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Chapter 08 THE ENDOCRINE SYSTEM
Human Anatomy & Physiology
5/2/2017
08.1 Endocrine System Introduction
A. Nervous System vs. Endocrine System
The Endocrine System is one of the ‘silent’ systems that plays a major
role in our lives every day. It works much quieter than the nervous
system, but its role is to communicate and coordinate organs and
tissues in the body.
We know that both the nervous system and endocrine system
communicate and coordinate the body’s tissues, but they work
differently in how they communicate and the window of time they make
changes in those tissues.
Draw the following:
N.S. (direct)
Endocrine (indirect)
Use the following information to fill out the above T chart.
Uses:
NS: electrical change
Endo: Hormones that travel in the blood
Controls:
NS: muscles & some glands
Endo: Tissues (regulatory action & homeostasis
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Feedback:
NS: quick!!!!!!!
Example of speed: using a phone to call someone.
Endo: seconds (ie adrenaline) to months.
Example of speed: mailing a letter to someone
How can both the nervous and endocrine system control and
communicate, but differ in the time it takes to make those changes?
The answer: The nervous systems uses direct wiring
(neurons) to communicate to the tissue and the endocrine system
uses chemical messengers (hormones) that use the blood
circulation to deliver their instructions.
An example to show the difference in timing:
The nervous system is much like a phone call. We dial in the number
(which is the receptor for who we want to talk to) and we get to deliver
our message instantly to the person.
The endocrine system is much like using the post office (‘snail mail’ as
it is referred to in this day). I will mail a letter to ‘John’ and in order
to get this letter to him, I must place his address on the envelope. The
address is now the ‘receptor’ for his house. I place the letter into the
‘circulation’ of all letters in the area. His ‘address’ helps the postal
office find his house in a couple of days to deliver the message.
Now…much like the postal office’s options of priority and express
mail, the endocrine system can also speed up delivery of certain
messages based on importance.
Now we can see the mechanism of message delivery for the nervous vs.
endocrine!
B. The makeup of Endocrine Glands:
1. The ‘ductless gland’:
Endocrine glands are referred to as ‘ductless glands’ because they do
not secrete their product (which is always a hormone) outside of itself
through a tube or duct. Instead, these glands make their product and
capillaries come into (endo-) the gland and pick up the product. A tube
or duct is not needed and therefore the gland is ‘ductless’.
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Helpful Hints:
Endo- refers to inside. Blood must go inside the gland to pick up the
product.
Endocrine glands are made of cuboidal cells and always release
hormones!
2. Who are the Endocrine Glands that affect our life?
- INSERT picture of the placement of the endocrine glands & get two
different map/marker colors.
- The first color represents the ‘true’ endocrine glands, which means this is the
only job…to be an endocrine gland.
- The second color represents glands that have other functions, but also have
endocrine tissue within.
Do not color these the same color as seen in the picture:
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Identification of the Endocrine Glands:
1. Hypothalamus: Even though the Pituitary is known as the
“Master Gland”, the hypothalamus sits below the midbrain and is
known as a neuroendocrine organ.
2. Pituitary Gland: This gland is known as the “Master Gland” (or
Boss Gland by some brilliant individuals).
It is also known as the Hypophysis.
3. Pineal Gland
4. Thyroid Gland
5. Parathyroid Glands
6. Thymus Gland
7. Adrenal Glands
8. Islets of Langerhans of the Pancreas
9. Ovaries
10. Testes
Remember to:
Reduce, Recite, Reflect, & Review!
Make your Flashcards & Study 3 x 5!
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