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55 Cards in this Set
- Front
- Back
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hormones
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chemical messenger molecules
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endocrine glands
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ductless glands, secretion directly into the blood circulation
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exocrine glands
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open to the outside medium through ducts
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pancreas
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is both an endocrine and exocrine gland
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types of cell mediation
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HPANE
hemocrine paracrine autocrine neurocrine ectocrine |
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hemocrine
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classical endocrine
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paracrine
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cell-cell
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autocrine
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auto-regulation
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neurocrine
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neurotransmission, neurosecretion
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ectocrine
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organism - organism
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some examples or uses of ectocrine signaling
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trail, substance, sexual attraction
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two sexual attraction pheromones
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1. sodefrin - stimulates courtship behaviour. cloacal glands of males. considered a decapeptide (cynops pyrrogaster)
2. silefrin cloacal gland of male newt also (cynops ensicauda) |
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4 classes of hormones
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ASPA
amino acid derivatives steroids polypeptides arachidonic acid derivative |
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examples of amino acid derived
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melatonin and seratonin are derived from tryptophan
thyroid hormones and catecholemines are derived from tyrosine |
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steroids are derived from
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cholesterol i.e. estrogen,
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2 parts of the vertebate endocrine system
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neuroendocrine and peripheral endocrine system
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three mian parts of the neuroendocrine system
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1. pineal
2. pituitray 3. hypothalamus |
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purpose of peripheral endocrine system
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no connected to nervouse system. includes thyroid, parathyrodi, adremnal, pancreas, gonads
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isle of langerhans
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cells that produce insulin and glucagon
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ectohormone for pig
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5-anol is secreted by the boar for the sow to attract
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examples of polypeptide hormones
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oxytosin, insulin, prolactin, growth hormone
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arachiodonic acid derivatives
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prostaglandins and leukotrienes
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amino acid derivative: tryptophan
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melatonin and seratonin
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amino acid derivative: tyrosine
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thyroid hormone and catecholamines
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thyroid hormone and t3,t4
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thyroid hormone mainly produces t4 that contains 4 iodide atoms. monodeiodinase is the enzyme that converts t4 into t3, removing an iodide now it is in a more active form
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how much more active is t3 than t4?
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10-15 more active
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examples of steroid hormones
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estrogen, testosterone, androgens, corticosterone
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how many rings is in a typical steroid hormone?
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4 aromatic rings, 3 are 6 carbon and 1 has 5 carbons
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3 types of polypeptide hormones
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1. small peptide (thyrotroponin releasing hormone)
2. simple polypeptides (growth hormone, insulin) 3. large protein - multiunit (gonadotropins - LH and FSH) |
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insulin is synthesized as a prohormone:
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proinsulin
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general info about preprohormones
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peptide hormone are often synthesized as large, inactive polypeptides
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how do you form a prohormone?
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signal sequence is cleaved from the preprohormone prior to being packaged into secretory vesicles
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how do we get an active hormone?
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proteolytic enzymes cut prohormone into the active form. the signaling cell then releases the active cell by exocytosis
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properties of polypeptide hormones
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most are hydrophilic
dissolve in an aqueous medium cannot pass through the plasma membrane elicit rapid changes is cell metabolism |
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summary of polypeptide hormone biosynthesis
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1. mrna transcribes it
2. preprohormone is cleaved from the ER and enter golgi apparatus 3. cleaved into secretory vessicle as a prohormone as it leaves GA 4. prolactice enzymes within the vessible cleave the inactive prohormone into an active hormone |
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example of fatty acid derivative
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prostaglandin
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what is prostaglandin?
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hormone secreted by the placenta they stimulate urine contraction during child birth
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prostaglandin role in inflamation
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increase blood flow to that area. also modulate blood flow to the lungs
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neurosecretory neurons
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modified axons terminate on blood vessels
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neurohormones
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connect the outside environment with the endocrine system
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peripheral endocrine system
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made up of endocrine glands located in the thoracic and abdominal cavity. seperate from the nervous system
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what is the peripheral endocrine system comprised of?
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thyroid gland, parathyroids, adrenal gland, pancreas, gonads
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hormone production, transport and action
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1. produced in endocrine gland
2. transport in blood using binding proteins 3. hormone recognition by receptor, hormone-receptor binding 4. receptor activation (signal transduction) 5. biological action 4. |
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types of regulation for hormone secretion
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1 hormone biosynthesis
2 stimulus secretion coupling negative feedback |
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layout for regulation of hormone secretion
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1 hypothalamo-pituitary-thyroid axis
2 TRH - thyrotropini releasing hormone 3 anterior pituitary 4 TSH - thyrotroponin stimulating hormone 5 thyroid 6 T3 and T4 |
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hormones are a special class of
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receptors
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hormones=
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protein
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Polypeptide, biogenic amine (amino acid) and eicosanoid hormones mechanism
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cell-surface receptors; second messenger systems
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Steroid and thyroid hormones mechanism
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intracellular receptors; bind to DNA and regulate transcription
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first hormone ever discovered
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secretin
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polypeptide hormone solubility
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not lipid soluable, bind to receptors of the surface of target cell
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amino acid derived
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not lipid soluable, bind to receptors of the surface of target cell
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thyroid hormone and steroid
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most are soluable, bind to receptors inside the target cell
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signal amplification
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hormones are produced in small quanities their effects are large and diverse
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action of hormone are diverse...
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one hormone could code for lots of action, one action could be induced from a variety of hormones
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