Transcript Endocrine System

The Endocrine System
• Hormones = chemicals that are used to pass
information around the body
– (In the NS it was electrical signals; now it’s
chemical signals)
• Endocrine Glands = organs that make and
secrete the hormones
• Blood Capillaries = run through the gland and
pick up the secreted hormones, then carry
them through the bloodstream
Hormones
• Hormones travel all through the body (in
blood), but only affect target organs.
• Insulin’s target organ is the liver
– (but it’s made and secreted by the pancreas!)
• Hormones eventually get broken down by
enzymes and excreted by the kidneys.
Endocrine Glands
Fight or Flight
Adrenaline
• Adrenaline = a hormone that increases your
metabolic rate
– Prepares your body for “fight or flight”
• Comes from the adrenal gland
– Just above your kidneys
• Your brain sends a nerve signal to adrenal
glands, stimulating them to secrete adrenaline
into the blood.
Adrenal Glands
Adrenaline’s Functions
• Increases heart rate
• Increases blood glucose
– (T.O. = Liver)
• Restricts blood to digestive system; increases
blood to muscles
– (T.O. = Arteries/arterioles)
• Increases width of lung passages
– (T.O. = Bronchii/bronchioles)
Adrenaline…
• What is its function?
• What endocrine gland does it come from?
• What is its target organ?
Let’s Compare…
Nervous System
Type of Signal
Speed of Signal
Where the Signal Travels
Where the Signal is
Delivered
How Long the Signal Lasts
Endocrine System
Let’s Compare…
Type of Signal
Speed of Signal
Where the Signal Travels
Where the Signal is
Delivered
How Long the Signal Lasts
Nervous System
Endocrine System
Electrical
Chemical
Let’s Compare…
Nervous System
Endocrine System
Type of Signal
Electrical
Chemical
Speed of Signal
several meters per second
~ speed of blood
Where the Signal Travels
Where the Signal is
Delivered
How Long the Signal Lasts
Let’s Compare…
Nervous System
Endocrine System
Type of Signal
Electrical
Chemical
Speed of Signal
several meters per second
~ speed of blood
Where the Signal Travels
In neurons and nerves
In blood vessels
Where the Signal is
Delivered
How Long the Signal Lasts
Let’s Compare…
Nervous System
Endocrine System
Type of Signal
Electrical
Chemical
Speed of Signal
several meters per second
~ speed of blood
Where the Signal Travels
In neurons and nerves
In blood vessels
Where the Signal is
Delivered
To a specific part of the
body
Throughout the body (but
only affects T.O.’s)
How Long the Signal Lasts
Let’s Compare…
Nervous System
Endocrine System
Type of Signal
Electrical
Chemical
Speed of Signal
several meters per second
~ speed of blood
Where the Signal Travels
In neurons and nerves
In blood vessels
Where the Signal is
Delivered
To a specific part of the
body
Throughout the body (but
only affects T.O.’s)
How Long the Signal Lasts
Seconds or less
Minutes/Hours/Days