L2 Flashcards
when hormones act on processes inside the cell
intracrine mediation
when autocrine substances feed back to influence the same cells that secreted them
autocrine mediation
when paracrine cells secrete chemicals that affect adjacent cells
paracrine mediation
when endocrine cells secrete chemicals into the bloodstream where they may travel to distant target cells
endocrine mediation
when ectocrine substances, such as pheromones are released into the environment by individuals to communicate with others
ectocrine mediation
endocrine glands are ____ and have a rich ____ supply (ie. relies on the _____ system)
ductless, blood, circulatory
endocrine glands produce hormones that are secreted into the bloodstream, which travel to _____ cell in the body
every
hormone receptors are ____ ____ cells for hormones and are located either ___ the cell or embedded in the ____ ____
specific binding, inside, cell membrane
amino acid derived hormones are made from ___ and ____, and contain a “-____” suffix. They are water ____, and stored in protein ____ inside ____ __ (vesicles). They are released from endocrine cells via ______ in response to some stimulus (_____ secretion). Amino acid derived hormones include ___ hormones, ____, and ____ derivatives
tyrosine, tryptophan, ine, soluble, matrices, secretory granules, exocytosis, regulatory, thyroid, catecholamines, tryptophan
Because amino acid derived hormones are ____ insoluble, they need a vesicle in order to pass through the lipid bilayer. The vesicle fuses with the ______ ___ and creates an opening, allowing the hormones to diffuse into the ____ _____. From there, the hormones enter the _____.
lipid, cell membrane, extracellular space, bloodstream
Thyroid hormones such as _____ act on receptors ____ the cell membrane
thyroxine, inside
Catecholamines such as ____, ____ and _____ are released from the ___ ___ and bind to receptors ____ the cell membrane
epinephrine, norepinephrine, dopamine, adrenal medulla, on
Tryptophan derivatives such as ____, bind to receptors ___ the cell membrane and are released by the ____ gland
melatonin, on, pineal
Protein and peptide hormones are chains of 20 _____ ____. They are synthesized as _____, or inactive molecules that are converted to active hormones either before or after they’re _____. They are _____ soluble, stored in ___ and released via ____. They bind to receptors ___ the membrane, and are much ___ than amino acid or lipid derived hormones. Larger protein hormones have ______ half-lives than shorter peptide hromones
amino acids, prohormones, secreted, water, vesicles, exocytosis, on, bigger, longer
Preprohormones have a _____ peptide that brings the molecule to the ___ _____. The chain is ____ into an inactive fragment and active prohormone. Sometimes, it is broken into several different ___ of hormones (e.g. POMC), and sometimes it is broken into many copies of the ___ hormone
signal, endoplasmic reticulum, cleaved, types, same
examples of peptide hormones
oxytocin, vasopressin, rfamide, kisspeptin, GnIH
examples of protein hormones
growth hormone, prolactin, insulin, glucagon, ghrelin, leptin, most hormones of pituitary gland
examples of glycoproteins
thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone
hormones that are Polypeptide chains with an added carbohydrate chain
glycoproteins
Lipid derived hormones are made of ___ rings and side chains that are either built from ___ ____ or _____. They are usually ___ or _____, and are separated into ___ ___ and ______. They are ____ in water, and can readily pass through the cell membrane. They bind to ____/_____ receptors, and require carrier proteins for transport in _____. Due to this, they have longer ____ than amino-acid derivatives and peptide protein hormones. They signal to trigger both hormone _____ and _____.
