3.4 The endocrine system Flashcards
What is the endocrine system?
Regulates growth, development, reproduction and homeostasis in humans and other animals.
What is the endocrine system composed of?
glands and organs that produce and secrete chemical messenger (hormones).
What are the three classifications of hormones?
- Amino acid derivative
- Peptide hormone
- Lipid derivative
What is a hormone pathway?
Describes the path of a hormone between secretory target cells in the body.
Are peptide hormones water or lipid soluble?
Water-soluble
*in-soluble to lipid-bilayer
What does a hormones form with a receptor?
A hormone-receptor complex
What is released when blood glucose levels decrease?
Alpha cells release Glucagon which initiates increase in blood glucose
Are steroid (lipid derivative) cells soluble in water?
No
*soluble in lipid-bilayer
What does insulin initiate when it binds to the liver and muscle cells?
The synthesis of glycogen when blood glucose levels are high.
What does removal of glucose stimulate?
- hunger
- thirst
- increase in urination
What is released into the blood when glucose levels increase?
Beta cells secrete insulin which initiate a decrease in blood glucose.
What is glycogen?
What animals store glucose as
What does glucagon initiate when it binds to the liver and muscle cells?
The breakdown of glycogen to form glucose when blood sugar is low.
What are triiodothyronine and thyroxine (T3 & T4)?
amino acid derivative hormones produced and secreted by follicle cell in the thyroid gland in response to changes in body temp.
What hormone is secreted when temp is below tolerance limit?
Thyrotropin releasing hormone (TRH).
