Teenagers, Hormones and Shaving Cream…Oh My! The Endocrine System

Hormones Hormones are chemical messengers in the body. Hormones are produced in endocrine glands. The endocrine glands are called ductless because they diffuse hormones directly into the bloodstream as they are produced. Although hormones go to ALL parts of the body, they only work in organs/locations that have receptors for that specific hormone. An imbalance of hormones can cause severe mood swings!

Plant Hormones Plants do not have endocrine glands, but all cells can produce hormones. Auxins are plant hormones that increase the rate of cell division. Are auxins helped or inhibited by direct sunlight? When a plant bends toward the light, it is called a phototropism.

More Plant Hormones… Gibberellins are plant hormones that increase stem length. Acid rain can increase the effectiveness of gibberellins making plants unusually tall and unstable.

The Endocrine Glands HW Pass Question: What is a Hypophysis Operation?

The information on the following slides will all be compiled on one chart that looks like this: Gland Hormone Function HyperHypo

Hypothalamus A BIG daddy of endocrine glands!! Secretes hormones that influence the pituitary gland

Pituitary Hormones Thyroid Stimulating Hormone (TSH): stimulates the production of the thyroid hormone thyroxin. Follicle Stimulating Hormone (FSH): stimulates either the ovaries to produce eggs or the testes to produce sperm. Growth Hormone (GH): stimulates the growth of bones and cartilage. Prolactin: stimulates the secretion of milk in the mammary glands

Hyper- Hypo- FSH: too many follicles….twins, triplets, etc!! FSH: too few follicles, hard to conceive baby. Growth: if in childhood, giantism if in adulthood, agromegaly Growth: dwarfism

Thyroid Hormone Thyroxin: Contains Iodine. Regulates the rate of metabolism for physical and mental development. Hyper- Causes goiter, bulging eyes, nervousness, irritability, weight loss. Hypo- In infancy, cretinism (disproportionate dwarf) and mental retardation. In adult, myxedema, weight gain and slow mental functioning

Parathyroid Hormones Parathormone: Regulates calcium and phosphate metabolism. Hyper-Hypo- Removal of Calcium from teeth and bones, leaving them brittle. Tetany-the skeletal muscle are hypertensive and contract violently.

Adrenal Gland Hormones Adrenaline: Secreted in response to sudden stress. Constricts blood vessels and increases rate of metabolism Cortisol: Regulates glucose level by converting fat and protein into glucose. Hyper- Cushing’s Disease: excess fat deposits, puffy face and facial hair Hypo- Addison’s Disease: Sluggish, weight loss, increased skin pigmentation, stressed

Pancreas Hormones ( Islets of Langerhans ) Insulin: Increases the rate of glucose absorption into cells, thus decreasing the blood sugar level. Hyper- Diabetic shock, convulsions, unconscious, low blood sugar level Hypo- Diabetes, dehydration, weight loss, high blood sugar level Glucagon: Converts glycogen (stored in the liver) to glucose in order to raise blood sugar level. Hyper- Hypo- Diabetes, high blood sugar level Low blood sugar level

Testes Testosterone: Influences secondary sex characteristics in men, development of the male reproductive system. Deeper voice Facial Hair Body Hair

Ovaries Estrogen: Influences secondary sex characteristics and regulates the menstrual cycle. Progesterone: Helps regulate the menstrual cycle and maintains the uterus during pregnancy.

FEED BACK LOOPS

Positive & Negative Feed Back Loops Positive Feed Back Loop: An increase in stimulus #1, causes an increase in stimulus #2, which causes a further increase of #1, etc Negative Feed Back Loop: An increase in stimulus #1, causes an increase in stimulus #2..that increase in #2, causes a decrease in #1, which then allows a decrease in #2. Example: Low Thyroxin causes higher TSH, higher TSH causes higher Thyroxin, higher Thyroxin causes lower TSH, lower TSH causes lower thyroxin.

Take 2: Feedback Loops Describe which of these is a negative feed back loop.

The Menstrual Cycle The Menstrual Cycle …hold on to your socks for some wild fun! The menstrual cycle is an example of a negative feed back loop. 1. FSH causes a follicle to mature. 2. Follicle produces Estrogen. Estrogen causes uterine lining to thicken. 3. Increase in Estrogen and a decrease in FSH causes an increase in Lutenizing Hormone, which causes ovulation (release of the egg). 4. The increase of LH causes the Corpus Luteum (the empty follicle) to produce progesterone which maintains the uterine lining. 5. If no pregnancy, FSH increases again and decreases progesterone. This results in menstruation.

Diabetes Type I Diabetes: Insulin Dependent Your body does not make enough (or any) insulin Type II Diabetes: Non-Insulin Dependent Your body does not know what to do with the insulin it makes.