Other Glands

• Synthesizes melatonin at night
• Causes drowsiness and drop in body temperature
• Regulates seasonal breeding, hibernation, and possibly puberty

• Site of maturation for T-cells (part of the acquired immune system)
• T-Cells undergo central tolerance (learn not to attack body)
• Releases hormones that regulate T-cell activity (there are 3 hormones)

• Four glands on posterior surface of thyroid
• Secrete parathyroid hormone (PTH): raises blood calcium levels by stimulating osteoclasts to break down bone and promoting calcium reabsorbtion by kidneys; opposite effects of calcitonin from thyroid

Excess PTH: excess blood calcium causes neurological symptoms (cognitive impairment, fatigue, depression), kidney stones, osteoporosis

Too little PTH: too little calcium causes pain, muscle spasms, seizures, brittle nails, lethal if not treated

• Alpha cells secrete glucagon when blood glucose falls
• It stimulates liver to convert glycogen to glucose in Pancreas

• Secrete insulin when blood glucose levels are high
• Causes liver, muscles, and fat cells to take up glucose and store it as glycogen

• Secrete Somatostatin
• Inhibits the release of glucagon and insulin

• Symptoms
• Polyuria: excess urination
• Polydipsia: excess thirst
• Polyphagia: excess hunger

• Hyperglycemia: elevated blood glucose
• Glycosuria: glucose in the urine
• Ketonuria: ketones in the urine

Formerly "juvenile" or "insulin dependent" diabetes

• Formerly "juvenile" or "insulin dependent" diabetes
• Body produces antibodies to pancreatic beta cells
• Insulin isn't secrete, so blood glucose skyrockets
• Patients must monitor blood glucose and receive insulin injections

• Most common form of diabetes Mellitus (95% of cases)
• Formerly "adult onset" or "insulin independent" diabetes
• Pancreas makes insulin, but target organs are unresponsive to it

• For non anterior pituitary controlled hormones, hormone is only around as long as signal is around
• Alpha cells stop releasing glucagon when blood glucose levels rise
• Parathyroid stops releasing PTH when blood calcium levels rise
• For anterior pituitary controlled hormones, negative feedback is used

A hormone "feeds back" to the hypothalamus and pituitary to stop the release of more of the hormone

• Typically estrogens use negative feedback
• Once a month, switch to positive feedback to get LH surge (and ovulation)

• Steroid hormones and thyroid hormone
• Often effects gene expression

• All other hormones
• "Second messenger cascade"