Hormones Flashcards
how many glands in the endocrine system
eight
liquid chemical messengers
hormones
produced and secreted in the blood when levels of glucose in blood becomes too high
insulin
is any member of a class of signaling molecules in multicellular organisms, that are transported to distant organs to regulate physiology and behavior.
hormone
hormone means
setting in motion
are required for the correct development of animals, plants, and fungi.
hormones
Among the substances that can be considered hormones are
eicosanoids
amino acid derivatives
protein/peptides
steroids
example of hormones
prostaglandins
thromboxanes
amino acid example
epinephrine
auxin
protein/peptides example
insulin
In ___, hormones are responsible for the regulation of many physiological processes and behavioral activities such as digestion, metabolism, respiration, sensory perception, sleep, excretion, lactation, stress induction, growth and development, movement, reproduction, and mood manipulation.
vertebrates
In ___, hormones modulate almost all aspects of development, from germination to senescence
plants
When a hormone binds to the receptor, it results in the activation of a _____ _____pathway that typically activates gene transcription, resulting in increased expression of target proteins.
signal transduction
generally act on the surface of target cells via second messengers.
water soluble hormones
water soluble hormones examples
peptides
amines
generally pass through the plasma membranes of target cells (both cytoplasmic and nuclear) to act within their nuclei.
lipid-soluble hormones
example of lipid soluble hormones
steroids and eicosanoids
can also act in rapid, non-genomic pathways that can be synergistic with genomic effects
hormones
are cellular processes that can lead to rapid cellular responses within seconds.
non genomic pathways
are mediated by nuclear receptors that regulate genes
genomic pathways
are specialized organs that secrete hormones into the endocrine signaling system.
endocrine glands
occurs in response to specific biochemical signals and is often subject to negative feedback regulation.
hormone secretion
For instance, high blood sugar (serum glucose concentration) promotes ____ ___
insulin snythesis
acts to reduce glucose levels and maintain homeostasis, leading to reduced glucose levels.
insulin
Upon secretion, ___-soluble hormones are readily transported through the circulatory system.
water
must bond to carrier plasma glycoproteins (e.g., thyroxine-binding globulin (TBG)) to form ligand-protein complexes
lipid-soluble hormones
what carrier does lipid-soluble hormones must bond to
carrier plasma glycoproteins
example of carrier plasma glycoproteins
thyroxine-binding globulin
Lipid-soluble hormones must bond to carrier plasma glycoproteins (e.g., thyroxine-binding globulin (TBG)) to form
ligand-protein complexes
Some hormones are completely active when released into the bloodstream
what example
insulin
growth hormones
that must be activated in specific cells through a series of activation steps that are commonly highly regulated
prohormones
secretes hormones directly into the bloodstream, typically via fenestrated capillaries
endocrine system
endocrine system secretes hormones directly into the bloodstream, typically via
fenestrated capillaries
are a type of blood vessel. They have tiny pores that allow nutrients, waste and oxygen to flow from the blood to the organs.
fenestrated capillaries
secretes its hormones indirectly using ducts
exocrine system
Hormones with ___ function diffuse through the interstitial spaces to a nearby target tissue.
paracrine
a term used in cellular biology to describe a type of cell signaling where a cell secretes a signal to change the behavior of nearby cells
paracrine
lack specialized organs for the secretion of hormones, although there is a spatial distribution of hormone production
plants
is produced mainly at the tips of young leaves and in the shoot apical meristem
auxin
The lack of specialized glands means that the main site of hormone production cannot/can change throughout the life of a plant
can
and the site of production is dependent on the plant’s
what two factors
age
environment
chemical messengers synthesized at one location that deliver messages to a different location
hormones
5 main types of hormones that influence plant growth
auxin
gibberellin
cytokinin
ethylene
abscisic acid
hormones that allows plants to bend towards the light
auxin
is the way plants and other organisms grow in response to light.
