Connection of a hormone to it's receptor for target cell response depends on what?
How much hormone is released
The rate of elimination from
A small amount of receptors means what?
There will be a small response
What is up-regulation?
When there is an increase in receptor number
What does up-regulation do?
Increases tissue sensitivity to the hormone
What is down-regulation?
When there is a decrease in receptor number
What does down-regulation do?
Decreases tissue sensitivity to the hormone
What is additive?
When you add the results of multiple hormones together
(ex. Gastrin and Histamine)
What is synergism?
When multiple hormones produce the same effect but results are greater than if they were alone
(ex. Epinephrin and Glucagon)
What is antagonism?
When multiple hormones have opposing effects
(ex. Insulin and Glucagon)
What is permissiveness?
One hormone allows another to have an effect
(ex. Estrogen causes up-reg. of Progesterone receptors)
Water soluble?
-Amino acid (protein)
-Can be stored in vesicles
-Free in plasma
-Cannot enter membrane alone
-Half-life is short (removed by kidneys)
-Receptors on plasma membrane
-Secondary messenger system
Lipid soluble?
-Steroid (except for TH)
-Enter membrane on its own
-Not stored in vesicles
-Bound to plasma protein
-Half-life is long (metabolized in liver)
-Receptors inside the cell
-Activate genes, causing synthesis of new proteins
Why is negative feedback homeostatic?
It returns you back to normal (set point)
What happens in a negative feedback?
Humoral pathways get turned off
What happens when blood calcium drops?
1.) Parathyroid gland detects the drop
2.) Release of PTH
3.) PTH acts on bones and kidneys
4.) Bone: increase calcium release Kidneys: decrease calcium loss in urine
5.) This all raises the calcium in the blood
*Back to normal calcium range
6.) Parathyro
What is the pathway when there is stress?
1.) Hypothalamus detects the stress
2.) Hypothalamus releases CRH to the Ant. Pit.
3.) CRH stimulates Ant. Pit. which then releases ACTH to the Adrenal Cortex
4.) ACTH stimulates the Adrenal Cortex to release Cortisol
5.) Cortisol then brings the body's s
If you are taking a steroid orally, why can it be fatal to stop taking it cold turkey?
Because the oral steroid stops your own production of that hormone
What is the first pathway called?
Tertiary Endocrine Pathway
What is the second pathway called?
Secondary Endocrine Pathway
What is the third pathway called?
Primary Endocrine Pathway
When is positive feedback used?
In childbirth and blood clotting
Why does positive feedback have to be self limiting?
Because it would be in a disease state
What kind of change is positive feedback?
Little change to big change (ex. childbirth)
How are hormones eliminated?
Removed from the blood by uptake into target cells kidney, or liver (enzymatic degradation)
Why are lipid soluble less likely to be degradated?
Because it has a protective carrier
What are the endocrine pathologies?
Hypersecretion and Hypocecretion
What makes up the Pituitary Gland?
Anterior lobe: epithelial tissue
Posterior lobe: nervous tissue
How is the hypothalamus connected to the pituitary?
By the infundibulum
What is the whole pituitary gland called?
Hypophysis
Where do nerve cell bodies in the hypothalamus send nerves to?
Down the infundibulum to the posterior pituitary
What does supraoptic nuclease make?
ADH
What does paraventricular nucleus make?
Oxytocin
How is ADH and Oxytocin stimulated?
1.) ADH/Oxytocin are synthesized in nuclei of hypothalamus
2.)Hormones are packaged into vesicles for transport
3.) Vesicles move down axon to nerve terminal, where they are stored
4.) When neurons of the supraoptic and paraventricular nuclei are stimulat
What is the hypothalamic hypophyseal tract (axons)?
Describes connection to hypothalamus and posterior pituitary
What has a single cell wall where oxygen and nutrients are given to tissues from blood?
Capillaries
What does the posterior pituitary NOT do?
It does not produce or synthesize any hormones. Instead is released ADH and Oxytocin that has been stored there
What is ADH?
Antidiuretic hormone (water retention)
What does ADH do?
Inhibits urination
Where does ADH retain fluid?
In the blood
What does ADH do to the kidneys?
