Endocrine 1 Flashcards
Mastery
Endocrine system includes:
Hypothalamus - Pituitary - Thyroid - Parathyroids - Adrenals - Pancreas - Ovaries and testes
Chemical Regulating Systems
Hormones:
Made in…
Transported by …
Distant target tissue receptors
Activates … response
Hormones: Function
Control of …
Transport of … across ….
Gene expression and protein ….
Exert effects at very low concentrations
Bind to …. receptors
Half-life indicates…
Endocrine system includes:
Hypothalamus - Pituitary - Thyroid - Parathyroids - Adrenals - Pancreas - Ovaries and testes
Chemical Regulating Systems
Hormones:
Made in gland(s) or cells
Transported by blood
Distant target tissue receptors
Activates physiological response
Hormones: Function
Control of enzymatic reactions
Transport of ions or molecules across cell membranes
Gene expression and protein synthesis
Exert effects at very low concentrations
Bind to target cell receptors
Half-life indicates length of activity
Hormonal Control
* Water balance and Blood volume * Metabolism * Energy balance and appetite * Digestion, circulation * Growth and development * Reproduction * RBC production * Stress management
Hormonal Control
* Water balance and Blood volume * Metabolism * Energy balance and appetite * Digestion, circulation * Growth and development * Reproduction * RBC production * Stress management
Tropic Hormones
Act on ….
Control of ….
from where?
Non –tropic hormones
Act on ….
from where?
Endocrine glands
Secrete …
Ductless
Tropic Hormones
Act on other endocrine glands
Control of hormone secretion
Hypothalamus and Anterior Pituitary
Non –tropic hormones
Act on effector organs
E.g. thyroid, adrenals, pancreas (not thyroid)
Endocrine glands
Secrete hormones
Ductless
Neurohormones / Neuropeptides
- Neuro-secretory cells
Secrete ….
Adrenal medulla
* C….
Hypothalamus
* Posterior …
Peptide hormones
- …
Steroid hormones
- ….
Amine hormones
- ….
Neurohormones / Neuropeptides
- Neuro-secretory cells
Secrete neuro-hormones (or neuro-peptides)
Adrenal medulla
* Catecholamines
Hypothalamus
* Posterior pituitary
Peptide hormones
- protein (water soluble, get into cell)
Steroid hormones
- Cholesterol (into cell easy, moving in blood is hard)
Amine hormones
- Tryptophan or tyrosine (amino acids)
Preprohormone
- size? activity?
Prohormone
- ….
TEST
Hormone
- Final cuts ….
- Travels freely in the blood but cannot cross the…
-… half-life
Preprohormone
- Large, inactive
Prohormone
- Post-translational modification. still inactive
Hormone
- Final cuts made before it exits the cell to make it an active hormone
- Travels freely in the blood but cannot cross the
cell membrane (needs a cell receptor, stay on outside, turn on kinases and enzymes)
- Short half-life
Peptide Hormone-Receptor Complex
Surface receptor
Hormone binds
- … activation, or
- Opens …, or
- …. systems
leads to a…
Peptide Hormone-Receptor Complex
Surface receptor
Hormone binds
- Enzyme activation, or
- Opens channels, or
- 2nd messenger systems
Cellular response
TEST
Peptide Hormones: Features
- water?
- travel?
- enter cell?
* Must use a ….
* … response
- speed? half-life?
Examples
…
Steroid Hormones: Features
- …-derived
- ….philic and enter?
- travel in blood?
- Cytoplasmic or nuclear receptors (mostly)
Activate …. for protein synthesis
- speed? half-life?
