BIOL 2260 Exam 1 UPDATED ACTUAL Questions and CORRECT
Answers
Compare and contrast the actions of the endocrine Both systems release ligands
system and the nervous system to control body function Unlike the nervous system, the endocrine system transmits hormones through the
blood, targets any cells in the body with correct receptors, exhibits longer
reaction times, & has longer lasting effects
Describe the general functions controlled by the Regulating development, growth, & metabolism
endocrine system Maintaining homeostasis of blood composition & volume
Controlling digestive processes
Controlling reproductive activities
Distinguish between the two types of organization of Some glands are endocrine organs with solely endocrine function
endocrine cells Some "glands" are clusters of cells in organs with another function
Identify the major endocrine glands and their location Endocrine organs with only endocrine function: Pituitary, pineal, thyroid,
within the body parathyroid, & adrenal glands
Non-endocrine organs with endocrine function: Hypothalamus, skin, thymus,
heart, liver, stomach, pancreas, small intestine, adipose connective tissue, kidneys,
& gonads
Explain the three reflex mechanisms for regulating Hormonal stimulation: A gland cell releases its hormone when some other
secretion of hormones hormone binds to it
Humoral stimulation: A gland cell releases its hormone when there is a certain
change in levels of a nutrient or ion in the blood
Nervous stimulation: A gland cell releases its hormone when a neuron stimulates it
Is the entire pancreas an endocrine organ? No
Parathyroid hormone is secreted when blood calcium Humoral stimulation
levels drop too low. What sort of stimulation is this?
Distinguish the hormones that are lipid-soluble from Lipid-soluble hormones use carrier molecules & can diffuse across target cell
those that are water-soluble membrane; small, nonpolar, & lipophilic
Most water-soluble hormones travel freely through blood & use membrane
receptors; polar, cannot diffuse through membrane
, Describe the general function of local hormones Short-lived signaling molecules that influence cells within the local tissue from
which they are produced (doesn't circulate in blood)
Compare autocrine and paracrine signaling that occurs Autocrine stimulation: Effects on the same cell where messenger was formed
through local hormones Paracrine stimulation: Effects on neighboring cells
Insulin is made up of a chain of amino acids. Is it water Water soluble
soluble or lipid soluble?
Compare the transport of lipid-soluble hormones with Lipid-soluble hormones use carrier molecules
that of water-soluble hormones Most water-soluble hormones travel freely through blood
Describe the two primary factors that affect the Hormone synthesis: Done by the gland; the faster the synthesis rate, the higher
concentration level of a circulating hormone the blood concentration
Hormone elimination: Occurs in multiple ways; enzymatic degradation in liver
cells, removal from blood via kidney excretion, or target cell uptake; the faster the
elimination rate, the lower the blood concentration
Explain what is meant by the half-life of a hormone Time necessary to reduce a hormone's concentration to half of its original level
If hormone X and hormone Y had the same rate of Hormone Y would be at a higher level in the blood because the faster the
synthesis, but X's elimination rate was faster, which would elimination rate, the lower the blood concentration
be at a higher level in the blood?
Which type of hormone generally has a protein carrier in Lipid-soluble hormones
the blood?
Describe how lipid-soluble hormones reach their target Diffuses across target cell membrane
cell receptors and the type of cellular change they Once hormone enters cell, it binds to receptor & forms hormone-receptor
initiate complex
Complex binds to a hormone-response element of DNA
Results in transcription of RNA, which is translated into a protein
Describe how water-soluble hormones induce cellular Signal Transduction Pathway
change in their target cells Water hormone (first messenger) must bind with receptor
G Protein binds with the receptor
G protein activated by GDP & GTP
G protein released (second messenger)
Where are target cell receptors for lipophilic hormones In the cytosol or nucleus
located?
