Download The Endocrine System Lecture

THE
ENDOCRINE
SYSTEM
Advanced Health
What is it?
THE ENDOCRINE SYSTEM IS THE COLLECTION OF GLANDS THAT
PRODUCE HORMONES THAT ARE RESPONSIBLE FOR THE FOLLOWING:
1.PRODUCING AND SECRETING HORMONES AND CHEMICAL
REGULATORS
2. REGULATING METABOLISM, GROWTH, AND SEXUAL
DEVELOPMENT
3. RESPONSES TO STRESS AND INJURY
4. MAINTAINING HOMEOSTASIS
What makes up
the Endocrine
System?
• The endocrine system is made up of the
following:
– Pituitary gland
– Pineal Gland
– Thyroid gland
– Parathyroid glands
– Adrenal glands
– Pancreas
– Ovaries (in females)
– Testicles (in males)
The Big Idea
• Hormones are a very powerful substance secreted by
an endocrine gland into the bloodstream, that
affects the function of another cell or "target cell".
The Pituitary Glanda.k.a. The Master Gland
(because it controls all of the
other glands):
a tiny organ, the size of a
pea, found at the base of the
brain that produces many
hormones that travel
throughout the body,
directing certain processes or
stimulating other glands to
produce other hormones.
Pituitary Gland
is actually TWO
Endocrine
Glands…
• Anterior Pituitary Gland which secretes several
major hormones including:
– Growth Hormone (GH)
– Prolactin (PRL)
– Thyroid-Stimulating Hormone (TSH)
– Adrenocorticotropic Hormone (ACTH)
– Follicle-Stimulating Hormone (FSH)
– Luteinizing Hormone (LH)
• Posterior Pituitary Gland releases two hormones
including:
– Antidiuretic Hormone (ADH)
– Oxytocin
The Pineal
Gland
• The Pineal Gland, also known as the
pineal body, is an important
endocrine gland found in the brain
that is responsible for your mood,
sleep/wake cycles, and more.
• The pineal gland produces and
secretes Melatonin, which helps
regulate your daily and seasonal
circadian rhythms, the sleep-wake
patterns that determine your
hormone levels, stress levels, and
physical performance.
The Thyroid
Gland
• The Thyroid Gland is a butterfly-shaped organ located
in the base of your neck. It releases hormones that
control metabolism (the way your body uses energy).
The thyroid's hormones regulate vital body functions,
including:
– Breathing
– Heart rate
– Central and peripheral nervous systems
– Body weight
– Muscle strength
– Menstrual cycles
– Body temperature
– Cholesterol levels
Why is it so
important?
• The thyroid gland uses iodine from the foods you eat to
make two main hormones:
– Triiodothyronine (T3)
– Thyroxine (T4)
• It is important that T3 and T4 levels are neither too high
nor too low.
• The hypothalamus produces TSH Releasing Hormone
(TRH) that signals the pituitary to tell the thyroid gland
to produce more or less of T3 and T4 by either increasing
or decreasing the release of a hormone called thyroid
stimulating hormone (TSH).
• When T3 and T4 levels are low in the blood, the pituitary
gland releases more TSH to tell the thyroid gland to
produce more thyroid hormones.
• If T3 and T4 levels are high, the pituitary gland releases
less TSH to the thyroid gland to slow production of these
hormones.
Hyperthyroidism
(too much T3 and
T4 in your body)
vs.
Hypothyroidism
(too little T3 and
T4 in your body)
Parathyroid
Glands
• The parathyroid glands are four small
glands found on the back of the thyroid
that have the sole purpose of secreting
Parathyroid Hormone (PTH) to regulate
the calcium level in our bodies.
• When the calcium level is high in the
bloodstream, the thyroid gland releases
calcitonin. Calcitonin slows down the
activity of the osteoclasts found in bone.
This decreases blood calcium levels. When
calcium levels decrease, this stimulates the
parathyroid gland to release parathyroid
hormone.
Adrenal
Glands
• The adrenal glands, located at the top
of each kidney, produce hormones
that help the body:
– Control blood sugar
– Burn protein and fat
– React to stressors like a major illness
or injury
– Regulate blood pressure
• The adrenal cortex, the outer
part of the gland, produces
hormones that are vital to life,
such as cortisol (which helps
regulate metabolism and helps
your body respond to stress)
and aldosterone (which helps
control blood pressure).
• The adrenal medulla, the inner
part of the gland, produces
nonessential (that is, you don’t
need them to live) hormones,
such as adrenaline (which helps
your body react to stress).
Pancreas
• The Pancreas is large gland behind the stomach that helps
the body to maintain healthy blood sugar (glucose) levels.
• Contains islands of cells called the Islets of Langerhans
which secrete glucagon and insulin.
Ovaries and
Testicles
• The ovaries maintain the health of the female reproductive
system. They secrete two main hormones, estrogen and
progesterone.
– Estrogen- hormone responsible for secondary sex
characteristics and the for the sex drive in females; the
“egg producing” hormone
– Progesterone- hormone that builds up the lining of the
uterus to prepare it for the fertilized ovum; the “egg
setting” hormone
• Found in men, this gland produces testosterone, which
promotes the growth of the penis as a male gets older as
well as facial and body hair. It also deepens the voice of a
male at a certain age. Other functions of testosterone
include:
– Maintaining sex drive
– Promoting production of sperm
– Maintaining healthy levels of muscle and bone mass