phototropism
the directional growth or turning of an organism in response to an external stimulus
tropism
where is auxin synthesized
stem tips
required for a plant to germinate
gibberellins
promote elongation of internodes
gibberellins
stem between notes
internodes
counters senescence in plants
cytokinin
produced in the root apical meristem
cytokinin
tips of the roots where cytokinin is produced
root apical meristem
uses this ratio to determine if the plant develops roots or shoots
cytokinin:auxin
more auxin promotes the formation of
roots
more cytokinin promotes the formation of
shoots
works with ethylene to cause the abscission of leaves, flowers, and fruits
cytokinin
ripens fruits
ethylene
gaseous, with low solubility in water
ethylene
more produced by rapidly growing and dividing cells
ethylene
important in germinating plants, preventing leaf expansion
ethylene
allows shoots to dig upward through the tsoil until it reaches llight
ethylene
hormone that signals dehydration
abscisic acid
synthesized in the chloroplast to makes leaves close their stomata to prevent water loss through phototranspiration
abscisic acid
a substance which produced in any one part of an organism, is transferred to another part and there influences a specific physiological prcoess
hormone
term hormone is derived from the greek word “___”
hormao
hormao means
to excite
the tissues where hormones are produced are called as
effectors
tissue or organs which hormoens exert their influence are called as
targets
hormones are produced in
duct-less glands/endocrine glands
hormone is a ___-cellular messenger
intra
what medium are hormones transported in from endocrine cell
blood
target cell has specific ___ to recognize homrone
receptor
have low molecular weight and diffuse readily
hormones
readily oxidized and their effects do not remain permanent unless supplied continuously
hormones
hormones are classified based on (2)
chemical nature
mechanism of action on target cell
chemically, hormones are group as (3)
protein or peptide hormones
steroid hormones
amino acid derivatives
example of protein or peptide hormones
insulin
glucagon
antidiuretic hormone
oxytocin
example of steroid hormones
glucocorticoids
mineralocorticoid
sex hormones
example of amino acid derivatives
epinephrine
norepinephrine
thyroxine
triiodothyronine
hormones based on mechanism of action on target cell (2)
group 1 hormones
group 2 hormones
bind to intracellular complexes, which then binds to the DNA and activates transcription of certain genes
group I hormones
bind to cell surface receptors and stimulate release of second messengers
group II hormones
group II hormones are further divided based on the type of group II messenger released on target cells (3)
cAMP
phosphatidylinositol/calcium
uncharacterized
all steroid hormones and amino acid derivatives fall in the category of
lipophilic
protein or peptide hormones are __
hydrophilic
steroid hormones and amino acid derivatives fall in what group of hormones
group I hormones
group I hormones are lipophilic/hydrophilic
lipophilic
group II hormones are lipophilic/hydrophilic
hydrophilic
protein or peptide hormones are what type of homrones
group II hormones
lipophilic hormone action
endocrine gland releases lipophilic hormone
hormones travels in the blood and reaches target cell (receptor is present in the cell nucleus)
cell is lipophilic so it can easily enter the cell through the cell membrane and through the nuclear pore
binds to the receptor and forms hormone receptor complex
complex binds to DNA and activates transcription to induce desired effect
hormones that act in the mechanisms of lipophilic hormone action
estrogens
progestins
androgens
glucocorticoids
mineralocorticoids
calcitriol
thyroid hormones
hydrophilic hormone action
endocrine gland releases hydrophilic hormone
hormone travels in the blood and reaches target cell
receptor of hydrophilic hormone is present in the cell membrane
hormone cannot enter the cell since it is hydrophilic
receptor induces the release of 2nd messengers (cAMP/phosphatidylinositol/calcium)
2nd messengers activates or deactives cellular enzymes to induce desired effect
hormones that undergo hydrophilic hormone action
Adenocotricotropic homrone (ACTH)
follicle stimulating hormone (FSH)
luteinizing hormone (LH)
chorionic gonadotropin (hCG)
thyroid stimulating hormone (TSH)
antidiuretic hormone (ADH)
glucagon
parathyroid hormone (PTH)
calcitonin
epinephrine
norepinephrine
insulin
gastrin
major endocrine glands found in the body
pineal gland
pituitary gland
thyroid gland
pancreas
adrenal glands
testis (male)
ovary (female)
endocrine gland found in the head
pineal
pituitary gland
endocrine gland located in the neck
thyroid gland
gland located in the abdomen
pancreas
adrenal gland
steps in hormone signaling
Biosynthesis of a particular hormone in a particular tissue
Storage and secretion of the hormone
Transport of the hormone to the target cell(s)
Recognition of the hormone by an associated cell membrane or intracellular receptor protein
Relay and amplification of the received hormonal signal via a signal transduction process: This then leads to a cellular response. The reaction of the target cells may then be recognized by the original hormone-producing cells, leading to a down-regulation in hormone production. This is an example of a homeostatic negative feedback loop.
Breakdown of the hormone.
are typical of a specialized cell type, residing within a particular endocrine gland, such as the thyroid gland, ovaries, and testes.
hormone producing cells
Hormones exit their cell of origin via ___ or another means of membrane transport.
exocytosis
refers to the fusion of secretory vesicles with the plasma membrane and results in the discharge of the vesicle content into the extracellular space and the incorporation of new proteins and lipids into the plasma membrane.
exocytosis
communication of ten invloves a signal sent from one location to another that instructs the second organ about the status of some cellular feature
insulin signalling
is a process that involves the use of signaling proteins and molecules to relay information within a cell and to the mitochondria
cytoplasmic signalling
process that occur when phosphate binds itself on the receptors during insulin signalling
autophosphorylation