Key DefinitionsEndocrine Gland: An organ in an animal’s

body that makes a substance for release (in this case a hormone) into the bloodstream.

Hormone: a chemical regulator that is made in one part of the body but acts on another part of the body.

Pituitary Gland (hypophysis)Located at the base

of the brain connected under the hypothalamus, the pituitary gland is about the size of a pea.

Pituitary Gland (hypophysis)The pituitary gland secretes hormones that help maintain

homeostasis.It can release special hormones called tropic hormones

which stimulate other endocrine glands to secrete hormones.

It is divided into two parts, the posterior (back) and anterior (front) pituitary.

Anterior Pituitary (adenohypophysis)

With encouraging from the hypothalamus, the anterior pituitary releases many peptide hormones responsible for reproduction, growth and dealing with stress.

Anterior Pituitary (adenohypophysis)

Hormones released from the anterior pituitary on its own include:

Human Growth Hormone (hGH)

Follicle-Stimulating Hormone (FSH)

Luteinizing Hormone (LH)

Thyroid Stimulating Hormone (TSH)

Prolactin (PRL)Adrenocorticotropic

Hormone (ACTH)

Anterior Pituitary (adenohypophysis)

Hormones released from the anterior pituitary with urging from the hypothalamus include:

Gonatropin-releasing Hormone (GnRH)

Anti-diuretic Hormone (ADH)

Somatostatin (SS)

Posterior Pituitary (Neurohypophysis)

Unlike the anterior pituitary, the posterior pituitary is not so much a gland, but more of a series of nerve cells.

It stores hormones produced in the hypothalamus, like ADH and oxytocin

HypothalamusAbout the size of an

almond, the hypothalamus is the link between the nervous system and the endocrine system through its control on the pituitary gland.

HypothalamusIts main role in terms of

the endocrine system, is to secrete releasing factor hormones that travel to the pituitary and stimulate/inhibit the release of pituitary hormones.

This is where the brain’s thirst, hunger, anger, fatigue and body temperature centers are located as well.

Pineal GlandThe pineal gland is a

small pinecone shaped gland located between the two hemispheres of the brain.

It is responsible for producing the hormone melatonin which controls sleep/wake patterns and seasonal functioning.

Thyroid GlandOne of the largest

glands in the body, the thyroid gland controls how quickly the body burns energy, how fast it makes protein and how sensitive the body is to other hormones.

Thyroid GlandThe three main

hormones produced by the thyroid gland are:

Thyroxine (T4)Triiodothyronine (T3)

Both used to regulate metabolism

CalcitoninUsed to control

calcium levels

Parathyroid GlandsThe parathyroid glands

are small endocrine glands found in the neck and are closely associated with the thyroid.

They release the parathyroid hormone (PTH)

Their main role is to control calcium levels in the body so that muscle flexion and nervous control are maintained.

Thymus GlandThe thymus gland is

located just above the heart and posterior to the sternum.

It is very important in the maturation of T cells (infection fighting cells) for the immune system.

It is the link between the endocrine system and the immune system.

Adrenal Glands (Suprarenal glands)They sit atop the kidneys.Their primary

responsibility is to regulate the body’s stress level.

The main hormones involved in stress regulation produced here are the protein hormones adrenalin and noradrenalin.

Fight or flight response.

PancreasThe pancreas is an

important gland for both digestion and blood sugar maintenance.

The hormones important to blood sugar maintenance include insulin and glucagon.

Gonads (Testes and Ovaries)Important body parts

as they make gametes, the sex cells of the body.

They also are glands that produce the male and female sex hormones, testosterone (male) and estrogen (female).

Their hormones are under the control of the hypothalamus and anterior pituitary.

Homework

p. 377 #1 and #3