The Endocrine System
The endocrine system consists of all of the
glands inside the body that secrete around
50 hormones into the blood. The glands are
controlled by the nervous system as well as
by chemical receptors in the blood and other
hormones secreted from other glands! These
hormones activate and stimulate different
organs and control metabolism, reproduction
and development. The chemicals control lots
of the body’s processes.
The Hypothalamus
Adrenal Glands
The hypothalamus is part of the brain and it
serves many functions in the nervous system,
as well as controlling the endocrine system
through the pituitary gland. It has special cells
called neurosecretory cells which are neurons
that secrete hormones. The hormones it releases
affect the pituitary gland.
The hormone adrenaline is what wakes your
body up when you feel at risk or before you kiss
someone. This is produced by your adrenal glands,
which are found by your kidneys. It increases your
cardiac rhythm, the pressure in your arteries and
the flow of blood to your muscles.
The Pituitary Gland
The pituitary gland is also known as the master
gland as it controls the rest of the endocrine
glands. It has an anterior lobe and a posterior lobe.
It is a small pea-sized lump of tissue connected
to the hypothalamus. There are lots of blood
vessels surrounding it to carry the hormones that
it releases through the body. Your pituitary gland
is also associated with psychological behaviours
such as affection.
The Pineal Gland
This is a small mass of glandular tissue found
below the brain. It helps to regulate our sleep-wake
cycle, known as the circadian rhythm, by producing
melatonin. The pineal gland is told not to release
melatonin when the photoreceptors in your retina
are stimulated – when they receive light. When
you are in low light or darkness, the pineal gland
produces melatonin, causing you to feel drowsy.
20 IGNIS
The Pancreas
The pancreas increases the glucose level in your
blood before you kiss someone. It is in charge of
the two hormones that control your blood sugar
level – glycogen and insulin. Glycogen increases
the blood sugar levels in the bloodstream and
insulin lowers blood glucose levels after a meal.
Pheromones
These are chemical substances released
by the glands in your skin that are related
to sexual attraction. They transmit
sensations of excitation, attraction and
also, unfortunately, rejection.
Oxytocin
Oxytocin is the hormone that
influences basic body functions – birth,
breast-feeding and being in love. It is
commonly associated with affection
and tenderness, and it stimulates the
formation of bonds of affection.