Chapter 45 Hormones And The Endocrine System Flashcards
The ways that signals are transmitted between and classified by…what two criteria?
- the type of secreting cell
- The route taken by the signal in reaching its Target
____________ signaling maintains homeostasis, mediate responses to stimuli, regulates Growth and development.
Endocrine
What are the two types of local regulators?
Paracrine and endocrine signaling
Local regulators act by diffusing very short distances to reach target cells
In ____________ signaling, secreted molecules diffuse locally and trigger a response in neighboring cells
Paracrine
In ____________ signaling, secreted molecules diffuse locally and trigger a response in the cell that secretes them.
Autocrine
In ____________ signaling, secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body.
Endocrine
In _____________ signaling, Neurotransmitters diffuse across synapses and trigger responses in cells of target tissues (neurons, muscles, or glands).
Synaptic
In ______________ signaling, neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body.
Nueroendocrine
Endocrine cells group together in ductless organs
Secrete hormones directly into surrounding fluid
Endocrine glands
Ex:ovaries and stomach
Ducts in which secrete substances onto body surfaces or into cavities
Exocrine glands
Ex:pancreas is both!
cells that communicate in the immune system
cytocines
what are the chemical classes of hormones? the three major classes of molecules function as hormones in vertebrates. which are water-soluble? which are lipid-soluble?
- polypeptides (proteins and peptides) (water-soluble)
- amines derived from amino acids (majority are water-soluble)
- steroid hormones (lipid-soluble)
_________ are secreted molecules that link neighboring cells or directly regulate the secreting cell
local regulators
what are the types of local regulators?
- cytocines and growth factor
- nitric oxide (helps with vasodilation)
- prostaglandins (involved in pain response)
what type of hormones involves a signaling transduction pathway?
water-soluble hormones
__________ hormones pass easily through cell membranes
lipid-soluble hormones (steroid hormones)
__________ hormones do not pass easily through the cell membranes. The receptors are on the plasma membrane.
water-soluble hormones
- secreted by exocytosis
- travel freely in the bloodstream
- bind to cell-surface receptors
water-soluble hormones
- diffuse across cell membranes
- travel in the bloodstream bound to transport proteins
- diffuse through the membrane of target cells
lipid-soluble hormones
- water-soluble
- has multiple effects in mediating the body’s response to short-term stress
- binds to receptors on the plasma membrane of liver cells
- releases glucose into the bloodstream
epinephrine
________ hormoens act via signal transcution pathways.
non-steroid
steroid hormones do not!
the response to a lipid-soluble hormone is usually a change in….
and where do they bind?
gene expression
protein receptors in the cytoplasm or nucleus
the same hormone may have different effects on target cells that have …
- different receptors for the hormone
- different signal transduction pathways
stimulus—> hormones are released from an endocrine cell —-> travel through the bloodstream —->interact with specific receptors with a target cell to cause a physiological response
simple hormone pathways
the release of acidic contents of the stomach into the duodenum —> stimulates endocrine cells there to secrete secretin —> target cells in the pancreas, —> raise the pH in the duodenum
simple endocrine pathway
stimulus —> received by a sensory neuron —> stimulates a neurosecretory cell —> secretes a neurohormone –> enters the bloodstream —-> travels to target cells
neuroendocrine pathway
the hypothalamus has neurosecretory cells
called a neurohormone when reaches target
the pancreas has clusters of endocrine cells called pancreatic islets the ______ cells produce glucagon and the _____ cells produce insulin.
alpha, beta
- Extention of the hypothalamus
- stores and secretes hormones that are made in the hypothalamus
posterior pituitary
what hormones is the posterior pituitary responsible for?
ADH and oxytocin ***
- endocrine gland makes and releases hormones under the regulation of the hypothalamus
- trophic hormones
- endocrine gland on its own
anterior pituitary
what hormones is the anterior pituitary responsible for?
prolactin, FSH, LH, etc.
do not regulate endocrine cells or glands
nontropic
- regulates the function of endocrine cells or glands
- stimulate activity of male and female gonads (FSH, LH)
- adrenocorticotropic hormone (ACTH)
- TSH
tropic
two hormones released from the posterior pituitary act directly on nonendocrine tissues…
- oxytocin
- ADH
this is from the hypothalamus that stimulates the anterior pituitary gland to secrete prolactin
prolactin-releasing hormone (PRL)
the release of thyroid hormone results from a _____________ pathway.
hormone cascade
hypothalamus to anterior pituitary, thyroid gland
explain the thyroid hormone cascade
- thyroid hormone levels drop
- the hypothalamus secretes TRH into the blood. vessels carry TRH to anterior pituitary
- anterior pituitary secrets TSH
- TSH stimulates endocrine cells in thyroid gland to secrete T4 and T3
- thyroid level return to normal
- thyroid hormone blocks TRH and TSH release
what atoms do T3 and T4 have?
iodine
caused by autoimmunity, is typified by protruding eyes, too much TSH is produced, goiters are typically seen also
Graves disease
what causes goiters?
iodine deficiency
is growth hormone tropic or nontropic?
Both!
tropic- liver (major target)—-IGFs—–stimulate bone and cartilage growth
nontropic- diverse metablic effects (raise glucose)
endocrine signaling regulates…
- homeostasis
- development
- behavior
this stimulates calcium release from the bones to increase blood calcium
parathyroid hormone
released by the thyroid gland to decrease levels of calcium, it stimulates deposition in bones and secretion by kidneys
calcitonin
two glands of the adrenals
-adrenal medulla (neuro) adrenal cortex (has true endocrine cells)
- made from the adrenal medulla
- includes epinephrine and norepinephrine that both function as neurotransmitters
- secreted in response to stress-activated impulses from the nervous system* increases energy by the liver and skeletal muscles, increases stroke volume and HR
catecholamine
- in response to stress
- triggered by a hormone cascade pathway via the hypothalamus and anterior pituitary ( ACTH) (tropic hormones)
what are the two categories?
corticosteroids
glucocorticoids (breakdown protein for fuel in the muscles), immune system
mineralocorticoids (maintain salt and water balance) ex: aldosterone
hypothalamus —-> anterior pituitary —> to realease ACTH —-> adrenal cortex
what controls sex hormones in the gonads?
FSH and LH
what secretes melatonin?
the pineal gland
