Graded A+
1.Hormonal Stimulation: stimulus for release of cortisol, mineralocorticoids, aldosterone) -
hormones by the binding of another hormone (eg ANSWER -Steroids
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 modified amino acids, water soluble (except
blood glucose levels rise so insulin is released thyroid)
from pancreas, or fall and glucagon is released) 1. Catecholamines (epinephrine and
3.Neural Stimulation: direct stimulation from norepinephrine)
nervous system to endocrine gland (eg 2. Thyroid Hormone → lipid soluble
epinephrine and norepinephrine by adrenal 3. Melatonin - ANSWER -Biogenic Amines
medulla during fight or flight) - ANSWER -3
reflex mechanisms that stimulate hormone
secretion
most hormones, small chains of amino acids,
water soluble
1. Small peptides and large polypeptides
Stimulus for release of hormones by the binding 2. Glycoproteins - ANSWER -Proteins
of another hormone (eg the TSH from anterior
pituitary binds to thyroid gland to release TH) -
ANSWER -Hormonal Stimulation
DO NOT circulate in blood, so only affect either
same cell that produced them (autocrine) or
neighboring cells (Paracrine)
release of hormone in response to change of 1. Eicosanoids: synthesized through enzymatic
blood nutrient levels (eg blood glucose levels rise cascade, Phospholipase A2 removes fatty acid
so insulin is released from pancreas, or fall and from phospholipid within the plasma membrane
glucagon is released) - ANSWER -Humoral --> prostaglandins - ANSWER -Local
Stimulation Hormones
direct stimulation from nervous system to -Famous eicosanoid
endocrine gland (eg epinephrine and -are diverse group: synthesized by most tissues
norepinephrine by adrenal medulla during fight or in the body
flight) - ANSWER -Neural Stimulation -Stimulate pain receptors, reduce fever, increase
inflammatory response - ANSWER -
Prostaglandins
lipid soluble molecules synthesized by
cholesterol
1. Gonads (Estrogen, Progesterone, Can cross membrane, but needs carrier protein
Testosterone) while circulating in blood, once unbound they can
2. Adrenal Cortex hormones (Corticosteroids like enter the nucleus
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, Bio 245 Klesath Exam 1 NCSU Test Questions with Answers
Graded A+
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 i. Phospholipase C is enzyme activated by G-
c. Once bound, forms a hormone receptor protein
complex which interacts with DNA directly in ii. Splits into PIP2 and second messengers, DAG
regions called Hormone Response Element and IP3
(HRE) iii. DAG activates kinase C
d. Initiates transcription/translation and iv. IP3 leaves membrane and causes increase in
production of a new protein - ANSWER - Ca2 in cytosol which can directly affect or act as
Lipid soluble hormones: 3rd messenger - ANSWER -Phospholipase
C
Travel free in blood so shorter half-life, cannot
enter plasma membrane so binds to a membrane When the amount of hormones is small, then the
bound receptor number of receptors increase in order to increase
a. Second messengers begin a signal the sensitivity and obtain more of the hormones
transduction pathway, which can cause an --> Occurs with changes in development, cell
amplified signal - ANSWER -Water soluble cycle, and cell activity - ANSWER -
hormones Upregulation
a. Hormone binds to G-Protein and activates it If there is an abundent amount of hormone in the
when GDP→ GTP blood, then the number of receptors decrease
b. Active G-Protein is released and receptor --> Occurs with changes in development, cell
moves along inside plasma mebrane, either to cycle, and cell activity - ANSWER -
activate or inhibit other intracellular cascades - Downregulation
ANSWER -G protein activation by water-
soluble hormones
hormones work together to have a greater effect
a. 1+1=3, estrogen and progesterone together
a. Hormone binds to G-Protein and activates it have a stronger effect than individually -
when GDP→ GTP ANSWER -Synergistic Hormone Interaction
b. Active G-Protein is released and receptor
moves along inside plasma mebrane, either to
activate or inhibit other intracellular cascades
c. Using ATP, cAMP is created and activates first hormone allows action of a second, one has
protein kinase A, which will phosphorylate things to occur before another does
→ small concentration of hormone can have a. Prolactin produces the milk and oxytocin
large effect on cell - ANSWER -Adenylate allows the release of milk - ANSWER -
Cyclase Permissive Hormone Interaction
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