Transcript Important Glands of the Endocrine System

Key Definitions
 Endocrine 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
Hypothalamus
 About 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.
Hypothalamus
 Its 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 Gland
 The 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 Gland
 One 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 Gland
 The three main
hormones produced by
the thyroid gland are:
 Thyroxine (T4)
 Triiodothyronine (T3)
 Both used to regulate
metabolism
 Calcitonin
 Used to control calcium
levels
Parathyroid Glands
 The 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 Gland
 The 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.
Pancreas
 The 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