Endocrine System Intro to Hormones Flashcards
- Classically endocrine glands were thought to secrete chemicals called hormones (in Greek, to excite or set into motion) that regulate or coordinate a wide variety of physiological processes.
- Survival of multicellular organisms depends on their ability to adapt to a constantly changing environment and modify their homeostasis in response to these changes.
- Classically endocrine glands were thought to secrete chemicals called hormones (in Greek, to excite or set into motion) that regulate or coordinate a wide variety of physiological processes.
- Survival of multicellular organisms depends on their ability to adapt to a constantly changing environment and modify their homeostasis in response to these changes.
•Functions to integrate and coordinate the actions of various organs and tissues.
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•Acts in concert with nervous system -neuroendocrine system - but has a longer latent period and a sustained effect.
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•Endocrine cells arranged individually, in cords, clumps or follicles.
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•Functions to integrate and coordinate the actions of various organs and tissues.
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•Acts in concert with nervous system -neuroendocrine system - but has a longer latent period and a sustained effect.
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•Endocrine cells arranged individually, in cords, clumps or follicles.
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- Removing the gland causes a ___
- Giving back an___ from the gland corrects the deficit.
- Effective in ___ amounts
___ regulators
____ Balance
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It wouldn’t be good to remove an endocrine gland.
You affect bodies ability to control whatever they control
You don’t secrete large amts of hormone
Thyroid can store hormone in large amts but most don’t do that.
They make it and secrete it.
- Removing the gland causes a deficit
- Giving back an extract from the gland corrects the deficit.
- Effective in minute amounts
- Physiogical regulators
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•Homeostatic Balance
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It wouldn’t be good to remove an endocrine gland.
You affect bodies ability to control whatever they control
You don’t secrete large amts of hormone
Thyroid can store hormone in large amts but most don’t do that.
They make it and secrete it.
–Amines
- Example-___
- Mostly water soluble
–Small peptides (___ amino acids)
- Example-_____
- Mostly water-soluble.
–Polypeptides (___ amino acids)
- Example-___
- Mostly water-soluble.
–Proteins (___+ amino acids
- Example-__ __
- Mostly water soluble
–Amines
- Example-epinephrine
- Mostly water soluble
–Small peptides (3-9 amino acids)
- Example-Antidiuretic Hormone (ADH)
- Mostly water-soluble.
–Polypeptides (10-100 amino acids)
- Example-Insulin
- Mostly water-soluble.
–Proteins (100+ amino acids
- Example-Growth Hormone
- Mostly water soluble
–Glycoproteins (protein + carbohydrate)
- Example-__ __ ___
- Mostly water soluble
–Iodinated thyroid proteins (protein + iodine)
- Example-___
- Mostly water soluble.
–Steroid Hormones
- Example-___ and ___
- Lipid soluble!
–Prostaglandins and Cytokines
–Glycoproteins (protein + carbohydrate)
- Example-Thyroid Stimulating Hormone (TSH)
- Mostly water soluble
–Iodinated thyroid proteins (protein + iodine)
- Example-Thyroxine
- Mostly water soluble.
–Steroid Hormones
- Example-Estrogen and Testosterone
- Lipid soluble!
–Prostaglandins and Cytokines
Two hormone categories based on solubility:
HYDROPHYLIC versus LIPOPHYLIC HORMONES
HYDROPHYLIC HORMONES:
- Circulate in the blood largely dissolved in blood plasma.
- Since they cannot cross the plasma membrane of the cell, they bind to specific receptors present on the surface of the cell.
- Primarily act through the second-messenger system to alter the specific activity of preexisting proteins, such as certain enzymes, within the target cell to produce their desired physiological response.
- Famous Examples: Peptide hormones, Catecholamines
LIPOPHYLIC HORMONES:
- Since they cannot dissolve in blood plasma, they circulate in the blood by specific binding to plasma proteins.
