Chemical classification of hormones PDF

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Chemical classification of hormones General - Hormones = chemical messengers - are produced by endocrine glands -> mostly released into the blood (distributed through the bloodstream the whole body) - act in very low concentrations - have an effect on target cells/tissues that have receptors for the respective hormone Differentiation of 4 chemical groups e.g. insulin (51) - Peptides = short proteins (less than 100 AS) - Neuro hormones also associated (e.g., thyroid calcitonin, parathyroid hormone, releasing parathyroid gland, releasing hormones of the hypothalamus) - long-chain protein hormones e.g. erythropoietin of the kidneys, growth hormones amino acid derivatives (amino acid derivatives) - important representatives: Adrenaline, noradrenaline (derived from amino acid L-tyrosine -> stress hormones). thyroxine (T4), triiodothyronine (T3) (iodine-containing thyroid hormones -> activation of the basic metabolism, accompany numerous body reactions) Steroid hormones - derived from cholesterol (originates from sterol backbone -> confers steroid hormones properties) e.g. aldosterone, estrogen/testosterone, cortisol (role in long-term stress responses) Arachidonic acid derivatives - smaller group - derived from arachidonic acid (polyunsaturated) e.g. prostaglandins (tissue hormone, mediates various physiological processes in the body) Important hormone glands General - Some (not all) endocrine glands are controlled by regulatory circuits. - Top instance of the control circuits = hypothalamus of the diencephalon -> controls activity of the anterior pituitary lobe by releasing hormones, inhibiting hormones

e.g. thyrotropin releasing hormone (THR) Hypothalamus releases hormone -> anterior lobe of hypothalamus secretes thyroid-stimulatinghormone (TSH) -> increases activity of thyroid gland -> triiodothyronine (T3) are formed, released -> influences energy metabolism of our cells Endocrine glands Thyroid gland - Iodine-containing amino acid derivatives thyroxine (T4), triiodothyronine (T3) -> cause general activation of the basic metabolism - Formation: peptide hormone calcitonin -> leads to a decrease in blood calcium level (via inhibition of reabsorption of calcium in kidney, decrease of intestinal absorption of calcium, inhibition of osteoclasts Osteoclasts that break down bone). Location: Below larynx, anterior cervical region....