Endocrine System Flashcards
Organization of the Endocrine System
2nd Major Control System that’s?
WIRELESS
Endocrine System Notes
- Endocrine gland =
- Hormone =
- any gland or anything that releases a chemical messenger directly into the bloodstream (endocrine release)
- chemical messenger released into the bloodstream
Categories of Endocrine Glands (Notes)
-
Central Endocrine Glands =
- (3)
-
Peripheral Endocrine Glands =
-
Dedicated Endocrine Structures =
- (3)
-
Mixed function Endocrine Glands =
- ______ -> erythropoietin (to control rate of RBC production)
- _____/_____ -> reproductive hormones/day job is to produce gametes, ova, sperm
-
Dedicated Endocrine Structures =
- Parts of the CNS (primarily the brain)
- Hypothalamus, Pineal Gland, Pituitary Gland
- Any gland outside of the CNS
- Endocrine structures that don’t have any other function besides endocrine release
- Thyroid, Parathyroid, Adrenal glands
- Organs of body that have a day job in addition to hormone release
- Kidneys
- Ovaries/Testes
- Endocrine structures that don’t have any other function besides endocrine release
Hormones Vs. Neurotransmitter
- A hormone can have a wide range of effects on the body dt different receptor _____ in diff organs
-
Neurohormonal cells =
- Ie (3)
- Comprises our basic ____transmission -> neuronal cell releases chemical messenger to neighboring ____ (____ bloodstream)
- So in the photo, all three pics can be releasing ADH, but in which examples are ADH a hormone?
- subtypes
- Neuronal cells that release hormones into bloodstream
- Hypothalamus, Pituitary gland, pituitary gland
- neurotransmission, cell, not bloodstream
- FIrst two examples
General Overview of Endocrine Control
The Effect that Hormones have on our body
- Very similar to that of ____, hormones are just _____ sources
- Determined by relationship between ____ and ____ it binds to
- drugs
- hormone and receptor
Endocrine Control (Notes)
- 3 Basic Responses
- Opening or closing of ____ ______: creating ______ or ______ where a change in membrane potential causes a physiologic response
- Acting through _____-_____ system to turn on or off _____ to create a change in function
- Activating specific ______ to turn on or off genes to either increase or decrease ______ of a protein (esp _____ hormones)
-
Ion Channels, depolarization, hyperpolarization
- ex) Cortisol released by adrenal cortex binds to receptors and causes depolarization -> increased brain excitability in stress response “thinking on your toes”/mental agility goes up
-
Second messenger, turns on or off enzymes
- ex) Insulin binds to insulin receptors on adipose tissue causing fat cells to not only take up glucose but insulin also increases activity of enzymes needed to turn glucose into fat
-
Genes, expression (steroid)
- ex) when children hit puberty and rise in estrogen or testosterone -> increased growth/muscle mass in boys
Chemical Types of Hormones and Significance
- Three types of Hormones (3)
- An Important distinction is between (2)
- This distinction will impact several factors (4)
- Peptide and Protein Hormones
- Amino Acid Derived Hormones
- Steroid Hormones
-
Water soluble vs. Lipid soluble
- Hormone Synthesis
- Hormone Storage
- Hormone Transport
- Hormone interaction with target
Hormone Types (Notes)
- Peptide and Protein hormones = _____ (peptide) or _____ (protein) chains of amino acids
- Amino acid derived hormones =
- Steroid hormones = all derived from ______ that is converted to ____ then converted to a variety of steroid hormones
- Which are Lipid soluble?
- Which are Water soluble?
- shorter, longer
- derived from a single amino acid that gets modified
- cholesterol -> pregnenolone
- Steroid hormones (easier ability to cross membrane)
- Peptide/Protein and Amino Acid hormones both water soluble with exception of Thyroid hormone which are lipid soluble even though it’s amino acid derived
Water Soluble Hormones
Usually protein or amino acid derived
- Hormone Synthesis = synthesized as a _____ and converted into ____
- Hormone Storage = usually via?
- Hormone Transport = usually free in _____
- Interaction with Target Cell = binds to _____ receptor, often uses ____-_____ system
- prohormone -> active
- intracellular vesicles
- plasma
- membrane receptor -> Second messenger
Fat Soluble Hormones
Usually a steroid hormone
- Hormone Synthesis = synthesized from _____
- Hormone Storage =
- Hormone Transport =
- Interaction with Target Cell = Usually binds to _____ receptor, then regulates?