- They readily cross the cell plasma membrane and bind to intracellular receptors which leads to the expression of specific genes, resulting ultimately in the synthesis of new proteins inside the target cell that carry out the desired physiological response.
- Famous Examples: Steroid hormones, Thyroid hormones
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Two hormone categories based on solubility:
HYDROPHYLIC versus LIPOPHYLIC HORMONES
HYDROPHYLIC HORMONES:
- Circulate in the blood largely dissolved in blood plasma.
- Since they cannot cross the plasma membrane of the cell, they bind to specific receptors present on the surface of the cell.
- Primarily act through the second-messenger system to alter the specific activity of preexisting proteins, such as certain enzymes, within the target cell to produce their desired physiological response.
- Famous Examples: Peptide hormones, Catecholamines
LIPOPHYLIC HORMONES:
- Since they cannot dissolve in blood plasma, they circulate in the blood by specific binding to plasma proteins.
- They readily cross the cell plasma membrane and bind to intracellular receptors which leads to the expression of specific genes, resulting ultimately in the synthesis of new proteins inside the target cell that carry out the desired physiological response.
- Famous Examples: Steroid hormones, Thyroid hormones
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•A single endocrine gland may produce multiple hormones. Example: the __ ___ gland secrets six different hormones, each having a distinct function.
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- A single hormone may be secreted by more than one endocrine gland. Example: ___n is secreted by both the ___ and ___•
- A single hormone may have multiple target-cell types which allows coordination of the activities of various tissues toward a common end. Example: the effects of the hormone insulin on muscle, liver, and fat all act in concert to store nutrients after the absorption of a meal.
- A single target cell may be influenced by more than one hormone and sometimes these hormones can have the opposite effect on the same target cell. Example: Insulin promotes the conversion of glucose into glycogen within liver cells by stimulating one particular hepatic enzyme; whereas another hormone, glucagon, by activating yet another hepatic enzyme in the same target cell, enhances the degradation of glycogen into glucose within liver cells.
•A single endocrine gland may produce multiple hormones. Example: the anterior pituitary gland secrets six different hormones, each having a distinct function.
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•A single hormone may be secreted by more than one endocrine gland. Example: Somatostatin is secreted by both the hypothalamus and the pancreas.
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•A single hormone may have multiple target-cell types which allows coordination of the activities of various tissues toward a common end. Example: the effects of the hormone insulin on muscle, liver, and fat all act in concert to store nutrients after the absorption of a meal.
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•A single target cell may be influenced by more than one hormone and sometimes these hormones can have the opposite effect on the same target cell. Example: Insulin promotes the conversion of glucose into glycogen within liver cells by stimulating one particular hepatic enzyme; whereas another hormone, glucagon, by activating yet another hepatic enzyme in the same target cell, enhances the degradation of glycogen into glucose within liver cells.
Development, Growth and Stress
1___-___ through ___
- ___
- ___
4____y production, storage, and use
Diff hormones can act at diff times.
Some will act thruout our life
Development, Growth and Stress
- Differentiation-conception through puberty
- Reproduction
- Growth
- Energy production, storage, and use
Diff hormones can act at diff times.
Some will act thruout our life
- Adaptation to stress
a. ____-shift in blood flow
b. ___metabolism, ANS
c____s-pain balance
d.___ ___ ____ e-water balance
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5.Adap
- Adaptation to stress
a. Epinephrine-shift in blood flow
b. Cortisol-metabolism, ANS
c. Endorphins-pain balance
d. Antidiuretic Hormone (vasopressin), Aldosterone, Atria Natriuretic Hormone-water balance
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Determinants of the Concentration of a Hormone at a Target Cell
1___ of Synthesis
- ___ of the hormone concentration. Typically acts in high concentration near the site of release (insulin/glucagon-liver) or lower concentration farther from release (pituitary- target organs)
- Disassociation constant from ___ proteins, if any
- Conversion of___ or less active form to a more active form- T4 T3
- Rate of ___ of the hormone-minutes versus hours
How much of a hormone is enough at a cell
Rate of syn Determines how much will be in the bloodstream
As it goes to the blood stream it is diluted out. Lower levels further away from the release
Autocrine vs Endocrine
Autocrine: High conc present. Maybe Not as many receptors present. You trying to get as much hormone to target what few receptors are present.
