BIO 226 Exam 1 UPDATED ACTUAL Questions and CORRECT
Answers
endocrine system works with the nervous system to control the body; epinephrine, dopamine- both
neuron transmitter and hormone
pituitary, thyroid, parathyroid, adrenal, pineal, thymus six endocrine glands
pancreas, gonads the two glands of the body that are both endocrine and exocrine
hormones chemical substances secreted by cells into the extracellular fluids (blood); will
travel long distances; produced by ductless glands; SLOWER to work than
neurotransmitter effects last LONGER than transmitter; under NEGATIVE
FEEDBACK CONTROL
cellular changes hormones can produce in target cells alter plasma membrane permeability; stimulate protein synthesis; activate or
deactivate enzyme systems; induce secretory activity; stimulate mitosis
eicosanoids a type of hormone; leukotrienes and prostaglandins; fatty acid derivatives- not
cholesterol; localized hormones- not truly a group of hormones
amino-acid based hormones water-soluble- must enter the cell through carrier proteins but can freely travel
through the blood; work rapidly- but duration is limited; includes amines,
thyroxine (does not follow the rules though), peptide, and protein hormones-
catecholamines (epinephrine, norepinephrine); most hormones belong to this
class
steroid hormones derived from cholesterol; lipid soluble- can directly enter cells through diffusion;
work slowly, but have long duration; require a plasma protein to be transported in
the bloodstream; includes gonadal (testosterone, estrogen, and progesterone)
and adrenocortical (cortisone, aldosterone, androgens) hormones; these
hormones usually have the suffix "one"
second messenger mechanism, direct gene activation the two mechanisms hormones use to alter target cell activity
second messenger mechanism used by all amino acid based hormones; requires membrane- bound receptors
(transport proteins) on target cell
direct gene activation used by all steroid and thyroxine hormones; requires intracellular (in the
cytoplasm or nucleus) receptor on target cell; directly enter cell- does not bind
to a receptor of cell membrane
second messenger mechanism steps 1. hormone (first messenger) binds to its receptor, which then binds to a G protein
2. the G protein is then activated as it binds GTP, displacing GDP
3. Second messenger (another molecule) is produced
4. a biological effect is achieved (e.g. enzymes produced, muscle contraction,
etc.)
, steroid hormone action direct-gene activation
1. hormone directly enters the target cell and binds to/activates a specific
intracellular receptor
2. the hormone-receptor complex travels to the nucleus and binds a DNA-
associated receptor protein
3. this interaction prompts DNA transcription to produce mRNA
4. the mRNA is translated into proteins, which bring about a cellular effect
(produce a biological effect)
latency period the time it takes the hormone to "turn on genes"
target cell hormones circulate to all tissues but only activate cells specific cells; must have
specific receptors to which the hormone binds; the receptors may be intracellular
(steroids) or located on plasma membrane (amino-acid based)
three factors target cell activation depends on blood levels of the hormone; relative number of receptors on the target cell; the
affinity of those receptors for the hormone; if any of the 3 missing- no biological
effect
up-regulation target cells form MORE receptors in response to the hormone (e.g. dopamine
receptors and schizophrenia); usually due to lack of hormone in the blood
down-regulation target cells LOSE receptors in response to the hormone (e.g. Type II diabetes);
usually due to too much hormone in the blood
pituitary gland two-lobed organ that secretes nine major hormones; anterior and posterior
neurohypophysis posterior lobe of the pituitary (neural tissue) and the infundibulum; DOES NOT
PRODUCE HORMONES; receives, stores, and releases hormones made in the
hypothalamus
adenohypophysis anterior lobe of the pituitary made up of glandular tissue- highly cellular; makes
and secretes a number of hormones; does most of the work of the gland- the true
"master gland"; no direct neural contact with the hypothalamus; vascular
connection- hypothalamohypophyseal portal system
formation of the pituitary posterior-outpocketing of brain tissue; anterior-originally mouth tissue pinched
off and combines with the posterior- why so cellular and similar to epithelial cells
hypothalamo-hypophyseal tract group of fibers that connects into the pituitary
oxytocin and antidiuretic hormone (ADH) hormones the nuclei of the hypothalamus synthesize that are transported to the
posterior pituitary
oxytocin synthesized in the hypothalamus and released by posterior pituitary; causes
smooth muscle contraction in uterus and breasts (milk "let down"); stimulated by
suckling of baby or baby's cry; under POSITIVE feedback (only hormone)
oxytocin in males causes sperm release; sexual arousal, orgasm, and bonding with mother and