carbon, fatty acids, cholesterol, ketones, alcohols, sex steroids, corticosteroids, insoluble, cytosolic/intracellular, blood, half-lives, release, production
all steroid hormones originate from the initial conversion of ______ to ______ and their genesis is regulated by ___ activity and concentration. This first step is the ____ _____ step
cholesterol, pregnenolone, enzyme, rate limiting
Some examples of elcosanoids/fatty acids
leukotrienes, prostaglandin E
some examples of steroids
androgens, estrogens, progestins, corticosteroids, calcitriol
mechanism in which proteins are modified, usually by second messengers, and is faster
protein hormone action (non genomic)
intracellular signalling molecules released by the cell to amplify intracellular signal transduction cascades
second messengers
The cAMP pathway was discovered by ______. When the hormone binds to the receptor, the receptor activates the ____ protein. ____ replaces GDP. Part of the activated G protein activates an effector protein (e.g. ____ _____), that converts thousands of reactants to products, thus amplifying the action of a single signal molecule (ex. ____ –> cAMP). cAMP activates ______ _____ ____ and this in turn ____ enzymes. The GTP on the G protein is hydrolyzed to GDP, but remains ___ to the protein
Sutherland, G, GTP, adenylyl cyclase, ATP, protein kinase A, phosphorylates, bound
In the phospholipase C pathway, the hormone again binds to the receptor ___ the cell membrane. Phospholipase C is activated by a _____ ____. Inside the cell, ____ which is derived from PIP2, is activated, which binds to a ____ channel inside the membrane of the ___ ___ and causes intracellular signals by the release of _____. On the cell membrane, _____ is activated, which activates ____ ___ ___ and causes cellular response by phosphorylation of target proteins
on, G protein, IP3, calcium, endoplasmic reticulum, calcium, DAG, protein kinase C
In the receptor tyrosine kinase pathway, ____ RTKs are activated through ____ RTKs, through ______. Signalling proteins are activated by binding to ____, which relays a signal to the cell _____, causing further downstream effects
inactive, dimerized, autophosphorylation, kinases, interior
when hormone action produces new hormones, have longer lasting effects, and are slower
steroid hormone action (genomic)
Steroid hormone action occurs with _______ hormones that diffuse through the plasma membrane to bind with a receptor in the ______. This forms a _______ ____, which enters the nucleus and triggers ___ ____. The transcribed ____ is translated into proteins that alter cell activity
lipid-soluble, cytoplasm, receptor-hormone comlpex, gene transcription, mRNA
Hormones that operate via the tyrosine kinase mechanism
- Growth hormone, 2. insulin, 3. prolactin
Hormones that operate via the steroid hormone mechanism
glucocorticoids, estrogens, aldosterone, testosterone, progesterones, thyroid hormones
hormones that operate via the IP3/Ca2+ mechanism
GnRH, GHRH, Epinephrine, Oxytocin, TRH, AVP,
The hypothalamus controls hormone ______, maintains _____, _____ _____, body ____, _____ balance, body _____, _____, and the ____ cycle. It also influences the ___ ____ and affect aspects of behaviour through its connection with the _____ system.
secretions, homeostasis, food intake, weight, electrolyte, temperature, reproduction, sleep-wake, emotional, motivational, limbic
The hypothalamic-pituitary system regulates ____ function. ___/____ hormones regulate the production and release of ___ hormones by the anterior pituitary gland. Hormones released by the posterior pituitary gland are ____ inside the hypothalamus, and maintained through ____ to the hypothalamus.
endocrine, releasing/inhibiting, tropic, synthesized, feedback
Gland responsible for reproductive maturation and body rhythms
pineal gland
The anterior pituitary gland is responsible for hormone secretion by the ____, ___ ___ and ____, as well as growth.
thyroid, adrenal cortex, gonads
the _____ system of the anterior pituitary ensures that blood flows primarily in one direction, from the ___ to the ____. Due to this, when axon terminals in the hypothalamus release ____ hormones in the _____, they circulate and do not go back up to the hypothalamus.
portal, hypothalamus, pituitary, releasing, capillaries
CRH from the hypothalamus causes the release of ______ in the anterior pituitary, which causes the release of ____ from the from the ___ __ which sits on top of the kidneys
ACTH, corticosteroids, adrenal cortex
TRH causes the release of _____ from the anterior pituitary, which causes the release of ____ ____ from the _____.
TSH, thyroid hormones, thyroid
GnRH ____, while _____ inhibits the release of both ____ and ___ from the anterior pituitary. This causes a release of _______ from the testes, and ____ and ____ from the ovaries
facillitates, GnIH, LH, FSH, androgens, estrogens, progestins
Prolactin releasing peptide, and ___ ____ ____ or _____ regulates the release of prolactin in the anterior pituitary. Prolactin release causes targets the ___ ____ for milk production
prolactin inhibitng factor, dopamine, mammary glands
somatocrinin stimulates, and _____ inhibits the release of ___ ___ from the anterior pituitary, which facilitates ____ ___
somatostatin, growth hormone, bone growth
the posterior pituitary is responsible for ____/_____ balance. It has no portal system, thus, hormones enter directly into ____ ____. The posterior pituitary ___ and ____ oxytocin and vasopressin, but they are synthesized in the hypothalamus by _____ cells in the _____ and ____ nuclei
salt/water, general circulation, stores, releases, magnocellular, paraventricular, supraoptic
The anterior and posterior pituitary gland are separated by the ____ ____, though this structure is not seen in all animals
pars intermedia
the cortex of the adrenal glands are responsible for ___ and ____ metabolism, and ____ reactions. The medulla is responsible for ____ arousal.
salt, carbohydrate, inflammatory, emotional
the pancreas is responsible for
sugar metabolism
The gut is responsible for
digestion and appetite control
the gonads are responsible for _____ development, and maintenance of ____ ____ in adults
body, reproductive organs
When hormones activate the target tissue, and the product made inhibits the endocrine gland to stop further production of hormone
negative feedback
when the hormones activate the target tissue, and the product made stimulates the endocrine glad fro more hormone
positive feedback
____ and ___ exhibit both positive and negative feedback. From day ____-___, it exhibits positive feedback, while the rest of the cycle is under negative feedback
LH, FSH, 12-14