Endocrine: Maybe the cells express lots of receptors so it doesn’t take much hormone to activate the cell at a distant site
Paracrine: Often express receptors close to where the receptor is coming from
T3 is the more active form.
Most of what you release is T4.
T3 has higher affinity.
Can also internalize receptors so that it can’t be stimulated again.
Determinants of the Concentration of a Hormone at a Target Cell
- Rate of Synthesis
- Dilution of the hormone concentration. Typically acts in high concentration near the site of release (insulin/glucagon-liver) or lower concentration farther from release (pituitary- target organs)
- Disassociation constant from carrier proteins, if any
- Conversion of inactive or less active form to a more active form- T4 T3
- Rate of clearance of the hormone-minutes versus hours
How much of a hormone is enough at a cell
Rate of syn Determines how much will be in the bloodstream
As it goes to the blood stream it is diluted out. Lower levels further away from the release
Autocrine vs Endocrine
Autocrine: High conc present. Maybe Not as many receptors present. You trying to get as much hormone to target what few receptors are present.
Endocrine: Maybe the cells express lots of receptors so it doesn’t take much hormone to activate the cell at a distant site
Paracrine: Often express receptors close to where the receptor is coming from
T3 is the more active form.
Most of what you release is T4.
T3 has higher affinity.
Can also internalize receptors so that it can’t be stimulated again.
Hormonal Adjustment
- In general, hormones either work together or have opposing effects.
Hormonal Adjustment
- In general, hormones either work together or have opposing effects.
2.Hormones do not ___ reactions, but instead they just ___ or ___ the ___of the reaction.
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Many times they do this by having___ effects on a pathway.
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2.Hormones do not initiate reactions, but instead they just INCREASE or DECREASE the speed of the reaction.
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Many times they do this by having opposing effects on a pathway.
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3.Must distinguish between physiological and pharmacological effects.
Gastric Inhibitory Peptide’s (GIP) effects on gastric motility are pharmacological, but its effect on insulin secretion is physiological and it is now called Glucose-dependent Insulinotrophic Polypeptide (GIP). GIP is one of the few feed-forward hormones.
If you give a drug at a certain [] you may get an effect. Often called a pharm effect.
Pharm: Given at such a high dose you got a response; maybe not the same response of low dose
Physi: Dose of body
High enough dose it will act on GI but that’s not its true fcn
At its true physiological conc, it will have certain effect.
If you increase that dose high enough you can get pharm effect that is diff from physio effect
3.Must distinguish between physiological and pharmacological effects.
Gastric Inhibitory Peptide’s (GIP) effects on gastric motility are pharmacological, but its effect on insulin secretion is physiological and it is now called Glucose-dependent Insulinotrophic Polypeptide (GIP). GIP is one of the few feed-forward hormones.
If you give a drug at a certain [] you may get an effect. Often called a pharm effect.
Pharm: Given at such a high dose you got a response; maybe not the same response of low dose
Physi: Dose of body
High enough dose it will act on GI but that’s not its true fcn
At its true physiological conc, it will have certain effect.
If you increase that dose high enough you can get pharm effect that is diff from physio effect
Types of Chemical Messengers
- Hormones
- Neurohormones or Neurohumors
- Autocrine
- paracrine
- __
- ___
Types of Chemical Messengers
- Hormones
- Neurohormones or Neurohumors
- Autocrine
- Paracrine
- Juxtacrine
- Parahormone
Endocrine and Related Secretions Either:
- Reach__ ___
- __ __
- Reach General Circulation
- Act locally