Describe the conditions that influence the number of Up & down regulation, depends on the amount of hormone in the blood & how
receptors available for a specific hormone many receptors there are
Define up-regulation and down-regulation Up-regulation: Increases number of receptors; increases sensitivity to hormone
Down-regulation: Decreases number of receptors; decreases sensitivity to
hormone
Answers
Compare and contrast the actions of the endocrine Both systems release ligands
system and the nervous system to control body function Unlike the nervous system, the endocrine system transmits hormones through the
blood, targets any cells in the body with correct receptors, exhibits longer
reaction times, & has longer lasting effects
Describe the general functions controlled by the Regulating development, growth, & metabolism
endocrine system Maintaining homeostasis of blood composition & volume
Controlling digestive processes
Controlling reproductive activities
Distinguish between the two types of organization of Some glands are endocrine organs with solely endocrine function
endocrine cells Some "glands" are clusters of cells in organs with another function
Identify the major endocrine glands and their location Endocrine organs with only endocrine function: Pituitary, pineal, thyroid,
within the body parathyroid, & adrenal glands
Non-endocrine organs with endocrine function: Hypothalamus, skin, thymus,
heart, liver, stomach, pancreas, small intestine, adipose connective tissue, kidneys,
& gonads
Explain the three reflex mechanisms for regulating Hormonal stimulation: A gland cell releases its hormone when some other
secretion of hormones hormone binds to it
Humoral stimulation: A gland cell releases its hormone when there is a certain
change in levels of a nutrient or ion in the blood
Nervous stimulation: A gland cell releases its hormone when a neuron stimulates it
Is the entire pancreas an endocrine organ? No
Parathyroid hormone is secreted when blood calcium Humoral stimulation
levels drop too low. What sort of stimulation is this?
Distinguish the hormones that are lipid-soluble from Lipid-soluble hormones use carrier molecules & can diffuse across target cell
those that are water-soluble membrane; small, nonpolar, & lipophilic
Most water-soluble hormones travel freely through blood & use membrane
receptors; polar, cannot diffuse through membrane
, Describe the general function of local hormones Short-lived signaling molecules that influence cells within the local tissue from
which they are produced (doesn't circulate in blood)
Compare autocrine and paracrine signaling that occurs Autocrine stimulation: Effects on the same cell where messenger was formed
through local hormones Paracrine stimulation: Effects on neighboring cells
Insulin is made up of a chain of amino acids. Is it water Water soluble
soluble or lipid soluble?
Compare the transport of lipid-soluble hormones with Lipid-soluble hormones use carrier molecules
that of water-soluble hormones Most water-soluble hormones travel freely through blood
Describe the two primary factors that affect the Hormone synthesis: Done by the gland; the faster the synthesis rate, the higher
concentration level of a circulating hormone the blood concentration
Hormone elimination: Occurs in multiple ways; enzymatic degradation in liver
cells, removal from blood via kidney excretion, or target cell uptake; the faster the
elimination rate, the lower the blood concentration
Explain what is meant by the half-life of a hormone Time necessary to reduce a hormone's concentration to half of its original level
If hormone X and hormone Y had the same rate of Hormone Y would be at a higher level in the blood because the faster the
synthesis, but X's elimination rate was faster, which would elimination rate, the lower the blood concentration
be at a higher level in the blood?
Which type of hormone generally has a protein carrier in Lipid-soluble hormones
the blood?
Describe how lipid-soluble hormones reach their target Diffuses across target cell membrane
cell receptors and the type of cellular change they Once hormone enters cell, it binds to receptor & forms hormone-receptor
initiate complex
Complex binds to a hormone-response element of DNA
Results in transcription of RNA, which is translated into a protein
Describe how water-soluble hormones induce cellular Signal Transduction Pathway
change in their target cells Water hormone (first messenger) must bind with receptor
G Protein binds with the receptor
G protein activated by GDP & GTP
G protein released (second messenger)
Where are target cell receptors for lipophilic hormones In the cytosol or nucleus
located?
Describe the conditions that influence the number of Up & down regulation, depends on the amount of hormone in the blood & how
receptors available for a specific hormone many receptors there are
Define up-regulation and down-regulation Up-regulation: Increases number of receptors; increases sensitivity to hormone
Down-regulation: Decreases number of receptors; decreases sensitivity to
hormone
