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BIO 245 KLESATH EXAM 1 NCSU 2025
UPDATED ACTUAL EXAM WITH
CORRECT SOLUTIONS.
3 reflex mechanisms that stimulate hormone secretion - correct
answer- 1.Hormonal Stimulation: stimulus for release of
hormones by the binding of another hormone (eg the TSH from
anterior pituitary binds to thyroid gland to release TH)
2.Humoral Stimulation: release of hormone in response to
change of blood nutrient levels (eg blood glucose levels rise so
insulin is released from pancreas, or fall and glucagon is
released)
3.Neural Stimulation: direct stimulation from nervous system to
endocrine gland (eg epinephrine and norepinephrine by adrenal
medulla during fight or flight)
Hormonal Stimulation - correct answer- Stimulus for release of
hormones by the binding of another hormone (eg the TSH from
anterior pituitary binds to thyroid gland to release TH)
Humoral Stimulation - correct answer- release of hormone in
response to change of blood nutrient levels (eg blood glucose
levels rise so insulin is released from pancreas, or fall and
glucagon is released)
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Neural Stimulation - correct answer- direct stimulation from
nervous system to endocrine gland (eg epinephrine and
norepinephrine by adrenal medulla during fight or flight)
Steroids - correct answer- lipid soluble molecules synthesized
by cholesterol
1. Gonads (Estrogen, Progesterone, Testosterone)
2. Adrenal Cortex hormones (Corticosteroids like cortisol,
mineralocorticoids, aldosterone)
Biogenic Amines - correct answer- modified amino acids, water
soluble (except thyroid)
1. Catecholamines (epinephrine and norepinephrine)
2. Thyroid Hormone → lipid soluble
3. Melatonin
Proteins - correct answer- most hormones, small chains of
amino acids, water soluble
1. Small peptides and large polypeptides
2. Glycoproteins
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Local Hormones - correct answer- DO NOT circulate in blood,
so only affect either same cell that produced them (autocrine)
or neighboring cells (Paracrine)
1. Eicosanoids: synthesized through enzymatic cascade,
Phospholipase A2 removes fatty acid from phospholipid within
the plasma membrane
--> prostaglandins
Prostaglandins - correct answer- -Famous eicosanoid
-are diverse group: synthesized by most tissues in the body
-Stimulate pain receptors, reduce fever, increase inflammatory
response
Lipid soluble hormones: - correct answer- Can cross
membrane, but needs carrier protein while circulating in blood,
once unbound they can enter the nucleus
a. Has a longer half-life bc protected by carrier proteins
b. Once inside the cells, hormone binds to intracellular receptor
either in nucleus of cytosol
c. Once bound, forms a hormone receptor complex which
interacts with DNA directly in regions called Hormone
Response Element (HRE)
d. Initiates transcription/translation and production of a new
protein
BIO 245 KLESATH EXAM 1 NCSU 2025
UPDATED ACTUAL EXAM WITH
CORRECT SOLUTIONS.
3 reflex mechanisms that stimulate hormone secretion - correct
answer- 1.Hormonal Stimulation: stimulus for release of
hormones by the binding of another hormone (eg the TSH from
anterior pituitary binds to thyroid gland to release TH)
2.Humoral Stimulation: release of hormone in response to
change of blood nutrient levels (eg blood glucose levels rise so
insulin is released from pancreas, or fall and glucagon is
released)
3.Neural Stimulation: direct stimulation from nervous system to
endocrine gland (eg epinephrine and norepinephrine by adrenal
medulla during fight or flight)
Hormonal Stimulation - correct answer- Stimulus for release of
hormones by the binding of another hormone (eg the TSH from
anterior pituitary binds to thyroid gland to release TH)
Humoral Stimulation - correct answer- release of hormone in
response to change of blood nutrient levels (eg blood glucose
levels rise so insulin is released from pancreas, or fall and
glucagon is released)
,2 | Page
Neural Stimulation - correct answer- direct stimulation from
nervous system to endocrine gland (eg epinephrine and
norepinephrine by adrenal medulla during fight or flight)
Steroids - correct answer- lipid soluble molecules synthesized
by cholesterol
1. Gonads (Estrogen, Progesterone, Testosterone)
2. Adrenal Cortex hormones (Corticosteroids like cortisol,
mineralocorticoids, aldosterone)
Biogenic Amines - correct answer- modified amino acids, water
soluble (except thyroid)
1. Catecholamines (epinephrine and norepinephrine)
2. Thyroid Hormone → lipid soluble
3. Melatonin
Proteins - correct answer- most hormones, small chains of
amino acids, water soluble
1. Small peptides and large polypeptides
2. Glycoproteins
, 3 | Page
Local Hormones - correct answer- DO NOT circulate in blood,
so only affect either same cell that produced them (autocrine)
or neighboring cells (Paracrine)
1. Eicosanoids: synthesized through enzymatic cascade,
Phospholipase A2 removes fatty acid from phospholipid within
the plasma membrane
--> prostaglandins
Prostaglandins - correct answer- -Famous eicosanoid
-are diverse group: synthesized by most tissues in the body
-Stimulate pain receptors, reduce fever, increase inflammatory
response
Lipid soluble hormones: - correct answer- Can cross
membrane, but needs carrier protein while circulating in blood,
once unbound they can enter the nucleus
a. Has a longer half-life bc protected by carrier proteins
b. Once inside the cells, hormone binds to intracellular receptor
either in nucleus of cytosol
c. Once bound, forms a hormone receptor complex which
interacts with DNA directly in regions called Hormone
Response Element (HRE)
d. Initiates transcription/translation and production of a new
protein
