BIOL 320 1st Edition Lecture 2 Outline of Last Lecture I Endocrinology II Endocrine Glands and Organs III cAMP 2nd Messenger System IV Plasma Membrane Receptors 2nd Messenger System V Direct Gene Activation VI Specificity Outline of Current Lecture VII Blood Hormone Levels VIII Hypothalamus and Pituitary IX Hormones Stored in Neurohypophysis X Hypothalamic Hormones XI Pituitary Hormones Current Lecture I Blood Hormone Levels slide 23 a Hormone levels in the blood are affected by i Release rate time for hormone to leave carrier and enter blood ii Half Life time for a hormone s blood level to decrease by half 1 Water soluble hormones have fastest shortest half life iii Speed of inactivation speed at which a hormone is removed from the body 1 Water soluble hormones are fastest can act within minutes 2 Lipids are much slower testosterone can take 12 days to act iv Hormone inactivation enzyme at site of target cell can shut off a hormone 1 Most are inactivated at kidneys pregnancy test diabetes or liver recycling a Kidneys filter entire blood volume multiple times a day Blood cells and big proteins bypass the filter and stay in blood everything else enters into filtering pool kidneys put back what s needed electrolytes glucose and discrete what is not preg hormones excess sugar Can tell if person has diabetes if too much sugar in urine b Liver takes excess hormones products breaks them down and recycles them for something better b Hormone interactions slide 24 i Target cells adipose liver and muscle cells can have different types of receptors which lets them bind multiple hormones simultaneously ii When multiple hormones bind simultaneously their interactions have different effects 1 Independent reactions These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 2 Synergistic hormones work together to produce greater effect 3 Permissive 1st hormone allows action of 2nd hormone 4 Antagonistic one hormone causes opposite effect of other a The effect is antagonistic not the release or the synthesis b Can be competitive or non competitive same or different binding site c Control of hormone release slide 25 i If a hormone is released in response to 1 Blood levels humoral a Low blood Ca2 levels PTH released to raise blood Ca2 level 2 Stimulation of Sympathetic Nervous System neural a Threat of danger stimulates SNS to release adrenaline aka epinephrine 3 Hormone A causes the release of Hormone B hormonal 4 Troponin hormone that acts on another endocrine tissue waterfall affect II Hypothalamus and Pituitary slide 26 a Release of neurohypophysis posterior pituitary hormones i Pareventricular and supraoptic nuclei in the hypothalamus produce hormones ii They travel down hypothalamic hypophyseal tract to neurohypophysis posterior lobe storage area for posterior pituitary hormones stored until axon terminal stimulated iii Release of PP hormones is neural because they require a neuron axon to fire iv Hypothalamic hypophyseal tract called tract because it is nerve tissue not portal b Release of hypothalamic anterior pituitary hormones i Neurons from Ventral Hypothalamus secrete releasing inhibiting hormones ii Those hormones travel to hypophyseal portal system carried down to inferior lobe of the pituitary adenohypothesis stimulate anterior pituitary to release its hormones III Hormones Stored in Neurohypophysis slide 29 a Paraventricular Nucleus i Stores oxytocin OT pop 1 Causes uterine contractions when giving birth and ejection of milk from nipple a Contractions start slow but get faster stronger as fetus releases oxytocin b Pop shot of oxytocin given to speed labor along c When breastfeeding baby sucking on nipple causes hypothalamic neurons to fire and release oxytocin d When twins are born let 1st baby nurse so more oxytocin is released 2nd baby comes out faster b Supraoptic Nucleus i Stores antidiuretic hormone ADH also known as vasopressin AVP 1 Purpose of ADH prevent dehydration 2 Targets kidney tubules via PIP2 mechanisms 3 Constricts blood vessels supplying kidneys and capillaries to make surface area smaller so that it takes longer for urine to be made 4 ADH is inhibited by drinking alcohol or lots of water 5 Diabetes Insipidus slide 30 a Tasteless overflow can t taste sugar in one s urine b Symptoms excessive urination and thirst c Cause head trauma damage to H H tract infundibulum or axon terminal posterior lobe results in lack of ADH and excessive urination d Hangovers are caused because alcohol inhibits ADH IV Hypothalamic Hormones a Ventral hypothalamus releases inhibiting releasing hormones into hypophyseal portal system b Target Anterior Pituitary or adenohypophysis c Regulation hormonal i Ex Gonadotropin Releasing Hormone GnRH causes Anterior Pituitary to release FSH LH which act on the gonads V Anterior Pituitary Hormones a Anterior adeno glandular undergrowth b Regulation hormonal i Growth hormone targets all body cells glucose sparing fat burning protein synthesis 1 Too little GH pituitary dwarfism 2 Too much GH before puberty gigantism ex 8 year old boy with facial hair 3 Too much GH after puberty acromegaly all bones except long bones keep growing big ears hands feet ii Prolactin targets mammary glands to release milk 1 PRL is tied to estrogen levels which is why breasts get tender during certain parts of menstrual cycle