Endocrine 2

What is the primary hormone produced by the thyroid gland that acts as a major metabolic hormone?

Thyroxine (T4)

What hormone produced by the thyroid gland helps to lower blood calcium levels?

Calcitonin

What disease is characterized by an underactive thyroid and what are some symptoms?

Myxoedema; symptoms include low metabolic rate, weight gain, feeling cold, constipation, and lethargy.

What is the common treatment for an underactive thyroid?

Iodine salts

What disease is associated with an overactive thyroid and what are some symptoms?

Graves' disease; symptoms include increased metabolic rate, weight loss despite high appetite, sweating, and protrusion of eyeballs.

What are the typical treatments for Graves' disease?

Surgery or medical treatment.

How does calcitonin function in the body?

Lowers blood calcium by decreasing release of Ca from bones and increasing uptake of Ca into bones.

Why is calcitonin important during childhood?

It is important for bone growth and remodeling.

What is the structure of the thyroid gland composed of?

Follicles that store thyroid hormones in a gelatinous mixture called colloid.

What is the effect of thyroid hormones on the body's tissues?

They affect nearly all body's tissues except the adult brain, testes, uterus, and the thyroid itself.

What is the core temperature of the human body according to thermoregulation?

37°C ± 0.5°C.

What are the four mechanisms of heat loss in the human body?

Radiation, convection, conduction, and evaporation.

What are some mechanisms activated by cold?

Shivering, increased hunger, increased secretion of hormones (thyroxine, adrenaline, noradrenaline), increased metabolic rate, blood vessel constriction in skin.

Which hormones from the hypothalamus regulate growth hormone release?

Growth Hormone Releasing Hormone (GHRH) and Growth Hormone Inhibiting Hormone (GHIH).

Where is the parathyroid gland located and how many are typically present?

Within the thyroid gland, usually four present.

What do chief cells in the parathyroid gland secrete?

Parathyroid Hormone (PTH).

What are the functions of Parathyroid Hormone (PTH)?

Controls blood calcium levels; increases blood calcium if levels drop and decreases PTH secretion if calcium levels are too high.

What condition results from excessive PTH secretion and its consequences?

Hyperparathyroidism; leads to calcium loss from bones, nervous system dysfunction, and kidney stones.

What condition can follow a thyroidectomy and what are its symptoms?

Hypoparathyroidism; symptoms include muscle twitches and untreated can lead to diaphragm dysfunction.