Ch 16 - Endocrine Sys Flashcards
What are hormones?
Chemicals analagous to neurotransmitters
What type of hormones are made from cholesterol?
Where are they made?
Steroids
Made in gonads and adrenal cortex
What are 3 ways the endocrine system is stimulated to release hormones?
Humoral - blood concentration
Neural - nervous system
Hormonal - one gland to another
What 2 things affect the concentration of hormones in the bloodstream?
Rate of release
Rate of absorption/removal
What is the other name for the pituitary gland?
Hypophysis
Where are oxytocin and antidiuretic hormone(ADH) stored?
Posterior pituitary
Where are oxytocin and ADH made?
Hypothalamus
What does oxytocin do?
What are its targets?
Targets: uterus and breast
- Releases breast milk
- Causes contractions for labor
- Acts as a neurotransmitter - sexual/affectionate behavior, promotong nurturing, couple bonding, trust - can be platonic (friends/pets)
What does ADH do?
What are its targets?
Maintains water levels, preventing dehydration and water retention
Targets the kidneys
What are topins?
Hormones that regulate that actions of other endocrine glands
What are the 4 tropic hormones and 3 direct hormones?
FLAT Follicle stimulating hormone Luteinizing hormone Adrenocorticotropic hormone Thyroid stimulating hormone
PEG
Prolactin
Endorphins
Growth hormone
How do the anterior pituitary and hypothalamus control the endocrine system?
Hypothalamus is the big main boss. It stimulates the anterior pituitary to release its hormones.
Anterior pituitary is the master endocrine gland that controls other endocrine glands - 4 of 6 hormones it releases are tropins
What are tropic hormones (tropins)?
They tell another gland to release its hormones
What is GH?
What does it do?
What are its targets?
- Growth hormone
- Tissue building hormone
- Triggers production of growth promoting proteins
- Triggers increase of glucose and fatty acids for fuel
- Targets liver, muscle, bone, cartilage and other tissues
- daily cycle - highest during sleep
Whats the other name for growth hormone?
Somatotropin
What is TSH and what does it do?
- Thyroid stimating hormone
- targets the thyroid gland
- controls its development and activity (tropin)
Which hormone stimulates the adrenal cortex?
Adrenocorticotropic hormone (ACTH)
What are the gonadotropins?
What do they do?
- They regulate the gonads (ovaries & testes)
- Follicle stimating hormone - production of gametes (egg/sperm)
- Luteinizing hormone - production of gonadal hormones (testosterone, estrogen, progesterone), triggers ovulation, works with FSH to maturation of egg-containing ovarian follicles
Which hormone is responsible for milk production?
Prolactin = PROduction
Oxytocin causes release
What 2 hormones are produced by the thyroid?
What do they do?
Thyroid hormone & Calcitonin
- Thyroid hormone - controls metabolic function of every tissue in the body
- Calcitonin - minor role in blood calcium levels
How are TSH, T3 & T4 related?
TSH comes from anterior pituitary and stimulates thyroid to release TH
T3 + T4 = Thyroid hormone
T4 has 1 more iodine and is more plentiful
T3 is stronger/more potent
What is the most important hormone in regulating blood calcium levels?
What are its targets?
Parathyroid hormone = PTH = Parathormone
Targets: skeleton, KD, intestines
Where are glucogon & insulin made?
What do they do?
In the pancreas
Glucogon - raises blood sugar
Insulin - lowers blood sugar
What is glycogen?
The storage form of glucose
What is hCG?
Where is it made?
Human chorionic gonadotropin
Made in placenta
Where is erythropoietin made?
What does it do?
EPO is made in the KD
It causes bone marrow to increase production of red blood cells
Where is cholecalciferol made?
What does it do?
Made in in the skin
in response to exposure to UV radiation
Inactive form of vitamin D3
Travels to the LIVER then becomes fully activated vitamin D3 in the KIDNEYS
Which hormones are produced by the adrenal medulla?
Epinephrine & norepinephrine
What 3 types of hormones are secreted by the adrenal cortex?
What do they do?
MINERALcorticoids - controls electrolytes (sodium & potassium)
GONADOcorticoids - control ssex hormones
GLUCOcorticoids - control sugar
How are hormones from the adrenal medulla and adrenal cortex different?
Adrenal MEDULLA handles ACUTE stressors
Adrenal CORTEX handles CHRONIC stressors
What hormone is secreted by the pineal gland?
What does it do?
Melatonin
- Influences the rythm or processes such as body temperature, sleep & appetite
- Effects timing of puberty - inhibiting it from occuring too early
- Controls protective antioxidant & detoxification molecules in cells
- Highest at night, lowest at noon
What is a hormone and how does it work?
Chemical form of neuro transmitter
Travel thru blood or lymph and target most cells in the body
Responses occur after a lag time of seconds to days
Long lasting, widespread & diverse results
Name the endocrine glands
Pituitary Thyroid Parathyroid Adrenal Pineal
Hypothalamus is neuroendocrine
Discribe the 2 categories of hormones
Amino acid based
- most common
- include simple amino acid derivatives, peptides or proteins
Steroids
- made from cholesterol
- made in thebgonads and adrenal cortex (EX)
What are the 2 ways hormones act on receptors?
Indirect
- act on receptors in the plasma membrane using G proteins and second messengers to mediate a target cell response
- water soluble hormones
- includes all amino acid based hormones except Thyroid hormone
Direct
- hormone acts ob receptors inside the cell to dorectly activste genes
- lipid soluble hormones
- Includes steroids and thyroid hormones
What are the 3 factors that determine target cell activation?
Blood levels of hormone
Amount of receptors the cell has
Affinity(strength) of the bond
Explain up-regulation and down-regulation
Up-regulation
- target cells form NEW receptors in response to persistently LOW hormone levels
Down-regulation
- target cells DECREASE the number of receptors in response to persistently HIGH hormone levels
Discribe the 3 types of hormone interaction when working together
Permissiveness
- hormone requires a 2nd hormone for full effect
Synergism
- when combined individual effects are amplified
Antagonism
- opposite effects of each other
What 2 hormones are stored in the posterior pituitary?
Where are they made?
Oxytocin & antidiuretic hormone
Both made in the hypothalamus
What is aldosterone?
Where is it made?
What does it target?
Most common and potent mineralocorticoid
Mineralocorticoids regulate electrolyte concentrations
Made in Adrenal Cortex
Main target is KD
What is the most common glucocorticoid in humans?
Cortisol
