Non-hormonal/non-neuronal (example: glucose) hormone secretions
are regulated by a substance that is not a hormone nor a nervous system input. Neuronal
(example exercise) hormone secretions are regulated by the influence of sensory
input. Hormonal (example: all releasing) hormone secretions are regulated by
Most of the functions of the pituitary gland are regulated by
the hypothalamus. The hypothalamus and the posterior pituitary gland are
connected by the infundibulum, through which the hypothalamohypophyseal tract
runs. Neurons in the hypothalamus connect to the blood supply that connects to
the hypothalamohypophyseal tract to carry secretions meant for the posterior pituitary
gland. The hypothalamohypophyseal tract
is a collection of axons which carry hormones from the hypothalamus to the posterior
pituitary gland. These hormones are oxytocin and ADH. The hypothalamohypophyseal
portal system is the blood supply that carries hormones from the hypothalamus to
the anterior pituitary gland. These hormones are inhibiting or releasing
hormones called GmRH, TRH, CRH, PrlRH, PrlIH, GHRH, and GHIH.
Hydrophobic hormones are built from cholesterol, are able to
move directly into the cell by diffusion, need a transport protein to move in
the blood (example: estrogen) Hydrophilic hormones are soluble in water, made
of proteins, mix easily in the blood. Cannot get past target cell barrier just
touch the surface on a membrane bound receptor (example: oxytocin)
4. Insulin is produced in the pancreas as we consume food and beverages,
glucose levels rise causing the pancreas to secrete insulin into the blood.
Insulin regulates glucose levels in the blood by communicating with cells in
the blood to absorb glucose. Some cells use that glucose for energy but other
cells store the glucose. Glucose stored in the muscles is called glycogen and
when you haven’t eaten uses this glycogen for fuel. Glucose storage in the liver is called
glycogen. If glucose levels in the blood become too low the pancreas will
release glucagon into the blood. Glucagon communicates to the body’s muscles
and liver to convert the glucagon back to glucose which is then released back
into the bloodstream.
Thyroid – located in the neck below the larynx, makes T3 and T4,
functions in metabolism, growth and development, makes calcitonin.
–located on top of the thyroid gland, makes parathyroid hormone which increases
blood calcium levels
– located on top of the kidneys, adrenal cortex produces steroid hormones such
as aldosterone which allows the body to release potassium and retain sodium
located deep in the brain, make melatonin which functions in helping the body
to sleep and controls the circadian rhythm.
located medial to the lungs, makes thymosin which helps some white blood cells
to mature to become T cells.