June 28 2013 Lecture 2 Ch 41 Sections 41 3 41 4 Pre read Ch 48 Sections 48 1 48 3 1 Describe the process of negative feedback in the regulation of different hormone systems 2 Explain the normal and regulatory processes of hormones from the thyroid pancreas adrenal glands pineal gland and gonads 3 Explain how hormones are measured using an immunoassay First exam Next Friday Negative feedback loops regulate hormone secretion Release hormones Release inhibiting hormones Inhibition by target hormones Long loop negative feedback Short loop negative feedback The thyroid gland secretes thryoxine and calcitonin Hypothalamus Anterior pituitary Thyroid releasing hormone TRH Thyroid stimulating hormone TSH Thyroid Thyroxine Thyroxine T3 and T4 Lipid soluble Nuclear receptor in most body cells anterior pituitary and hypothalamus Activates transcription of many enzymes transport and structural proteins which increase the metabolic rate Regulated by the hypothalamus and the pituitary Thyroxine regulates cell metabolism Iodine follicle lumen Follicles big open spaces are surrounded by epithelial cells small purple dots Epithelial cells take in iodine and causes the cell to synthesize intermediate product Then adds iodines to intermediate product which is secreted into the lumen open space of follicle It is then brought back in by endocytosis and meets up with a lysosome which breaks product apart into T3 and T4 Non polar amine hormones Modified tyrosine Acts as a transcription factor Makes enzymes for metabolism Goiter Hyperthyroidism More TRH leads to more TSH stimulates cells which make thyroxine Autoimmune disease Attacks cells with the receptors High metabolic rate build up of thyroxine that cannot leave thyroid hormone Hypothyroidism T3 and T4 cannot be made and the process shuts down enlarging the thyroid T3 and T4 regulate metamorphosis in amphibians Acts as a transcription factor Make enzymes for metamorphosis Positive feedback T3 T4 stimulate hypothalamus growth Hormone concentration High amount of prolactin lowers high amount of TRH lowers high amount of TSH raises high amount of T3 and T4 Blood calcium levels are regulated by three hormones Calcitonin Released by thyroid Released due to high Ca2 levels in blood When released bones take up calcium and blood calcium levels drop Calcitonin release is controlled by Ca2 levels in the blood Calcitonin decreases the activity of osteoclasts breaking down of bone Parathyroid hormone PTH Released by parathyroid Released due to low Ca2 levels in blood When released increases bone turnover to release calcium and blood calcium levels rise Increases the calcium uptake by kidney Vitamin D hormone can be made in the body Calcitriol made from Vitamin D Increases calcium uptake by digestions Kidneys Can remove or keep extra calcium in the body Blood glucose is regulated by insulin and glucagon from the pancreas Islets of Langerhans in pancreas Beta cells Alpha cells Produce glucagon Delta cells Produce insulin Insulin binds to cells which take up glucose and cause cell membrane transport proteins for glucose to come to the cell surface Produce somatostasin Turns of both insulin and glucagon Increase in blood glucose Stimulates insulin Helps with uptake of glucose from blood into the cells Used for energy production fat synthesis or glycogen synthesis Decrease in blood glucose Stimulates glucagon Tells liver to break down stored glycogen and release glucose into the blood Type I diabetes Individuals cannot produce insulin Problem with beta cells Glucose that is put into the blood exits the body as waste Individuals are born with this or have juvenile onset Type II diabetes Adult onset The cells don t respond to insulin when it is released into the body Glucose leaves the body as waste Brought on my diet or weight gain Why is there no response to insulin in Type II diabetes The adrenal gland is composed of two different glands Releases epinephrine and norepinephrine Water soluble bind to similar sets of receptors on the surface of cells Increase heart rate blood pressure blood to muscle decreases digestion Adrenal medulla Middle Adrenal cortex Outside Adrenergenic receptors Alpha favor epinephrine Beta respond to both Beta blockers Body doesn t respond to epinephrine and norepinephrine Sympathetic nervous system Medulla is stimulated by the nervous system The adrenal cortex is controlled by hormones Based on external conditions Steroid hormones Mineralcorticoid Glucocorticoid Sex hormones Corticosteroids Cortisol Alters use of glucose by cells block immune system Released as a reaction to stress Sex steroid are produced primarily by the gonads Androgens Testosterone Estrogen progesterone Aromatase Gonadotropins Changes testosterone to estrogen in females Females increase growth of follicle Follicle stimulating hormones FSH Males stimulates production of testosterone Luteinizing hormone LH Females release of follicle Males stimulates production of Melatonin is involved in biological rhythms Pineal gland Melatonin is produced in the dark Causes individuals to be sleepy Light inhibits the production of melatonin Photoperiodicity Tryptophan Amino acid that melatonin is made from Hormones are measured using immunoassays Antibody Created for the hormone in question Puberty Hypothalamus Gonadotropin RH Anterior pituitary Gonadotropins FSH LH Gonads Androgens estrogens Secondary sex characteristics Labeling Add labeled hormone and wash away unbound Take unlabeled hormone and they will replace labeled hormone Gives you standard curve Must know half life how long it takes for hormone to disappear in body Hormone half life Standard curve Competition for binding site Measure how much of hormone is present Competition Hormonal response Threshold dose Minimum response Decrease in sensitivity Maximum response Decrease in responsiveness When amount of hormone around target cells is increased What happens in Type II diabetes Block receptor Hormone is being produced but cannot bind There are more sensors in cell can lead to anxiety