PHGY 216 MIDTERM QUESTIONS WITH VERIFIED
ACCURATE ANSWERS
They are written in simple Question → Answer format, one card per line, using " -
Answers - " as the separator (Quizlet accepts this format directly).
You can copy-paste the entire set into Quizlet and upload as Import. - Answers -
Endocrine System - Quizlet Q Cards - Answers -
What makes the endocrine system different from other physiological systems? -
Answers - It is composed of many separate glands dispersed throughout the body
rather than one connected structure.
How do endocrine glands function as a coordinated system? - Answers - They all
secrete hormones that interact functionally to regulate body processes.
What is the main role of the endocrine system? - Answers - It regulates body functions
using hormones to maintain homeostasis and control long-term processes.
How do hormones reach their target tissues? - Answers - They are secreted directly into
the bloodstream and travel to distant target cells.
Six Major Functions of the Endocrine System - Answers -
What is the first major function of the endocrine system? - Answers - Maintaining a
constant internal environment by regulating metabolism and water/electrolyte balance.
What is the endocrine system's role in stress? - Answers - It produces adaptive stress
responses.
How does the endocrine system affect growth and development? - Answers - It
regulates cell growth, tissue development, and maturation.
How does the endocrine system regulate reproduction? - Answers - It controls sexual
development, gamete production, and reproductive cycles.
How does the endocrine system contribute to red blood cell production? - Answers - It
regulates hormones that stimulate red blood cell formation.
How does the endocrine system integrate with the autonomic nervous system? -
Answers - It helps regulate circulation and digestive functions.
,Hormones - General Concepts - Answers -
What is a hormone? - Answers - A chemical substance secreted into the blood that
exerts effects on distant target tissues.
Why do hormones act only on specific cells? - Answers - Only cells with the appropriate
receptors can respond to a hormone.
What determines a hormone's target cell? - Answers - The presence of specific
receptors on the cell.
Hormone Classification - Answers -
What are the two major categories of hormones? - Answers - Hydrophilic hormones and
lipophilic hormones.
What does hydrophilic mean? - Answers - Highly water-soluble and poorly lipid-soluble.
What does lipophilic mean? - Answers - Highly lipid-soluble and poorly water-soluble.
Hydrophilic Hormones - Answers -
How do hydrophilic hormones travel in the blood? - Answers - Mostly unbound to carrier
proteins.
What types of hormones are hydrophilic? - Answers - Peptide hormones and most
amine hormones.
What are peptide hormones made of? - Answers - Short or long chains of amino acids.
What are amine hormones derived from? - Answers - Single amino acid residues.
What are the two types of amine hormones? - Answers - Catecholamines and thyroid
hormones.
Which amine hormones are catecholamines? - Answers - Epinephrine and
norepinephrine.
Why are thyroid hormones an exception among amines? - Answers - They are
lipophilic, not hydrophilic.
What is unique about catecholamines in the blood? - Answers - They can be found both
free and bound to carrier molecules.
Lipophilic Hormones - Answers -
,Why do lipophilic hormones require carrier proteins? - Answers - Because they are
poorly soluble in water.
Which hormones are lipophilic? - Answers - Steroid hormones and thyroid hormones.
What molecule are all steroid hormones synthesized from? - Answers - Cholesterol.
Why are steroid hormones not stored in cells? - Answers - Because they diffuse out of
cells as soon as they are synthesized.
How is steroid hormone secretion regulated? - Answers - By regulating their rate of
synthesis.
Peptide Hormone Synthesis and Secretion - Answers -
Where are peptide hormones synthesized? - Answers - On ribosomes of the
endoplasmic reticulum as preprohormones.
What is a preprohormone? - Answers - A large inactive precursor protein.
What happens to preprohormones in the ER and Golgi? - Answers - They are
processed into active hormones and packaged into vesicles.
Where are peptide hormones stored? - Answers - In secretory vesicles within the cell.
How are peptide hormones released? - Answers - By exocytosis in response to a signal.
Free vs Bound Hormones - Answers -
Which form of a hormone is biologically active? - Answers - The free (unbound)
hormone.