Causes them to have water retention
What would stimulate the release of ADH?
Dehydration
-high osmolarity in the blood
-low blood volume
Summary of ADH release
1.) Increase plasma osmolarity which is detected by osmoreceptors in the hypothalamus. ADH is released from the posterior pituitary which causes water retention in the blood. Plasma osmolarity returns to normal which feeds back to the hypothalamus to stop
What detects osmolarity?
Osmoreceptors
What inhibits ADH release?
Alcohol (why a drunk person pees so much!)
What are the 2 fates for water and solutes in the urine?
1.) Out of the body in urine
2.) Return to bloodstream (plasma)
What happens if you have low urine output?
Increase BV and BP because you are retaining water and storing it in the bloodstream
What happens if you have high urine output?
Decrease BV and BP because there is a high amount of water coming out of the bloodstream and being urinated
What is SIADH?
Syndrome of Inappropriate ADH release
What does SIADH do?
Constantly producing ADH for no reason
-start retaining water
-have high BP
What is the function of Oxytocin?
Child birthing and breastfeeding
What connects the Hypothalamus to the Anterior Pituitary?
Blood vessels...NOT axons!
How do hormones in the Hypothalamus travel?
1.) Travel down axons to hypothalamic capillary network
2.) Then travel down hypophyseal portal system into the anterior pituitary capillary network
-Tracts (axons) for posterior pituitary and Portal System for anterior pituitary
What is a portal system?
Special arrangement of blood vessels
Capillary Network to Veins or Venuoles to Capillary Sys.
Summary of how hormones travel from the hypothalamus to the ant. pit.
Hormone from hypothalamus enter blood stream in hypothalamic capillary network. Travel to ant. pit. in portal veins and exit blood stream through ant. pit. capillary network.
Where are the target cells for hormones made in the hypothalamus?
In the anterior pituitary
What are the two types of Thyroid Hormone?
T3
-more active form
-most is formed in target cells from T4
T4
-prodominate form released from thyroid
-prodominate form in plasma
What is the difference in T3 and T4?
T4 has one more iodine than T3
What stimulates the release of Thyroid Hormone (TH)?
Low TH
Cold weather (TH generates heat)
Pregnancy (TH develops nervous system)
What is the pathway for TH?
1.) Hypothalamus releases TRH to the ant. pit.
2.) TRH stimulates the anterior pituitary to release TSH to the thyroid
3.) TSH stimulates the thyroid to release TH (T3,T4)
4.) TH increases breathing rate and heart rate
Net Effect: Cells increase, oxygen t
What does TH cause adipose tissue to do?
Release fatty acid into the blood
What does TH cause the liver to do?
Release glucose into the blood which turns into ATP
Since TH increases metabolic rate and generates heat, what would happen if you had too much TH?
You would loose weight, feel hot and be hungry
What works with TH to aid growth?
Growth Hormone (GH)
GHRH pathway
1.) Hypothalamus releases GHRH to the ant. pit.
2.) Ant. Pit. then releases GH into the blood
3.) GH reaches its target which is cartilage, bone, muscle, liver, and adipose tissue.
-The effect of GH on cartilage, bone, and muscle is growth
-The effect of
What is TRH, CRH, GnRH, and PRH?
Thyrotropin
Corticotropin
Gonadotropin
Prolactin
Pathway for GnRH
1.) GnRH is released from the hypothalamus to the ant. pit.
2.) The ant. pit. then releases FSH (follicle stimuli) and LH (lutenizing) into the blood
3.) FSH and LH then reach the gonads (ovaries/testis)
4.) The gonads then release sex hormone (estrogen,
Pathway for PRH
1.) PRH is released from the hypo. to the ant. pit.
2.) PRL is then released into the blood by the ant. pit.
3.) PRL reaches the breast tissue which enables milk production
What is a goiter?
Any enlargement of the thyroid gland.
What must you have to make a thyroid hormone?
Iodine
Why would someone not producing T3,T4 get a goiter?
Because they would produce too much TSH and if the thyroid isn't producing T3,T4 to feed back and stop this then the thyroid would continue being stimulated.
Why would antibodies cause a goiter?