Examples
…
Peptide Hormones: Features
- Hydrophilic (water soluble)
- Can travel freely in the blood
- Cannot enter the cell (cross lipid membrane)
* Must use a membrane receptor
* Second messenger response
- Quick-acting, short half-life
Examples - IGC
Insulin, glucagon, calcitonin, parathyroid H
Steroid Hormones: Features
- Cholesterol-derived
- Lipophilic and can enter target cell
- Must travel in blood bound to a protein
- Cytoplasmic or nuclear receptors (mostly)
Activate DNA for protein synthesis
- Slower acting, longer half-life
Examples - TEC
Cortisol, estrogen, and testosterone
Amine Hormones: Features
- … structure
- Derived from …
Tryptophan
* melatonin
Tyrosine
- Thyroid hormones
- Catecholamines
* 3 hormones
Catecholamines behave similarly to …
Thyroid hormones behave similarly to …
Amine Hormones: Features
- Ring structure
- Derived from one of two amino acids
Tryptophan
* melatonin
Tyrosine
- Thyroid hormones
- Catecholamines - DEN
* Dopamine
* Epinephrine
* Norepinephrine
Catecholamines behave similar to peptides
Thyroid hormones behave similar to steroids
Blood Hormone levels depend on:
Rate of hormone …
Rate of hormone …
Rate of hormone …
Blood Hormone levels depend on:
Rate of hormone secretion
Rate of hormone degradation
Rate of hormone excretion (kidneys)
PEPTIDE HORMONES
STEROID HORMONES
CATECHOLAMINES
THYROID
cell receptor
half-life
transport in blood
peptide and steroid hormone differences
speed, half-life, ….-based, move in blood, into cell?
peptide quick, water, move in blood, cant get into cell need a receptor
steroid
cholesterol base, slow, longer half life, easily get into cell but hard to travel in blood. must be on a carrier or protein in blood
Hormone Interactions
Synergism
….. stimuli—more than additive
* Eg. ….
Permissiveness
Need …. to get full expression
* Eg. ….
⬧ … increases # receptor sites for …
Antagonism
what is it?
eg.
AFTER
***
Negative Feedback
Self- regulates hormone levels
* Turns off response homeostatically
Hormone Interactions
Synergism
Multiple stimuli—more than additive
* Eg. Glucagon, epi, and cortisol. All affect blood sugar, when all are working, larger response
Permissiveness
Need second hormone to get full expression
* Eg. TH and epinephrine
⬧ TH increases # receptor sites for epi
TH increases the effect of epinephrine. But epinephrine does not necessarily increase the effect of TH
Antagonism
Pairs of hormones with opposing effects
Glucagon opposes insulin
Endocrine Control - Three levels
Hypothalamic
* from …
Pituitary stimulation
* … hormones
Endocrine gland stimulation
*… hormones
Hormone secretion is also affected by:
… state
…. state
Stress
Diet, sleep
Body cycles
* Circadian rhythm, menstrual cycle
Endocrine Control - Three levels
Hypothalamic
* from CNS
Pituitary stimulation
* hypothalamic trophic hormones
Endocrine gland stimulation
* pituitary trophic hormones
Hormone secretion is also affected by:
Emotional state
Disease state
Stress
Diet, sleep
Body cycles
* Circadian rhythm, menstrual cycle
Endocrine Dysfunction
Abnormal …. of a hormone
Primary hyposecretion
what is it?
Causes
* …. (eg….)
* … (eg. )
* Chemical or toxic
* Immunologic / auto-immune (eg. Hashimoto’s)
* Diseases / cancer
Secondary hyposecretion
Gland is normal but too little hormone is secreted due to decreased … hormone (Eg. …)
Hypersecretion
Causes?
Primary hypersecretion
gland?
Secondary hypersecretion
gland?
Endocrine Dysfunction
Abnormal plasma concentrations of a hormone
Primary hyposecretion
Too little hormone is secreted due to gland abnormality
Causes
* Genetic (eg. Type I diabetes)
* Dietary (eg. Iodine and TH)
* Chemical or toxic
* Immunologic / auto-immune (eg. Hashimoto’s)
* Diseases / cancer
Secondary hyposecretion
Gland is normal but too little hormone is secreted due to decreased tropic hormone (Eg. Ant. Pit.)
Hypersecretion
Causes
Tumours * Can continuously secrete excess hormone
Primary hypersecretion
Too much hormone is secreted due to abnormality within gland
Secondary hypersecretion
Excessive stimulation from outside the gland causes oversecretion
Hypothalamus - Homeostasis
Controls …. which then controls other …. glands
Hypothalamus - Homeostasis
Controls Anterior Pituitary which then controls other endocrine glands
