* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Endocrine PP - Laura Banks
Survey
Document related concepts
History of catecholamine research wikipedia , lookup
Hormonal contraception wikipedia , lookup
Neuroendocrine tumor wikipedia , lookup
Xenoestrogen wikipedia , lookup
Hormone replacement therapy (menopause) wikipedia , lookup
Triclocarban wikipedia , lookup
Hyperthyroidism wikipedia , lookup
Menstrual cycle wikipedia , lookup
Mammary gland wikipedia , lookup
Breast development wikipedia , lookup
Endocrine disruptor wikipedia , lookup
Hormone replacement therapy (male-to-female) wikipedia , lookup
Bioidentical hormone replacement therapy wikipedia , lookup
Hyperandrogenism wikipedia , lookup
Transcript
Endocrine system Unit 9 • What are the 8 glands of the endocrine system? • Think back a few chapters, what is translation and transcription? Activator: 2.9.2016 • Regulates reproduction, growth and development, defenses, balance of nutrients in the blood, metabolism, and energy use • 0.5 pounds of endocrine tissue Role of endocrine system • Chemical messengers • Hormone means “to arouse” by altering cellular activity What are hormones? • Start by circulating in the blood • Hormones bind to certain cells or organs Mechanisms of hormones action • Target Cell/Organ- The cell or organ a hormone attaches to • In order for the target to respond to the hormone, a protein receptor must be present on the plasma membrane or in the cell Hormone attachment • Activation means the hormone causes a change in the target cell 2 types of hormone activation: 1. Steroids (cholesterol and sex hormones) are lipid soluble 2. Amino-acid based (proteins, peptides, and amines) are non-lipid soluble Hormone activation • Lipid-soluble, so they can move through the plasma membrane 1. Steroidal hormone activation • Hormone diffuses through plasma membrane Step 1 • Hormone binds to specific receptor protein • Becomes a hormone-receptor complex (HRC) • HRC enters the nucleus • Hormone (H) + Receptor Complex (RC) = HRC Step 2 • The HRC binds to DNA Step 3 • Certain genes in the DNA are altered, new mRNA is transcribed • Think back to translation and transcription Step 4 • mRNA is translated, new protein is created • This protein will cause the desired effect to the cell Step 5 • Non lipid soluble, so the hormones must attach to the plasma membrane directly Amino-acid hormone activation: • Hormone binds to membrane receptor attached to membrane Step 1 • Binding sets off a series of reactions that activates enzymes w/in the cell Step 2 • The enzyme then catalyzes (speeds up) a reaction that produces a messenger molecule Step 3 • Messenger molecule creates the change desired within the cell Step 4 1. 2. 3. 4. 5. Diffuse thru PM H + R = HRC, enters nucleus Bind to DNA Alter genes of DNA & makes new mRNA Make a new protein STEROIDAL 1. 2. 3. 4. Attach to receptor in PM Enzymes are released Speed up the production of a messenger molecule Messenger molecule creates the desired effect on cell NON- STERIODAL How do glands know when to release hormones? • Use negative feedback mechanisms to maintain hormone levels in the blood How do glands know when to release hormones? • Too much of a hormone, the glands stop producing • Too little, and the glands produce more What are negative feedback mechanisms? • • • • 3 main categories of stimuli: Hormonal Humoral Neural What kinds of stimuli activate endocrine glands? • Endocrine organs are prodded by other hormones to create their own hormones • rhythmic/always working Hormonal stimuli • Step 1: Hypothalamus secretes hormones that activate pituitary gland to release hormones. Example of hormonal stimuli • Step 2: Pituitary gland releases hormones that activates adrenal glands AS WELL AS cut off the hormones of the hypothalamus • Step 3: New hormones are released by the adrenal glands into the body AS WELL AS cutting off the hormone production in the pituitary glands • This allows the hypothalamus to start producing hormones again • Initiated by low levels of ions or nutrients monitored by endocrine organs • Works in short bursts/ Used only when needed Humoral stimuli • Hormones respond to neural activity • Ex) responding