The Endocrine System
The Third Date ;)
DON’T FREAK OUT
What do we know that we need to
know?
• types and location of endocrine glands
including pituitary, thyroid, parathyroid,
pancreas, adrenal glands, gonads
• relationship between the hypothalamus and
pituitary
• production site, target organ and effect of
hormones associated with the specified
glands
• feedback loops involving endocrine activity
• hormonal modes of action.
Types Glands in the Body
• Exocrine glands secrete into a duct that carries
the secretion to the body surface or to one of
the body cavities. Sweat glands, mucous glands,
salivary glands and the glands of the alimentary
canal are examples of exocrine glands.
• Endocrine glands secrete hormones into the
extracellular fluid that surrounds the cells
making up the gland. The secretion then usually
passes into the capillaries to be transported by
the blood. Endocrine glands are sometimes called
ductless glands.
Location of endocrine glands
Pituitary and Hypothalamus sitting in
the tree….
Hypothalamus- base of brain
Pituitary- just under Hypothalamus
Joined by the
INFUNDIBULUM
Pituitary/ Hypothalamus
Communication
• The hypothalamus produces many different
hormones.
• Some of them are carried by the blood to the
anterior lobe of the pituitary where they
stimulate or inhibit the release of hormones
made in the anterior lobe.
• Other hormones pass along the nerve fibres
from the hypothalamus to the posterior lobe
of the pituitary where they are then secreted.
Structure of Pituitary
ANTERIOR- glandular tissue
POSTERIOR- nervous tissue
Anterior Pituitary
• Hormone secretion regulated by releasing and
inhibiting factors from hypothalamus
• FSH
• LH
• GH
• TSH
• ACTH
• Prolactin
ROAD BLOCK
• CREATE AN ANAGRAM TO HELP YOU
REMEMBER THE ANTERIOR HORMONES!!
• Eg. A Fishing Line Gets Thrown After Pinkies
• Or A Good Friend Lets People Talk After
• Or just learn one of these 
FSH
• Female- acts on ovaries to stimulate the
follicle that contains the egg
• Male- stimulates production and maturation
of sperm in the testes
LH
• Female- Works with FSH to bring about
ovulation and form corpus luteum. (ovaries
and uterus)
• Male- LH stimulates interstitial cells in the
testes to secrete male sex hormones
GH
• Stimulates body growth particularly growth of
the skeleton.
• It increases the rate at which amino acids are
taken up by cells and built into proteins.
• GH is secreted throughout life as it helps to
maintain the size of organs once maturity is
reached
TSH
• Stimulates production and release of
hormones from the thyroid gland
ACTH
• controls production and release of some of
the hormones from the cortex of the adrenal
gland
Prolactin
• works with other hormones to initiate and
maintain milk secretion in females (mammary
glands)
POSTERIOR PITUITARY
• releases the hormones oxytocin and antidiuretic
hormone
• neither is manufactured in the posterior lobe. Both
hormones are produced in special nerve cells in the
hypothalamus of the brain.
• These cells have long extensions that pass through the
infundibulum to the posterior lobe.
• Hormones manufactured in the cells move down the
extensions and are stored ready for release into the
bloodstream. The release of the hormones is triggered
by nerve impulses initiated in the hypothalamus and
conducted along the cell extensions
OXYTOXIN
• Stimulates contraction of the muscles of the
uterus. It
• Is released in large quantities during labour.
• Oxytocin also stimulates contraction of cells in
the mammary glands, resulting in release of
milk during breastfeeding
ADH
• causes the kidneys to remove water from
urine that is forming. This water is returned to
the bloodstream.
• In this way, ADH helps to retain fluid within
the body.
• At higher concentrations, ADH can also cause
constriction of small arteries, the arterioles.
THYROID
THYROID
• Thyroxine
• controls body metabolism by regulating reactions in
which complex molecules are broken down to release
energy and in which complex molecules are
synthesised from simple ones.
• The overall effect of thyroxine is to bring about the
release of energy and, since some of the energy
released is in the form of heat, to maintain body
temperature.
• Thyroxine is secreted in response to thyroid stimulating
hormone from the anterior lobe of the pituitary.