Physiology 206 1STedition Lecture 30 Outline of Last Lecture I Neural Communication II Hormones Outline of Current Lecture I Endocrine disorders II Hypothalamus III Pituitary IV Hormones Current Lecture Endocrine Disorders include situation in which blood concentrations are pathologically high secrete too much Plasma levels are low secrete too little Target cell responses abnormal some effects are if concentrations were low When plasma level is too low give them hormone When too high depends on reason why it is too high Tumor is not subject to same regulations as endocrine gland When gland secreting too much have to find out why it is not regulating Hypothalamus secretes tropic hormones have cells that secrete through the posterior Infundibulum Pituitary Hormone Anterior Adenohypophysis Posterior Neurohypophysis An endocrine gland that has function mechanism in brain Many animals have MSH Melonocyte Stimulating Hormone in intermediate lobe has no function in humans 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 Pathological case in which skin color darkens there is a connection or identity to the posterior and hypothalamus relationship close hypothalamus is main link between neural and endocrine Blood Flow arteries capillaries hypothalamus Blood in Pituitary have already been in hypothalamus Hypothalamus in good position to secrete things that influences the pituitary where it can exert its action Posterior Pituitary Secretion made in hypothalamus Produces 2 hormones both neural hormones polypeptides made on ribosomes 1 ADH Vasopressin has two names because have 2 known effects ADH increasing water permeability in collecting ducts Vaso constricts the blood vessels increasing resistance the BP up increasing arteriole pressure 2 Oxytocin stimulated by reflexes or mechanical stimulation major effect is it stimulates contractions during childbirth and promotes release of milk in breasts they get synthesized in hypothalamus migrate down the axons eventually reaching axon terminals action potentials release transmitters but don t terminate on target cell but instead into circulation Anterior Pituitary once called master gland but now obsolete because hypothalamus controls the pituitary makes the thing it secretes in gland makes 6 hormones 1 somatotropin growth hormone GH promotes growth 2 thyrotropin thyroid stimulating hormone TSH stimulates thyroid 3 Adrenocorticotropin adrenocortical stimulating hormone ACTH stimulates adrenal cortex 4 Follicle Stimulating FSH stimulates ovary 5 Luteinizing Hormone LH female ovary or ICSH male testes both have effects on other endocrine glands 6 Prolactin PRL stimulates milk Mechanism of Control 1 Feedback from target organ 2 Secretion of all pituitary hormones under control of at least one hormone from hypothalamus causing their rate of secretion controlled all hormones of hypothalamus are peptides Hypothalamus Hormones difference in these and posterior are where axons are hypo is a endocrine organ in brain very busy 1 GHRH stimulates GHIH inhibits growth hormone in pituitary 2 TRH stimulates thyroid stimulation 3 CRH controls secretion of ACTH 4 Since both FSH and LH stimulates gonads GNRH in hyp controls both FSH and LH 5 PRH stimulates PIH inhibits protection at least nine hormones synthesized by hypothalamus Hypothalamus gets excitatory and inhibitory stimulus from lots of other parts of brain can have great endocrine change secretion from physiological stress Growth Hormone makes you grow this is the one of the anterior pituitary hormones that is secreted the most even in adults stimulates protein synthesis inhibits protein breakdown tends to increase the net amount of protein which leads to secondary effect which is it stimulated cell division has particular influence on long bones in adults has metabolic process which decreases glucose uptake by muscle therefore increases plasma glucose as a result muscles metabolize fat fat stores decrease fat mobilizing effect many tissues will show incease cell size under increase of growth hormone tip of long bone covered with cartilage the growing region is here In adolescence the cartilage ossifies bone growth ends Hypothalamic hormones secretes growth hormone inhibitor hormone GHIH depresses amount of growth hormone released GHIR stimulates GH release Growth Hormone Defiency can come from a depression in secretion in pituitary gland if your hypothalamus isn t producing adequate amount of GHRH In adults not real dramatic results in lack of muscle strength and bone density be reduced In children it is known as dwarfism and will not get to average stature usually have under developed muscluatur and have rather large fat deposits Excess Growth Hormone very different in kids and adults leading cause is pituitary tumor Children great heigh but normal body proportions gigantism can grow to heights of 7 or 8 feet When the growing ends they can t get any taller but there is still continued thickening to other bones Hands become abnormally large jaw chin eyebrow got very prominent Acromegaly Andre the Giant These people die young Adult effects can happen to people that didn t have it as kids Thyroid consists on two lobes on each side of trachea and one thin bridge arrangement of secretory cells called thyroid follice cells that make up boundary called follicular cell and sac inside colloid Colloid given name because historical throughout that their were 2 types of chemicals ones that could be crystallized and these can t colloid means glue like uncrystalizable