to stress • Sympathetic nervous system produces norepinephrine which when stressed, which causes increased heart rate, blood pressure, etc. Neural stimuli Endocrine organs • “Master gland” • Hangs by a stalk under the hypothalamus 2 parts: 1. Anterior 2. Posterior Pituitary Gland • 6 total hormones produced here. • 2 work on non-endocrine targets • 4 work on other endocrine glands, these are called trophic hormones Anterior pituitary 1. Growth hormone (GH)- division of cells, growth of bones and muscle 2. Prolactin (PRL) - Milk production of the breasts 2 Non-endocrine targets The 4 tropic hormones stimulate: • Follicle-stimulating (FSH)- Helps regulates menstrual cycle and egg production in women, sperm production in men • Luteinizing (LH)• Thyroid-stimulating (TSH)- stimulates the thyroid to release its hormones • Adrenocorticotrophic (ACTH)- stimulates the adrenal glands to release their hormones 4 endocrine gland targets • Works directly with the hypothalamus to secrete the hormones produced by the hypothalamus Posterior pituitary • • 1. Oxytocin (OT) :common in women, stimulates contractions during labor, sex, and also causes milk ejection 2. Antidiuretic hormone (ADH) Kidneys reduce water excretion (inhibits urine production) 2 hormones from posterior pituitary Large gland made up of two bulbs on each side of the trachea 1. Thyroid hormone 2. Calcitonin Thyroid gland • Major metabolic hormone- Controls the rate at which glucose is converted into energy and heat • Also controls normal tissue growth and development Thyroid Hormone • Decreases calcium levels in the blood by depositing calcium in the bones • Only secreted when calcium levels are high Calcitonin • Tiny masses of tissue found on the posterior surface of the thyroid gland Parathyroid glands (4) • Releases osteoclasts • Opposite role of calcitonin Effect of PTH • Curve over the top of the kidneys 1. Adrenal cortex 2. Adrenal medulla Adrenal glands • • • • 3 types: Mineralocorticoids Glucocorticoids Sex hormones Hormones of the adrenal cortex • Regulate mineral (or salt) & water balance in the blood Mineralocorticoids • Increase blood glucose levels • Inhibit some pain-causing molecules (anti-inflammatory) Glucocorticoids • Both produced in small amounts throughout life regardless of gender i. ii. Androgens (male sex hormone) Estrogens (female sex hormone) Sex hormones 1. Epinephrine 2. Norepinephrine • Produced by stimulating SNS Hormones of the adrenal medulla • AKA adrenaline and noradrenaline • Increase blood glucose and rate of metabolism • Spark the “fight or flight” response Epinephrine and norepinephrine • The pancreas houses tiny little endocrine glands called the pancreatic islets 1. Insulin 2. Glucagon Pancreas • Both regulate the amount of sugar in the blood, but in opposite ways Roles of insulin and glucagon • Small gland located in the brain Pineal gland • Effects how tired we are • Levels rise and fall throughout the day: • High levels = drowsy • Levels are lowest around noon Melatonin • Located in the upper thorax, posterior to the sternum • Produces thymosin Thymus gland • Highly useful in immunity and defenses of the body • Stimulates the production of disease fighting T-cells • Only active until you hit puberty – slowly shrinks and is replaced by fat Thymosin • Grouped by male and female organs • Female gland: ovaries • Male gland: testes Gonads • Produce sex cells (ova, or eggs) • Also produce 2 hormones: 1. Estrogen 2. Progesterone Ovaries • Estrogen stimulates development of the female reproductive organs • Progesterone acts with estrogen to bring about and regulate the menstrual cycle Hormones of the ovaries • Produce sex cells (sperm) • Also produce androgens (testosterone is the most common) Testes • Androgens stimulate: 1. Development of the male reproductive organs 2. Secondary sex characteristics 3. Increases sex drive Hormones of the testes • The placenta is a temporary organ formed during pregnancy, found in the uterus developmental gland: the placenta • Helps to increase levels of estrogen and progesterone in the mother • This improves the lining of the uterus, further development of breasts, and lactation What does the placenta do?