BIO 202 Quiz 1
Discuss the way in which hormones promote body homeostasis. - answer Get
stimulated when homeostasis is thrown off
Compare and contrast the endocrine system and the nervous system. Make sure you
understand the differences between a neurotransmitter and a hormone, addressing the
importance of receptor specificity. - answer Endocrine - Uses hormones released by
endocrine glands
Effects many effector organs (i.e. HGH to all muscles)
Is slower and longer lasting
Nervous - Uses electricity and chemicals to send a fast message
Has a specific effector organ (i.e. certain muscle)
Uses neurotransmitters released by neurons
Define negative feedback and describe its role in regulating blood levels of the various
hormones. Use an example if you like! ☺ - answerResponse to changed body condition
if body is high or low from normal level
signal tells body to make changes that will bring body back to normal level
once body is back
to normal level,
signal is
turned off
List AND describe the four types of intercellular communication pathways that enable
the body to maintain homeostasis. - answer- Direct communication
-- Exchange of ions and molecules between adjacent cells across gap junctions
-- Occurs between two cells of same type
-- Where have we seen these before?
-- Cardiac muscle cells
- Paracrine communication
-- Uses chemical signals to transfer information from cell to cell within single tissue
-- Most common form of intercellular communication
-- i.e. Certain growth factors
-Endocrine communication
-- Endocrine cells release chemicals (hormones) into bloodstream
-- Alters metabolic activities of many tissues and organs simultaneously
-- Analogy once again: Bulk mail - in Russian
-Synaptic communication
Define hormone and target organ. - answerHormone - Stimulate synthesis of enzymes
or structural proteins
, Increase or decrease rate of synthesis
Turn existing enzyme or membrane channel "on" or "off"
Target organ - Are specific cells that possess receptors needed to bind and "read"
hormonal messages
What does the "lock and key system refer to? Explain! - answerhormone fits receptor on
"target" cell
What are the three ways in which hormones are classified? Yes, you will have to which
type of chemical structure each hormone that we study falls under. For example, you
will need to know that catecholamines are amino acid derivatives. - answerAmino acid
derivatives -Where have we seen amino acids before?
Peptide hormones
Lipid derivatives
Steroids
Corticosteroids/
anabolic steroids
All of these either circulate freely in the blood or are bound to transport proteins
Compare and contrast the functionality of free vs. protein bound hormones in the
plasma (bloodstream). - answer- Free Hormones
Remain functional for less than 1 hour
Diffuse out of bloodstream: bind to receptors on target cells
Are broken down and absorbed by cells of liver or kidney
Are broken down by enzymes in plasma or interstitial fluids
- Protein bound
Thyroid and Steroid Hormones
Remain in circulation much longer
Enter bloodstream
More than 99% become attached to special transport proteins
Bloodstream contains substantial reserve of bound hormones
A reserve
Why do thyroid and steroid hormones stay in circulation longer?
Diagram the general mechanism of action of a lipid soluble hormone. Then, compare
and contrast a steroid hormone vs. thyroid hormone mechanisms of action. Yes, they
are both lipid soluble hormones, but they have slightly different mechanisms of action. -
answer- Lipid soluble hormones:
Glucocorticoids
Estrogens
Androgens
Thyroid hormone (T3)
Calcitriol (the active form of vitamin _?_)
Diffuse across the plasma membrane to reach receptor proteins on inner surface of
membrane (intracellular receptors)
Discuss the way in which hormones promote body homeostasis. - answer Get
stimulated when homeostasis is thrown off
Compare and contrast the endocrine system and the nervous system. Make sure you
understand the differences between a neurotransmitter and a hormone, addressing the
importance of receptor specificity. - answer Endocrine - Uses hormones released by
endocrine glands
Effects many effector organs (i.e. HGH to all muscles)
Is slower and longer lasting
Nervous - Uses electricity and chemicals to send a fast message
Has a specific effector organ (i.e. certain muscle)
Uses neurotransmitters released by neurons
Define negative feedback and describe its role in regulating blood levels of the various
hormones. Use an example if you like! ☺ - answerResponse to changed body condition
if body is high or low from normal level
signal tells body to make changes that will bring body back to normal level
once body is back
to normal level,
signal is
turned off
List AND describe the four types of intercellular communication pathways that enable
the body to maintain homeostasis. - answer- Direct communication
-- Exchange of ions and molecules between adjacent cells across gap junctions
-- Occurs between two cells of same type
-- Where have we seen these before?
-- Cardiac muscle cells
- Paracrine communication
-- Uses chemical signals to transfer information from cell to cell within single tissue
-- Most common form of intercellular communication
-- i.e. Certain growth factors
-Endocrine communication
-- Endocrine cells release chemicals (hormones) into bloodstream
-- Alters metabolic activities of many tissues and organs simultaneously
-- Analogy once again: Bulk mail - in Russian
-Synaptic communication
Define hormone and target organ. - answerHormone - Stimulate synthesis of enzymes
or structural proteins
, Increase or decrease rate of synthesis
Turn existing enzyme or membrane channel "on" or "off"
Target organ - Are specific cells that possess receptors needed to bind and "read"
hormonal messages
What does the "lock and key system refer to? Explain! - answerhormone fits receptor on
"target" cell
What are the three ways in which hormones are classified? Yes, you will have to which
type of chemical structure each hormone that we study falls under. For example, you
will need to know that catecholamines are amino acid derivatives. - answerAmino acid
derivatives -Where have we seen amino acids before?
Peptide hormones
Lipid derivatives
Steroids
Corticosteroids/
anabolic steroids
All of these either circulate freely in the blood or are bound to transport proteins
Compare and contrast the functionality of free vs. protein bound hormones in the
plasma (bloodstream). - answer- Free Hormones
Remain functional for less than 1 hour
Diffuse out of bloodstream: bind to receptors on target cells
Are broken down and absorbed by cells of liver or kidney
Are broken down by enzymes in plasma or interstitial fluids
- Protein bound
Thyroid and Steroid Hormones
Remain in circulation much longer
Enter bloodstream
More than 99% become attached to special transport proteins
Bloodstream contains substantial reserve of bound hormones
A reserve
Why do thyroid and steroid hormones stay in circulation longer?
Diagram the general mechanism of action of a lipid soluble hormone. Then, compare
and contrast a steroid hormone vs. thyroid hormone mechanisms of action. Yes, they
are both lipid soluble hormones, but they have slightly different mechanisms of action. -
answer- Lipid soluble hormones:
Glucocorticoids
Estrogens
Androgens
Thyroid hormone (T3)
Calcitriol (the active form of vitamin _?_)
Diffuse across the plasma membrane to reach receptor proteins on inner surface of
membrane (intracellular receptors)