Why does binding matter for lipophilic hormones? - Answers - Only unbound hormone
can leave the blood and enter target cells.
What is meant by dynamic equilibrium in hormone binding? - Answers - Hormones
continuously bind and unbind from carrier proteins.
Hormone Receptors - Answers -
Where are receptors for peptide hormones located? - Answers - On the cell surface
(plasma membrane).
Where are receptors for lipophilic hormones located? - Answers - In the cytoplasm or
nucleus.
, Peptide Hormones & Catecholamines - Second Messengers - Answers -
How do peptide hormones exert their effects? - Answers - By activating second
messenger systems inside the cell.
Why are second messenger systems effective? - Answers - They amplify the hormonal
signal.
cAMP Second Messenger Pathway - Answers -
What initiates the cAMP pathway? - Answers - A hormone binding to a membrane
receptor.
What protein is activated after receptor binding in the cAMP pathway? - Answers - A G
protein.
What enzyme does the G protein activate? - Answers - Adenylyl cyclase.
What does adenylyl cyclase produce? - Answers - Cyclic AMP (cAMP).
What does cAMP activate? - Answers - Protein kinase A.
What does protein kinase A do? - Answers - Phosphorylates target proteins to produce
a cellular response.
Calcium (Ca²⁺) Second Messenger Pathway - Answers -
What enzyme is activated in the calcium second messenger pathway? - Answers -
Phospholipase C.
What does phospholipase C convert PIP2 into? - Answers - IP3 and DAG.
What is the role of IP3? - Answers - It releases calcium from intracellular stores.
What does calcium bind to inside the cell? - Answers - Calmodulin.
What does the calcium-calmodulin complex activate? - Answers - Ca²⁺-calmodulin-
dependent protein kinase (CaM kinase).
What is the final effect of CaM kinase activation? - Answers - Phosphorylation of target
proteins and cellular response.
Lipophilic Hormone Mechanism of Action - Answers -
How do lipophilic hormones enter cells? - Answers - By diffusing across the plasma
and/or nuclear membrane.
ACCURATE ANSWERS
They are written in simple Question → Answer format, one card per line, using " -
Answers - " as the separator (Quizlet accepts this format directly).
You can copy-paste the entire set into Quizlet and upload as Import. - Answers -
Endocrine System - Quizlet Q Cards - Answers -
What makes the endocrine system different from other physiological systems? -
Answers - It is composed of many separate glands dispersed throughout the body
rather than one connected structure.
How do endocrine glands function as a coordinated system? - Answers - They all
secrete hormones that interact functionally to regulate body processes.
What is the main role of the endocrine system? - Answers - It regulates body functions
using hormones to maintain homeostasis and control long-term processes.
How do hormones reach their target tissues? - Answers - They are secreted directly into
the bloodstream and travel to distant target cells.
Six Major Functions of the Endocrine System - Answers -
What is the first major function of the endocrine system? - Answers - Maintaining a
constant internal environment by regulating metabolism and water/electrolyte balance.
What is the endocrine system's role in stress? - Answers - It produces adaptive stress
responses.
How does the endocrine system affect growth and development? - Answers - It
regulates cell growth, tissue development, and maturation.
How does the endocrine system regulate reproduction? - Answers - It controls sexual
development, gamete production, and reproductive cycles.
How does the endocrine system contribute to red blood cell production? - Answers - It
regulates hormones that stimulate red blood cell formation.
How does the endocrine system integrate with the autonomic nervous system? -
Answers - It helps regulate circulation and digestive functions.
,Hormones - General Concepts - Answers -
What is a hormone? - Answers - A chemical substance secreted into the blood that
exerts effects on distant target tissues.
Why do hormones act only on specific cells? - Answers - Only cells with the appropriate
receptors can respond to a hormone.
What determines a hormone's target cell? - Answers - The presence of specific
receptors on the cell.
Hormone Classification - Answers -
What are the two major categories of hormones? - Answers - Hydrophilic hormones and
lipophilic hormones.