child- dad will have high levels after childbirth
Answers
endocrine system works with the nervous system to control the body; epinephrine, dopamine- both
neuron transmitter and hormone
pituitary, thyroid, parathyroid, adrenal, pineal, thymus six endocrine glands
pancreas, gonads the two glands of the body that are both endocrine and exocrine
hormones chemical substances secreted by cells into the extracellular fluids (blood); will
travel long distances; produced by ductless glands; SLOWER to work than
neurotransmitter effects last LONGER than transmitter; under NEGATIVE
FEEDBACK CONTROL
cellular changes hormones can produce in target cells alter plasma membrane permeability; stimulate protein synthesis; activate or
deactivate enzyme systems; induce secretory activity; stimulate mitosis
eicosanoids a type of hormone; leukotrienes and prostaglandins; fatty acid derivatives- not
cholesterol; localized hormones- not truly a group of hormones
amino-acid based hormones water-soluble- must enter the cell through carrier proteins but can freely travel
through the blood; work rapidly- but duration is limited; includes amines,
thyroxine (does not follow the rules though), peptide, and protein hormones-
catecholamines (epinephrine, norepinephrine); most hormones belong to this
class
steroid hormones derived from cholesterol; lipid soluble- can directly enter cells through diffusion;
work slowly, but have long duration; require a plasma protein to be transported in
the bloodstream; includes gonadal (testosterone, estrogen, and progesterone)
and adrenocortical (cortisone, aldosterone, androgens) hormones; these
hormones usually have the suffix "one"
second messenger mechanism, direct gene activation the two mechanisms hormones use to alter target cell activity
second messenger mechanism used by all amino acid based hormones; requires membrane- bound receptors
(transport proteins) on target cell
direct gene activation used by all steroid and thyroxine hormones; requires intracellular (in the
cytoplasm or nucleus) receptor on target cell; directly enter cell- does not bind
to a receptor of cell membrane
second messenger mechanism steps 1. hormone (first messenger) binds to its receptor, which then binds to a G protein
2. the G protein is then activated as it binds GTP, displacing GDP
3. Second messenger (another molecule) is produced
4. a biological effect is achieved (e.g. enzymes produced, muscle contraction,
etc.)
, steroid hormone action direct-gene activation
1. hormone directly enters the target cell and binds to/activates a specific
intracellular receptor
2. the hormone-receptor complex travels to the nucleus and binds a DNA-
associated receptor protein
3. this interaction prompts DNA transcription to produce mRNA
4. the mRNA is translated into proteins, which bring about a cellular effect
(produce a biological effect)
latency period the time it takes the hormone to "turn on genes"
target cell hormones circulate to all tissues but only activate cells specific cells; must have
specific receptors to which the hormone binds; the receptors may be intracellular
(steroids) or located on plasma membrane (amino-acid based)
three factors target cell activation depends on blood levels of the hormone; relative number of receptors on the target cell; the
affinity of those receptors for the hormone; if any of the 3 missing- no biological
effect
up-regulation target cells form MORE receptors in response to the hormone (e.g. dopamine
receptors and schizophrenia); usually due to lack of hormone in the blood
down-regulation target cells LOSE receptors in response to the hormone (e.g. Type II diabetes);
usually due to too much hormone in the blood
pituitary gland two-lobed organ that secretes nine major hormones; anterior and posterior
neurohypophysis posterior lobe of the pituitary (neural tissue) and the infundibulum; DOES NOT
PRODUCE HORMONES; receives, stores, and releases hormones made in the
hypothalamus
adenohypophysis anterior lobe of the pituitary made up of glandular tissue- highly cellular; makes
and secretes a number of hormones; does most of the work of the gland- the true
"master gland"; no direct neural contact with the hypothalamus; vascular
connection- hypothalamohypophyseal portal system
formation of the pituitary posterior-outpocketing of brain tissue; anterior-originally mouth tissue pinched
off and combines with the posterior- why so cellular and similar to epithelial cells
hypothalamo-hypophyseal tract group of fibers that connects into the pituitary
oxytocin and antidiuretic hormone (ADH) hormones the nuclei of the hypothalamus synthesize that are transported to the
posterior pituitary
oxytocin synthesized in the hypothalamus and released by posterior pituitary; causes
smooth muscle contraction in uterus and breasts (milk "let down"); stimulated by
suckling of baby or baby's cry; under POSITIVE feedback (only hormone)
oxytocin in males causes sperm release; sexual arousal, orgasm, and bonding with mother and
child- dad will have high levels after childbirth
