Download The Endocrine System

The Endocrine
System
functions
• Controls body functions and helps maintain
homeostasis by using hormones.
• hormone – chemical messenger made in one
cell or tissue that causes a change in another
cell or tissue elsewhere in the body.
• gland – a group of cells that make special
chemicals for your body.
organs
• hormones
• glands
– pituitary
– hypothalamus
– pineal
– thyroid
– pancreas
– adrenal
– ovaries
– testes
pituitary and hypothalamus:
Produces hormones that
help control growth and the
release of hormones from
other glands. “control
center”
thymus:
Immune system cells
develop here
pancreas:
Produces insulin that
helps control glucose
movement to the cells.
ovaries:
Produces female
reproductive hormones
like estrogen.
pineal:
Produces hormones that
help control sleep, aging,
reproduction and body
temperature.
thyroid:
Produces hormones that
help control your
metabolism (how fast
your body uses energy)
adrenals:
Produces adrenaline that
helps control your heart
beat and breathing rate.
testes:
Produces male
reproductive hormones
like testosterone.
• Hormones travel through the bloodstream.
• They travel from the gland that makes them
to every cell in the body.
• But, only certain cells can respond to certain
hormones.
– target cell – the cell a certain hormone can
affect.
https://www.youtube.com/watch?v=gjmS4_7k
vDM
Controlling hormone levels
• The endocrine glands help keep the body in
homeostasis by maintaining the right level of
hormones.
• feedback mechanism – a cycle of events in
which information from one step controls or
affects another step
• negative feedback – effects of a hormone in
the body cause the release of that hormone
to be turned down.
• positive feedback – effects of a hormone in
the body cause the release of more of that
hormone.
• The endocrine system and the nervous
system both send messages around the body.
– Nervous system sends quick signals.
– Endocrine system sends long lasting signals.
• The endocrine system controls levels of
growth hormone and tells your body when to
stop producing it.
Too much = gigantism
Not enough = pituitary dwarfism