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Biol 221 Worksheet
Endocrine System
If you can’t find the answers in the lecture notes, then refer to the corresponding
chapter in the textbook.
1.
Complete the following definitions:
a. Endocrine gland
b. Hormone
c. Target organ
2.
Mechanisms of Hormone Action
a. _____________ hormones diffuse through the plasma membrane of their
target cells. Once inside they bind to ____________________ forming a
____________________________ complex. The complex then binds to
DNA, affecting the activity of specific ______________.
b. Give one example of this type of hormone________________________.
c. Some hormones are unable to diffuse across the cell membrane, and,
therefore, can’t enter the cell. Instead, these hormones called _________
messengers bind to ______________ on the __________
_________________. This eventually results in the formation of a
_________ messenger. This molecule then alters the activity of the target
cell.
d. Give one example of this type of hormone_________________________.
3.
Control of Hormones
a. The release of a hormone is usually stimulated by the action of one of
these three means:
1. The action of other hormones called ___________________
hormones.
2. The changing concentrations of ________________ or
___________________ in the blood, referred to as
___________________stimulation.
3. By the nervous system, called ________________ stimulation.
4.
Types of Cellular Responses – the specific response depends on the type
of target cell and the receptor molecules made by that specific target.
a. Non-steroidal hormones often activate or deactivate ______________.
b. Some non-steroidal hormones result in the opening or closing of ion
____________________.
c. Steroid hormones change the activity of genes, affecting protein
____________________.
d. Special hormones called cytokines can affect the growth, division, or
differentiation of the same or other cells.
5.
Target cells can respond to changing levels of hormones.
a. If hormone levels become too low, target cells may
_______________(increase/decrease) the number of receptors for that
hormone, thereby _____________________ (increasing/decreasing) the
target’s responsiveness to that hormone. This is called ________________
(up/down) regulation.
6.
Pituitary Gland
This gland hangs from the __________________ by a stalk called the
infundibulum, and lies within a depression in the _____________ bone called
the ____________ ____________.
a. Anterior Pituitary Gland
i. Human Growth Hormone
1. Target:
___________________________
2. Function:
___________________________
ii. Prolactin
1. Target:
2. Function:
___________________________
___________________________
iii. Thyroid Stimulating Hormone
1. Target:
___________________________
2. Function:
___________________________
iv. Adrenocorticotropic Hormone
1. Target:
___________________________
2. Function:
___________________________
v. Follicle Stimulating Hormone
1. Females:
a. Target
___________________________
b. Function ___________________________
2. Males:
a. Target
b. Function
___________________________
____________________________
vi. Luteinizing Hormone
1. Females:
a. Target
b. Functions
___________________________
___________________________
2. Males (Interstitial Cell-stimulating Hormone):
a. Target
___________________________
b. Function
____________________________
b. Posterior Pituitary Gland (only stores & releases these hormones)
i. Oxytocin
1. Target:
___________________________
2. Function:
___________________________
ii. Antidiuretic Hormone
1. Target:
2. Function:
4.
5.
6.
___________________________
___________________________
Thyroid Gland
a. Thyroid Hormone (T3:Triiodothyronine/T4:Thyroxine)
1. Target:
___________________________
2. Function:
___________________________
b. Calcitonin
1. Target:
2. Function:
___________________________
___________________________
Parathyroid Glands
a. Parathyroid Hormone
1. Target:
2. Function:
___________________________
___________________________
Adrenal Glands
a. Adrenal Cortex (outer)
i. Cortisol (Glucocorticoids)
1. Target:
___________________________
2. Function:
___________________________
ii. Aldosterone (Mineralocorticoids)
1. Target:
___________________________
2. Function:
___________________________
c. Adrenal Medulla (inner)
i. Epinephrine/Adrenalin (Fear/Flight)
ii. Norepinephrine/Noradrenalin (Anger/Fight)
1. Targets:
___________________________
2. Functions:
___________________________
7.
8.
Pancreas
a. Insulin
i. Target:
ii. Function:
___________________________
___________________________
b. Glucagon
i. Target:
ii. Function:
___________________________
___________________________
Pineal Gland
a. Melatonin
i. Target:
ii. Action:
___________________________
___________________________
9.
Thymus Gland
a. Thymosins
i. Target:
_____________________________________
ii. Action:
_____________________________________
10.
Gonads
b. Ovaries
i. Estrogen
1. Target:
2. Function:
ii. Progesterone
1. Target:
2. Function:
c. Testes
i. Testosterone
1. Target:
2. Function:
___________________________
___________________________
___________________________
___________________________
___________________________
___________________________