What does hydrophilic mean? - Answers - Highly water-soluble and poorly lipid-soluble.
What does lipophilic mean? - Answers - Highly lipid-soluble and poorly water-soluble.
Hydrophilic Hormones - Answers -
How do hydrophilic hormones travel in the blood? - Answers - Mostly unbound to carrier
proteins.
What types of hormones are hydrophilic? - Answers - Peptide hormones and most
amine hormones.
What are peptide hormones made of? - Answers - Short or long chains of amino acids.
What are amine hormones derived from? - Answers - Single amino acid residues.
What are the two types of amine hormones? - Answers - Catecholamines and thyroid
hormones.
Which amine hormones are catecholamines? - Answers - Epinephrine and
norepinephrine.
Why are thyroid hormones an exception among amines? - Answers - They are
lipophilic, not hydrophilic.
What is unique about catecholamines in the blood? - Answers - They can be found both
free and bound to carrier molecules.
Lipophilic Hormones - Answers -
,Why do lipophilic hormones require carrier proteins? - Answers - Because they are
poorly soluble in water.
Which hormones are lipophilic? - Answers - Steroid hormones and thyroid hormones.
What molecule are all steroid hormones synthesized from? - Answers - Cholesterol.
Why are steroid hormones not stored in cells? - Answers - Because they diffuse out of
cells as soon as they are synthesized.
How is steroid hormone secretion regulated? - Answers - By regulating their rate of
synthesis.
Peptide Hormone Synthesis and Secretion - Answers -
Where are peptide hormones synthesized? - Answers - On ribosomes of the
endoplasmic reticulum as preprohormones.
What is a preprohormone? - Answers - A large inactive precursor protein.
What happens to preprohormones in the ER and Golgi? - Answers - They are
processed into active hormones and packaged into vesicles.
Where are peptide hormones stored? - Answers - In secretory vesicles within the cell.
How are peptide hormones released? - Answers - By exocytosis in response to a signal.
Free vs Bound Hormones - Answers -
Which form of a hormone is biologically active? - Answers - The free (unbound)
hormone.
Why does binding matter for lipophilic hormones? - Answers - Only unbound hormone
can leave the blood and enter target cells.
What is meant by dynamic equilibrium in hormone binding? - Answers - Hormones
continuously bind and unbind from carrier proteins.
Hormone Receptors - Answers -
Where are receptors for peptide hormones located? - Answers - On the cell surface
(plasma membrane).
Where are receptors for lipophilic hormones located? - Answers - In the cytoplasm or
nucleus.
, Peptide Hormones & Catecholamines - Second Messengers - Answers -
How do peptide hormones exert their effects? - Answers - By activating second
messenger systems inside the cell.
Why are second messenger systems effective? - Answers - They amplify the hormonal
signal.
cAMP Second Messenger Pathway - Answers -
What initiates the cAMP pathway? - Answers - A hormone binding to a membrane
receptor.
What protein is activated after receptor binding in the cAMP pathway? - Answers - A G
protein.
What enzyme does the G protein activate? - Answers - Adenylyl cyclase.
What does adenylyl cyclase produce? - Answers - Cyclic AMP (cAMP).
What does cAMP activate? - Answers - Protein kinase A.
What does protein kinase A do? - Answers - Phosphorylates target proteins to produce
a cellular response.
Calcium (Ca²⁺) Second Messenger Pathway - Answers -
What enzyme is activated in the calcium second messenger pathway? - Answers -
Phospholipase C.
What does phospholipase C convert PIP2 into? - Answers - IP3 and DAG.
What is the role of IP3? - Answers - It releases calcium from intracellular stores.
What does calcium bind to inside the cell? - Answers - Calmodulin.
What does the calcium-calmodulin complex activate? - Answers - Ca²⁺-calmodulin-
dependent protein kinase (CaM kinase).
What is the final effect of CaM kinase activation? - Answers - Phosphorylation of target
proteins and cellular response.
Lipophilic Hormone Mechanism of Action - Answers -
How do lipophilic hormones enter cells? - Answers - By diffusing across the plasma
and/or nuclear membrane.
