Fight or Flight What changes occur in your

Fight or Flight?

What changes occur in your body when you get scared?

Endocrine System a group of glands in the body which secrete hormones directly into the blood.

Don’t look here either

Why does FSH (Follicle Stimulating Hormone affect the ovaries but no other organs such as the stomach?

Hormone

Hormones molecules secreted into the blood by the endocrine glands. They evoke specific responses in target cells of the body.

Comparing the Nervous and Endocrine Systems Similarities respond to stimuli • maintain homeostasis • secrete chemical messengers that attach to receptors • same target organs

Comparing the Nervous and Endocrine Systems Differences Nervous response is faster ex. Blink of an eye Endocrine response lasts longer ex. Changes during puberty

The Pancreas

The Pancreas Endocrine Gland Exocrine Gland secretes hormones secretes enzymes into intercellular fluid into a duct (tube) into blood leading to small intestine target organ(s)

Islets of Langerhans

The pancreas produces the hormones insulin and glucagon Why is insulin important?

diabetes http: //www. youtube. com/watch? v=n. BJN 7 DH 83 HA&NR=1 http: //www. youtube. com/watch? v=V 1 Lj. Ri 8 N vv 4

Insulin Regulates blood glucose (sugar) in the normal range Stimulates cells of the body to absorb and use glucose thereby decreasing blood sugar levels Secreted in response to: High blood glucose Secretion inhibited by: Low blood glucose

Glucagon Assists insulin in regulating blood glucose (sugar) in the normal range Actions are opposite of insulin Stimulates many cells of the body to release (or produce) glucose (increasing blood sugar) Secreted in response to: Low blood glucose Secretion inhibited by: High blood glucose

How does a thermostat work?

Sensor detects high blood sugar level Negative Feedback: Pancreas secretes insulin Lowered blood sugar leads to shutting off of insulin production Blood sugar level drops

Sensor detects low blood sugar level Negative Feedback: Pancreas secretes glucagon Higher blood sugar leads to shutting off of glucagon production Blood sugar level rises

INSULIN VS. GLUCAGON

Disease due to insulin deficiency: Diabetes Disease due to excess insulin: Hypoglycemia

1 Pituitary Gland 2 Pancreas Thyroid 4 Adrenal 5 Glands 3 Testes 6 Ovaries

Goiter

Goiter

Thyroid Gland

Goiter • noncancerous enlargement of the thyroid gland • often associated with iodine deficiency; • iodine is needed to make thyroid hormone

Thyroid Hormones

The Pituitary is the “master gland” of the endocrine system

Hormones from the Anterior Pituitary • Thyroid stimulating hormone • Adrenocorticotropic hormone (ACTH) • Follicle stimulating hormone (FSH) • Leutenizing Hormone (LH) • Prolactin • Growth Hormone

(cortisol)

So what causes Goiter?

Regulation of Thyroxin Hypothalamus No TRHTRH Pituitary Gland TSH No TSH Thyroid Gland thyroxin

Negative feedback when the concentration of a product reaches a certain level, the product will inhibit it’s own synthesis

Goiter

Thyroid Hormones

Deregulation of Thyroxin in Goiter Hypothalamus No TRHTRH Pituitary Gland TSH No TSH Thyroid Gland NO iodine in diet thyroxin

Thyroid releasing hormone Thyroid stimulating hormone

cycle A recurring sequence of events; e. g. the secretion of certain hormones at regular intervals. negative feedback loop A biochemical pathway where the products of the reaction inhibit production of the enzyme that controlled their formation.

Sensor detects high blood sugar level Negative Feedback: Pancreas secretes insulin Lowered blood sugar leads to shutting off of insulin production Blood sugar level drops

Sensor detects low blood sugar level Negative Feedback: Pancreas secretes glucagon Higher blood sugar leads to shutting off of glucagon production Blood sugar level rises

Regulation of Thyroxin Hypothalamus No TRHTRH Pituitary Gland TSH No TSH Thyroid Gland thyroxin

Deregulation of Thyroxin in Goiter Hypothalamus No TRHTRH Pituitary Gland TSH No TSH Thyroid Gland NO iodine in diet thyroxin

Use the information in the following paragraph to create a map showing the hierarchy of regulation involved in the secretion of cortisol Ø Since cortisol is so vital to health, the amount of cortisol produced by the adrenals is precisely balanced. Like many other hormones, cortisol is regulated by the brain’s hypothalamus and the pituitary gland, a bean sized organ at the base of the brain. First, the hypothalamus sends a “releasing hormone” CRH (corticotropin releasing hormone) to the pituitary gland. The pituitary responds by secreting ACTH (adrenocorticotropin), a hormone that stimulates the adrenal glands. When the adrenals receive the pituitary’s signal in the form of ACTH, they respond by producing cortisol. Completing the cycle, cortisol then signals the pituitary to lower secretion of ACTH. Similar to

Regulation of Cortisol Hypothalamus CRHCRH No Pituitary Gland No ACTH Adrenal Gland cortisol

Grave’s Disease

Male athletes who abuse anabolic steroids often develop sterility, testicular atrophy, and enlarged breasts. EXPLAIN WHY.

Massive Hint: Anabolic Steroids are synthetic versions of testosterone

Negative feedback when the concentration of a product reaches a certain level, the product will inhibit it’s own synthesis so… when the body detects elevated levels o “testosterone” (anabolic steroids), it stops making it’s own testosterone and. . .

converts testosterone to estrogen (the female hormone)!

How did the mouse on the left get so huge?

Both of these mice have a defect in a gene called obese (ob). This mutation usually results in a marked increase in the amount of fat.

Administration of the protein encoded by the ob gene, called leptin, reduced the body weight of the ob mouse on the right.

After four and a half weeks, the ob mouse on the left, which did not receive leptin, weighed approximately 67 grams while the mouse on the right who received daily injections of leptin, weighed 35 grams.

Normal mice weigh approximately 24 grams, a weight equivalent to that of an orange.

How did the injections of leptin make the animal lose weight?

Daily injections of leptin to ob mice reduced body weight via effects on food intake and energy expenditure (treated animals ate less and also burned more calories)

Research suggests that fat cells normally produce leptin to tell the brain how fat the body is and, therefore, whether an organism should eat more or stop eating.

Obesity Ø Obese people may be lacking receptors for leptin in their brains –orØ May have a mutated (defective) form of leptin that fails to tell the brain that the body has enough fat

Over 80% of adult-onset diabetics are obese. What is the link between obesity and diabetes?

is it Resistin? • discovery reported Jan. 2001 • hormone produced by fat tissue • resistin levels reduced by antidiabetic drug rosiglitazone • resistin levels increased in dietinduced and genetic forms of obesity

Treatment of normal mice with resistin • impairs glucose tolerance • impairs insulin action • impairs uptake of glucose by cells

Mice with diet-induced obesity were treated with anti-resistin antibody results of treatment w/antibody • lowered blood sugar levels • improved action of insulin

Acromegally

Acromegally Too much growth hormone in adulthood

Parathyroid Glands, patches of tissue embedded in the thyroid gland, produce & secrete parathormone.

Ø Parathormone controls the metabolism of calcium which is necessary for nerve function, blood clotting and proper growth of teeth and bones.

1 Pituitary Gland 2 Pancreas Thyroid 4 Adrenal 5 Glands 3 Testes 6 Ovaries

The Pineal Gland

The Pineal Gland • produces melatonin • production of melatonin by the pineal gland is stimulated by darkness and inhibited by light • affects the modulation of sleep patterns • both seasonal and circadian rhythms