Because the antibodies bind to the TSH receptors which stimulates the thyroid. This would produce T3,T4 which would cause the TRH and TSH levels to be low but the antibodies would still stimulate the thyroid.
What is exophthalmus?
Elevated thyroid levels causes eye tissue to grow
What are the hormones from the Adrenal Cortex called?
Corticosteroids
What are the 3 corticosteroids called?
Glucocorticoids (cortisol)
Mineralocorticoids (aldosterone)
Adrenal androgens (sex hormones)
Where does Cortisol come from?
Adrenal Cortex
How does Cortisol effect your brain?
It gives it glucose
What does Cortisol do in the body?
-Anti-inflamatory
-Pain reducer
-Supreses the immune system
Forms of cortisol can be injected into the body, called glucocorticoid, what happens in the body if you receive this injected for a long period of time?
Protein catabolism will happen which will break down bone, muscle and cartilage.
What is another form of cortisol?
Prednisone
What is endogenous?
Made within the body
What is exogenous?
Made outside the body
What is Cushing's Disease/Syndrome?
Disease: due to high endogenous cortisol for a long period of time
Syndrome: due to high exogenous glucocorticoid (cortisone or prednisone) for a long period of time
What is a Buffalo Hump?
Fat on the upper back of the neck (caused from high cortisol)
What is Trunkal Obesity?
Big belly but small arms and legs. The arms and legs begin to atrophy which caused from the breaking down of proteins due to the high levels of cortisol.
What are two hormones released by humoral factors?
Aldosterone and Calcitonin
Where is aldosterone released from?
Adrenal cortex
What is aldosterone?
Sodium (salt) retention
What stimulates the release of aldosterone?
Low sodium in the blood
High potassium in the blood
Low BV and Low BP
Pathway from aldosterone
1.) A. Cortex releases aldosterone to the kidneys
2.) Aldosterone stimulates the kidney to either elevate K+ loss in the urine (lower K+ in the blood) or elevate Na+ reabsorption in the blood (lower Na+ in the urine)
3.) Either option will return K+ or Na
How could aldosterone cause you to pee a lot?
Aldosterone indirectly causes water retention because water follows salt so as Na+ is reabsorbed into the blood (in kidney), water is also reabsorbed
What is Hyperaldosteronesim?
Too much aldosterone
-high blood Na+ (hypernatremia)
-low blood K+ (hypokalcemia)
-high BV and BP
What is Hypoaldosteronesim?
Not enough aldosterone
-low blood Na+ (hyponatremia)
-high blood K+ (hypokalcemia)
-low BV and BP
-Dehydration
-In extreme cases, cardiovascular collapse
Where is Calcitonin released from?
Thyroid Gland
What stimulates the release of calcitonin?
High blood calcium levels
Pathway of calcitonin
1.) High blood calcium levels causes "C" cells (parafollicular cells) to stimulate the thyroid
2.) The thyroid then releases calcitonin
3.) Calcitonin heads to its target cells in the bone
4.) The bone will then stop producing osteoclasts (builds bone so
Which gland and hormone is stimulated if there is a low blood calcium level?
Parathyroid gland and PTH
Pathway from PTH
1.) Low blood calcium levels are detected by the parathyroid gland
2.) Parathyroid they releases PTH to the bone and the kidney
-the bone with elevate osteoclasts and decrease osteoblast
-the kidney with elevate calcium reabsorption into the blood (decrea
What is hypoparathyroidism?
-Not releasing PTH
-Low blood Ca+ (hypocalcemia)
What is hyperparathyroidism?
-Too much PTH
-High blood Ca+ (hypercalcemia)
What did Dr. Hicks call hormones?
Hormones are powerful little things!
The pancreas has an exocrine and endocrine, what do they do?
Exocrine: digestive enzyme that goes into duodenum
Endocrine: makes hormones
What is pancreatic islet?
Beta Cells and Alpha Cells
What are beta cells?
Insulin
What are alpha cells?
Glucagon
Where does insulin travel?
Out of the blood and into the cells
What stimulates insulin?
High blood sugar
What does insulin do?
Lowers blood sugar and stimulates protein synthesis (fatty acids and amino acids)
Opposite from every other hormone
What is glucagon stimulated by?
Low blood sugar
What does glucagon do?
