Glands of Endocrine System

Endocrine glands produce…

Hormones

Hormones are often referred to as..

chemical messengers

A hormone is created and released by a..

gland

Hormones are sent from their original gland to... We call the organ the hormone is sent to a…

another organ/tissue (often through the bloodstream)/target organ.

In the target organ hormones … the organ/tissue’s activity

regulate

There are 8 major endocrine glands

• 3 in the brain

• 5 scattered throughout the body

• 2 organs also function as endocrine glands

3 glands in the brain

pineal gland, hypothalamus, pituitary gland

5 glands scattered throughout the body

thyroid gland, parathyroid gland, adrenal glands, thymus gland, pancreas

2 organs also function as endocrine glands

ovaries, testes

Pineal gland

• Found between the two cerebral hemispheres (behind the corpus callosum)

• Produces melatonin when light levels are low

Hypothalamus

• Receives information from the brain and bloodstream on the conditions of the body

• Responds to this information by creating hormones, which it sends to the pituitary gland beneath it

• Produces : oxytocin and antidiuretic hormone (ADH)

Pituitary gland

• roken into two lobes (anterior & posterior)

• Small, pea-sized gland located beneath the hypothalamus

• Known as the “master endocrine gland” because it controls so many other endocrine glands

Anterior pituitary gland

Produces many hormones:

• follicle-stimulating hormone (FSH)

• growth hormone

• luteinizing hormone (LH)

• prolactin

• thyroid-stimulating hormone

• adrenocorticotropic hormone (ACTH)

Posterior pituitary gland

Receives hormones from the hypothalamus (oxytocin & ADH), stores them, and sends them to other places in the body when the hypothalamus tells it to

Thyroid gland

• Located near the lower part of the larynx (voice box)

• Split into 2 lobes

• 2 hormones: thyroxine (T4) and triiodothyronine calcitonin (T3)

Parathyroid glands

• Embedded within the back of the thyroid gland

• 2 in each lobe of the thyroid gland (4 total)

Hormone: parathyroid hormone

Thymus gland

• Located behind the sternum and in front of the lungs

• Part of the endocrine system and the immune system

• Hormone: thymosin (helps our T cells to mature prior to puberty)

• After puberty, the thymus gland shrinks and is replaced by fat in the chest cavity 

Adrenal glands

• Pair of triangular glands (one above each kidney)

• Have an inner core called the medulla and an outer layer called the cortex

“Ad” means…

towards

“renal” means…

kidneys

Hormones produced by the medulla:

epinephrine (adrenaline) and norepinephrine (noradrenaline)

When a person is stressed, the … gland releases adrenocorticotropic hormone (ACTH). ACTH triggers the adrenal cortex to produce ...

anterior pituitary/cortisol and aldosterone

Pancreas

• Part of the endocrine system and the digestive system

• Contains specialized cells called islets of Langerhans, which are classified as an endocrine gland

• Islets of Langerhans produce insulin (lowers BS) and glucagon (raises BS) - both regulate blood sugar)

Testes

• Male gonads

• Produce sperm, but also produce hormones

• Levels of LH from the anterior pituitary gland trigger the testes to produce testosterone

Ovaries

• Female gonads

• Produce eggs, but also produce hormones

• Levels of FSH and LH from anterior pituitary gland trigger the ovaries to produce proestrogen and estrogen

Estrogen

• Promotes female sexual development during puberty

• Prepares the uterine lining for a potential pregnancy

• Regulates the menstrual cycle.

Progesterone

• Maintains the uterine lining to support a pregnancy

• prevents uterine contractions

Acromegaly

Too much growth hormone produced in adults.  Caused by increased production of GH or by a tumor in the pituitary gland.

Gigantism

Too much growth hormone produced during childhood.

Cretinism

An extreme form of hypothyroidism that is present just before or soon after birth.  Related to the absence or malformation of the thyroid gland or pituitary failure that results in the lack of thyroid stimulation. (Stunted growth)

Cushing Syndrome

Also known as hypercortisolism.  (Produces too much cortisol - ACTH).  

• Round face

• Hump on back

• Fatigue

• Large abdomin

• Thin skin

• High blood pressure

• Body aches in muscles

Diabetes Mellitus

Also known as Type I or II Diabetes.  Chronic disease characterized by a high glucose level in blood. 

Type 1 Diabetes

referred to as early-onset diabetes or insulin dependent mellitus (IDDM).  

Type 2 Diabetes

most common and is late-onset or noninsulin dependent NIDDM)