BIOM 320 1st Edition Lecture 3 Outline of Last Lecture I Blood Hormone Levels II Hypothalamus and Pituitary III Hormones Stored in Neurohypophysis IV Hypothalamic Hormones V Pituitary Hormones Outline of Current Lecture VI Thyroid Gland VII Thyroid Hormones VIII Parathyroid Gland IX Adrenal Glands X Adrenal Corticosteroids Current Lecture I Thyroid Gland slide 36 a Largest wholly endocrine gland in body b Gland joined in middle by narrowed region called isthmus c Very vascular tracheotomy is very bloody because thyroid has large blood supply d Follicles are filled with colloid If cells touch a follicle they are follicular cells II Thyroid Hormones Slide 37 a Follicular cells make thyroid hormones T3 T4 i T4 inactive form has 2 tyrosines and 4 iodines most common ii T3 active form has two tyrosines and 3 iodines iii Synthetic hormones T3 T4 1 Used for hypothyroidism or myxedema 2 Edemas swelling body forms antibody identical to TSH so body things it has too much TSH ramps up thyroid must remove thyroid gland and use synthetic thyroid hormones T3 T4 3 Hyperthyroidism or graves disease yellow skin veiny bulging eyeballs Exothalmus protruding eyeballs b Parafollicular cells c cells produce calcitonin i Calcitonin lowers blood calcium levels by inhibiting osteoclasts stimulating osteoblasts ii Regulation humoral iii Target osteoclasts blasts in the human skeleton iv Higher in kids than adults v Not required for calcium homeostasis c Thyroid Hormone Effects slide 39 i Promotes normal BMR HR BP muscle function bone growth nervous system development and function gastrointestinal motility female reproduction function skin condition III Parathyroid Gland PTG slide 41 a Located on the back of the thyroid as clumps of tissue b Unknowingly take parathyroid gland when removing thyroid gland c Produces parathyroid hormone PTH slide 42 i PTH raises blood calcium level when it gets too low hypocalcaemia ii PTH has 3 targets 1 Activates osteoclasts bone breakers causing calcium to be released into blood 2 Acts on small intestine in the GI tract increases absorption of calcium in food you eat all the calcium you eat is absorbed in the blood stream 3 Acts on kidneys so that they reabsorb calcium within the kidneys iii Underactive PTG hypoparathyroidism1 Less acetylcholine released at the junction 2 Gives us excitable neurons loss of sensation twitching convulsions respiratory paralysis 3 Lots of patients dead from accidentally taking out PTG tetini rapid twitching stimulation iv Overactive PTG hyperparathyroidism 1 Calcium moved out of bone and into blood osteoporosis 2 Too much calcium in blood depressing affect on nervous system muscle weakness and kidney stones from extra calcium IV Adrenal Glands slide 43 a We have 2 adrenal glands one on the end of each kidney i Capsule tough protective outer layer made up of fibrous connective tissue ii Adrenal cortex middle layer made up of the 3 zona layers 1 Zona glomerulosa produces corticosteroids mineralocorticoids 2 Zona fasciculate and reticularis produces glucocorticoid and androgens iii Adrenal medulla inner layer produces catecholamine s epinephrine norepinephrine V Adrenal Corticosteroids slide 44 a Mineralocorticoids Aldosterone i Made in zona glomerulosa ii Targets kidney tubules iii Aldosterone balances minerals retains Na excretes K iv Effects BP and concentration of sweat composition v Stimulated by decreased Na or increased K in blood decreased blood volume BP increased blood volume BP and stress b Glucocorticoids Cortisol i Balances body energy i e Brain requires glucose so rest of body needs other energy source ii Effects 1 Gluconeogenesis creating new glucose from non carb source 2 Mobilize fat from adipose tissue for energy 3 Break down potential proteins to make different proteins for energy 4 Depresses immune system so body isn t wasting resources 5 Resists stress 6 Anti inflammatory c Gonadocorticoids testosterone i Male hormone also in women after menopause ii Question asked by professor In which gender would a tumor in the zona reticularis of the adrenal cortex be most noticeable Answer female because testosterone has a masculine effect iii Imbalances 1 Addison s disease insufficient cortisol aldosterone a Hypotension very tan skin low BP weight loss b Treatment corticosteroid c Iatrogenic Addison s disease physician induced 2 Cushing s disease elevated cortisol a High blood sugar muscle bone wasting weight loss puffy face lump on neck depressed immune system b Treatment remove tumor and give appropriate levels of cortisol