1. Endocrine System Worksheet
Biology 100C
1. What is an Endocrine Gland?
This is a gland that secretes hormones
2. Endocrine glands are also called ___ductless glands____________ because they
secrete their chemical messengers into _____body fluids_(usually the
blood)_______.
3. The chemical messenger secreted by an endocrine gland is called a
Hormone
4. How does an Endocrine Gland differ from an Exocrine Gland?
Exocrine glands secrete fluid into a duct which conveys the products to the location
5. What are Neurosecretory Cells and why do they show that the endocrine system and the
nervous system are related structurally, chemically, and functionally?
They are specialized nerve cells that secrete hormones. Several chemicals serve as
both hormones and neurotransmitters.
6. Name three different local regulators, tell what the chemical composition is for each one,
and give one function for each local regulator.
Nitric Oxide (NO) – secreted by neurons as a neurotransmitter, by WBC kills
bacteria and cancer cells, by endothelia cells in blood vessels causes smooth muscle
to relax.
Growth Factors – these are peptides and proteins, stimulate growth of various
tissues
Prostaglandins – modified fatty acids, often derived from lipids of cell membrane,
7. Where could a hormone receptor be located?
On cell membrane, in cytoplasm or in nucleus
8. A protein hormone and many peptide hormones would bind with a receptor
located in this place. On cell membrane
2. 9. Steroid hormones, thyroid hormones, and some local regulators would bind to receptors
located in these places. In cytoplasm or in nucleus
10. Name 9 endocrine glands in a human body. Hypothalamus, pituitary gland, thyroid
gland, parathyroid glands, pancreas, adrenal glands, gonads, pineal gland, thymus
11. What is the anatomical relationship between the hypothalamus and the anterior pituitary?
(see Figure 45.7 and text on page 900) Be detailed about the connections between the two
structures.
See figure and text for description
12. What is the anatomical relationship between the hypothalamus and the posterior
pituitary? (see Figure 45.6 and text on page 963) Be detailed about the connections between the
two structures.
See figure and text for description
13. What hormones are released by the hypothalamus to control the anterior pituitary gland.
What is the chemical composition of these hormones and what is the action of each
hormone? Releasing Hormones and Inhibiting Hormones, peptide in
composition, to stimulate or inhibit the production and release of anterior pituitary
gland
14. Where does the posterior pituitary come from during embryological development?
From the brain
15. Where does the anterior pituitary come from during embryological development?
From the roof of the mouth
16. What hormones are released from the posterior pituitary, where are they produced, what is
their chemical composition, and what is the target organ and action for each hormone. See
Table 45.1 Oxytocin and Antidiuretic Hormone, hypothalamus, peptide, target
organ for Oxytocin is the uterine smooth muscle and mammary gland cells
3. 17. What hormones are released from the anterior pituitary, where are they produced, what is
their chemical composition, and what is the target organ and action for each hormone. See
Table 45.1 Growth Hormone, Prolactin, Follicle Stimulating Hormone,
Luteinizing Hormone, Thyroid-stimulating Hormone, ACTH, MSH, Endophins;
anterior pituitary, peptide,
18. What single molecule from the anterior pituitary is cleaved into a number of smaller
hormones and what are these hormones? Pro-opiomelanocortin – ACTH, MSH, and
endorphins
19. What hormones are secreted by the Thyroid gland, what is the chemical composition of the
hormones, and what do these hormones do in humans or other vertebrates? What element do
these hormones contain (this element is found nowhere else in the body)? See Table 45.1
and pages 965-966. Triiodothyronine (T3) and Thyroxine (T4), modified amino
acid, metamorphosis of the frog, metabolism in humans/mammals
19. Explain the concept of a Negative Feedback Control Loop using the Thyroid Hormone
system. Use Figure 45.8 for your answer.
See Figure and text for example
20. What hormone is secreted by the Parathyroid Gland, what is the chemical
composition of this hormone and what does this hormone do in the body?
Parathyroid Hormone!! Peptide, elevates blood Ca levels by
stimulating Ca reabsorption from bone and kidneys
21. What hormone is secreted by alpha cells and what hormone is secreted by beta cells in the
Pancreas, what is the chemical composition of these hormones, and what do these hormones
do in the body? See page 966 and Figure 45.9 alpha cells = glucagon while beta
cells = insulin, protein, insulin decreases blood glucose levels while glucagon increases
blood glucose levels
4. 22. What cells are stimulated by insulin and what cells are not stimulated by insulin? And
stimulated to do what? Stimulated = all cells except neurons, to take up glucose from
the blood. Neurons are always able to do this, even without insulin
23. What is meant by Type I and Type II diabetes (juvenile versus adult onset diabetes) and what
is the cause of each type? See page 968 and Figure 45.10
Type I – Juvenile Onset, destruction of beta cells so no insulin is
produced or secreted Type II – Adult Onset, fewer receptors on cell membrane so
insulin has less of an effect.
24. What are the two parts of the Adrenal Gland, what hormones are secreted by each part, and
what do these hormones do in the body?
Cortex – responds to endocrine signals by ACTH by secreting glucocorticoids
such as cortisol and mineralocorticoids such as aldosterone which both have effects on
glucose metabolism and bioenergetics.
Medulla – responds to nervous signals from autonomic nervous system,
causing release of epinephrine and norepinephrine
25. What is the chemical composition of the adrenal medulla hormones? Modified amino acid
hormones
26. The adrenal medulla has close developmental and functional ties with the Nervous System.
27. How is the adrenal gland involved in the stress response? See Figure 45.14
28. Give some examples of hormones found in invertebrate animals and give the function for
these hormones.
See pages 956 and 957
29. Where is the pineal gland? What hormone does it produce? What is the chemical
composition of the hormone, when is the hormone secreted, and what does the hormone do?
5. (page 902-903) in the brain, Melatonin, modified amino acid, during the dark part of
24-hr cycle, regulates reproductive cycles, biological clock, pigment cells in certain
vertebrates
30. Endorphins are called the body’s natural Opiates, because they inhibit the perception of
Pain. (page 902) The receptors for endorphins are also receptors for these exogenous
compounds or drugs: Heroin and other opiate drugs
