4. The nervous system sends electrical
messages to control and coordinate
the body. The endocrine system
has a similar job, but uses
chemicals to “communicate”. These
chemicals are known as hormones.

5. A hormone is a specific messenger
molecule synthesized and secreted
by a group of specialized cells
called an endocrine gland.

6. These glands are ductless, which
means that their secretions
(hormones) are released directly
into the bloodstream and travel to
elsewhere in the body to target
organs, upon which they act.

9. The pituitary gland is just the size of a
pea. It hangs from the hypothalamus.
-most important endocrine gland
-produces growth hormone: which
stimulates cell division and the growth of
muscles and bones
-other hormones it produces stimulate
and control other glands

10. The pituitary gland is called the “master
gland” but it is under the control of the
hypothalamus. Together, they control
many other endocrine functions.
They secrete a number of hormones,
especially several which are important to
the female menstrual cycle, pregnancy,
birth, and lactation (milk production).

11. This gland is located near the center
of the brain in humans, and is
stimulated by nerves from the eyes. The
pineal gland secreted melatonin at
night when it’s dark, thus secretes more
in winter when the nights are longer.
Melatonin promotes sleep (makes you
feel sleepy). Melatonin also affects skin
pigmentation.

12. -located at the base of the neck.
-produces thyroxine that controls the
rate at which the body cells use food to
release energy.
-also produces calcitonin: reduces blood
calcium levels by causing calcium to be
deposited in bones.
-helps in regulating body growth and
development

13. Thyroid hormones regulate
metabolism, therefore body temperature
and weight. The thyroid hormones
contain iodine, which the thyroid needs
in order to manufacture these hormones.
If a person lacks iodine in his/her diet,
the thyroid cannot make the hormones,
causing a deficiency.

14. Parathyroid glands are two-pairs of
pea size glands found near the thyroid
gland.
The hormone produced by this glands
help control level of calcium in the
blood.

15. The thymus is located in the upper
thorax behind the breast bone and
extends below the thyroid gland.
The thymus forms part of the body’s
immune system by causing
lymphocytes
(white blood cells) to become T cells –
cells which become parts of the body’s
defense against infection.

16. The adrenal glands are a pair of cone-
shaped glands, each on top of the
kidneys. They consist of two parts, the
outer cortex and the inner medulla.
The cortex produces hormones that
affect the body metabolism. The cortex
secretes corticosteroids .

17. The hormones produced by the adrenals
prepare the body for stress.
The medulla secretes epinephrine
(adrenaline) and other similar
hormones in response to stressors such
as fright, anger, caffeine, or low blood
sugar.

19. -lies behind the stomach.
Scattered throughout the pancreas are
tiny glandular tissues called “islets of
Langerhans”– that produces
hormones glucagon and insulin.
Insulin lowers blood sugar level while
glucagon raises blood sugar levels.

20. This organ has two functions. It serves
as a ducted gland, secreting
digestive enzymes into the small
intestine. The pancreas also serves as
a ductless gland in that the islets of
Langerhans secrete insulin and
glucagon to regulate the blood
sugar level.

21. The female ovaries and male testes
secretes sex hormones. The secretion of
sex hormones by the gonads is controlled by
pituitary gland hormones. Typically male
testes secrete primarily androgens including
testosterone. Female ovaries
make estrogen and progesterone in
varying amounts depending on where in her
cycle a woman is.

23. Identify the glands being described.
1. A gland located at the base of the neck.
2. An organ that controls the pituitary gland.
3. A gland that secretes epinephrine
4. The master gland
5. Male sex gland
6. Female sex gland
7. A gland that lies behind the stomach
8. Two-pairs of pea sized glands found near the
thyroid
9. A gland that is part of the body’s immune system
10.Hormone produced by the pineal gland that
regulates body’s day and night activities.