chapter 11 Flashcards
function of the endocrine system
- regulation
- The regulation is specific to the receptor controlled by its hormone.
hormone
chemical message produced by an endocrine tissue and travels through the bloodstream to target cell receptor.
most hormones are screwed-released by ________ from a cell
exocytosis
Endocrine gland–>Adrenal Cortex major hormones
- Glucocorticoids (mainly cortisol)
- Mineralocorticoids (mainly aldosterone)
Endocrine gland–>Adrenal medulla major hormones
epinephrine
Endocrine gland–>Hypothalamus major hormones
-releasing and inhibiting hormones
Endocrine gland–>Islets of Langerhans (pancreas) major hormones
insulin and glucagon
Endocrine gland–>anterior pituitary major hormones
trophic hormones
endocrine gland–>posterior pituitary major hormones
antidiuretic hormone oxytocin
hormones cause a sequence of changes in their ______
targets (receptors)
hormones also have an on/off switch to allow for concentration regulation or in other words physiological control of the hormone (feedback system)
((TRUE OR FALSE)
true
neurotransmitter vs hormones and similarities
- neurotransmitter diffuses across synapse to postynpatic cells
- hormones travel through the blood
- similarities: receptors, a change in the target cell, regulation
Amines hormones classification (method of travel, receptor location, most common example)
-composition: amino acids
-method of travel: bound/unbound
-receptor location: intracellular (protein free)/ membrane
most common example: thyroid, catecholamines
Peptide/protein hormones classification (method of travel, receptor location, most common example)
- method of travel: free
- receptor location: membrane
- most common example: Insulin, ADH
Glycoprotein hormone classification (method of travel, receptor location, most common example)
- method of travel: bound
- receptor location: membrane
- most common example: FSH, LH, in reproductive organs
Steroid hormone classification ((method of travel, receptor location, most common example)
- method of travel: bound
- receptor location: typically intracellular
- most common example: Cortisol, testosterone, estradiol
how a cell responds to a hormone depends on what
- amount of hormone
- the combination of all hormones
Synergistic hormones:
Occur when two or more hormones work together to produce a particular effect
–Epi and norepi
Permissive hormone:
: Occur when one hormone makes the target cell more responsive to a second hormone
–Ex: estradiol, progesterone
Antagonistic hormone
Occur when hormones work in opposite directions.
what 2 aspects of receptors themselves can be regulated
- number and affinity of receptors
- Can be up-regulated (increase in #) or down-regulated.
- Done to receptors of hormone or by hormone for other receptors
- Prolonged exposure to high concentrations of hormone may result in a decreased number of receptors for that hormone.***
relationship between hypothalamus and pituitary gland
- posterior pituitary is More of an extension of the hypothalamus than its own gland
- Hormone stored in vesicles in posterior pituitary???
- Action potentials trigger release by exocytosis
2 Posterior Pituitary Hormones (synthesized in hypothalamus)
- both belong to the peptide class
- Oxytocin is involved in the milk ejection reflex of nursing mothers and during labor. Stimuli in the nipple and cervix send neural signals to release hormone.
-Antidiuretic hormone (AKA Vasopressin and ADH) is involved in regulation of water balance and contracts blood vessels increasing blood pressure, stimuli occurs from changing the plasma osmolality
Antidiuretic hormone (AKA Vasopressin and ADH)
- posteior pituitary hormones
- peptide class
- is involved in regulation of water balance and contracts blood vessels increasing blood pressure, stimuli occurs from changing the plasma osmolality
Anterior Pituitary
- hormones secreted here are trophic hormones
- A hormone that controls the secretion of another hormone is called a tropic hormone (the h is dropped)
Hypothalamic Control of the Anterior Pituitary
The anterior pituitary is controlled via releasing and inhibiting hormones transported through the hypothalamo-hypophyseal portal system
Hypothalamo-hypophyseal portal system hormones(produced by Hypothalamus) sequence of events
- Regulatory hormone controls secretion of anterior pituitary hormone
Ex: TRH - Anterior pituitary hormone then controls the secretion of a hormone from another endocrine gland
- The last hormone does the action on its target cell
Example: thyroid releases T3 and T4 hormones to do the action intended of this sequence
TRH -> TSH -> T3 & T4
what controls the original release (hypothalamus)?
- Specific Higher neural pathways influence secretion
- Neurotransmitters (ex. Catecholamines, serotonin) are released across the synapses to the neurons of the hypothalamus that produce the original hormones
- Also the negative feedback of a hormone in the sequence:
- ->CRH is inhibited with the rise of concentration of the last hormone in sequence, cortisol in the plasma.
-None of the sequences should be thought of as isolated, outside factors can always influence (such as other hormones, drugs)
hypothalamo-hypophyseal tract
hypothalamus to posterior pituitary – neural input
Hypothalamo-hypophyseal portal system
hypothalamus to anterior pituitary, vascular link for hormones to input on the pituitary
Relationship between pituitary and certain organ is referred to as an ____.
axis.
- pituitary _____ axis
example: Hypothalamo-pituitary-adrenal axis
adrenal cortex hormones names (3)
-Mineralocorticoids from the zona glomerulosa regulate Na+ and K+ balance.
Example: aldosterone
-Glucocorticoids from the zona fasciculata regulate glucose metabolism.
Example: cortisol
-Exogenous glucocorticoids are used medically to suppress immune response and inhibit inflammation; can have many negative side effects
Mineralocorticoids
-adrenal cortex hormone
–Mineralocorticoids from the zona glomerulosa regulate Na+ and K+ balance.
Example: aldosterone
Glucocorticoids
-adrenal cortex hormone
–Glucocorticoids from the zona fasciculata regulate glucose metabolism.
Example: cortisol
Exogenous glucocorticoids
- adrenal cortex hormone
- Exogenous glucocorticoids are used medically to suppress immune response and inhibit inflammation; can have many negative side effects
adrenal medulla hormones
-Stimulated by sympathetic axons
-Release Epinephrine & Norepinephrine:
Increase cardiac output, respiratory rate, and mental alertness; dilate coronary blood vessels; elevate metabolic rates
-connection to heart??
the Hormone Cortisol under stress (produced by Adrenal Cortex)
- Stress increases secretion of ACTH, which results in increased glucocorticoid release.
- The stress hormones are glucocorticoids, epinephrine, and CRH
Functions of the Hormone Cortisol under stress (produced by Adrenal Cortex)
- Maintain blood pressure - vascular effects (normal and under stress)
- Shutdown nonessential functions like reproduction (changes during stress)
- Inhibits inflammation and certain immune responses (most common)
- Complete absence of cortisol always fatal!
Pancreatic Hormones
- Glucagon & Insulin
- Regulate blood glucose levels, Causes an antagonistic effect (blocking)-insulin lowers blood glucose levels by enhancing transport of glucose, it counters any activity that would increase levels of glucose. Glucagon promotes raising the glucose concentrations
how insulin and glucagon work
- eat a meal=high blood sugar concentration, promotes insulin releases and stimulates glycogen formation (glucose->glycogen). insulin also stimulates glucose uptake from blood, and they both lower blood sugar
- hungry=low blood sugar. promotes glucagon release, which stimulates glycogen breakdown into glucose, which raises blood sugar
type 1 diabetes
pancreases no longer makes insulin
type 2 diabetes
pancreases makes insulin, but their bodies don’t reopens well to it
Pineal Gland
-located in brain
-secretes melatonin
-Secretion Regulated by the hypothalamus
-At this location, action potentials are released during the day and almost no activity at night. AP inhibit melatonin secretion, therefore highest levels of melatonin occurs during the night.
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