TRUE/FALSE
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TRUE. This converts ATP to the ring shaped molecule cyclic -AMP. Cyclic AMP then functions as a 2nd messenger, typically by activating a kinase, which performs phosphorylation, the attachment of a PO4 group to another molecule.
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What is the relationship between a G protein and cAMP?
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Many G proteins, once activated exert their effects by changing the concentration of the 2nd messenger cyclic-AMP(cAMP), within the cell.
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What is the relationship between G protein and phospholipase C(PLC)?
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The G protein first activates PLC. This enzyme triggers a receptor cascade that begins with the production of Diacylglycerol(DAG) and Insoitol triphosphate(IP3). The end result is the release of calcium.
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What does IP3 do?
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It diffuses into the cytoplasm and triggers the release of Ca+ from intracellular reserves, from the smooth endoplasmic reticulum.
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What does DAG do?
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The combination of DAG and intracellular calcium ions activates another membrane, protein kinase C(PKC) The activation of PKC leads to phosphorylation of calcium channel proteins, a process that opens the channels and permits the entry of extracellular calcium.
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What is Calmodulin/
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The calcium ions themselves serve as messengers generally in combination with an intracellular protein called calmodulin.
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what is a fenestrated capillary?
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It allows relatively large molecules to enter or leave the ciculatory system.
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Estradiol is the most important estrogen. TRUE/FALSE
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TRUE.
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What is the Glucose sparing effect?
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GH stimulates the breakdown of stored triglycerides by adipocytes, which then release fatty acids into the blood. As fatty acids rise, many tissues stop breaking down glucose and start breaking down fatty acids to generate ATP.
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List 7 hormones secreted by the adenohypophysis pars distalis?
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1. TSH
2. ACTH 3. Gonadotropins 4. FSH 5. LH 6. Prolactin 7. GH |
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From what anatomical region does MSH derive/
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Pars intermedia
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What does thyroid peroxidase do?
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Iodide ions diffuse to the apical surface of each follicle cell, where they are converted to an activated form of iodide (I+) by the enzyme thyroid peroxidase.
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The thyroid hormones binding to mitochondria increase the rates of mitochondrial ATP production. TRUE/FALSE
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TRUE.
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What are the two cell populations of the parathyroid glands?
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1. Chief cells-produce parathyroid hormone.
2. Oxyphils |
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What are the C cells of the thyroid?
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C cells produce the hormone calcitonin(CT) which aids in the regulation of CA+ concentrations in body fluids.
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The adrenal gland weighs app. 5.0 grams. TRUE/FALSE
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TRUE.
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Epinephrine makes up 75-80% of the secretions from the adrenal medulla, the rest being norepinephrine. TRUE/FALSE
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TRUE.
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In the heart, the stimulation of beta-1 receptors triggers an increase in the rate and force of cardiac muscle contraction. TRUE/FALSE
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TRUE.
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Besides insulin, what other substance is secreted by the beta cells of the pancreas?
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Amylin. Its role is unclear.
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What do pancreatic delta and F cells secrete?
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Delta cells produce GH-IH. it suppresses the release of glucagon and insulin by other islet cells and slows the rate of food absorption.
F cells produce pancreatic polypeptide. This inhibits gallbladder contractions and regulates some pancreatic enzymes. |
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Secretion is sometimes secreted by elevated levels of some amino acids, including arginine and leucine. TRUE/FALSE
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TRUE.
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What is gluconeogenesis?
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Liver cells absorb amino acids from the bloodstream, convert them to glucose, and release the glucose into the circulation.
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What is Leptin?
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After eating, adipose tissues absorb glucose and lipids and synthesizes triglycerides for storage. At the same time it releases leptin into the bloodstream. leptin binds to hyppthalamic neurons involved with emotion and appetite control. It results in the suppression of apetite.
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