HUBS 191 - Endocrine System Exam Questions and Answers Fully Solved Latest Version 2025-
2026
what is homeostasis? - Answers the presence of a stable internal environment
can the sensors and control center be in the same tissue? are they always? - Answers yes, no
do the sensors always detect both increases and decreases from the set point? - Answers no
synaptic (neural) control systems vs. endocrine (hormonal) control system - Answers specific
wiring of neurons, fast transmission speed, good for brief responses (distribution of effects in
limited to a specific area) vs.
hormones that are released into the blood, targeted due to the presence of target cells. it's a
relatively slow process but has long lasting action; good for systemic (widespread) and
sustained responses
what is the chemical classification of water soluble hormones? - Answers peptides and
catecholamides
what is the chemical classification of lipid (fat) soluble hormones? - Answers steroids and
thyroid hormones
what hormones are stored, and what are made and released when required? - Answers stored =
water soluble hormones and thyroid hormones, made as required = steroids (made from
cholesterol)
which hormones require a carrier protein to travel through the blood? - Answers lipid/fat soluble
which hormones are can travel through the cell membrane freely and thus have receptors on the
inside of cells (cytoplasm or nucleus)? - Answers lipid/fat soluble
what is the mechanism of action for water soluble hormones? - Answers through second
messengers
what is the mechanism of action for lipid soluble hormones? - Answers altering gene
transcription
what is the comparative speed of response of water vs. lipid soluble hormones? - Answers
water is fast (milliseconds - minutes), lipid is slow (hours - days)
what are the 3 mechanisms of intercellular communication? - Answers paracrine, autocrine, and
endocrine
paracrine communication - Answers transmission through ECF using paracrines as the
chemical signal; effects are primarily limited to the local area where paracrine concentration is
high, target cells must have the appropriate receptors
, autocrine communication - Answers transmission through the ECF, autocrines are the chemical
signal, the effects are limited to the cell that secreted them
endocrine communication - Answers the chemical signals are hormones which travel through
the bloodstream to target cells which are mainly in distant tissue and organs and must have
appropriate receptor cells
what is the definition of a true hormone? - Answers a chemical signal produced in one cell and
transported via the blood stream to a second location (target cells) where they cause a
response in those cells
where are the receptors for water soluble hormones (peptides and catecholamides)? - Answers
in the target cell's membrane
what is the cellular response to receptor activation with water soluble hormones? - Answers the
hormone binds to the protein receptor on the cell surface and activates the intracellular G
protein. changes occur within the cell as a result of this and a second messenger pathway is
activated, causing a response within the cells (downstream proteins and pathways are
activated/inactivated)
how do lipid soluble hormones induce a cellular response? - Answers the lipid soluble hormone
dissociates from the carrier protein and the hormone diffuses across the membrane. the
hormone binds to the intracellular receptor and this hormone-receptor complex acts as a
specific transcription factor. The target gene is activated, new mRNA is generated, the
translation of which produces a new protein which mediates cell specific response
how are hormone levels usually maintained? - Answers by negative feedback, reducing the
change until the stimulus is removed or directly preventing further release
what is positive feedback? - Answers the amplification of a change until the desired outcome is
achieved eg. childbirth (hormonal) or blood clotting (non-hormonal)
what can having too much or too little hormone lead to? - Answers endocrine disorders
is the pancreas endocrine or exocrine? - Answers both
how does the pancreas act as an exocrine gland? - Answers the cells of the pancreatic acini
secrete digestive enzymes
how does the pancreas act as an endocrine gland? - Answers made of pancreatic islets (only
~1% of its mass), within a pancreatic islet are alpha cells (which secrete glucagon) and beta
cells (which secrete insulin)
what happens if blood glucose concentration is too high for too long? - Answers diabetes (type
2) develops
2026
what is homeostasis? - Answers the presence of a stable internal environment
can the sensors and control center be in the same tissue? are they always? - Answers yes, no
do the sensors always detect both increases and decreases from the set point? - Answers no
synaptic (neural) control systems vs. endocrine (hormonal) control system - Answers specific
wiring of neurons, fast transmission speed, good for brief responses (distribution of effects in
limited to a specific area) vs.
hormones that are released into the blood, targeted due to the presence of target cells. it's a
relatively slow process but has long lasting action; good for systemic (widespread) and
sustained responses
what is the chemical classification of water soluble hormones? - Answers peptides and
catecholamides
what is the chemical classification of lipid (fat) soluble hormones? - Answers steroids and
thyroid hormones
what hormones are stored, and what are made and released when required? - Answers stored =
water soluble hormones and thyroid hormones, made as required = steroids (made from
cholesterol)
which hormones require a carrier protein to travel through the blood? - Answers lipid/fat soluble
which hormones are can travel through the cell membrane freely and thus have receptors on the
inside of cells (cytoplasm or nucleus)? - Answers lipid/fat soluble
what is the mechanism of action for water soluble hormones? - Answers through second
messengers
what is the mechanism of action for lipid soluble hormones? - Answers altering gene
transcription
what is the comparative speed of response of water vs. lipid soluble hormones? - Answers
water is fast (milliseconds - minutes), lipid is slow (hours - days)
what are the 3 mechanisms of intercellular communication? - Answers paracrine, autocrine, and
endocrine
paracrine communication - Answers transmission through ECF using paracrines as the
chemical signal; effects are primarily limited to the local area where paracrine concentration is
high, target cells must have the appropriate receptors
, autocrine communication - Answers transmission through the ECF, autocrines are the chemical
signal, the effects are limited to the cell that secreted them
endocrine communication - Answers the chemical signals are hormones which travel through
the bloodstream to target cells which are mainly in distant tissue and organs and must have
appropriate receptor cells
what is the definition of a true hormone? - Answers a chemical signal produced in one cell and
transported via the blood stream to a second location (target cells) where they cause a
response in those cells
where are the receptors for water soluble hormones (peptides and catecholamides)? - Answers
in the target cell's membrane
what is the cellular response to receptor activation with water soluble hormones? - Answers the
hormone binds to the protein receptor on the cell surface and activates the intracellular G
protein. changes occur within the cell as a result of this and a second messenger pathway is
activated, causing a response within the cells (downstream proteins and pathways are
activated/inactivated)
how do lipid soluble hormones induce a cellular response? - Answers the lipid soluble hormone
dissociates from the carrier protein and the hormone diffuses across the membrane. the
hormone binds to the intracellular receptor and this hormone-receptor complex acts as a
specific transcription factor. The target gene is activated, new mRNA is generated, the
translation of which produces a new protein which mediates cell specific response
how are hormone levels usually maintained? - Answers by negative feedback, reducing the
change until the stimulus is removed or directly preventing further release
what is positive feedback? - Answers the amplification of a change until the desired outcome is
achieved eg. childbirth (hormonal) or blood clotting (non-hormonal)
what can having too much or too little hormone lead to? - Answers endocrine disorders
is the pancreas endocrine or exocrine? - Answers both
how does the pancreas act as an exocrine gland? - Answers the cells of the pancreatic acini
secrete digestive enzymes
how does the pancreas act as an endocrine gland? - Answers made of pancreatic islets (only
~1% of its mass), within a pancreatic islet are alpha cells (which secrete glucagon) and beta
cells (which secrete insulin)
what happens if blood glucose concentration is too high for too long? - Answers diabetes (type
2) develops
