endocrine Flashcards
define endocrinology
study of hormones and endocrine organs
define endocrine
glands that secrete hormones or other products directly into the blood
what is a neurotransmitter
a chemical that travels from one neuron to another
what is a hormone
bodies chemical messengers
what is a paracrine signal
allows cells to communicate with each other by releasing signaling molecules that bind to and activate surrounding cells
what is the difference between hormone, paracrine signal
hormones are signaling molecules act locally to affect behavior of nearby cells. paracrine signals are a molecule released by one cell that acts on neighboring target cells.
define receptor
an organ able to respond to light, heat, or other external stimulus and transmit a signal to a sensory nerve
define target organ
organs that respond to a particular hormone
define target cell
cells within an organ that respond to a particular hormone
what does neural signaling do
releases signals directly onto target cells
what does endocrine signaling do
releases signals into the blood
can the same signal be a neurotransmitter or hormone?
yes, depending on whether it is released into the blood or at a synapses
what is a synapse
gap between neurons
identify the major endocrine glands
hypothalamus , pituitary, thyroid, thymus, adrenal gland, pancreas, and gonads
what hormones are produces by each endocrine gland
hypothalmus: GHRH, TRH, GnRH, CRH
pituitary: vasopressin, ACTH, GH, LH, FSH, oxytocin, TSH
thyroid: thyroid hormone
thymus: humoral factors
adrenal gland: corticosteroids
pancreas: glucagon, insulin
gonads: testerone and estrogen
know this:
a number of organs that are not endocrine glands produce hormones
what are the three main chemical classes of hormones
steroid hormones, monoamines, peptides
what are steroid hormones
lipids derived from cholesterol
what are the three main groups of steroid hormones
prostagens, androgens, oestrogens
what are monoamines
regulatory molecules derived from amino acids, include hydrophobic and hydrophilic molecules
what are peptide hormones
short chains of amino acids include hypothalamic releasing and inhibiting hormones, most anterior pituitary hormones, both posterior pituitary hormones, insulin and glucagon
significance of hydrophobic in hormone actions
able to diffuse through the membrane and interact with an intercellular receptor
hormones alter cell function by acting on cell surface proteins or through intracelluar mechanisms
true
what does hydrophobicity determine of a hormone
determines which of these a particular hormone does
what do many hydrophilic hormones act through
second messenger systems
what are second messenger systems
small molecules and ions that relay signals received by cell surface receptors effector proteins
what are the main second messenger systems
cAMP, cGMP, DAG, IP3
what is the basic function of the adenylate cyclase and IP3 second messenger systems
IP3: stimulates the release of calcium
adenylate cyclase: catalyzes the conversion of ATP and cAMP
what is an adenylate cyclase system
membrane bound enzyme catalyzes the conversion ATP and cAMP
define protein kinase
an enzyme that transfers phosphate groups from ATP to a protein
what role does protein kinase have in hormone actions and second messenger systems
how does protein kinase alter the activity of enzymatic pathways
how does protein kinase alter the activity of enzymatic pathways
they change their confirmation
what does phosphorylation mean
the process of adding a phosphate to something
the effects of activating second messenger systems are
cell dependent, and different cell types can use different hormones to activate the same system with cell specific effects
what do hydrophobic hormones do in a cell
they enter the cell and alter gene expression
how can cell sensitive be adjusted
upregulation and downregulation of receptors
define trophins
a hormone released in the body by a certain gland and which produces a response in other glands, stimulating the release of other hormones
define trophinc hormones
hormones of the anterior lobe of the pituitary
define stimulating hormones
a hormone made in the pituitary gland
define releasing hormones
a hormone that prompts the release of another hormone
define inhibiting hormones
hormones whose main purpose is to control the release of other hormones
what do hypophysiotrophic hormones act on
act on the anterior pituitary to release hormones
what do gonadotrophins act on
the gonads to release hormones
what do ACTH act on
the adrenal cortex to release hormones
what acts more quickly, a hormone with actions vs a second messenger system or one that causes changes in gene expression
??
define upregulation
the increase at the cellular level of the rate of a physiological response
define downregulation
the reduction at the cellular level of the rate of a physiological response
how do up and down regulation influence the sensitivity of the cell to the hormone
in upregulation, the number of receptors increases in response to rising hormone levels, making the cell more sensitive to the hormone allowing for more cellular activity.
when the number of receptors decrease in response to rising hormone levels, that is called down regulation
to study the endocrine system, it is useful to think about each gland like this :
- what hormones does it secrete
- what do those hormones do
- what causes their release
hypothalamus question guide
- what hormones does it secrete: TRH, GnRH, GHRH, CRH
- what do those hormones do: stimulate the release of pituitary hormones
- what cause their release: act on the pituitary gland
the thymus secretes what hormones
thymosins and thymopoietin, which regulate development and later activation of T-lymphocytes
undergo shrinkage after puberty
what are the thyroid hormones
T3, T4; increase the metabolic rate and heat production, and respiratory rate
what do interstitial cells produce
testosterone
what do granulosa cells produce
estrogen
ovarian follicles produce:
estrogen known as estradiol
androgen
male sex hormone
estrogen
female sex hormones
what are gonads
ovaries in female, testes in males
define insulin shock
hypoglycemia resulting in an overflow of insulin in the blood
blood glucose <40
what is ketonuria
ketones in the urine
what is glycosuria
sugar in the urine
what is hyperglycemia
excessive sugar in the blood
what is polyphagia
excessive hunger
what is polydipsia
excessive thirst
what is polyuria
excessive ruination
know the signs and symptoms of diabetes mellitus
polyuria, polydipsia, polyphagia, hyperglycemia, glycosuria, ketonuria
basic cause of type 2 diabetes i
insulin resistance
basic cause of type 1 diabetes
loss of beta cells, possibly from autoimmune destruction
begins at young age
what is glucose homeostasis
maintaining glucose levels in the body at near constant level
pancreas beta cells produce
insulin, which lowers blood glucose by allowing cells to take it into the cell
pancreas alpha cells produce
glucagon to raise blood glucose
pancreas
endocrine function: makes insulin to control blood sugar
exocrine function: secretion of digestive enzymes
islets: control blood glucose levels
describe the general adaptation syndrome:
describes the physiological changes your body goes through as a response to stress (GAS)
three phases: alarm reaction, resistance phase, and period of exhaustion.
describe the stress response
alarm reaction stage, resistance stage, exhaustion stage
what is a corticosteroid
a group of hormones, including cortisol, released by adrenal glands under stress
what is calcitonin
a hormone secreted by the thyroid that has the effect of lowering blood calcium
what are the symptoms of adult onset hypothyroidism
know the endocrine glands and the hormones released by all
