HORMONES B6

Hormones – chemical messengers

• Produced in the endocrine glands and secreted directly into the blood. Only effect cells that have “target cells”.

Examples-

• Adrenaline (epinephrine) – produced in the adrenal cortex. Stimulant that is released in times of excitement. Increases heart rate and release of glucose into bloodstream.

• Thyroxine – produced in thyroid glands in the neck. Contains iodine. Low levels (hypothyroidism) cause lethargy, sensitivity to cold, and dry skin. High levels (hyperthyroidism) causes anxiety, weight loss, intolerance to heat, and protruding eyes. Needed for growth and development.

• Insulin – produced in the pancreas. Regulates blood sugar levels. Hyperglycemia is caused by too little insulin (thirst, weight loss, circulatory problems). Hypogycemia causes dizziness and fainting. Decreases blood glucose level by increasing the uptake by cells. Also increases glucose to glycogen conversion in the liver.

• Testosterone – produced in the testes – important in development male secondary sexual characteristics.

• ADH (anti-diuretic) – produced in the pituitary gland – increases uptake of water and raises concentration of urine

• Aldosterone – produced in the adrenal cortex – increases uptake of Na+ by the kidneys, raises blood pressure

• Estrogen and Progesterone- produced by the ovaries – important for the development of secondary female characteristics, control of menstrual cycle, and growth and development of the placenta and fetus.

estrogen

common steroid backbone but the difference in functional groups

Aromatic ring (benzene)

Contraceptives

• Oral pill – most effective– Prevents ovulation, the release of an egg– Contains a mixture of progesterone and

estrogen and suppresses the secretion of FSH and LH which trigger ovulation

– Mimics hormonal conditions of pregnancy

Anabolic Steroids –

(anabolic = building up)

Uses – increase muscle

mass and endurance

(has become a problem in

many sports)

Problems:• Impotence, baldness, problems

urinating, smaller testes (in men),

build up muscles, facial hair (in women),temper, aggressive behavior, liver cancer, high blood pressure, heart attacks