Raised blood sugar
Increases glycogenolysis and glucoenogenesis
Lowers glycogenesis
Will not break down proteins
What hormones are used to get hyperglycemia (high blood sugar)?
Glucagon
GH
Epinephrine and Norepinephrine
Cortisol
TH
What hormone is used to get hypoglycemia (low blood sugar)?
Insulin
What is Type I Diabetes Mellitus?
-Insulin-dependent
-Complete destruction of B cells
-In genes, but exposed to a virus (autoimmune disease which attacks B cells)
What is Type II Diabetes Mellitus?
-Insulin resistant
-90% of people diagnosed with diabetes have this
-Has insulin but receptors do not accept it
-Associated with over weight problems
-"Boder-line"
-Can be reversible
What are symptoms of both Type I and II?
-Polyuria
-Polydipsia
-Polyphagia
-Hyperglycemia
-Glycosuria
-Ketonuria
What is polyuria?
Frequent urination
Normal U.O. is 1-2 liters daily but an untreated diabetic's U.O. would be 12-15 liters daily
What is polyuria caused by?
Osmotic diuresis: high glucose in urine
-this attracts water into the urine and causes a high U.O.
Why do diabetics urinate so much?
Too much sugar in the blood causes a lot of sugar in the urine which keeps water i urine which makes diabetics pee so much
What is polydipsia?
Extreme thirst
What is polyphagia?
Extreme hunger (cells aren't getting enough food)
What is glycosuria?
Sugar in the urine
What is ketonuria?
Ketons in the urine and blood
-blood can become acidic (ketonacidosis)
What is Diabetes Insipidus?
No sugar in urine
What causes polyuria in diabetes insipidus?
1.) No ADH (central DI)
2.) No ADH receptors (nephrogenic DI) (kidney)
What can diabetes insipidus cause?
Hypercicimia: nerve damage (neropothy)
What are hormones that are released from the adrenal medulla? (hormones released by the nervous system)
80% epinephrine (adrenaline)
20% norepinephrine
What does epinephrine and norepinephrine do?
-Elevate blood flow, heart rate and BP
-Dilates are ways so you can breath
-Elevate blood sugar
-Lower fat
-Can cause chromaffin cells (tumor called pheochromocytoma)
What three hormones are released from the adrenal cortex? (hormones released by the nervous system)
1.) Glucocorticoids (cortisol)
2.) Mineralocorticoids (aldosterone)
3.) Sex hormones
An overproduction of sex hormones can cause a tumor called what?
Adrenogenital Syndrome
How does adrenogenital syndrome effect different people at different ages?
Newborn Female: masculinized genitalia
Children: Enlargement of penis/clitoris
Adult Female: More body hair, deep voice and beard
Adult Male: Femalization
What hormone is secreted from the pineal gland?
Melatonin
What does melatonin do and when is it used?
It regulates your 24 hour sleep cycle and it increases at night
What is SAD?
Seasonal Affective Disorder: high levels of melatonin all the time
What hormone does the heart release?
Atrial Natriuretic Hormone/Peptide (ANH or ANP)
What is ANH/ANP?
-Opposite of aldosterone
-Loss of Na+ in urine and water follows
-Lower BV and BP
What variables stimulate Growth Hormone?
-Children's age
-Sleep/night
-Low levels of glucose and fatty acids
-Stress and exercise (increases GH)
Pathway of Growth Hormone
1.) Hypothalamus responds to various stimuli
2.) Hypothalamus releases growth hormone releasing hormone (GHRH) into hypothalamo-hypophyseal portal system
3.) In response to GHRH, the ant. pit. releases GH
4.) GH stimulates hepatocytes to release insulin l
What is the net effect of growth hormone?
-Increased protein synthesis in cartilage, bone, and muscle except for amino acids.
-Overall effect is metallic and growth promoting
-Has a protein-sparing effect
How do different target cells respond to GH and IGF?
-Amino acids in the blood are taken into bone, cartilage, muscle, and all cells
-Liver cells release glucose into the blood
-Adipose tissue releases glycerol and fatty acids into the blood
What is the 1/2 life of GH and IGF?
GH is 6-20 min.
IGF is 20 hr.