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29 Cards in this Set
- Front
- Back
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What are Glycoproteins?
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A type of Peptide Hormone, 200 amino acids and have a carbohydrate side chain:
:TSH FSH LH |
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What are examples of Short chain polypeptids
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ADH and OXT
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What are the examples of peptide hormones that are small proteins.
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GH and PRL
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Which hormones have strong paracrine factors?
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Eicosanoids
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What are the steroid hormones?
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Androgens in testes
Estrogens and progestins in ovaries Coritocsteroids Calcitriol |
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What are Free Hormones?
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Remain functional for less than 1 hour,
1. Diffuse out of bloodstream and bind to receptors on target cells 2. Are broken down and absorbed by cells of liver or kidneys 3. Are broken down by enzymes in plasma or interstitial fluids. |
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What are 2 steroids that become 99% attached to special transport proteins?
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Thyroid and Steroid hormones
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Are Catecholamines and Peptide Hormones Lipid soluble?
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No. They are therefore unable to penetrate plasma membrane and bind to receptro proteins
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Are Eicosanoids lipid soluble?
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YEs, therefore they diffuse across plasma membrane to reach receptor proteins.
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What are the 3 important 2nd messengers?
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Cyclic AMP
Cyclic GMP Calcium Ions |
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What is amplification?
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The binding of a small number of hormone molecules to membrane receptors. Leads to thousands of second messengers in cell. Magnifies effect of hormone on target cell.
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What is the difference between down-regulation and up-regulation?
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Presence of a hormone triggers decrease in number of hormone receptors is Down regulation. When levels of particular hormone are high, cells become less sensitive to it.
Up-regulation is when absence of a hormone triggers increase in number of hormone receptors. When levels of particular hormone are low, cells become more sensitive to it. |
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What is a G protein?
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Enzyme complex coupled to membrane receptor, involved in link between first messenger and second messenger
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What is Adenylate cyclase?
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Activated when hormone binds to receptor at membrane surface and changes concentration of second messenger cyclic-AMP (cAMP) within cell. Increase cAMP level accelerates metabolic activity within cell.
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Activated G proteins trigger:
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Opening of calcium ion channels in membrane
Release of calcium ions from intracellular stores G protein activates enzyme phospholipase C (PLC) Enzyme triggers receptor cascade Production of DAG, IP3, Protein kinase C Calcium ions may activate calmodulin which causes further cellular changes |
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Hormones with intracellular receptors, such as steroids and thyroid hormons interact with DNA how?
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Alter rate of DNA transcription in nucleus and change patterns of protein synthesis.
Directly affect metabolic activity and structure of target cell |
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What are the things that can trigger endocrine reflex?
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Humoral stimuli, Hormonal stimuli, Neural stimuli
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What is the difference between simple and complex endocrine reflexes?
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Simple=1 hormone
Complex=2 or more hormones. |
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What hormone provides the highest level of endocrine control?
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Hypothalamus
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What are the 4 types of hormone interaction?
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Antagonistic, Synergistic, Permissive, Intergrative.
Integrative means the effects occur when the hormone action differs with differing target organs. |
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What are the Neuroendocrine reflexes?
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Neural and endocrine components are included in pathways.
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What are complex commands issued by?
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Changing of amount of hormone secreted,
Pattern of hormone release, Hypothalamic and pituitary hormones are released in sudden bursts. Frequency changes response of target cells. |
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What hangs inferior to hypothalamus and is connected by infundibulum?
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Pituitary gland
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What class of hormones are released by the pituitary?
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Peptides. They use cAMP as second messengers.
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What is the Median Eminence?
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Swelling near attachment of infundibulum where hypothalamic neurons release regulatory factors into interstial fluids through FENESTRATED CAPILLARIES
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What do the hypothalamic neurons release regulatory factors through?
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Fenestrated capillaries
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Why is a portal system necessary in the pituitary?
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Ensures that regulatory factors reach target cells before entering general circulation.
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What are the two classes of hypothalamic regulatory hormones?
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1. Releasing hormones
2. Inhibiting hormones |
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What are 2 disorders abnormal GH secretion
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Pituitary Dwarfism
Hyposecretion in children Pituitary Gigantism in children Acromegaly Hypersecretion of GH after the epiphyseal plates |
