The Endocrine System
1. Homeostasis is achieved through the actions of two major regulatory systems, the nervous
system and the _________ system.
2. A ______ is a regulatory chemical that is secreted into the blood by an endocrine gland.
3. The glands of the endocrine system secrete hormones into the bloodstream or other body
fluids and so are said to have ____________ glands.
4. All hormones can be characterized as ________ (fat-soluble) or water soluble.
5. Some intercellular regulatory molecules that exert only very local effects are called
________ regulators.
6. The water-soluble hormones cannot pass through the plasma membrane; they must rely on
______ messengers within their target cells to mediate their action.
7. The ________ lobe of the pituitary gland appears fibrous because it contains axons
originating from neurons in the hypothalamus.
8. Match each of the following.
_____A. Stimulates uterine contraction.
1. adrenocorticotropic hormone
_____B. Helps regulate sperm production.
2. follicle-stimulating hormone
_____C. Stimulates production of testosterone.
3. luteinizing hormone
_____D. Stimulates secretion of adrenal cortical
hormone.
4. oxytocin
_____E. Regulates level hormone of blood calcium.
5. parathyroid
9. The anterior pituitary gland is controlled by both the hormones secreted by the
hypothalamus, and the hormones secreted by itself through a ________ feedback
mechanism.
10. Besides aldosterone, _________ hormone is the other hormone which is an absolute
requirement for the survival of humans.
11. The islets of Langerhans located in the _______ secrete both insulin and glucagon.
12. Molting hormone, or ecdysone, and juvenile hormone regulate ____________ and molting
in insects.
13. Hormones that affect changes in their target cells by entering the nucleus and initiating
transcription of certain genes are called
A. steroid hormones
B. paracrine hormones
C. lipophilic hormones
D. prostaglandins
E. second messenger hormones
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