- cholesterol
- Often not stored, made on demand, use of hormone binding proteins (intracellular or in circulation)
- Bound to plasma protein
- nuclear receptor -> gene transcription
Water Soluble vs. Lipid Soluble (Notes)
- Water Soluble
- Hormone synthesis: more _____
- Hormone transport: moves ____ through ______
- Interaction with a target: ____ to binding to a membrane receptor
- Lipid Soluble
- Hormone synthesis: steroid hormones tend to be synthesized on ____
- Hormone storage: we ____ tend to make steroid hormones in lareg amounts in advance and store them bc harder to store, but protein hormones we do
- Hormone transport: don’t move easily though bloodstream, need a binding ___ such as ____
In general, Lipid soluble hormones are going to effect ____ _____ bc more easily moves through membrane and enters ______
- Water soluble
- complicated
- freely through bloodstream
- limited to membrane receptor
- Lipid soluble
- on demand
- don’t tend to store
- protein, albumin
gene expression, nucleus
Peptide Hormones
List
- ACTH, Atrial Natruretic peptide, ADH
- Calcitonin, Cholecystokinin, CRH
- FSH
- Glucagon, GnRH
- Inhibin, Insulin, IGF’s
- LH, Oxytocin, PTH, PRL
- Secretin, Somatostatin
- TSH, TRH
- Vasoactive intestinal peptide
Amino Acid-Derived Hormones
(6)
- Dopamine
- Epinephrine
- Norepinephrine
- Serotonin
- T4* (lipid soluble)
- T3* (lipid soluble)
Steroid Hormones
(5)
- Aldosterone
- Cortisol
- Estrogen
- Progesterone
- Testosterone
Peptide Hormone
Ex (1)
- Background
- Synthesized by _____, released by _____
- __ amino acid chain, __ cystins: creating _____ bridge
- Released in the ____ way: stored in ____cellular vesicles, released when needed, travels ____ in bloodstream
-
2 Receptor subtypes = ____/_____\_
- __Cardiac physiologist discovered ____ bc causes vaso_____
- Renal physiologist discovered it as ___ -> binds to ___ receptor in ____ to ____ water retention
- When seq____ was done they realized it was the same hormone
- Since vasopressin discovered first: labeled as __ and __ receptor subtypes of ADH hormone (same hormone, 2 receptor subtypes)
ADH
- Background
- hypothalamus, posterior pituitary
- 9, 2, disulfide
- classiv, intracellular vesicles, freely
-
ADH/Vasopressin
- __Vasopressin, vasoconstriction
- ADH, V2, kidneys, increase
- sequencing
- V1, V2
Catecholamines
Subtype of _____ hormone
(3) that are dervied from _____
- Released as hormones by the ____ _____
- Example of chemical messenger that is ____ a hormone and neurotransmitter depending on how its released
- ____ is also a neurotransmitter when released by s_____ n____
Amine hormone
Epinephrine, Norepinephrine, Dopamine, Tyrosine
- Adrenal Medulla
- both
- Norepi, sympathetic nerves
T3 and T4
Subtype of ____ derived hormone
- Background
- Derived from amino acid ____
- T___ thyronine vs. T____thyronine
- 3 vs. 4 refers to the # of ____ atoms attached to structure
- ____ is the active form, T4’s extra iodine must be ____ by liver/target cell to be active
- Iodine atoms evens out distribution structure of the molecule making it nonpolar -> _____ soluble
- Note: Anything that is ______ is lipid soluble -> T3 and T4 similarly to ____ hormones effect gene expression bc can cross the membrane
- Most of those genes code for proteins that consume lots of ___ such as the Na/K+ ____ -> thyroid hormone connected to overall _____ rate -> more thyroid hormone = _______ metabolism
Amino acid
- Background
- thyronine
- Triiodo, Tetraiodo
- iodine
- T3 active, T4 removed to be active
- lipid (fat) soluble
- Notes: nonpolar, steroid
- energy, pumps, metabolic, increased
Steroid Hormones
(2) Examples
- All derived from ______: a rigid ___ structure that is ____ soluble
- From cholesterol -> diff _____ and hormones are created through small modifications
Testosterone
Estradiol (Estrogen)
-
Cholesterol, ring, lipid
- intermediates
Steroid Hormone Synthesis
- Sources of cholesterol (2)
- Liver packages some of the cholesterol into ___’s (low density lipoproteins)
- LDL’s find _____ cells that produce steroid hormones
- Steroid ____ bindss to LDL ____
- LDL is in_____, gets broken down, and cholesterol is _____
- Cholesterol turned into _______ in all first steps
- Pregnenolone (depending on what gland, the enzymes present) produce either (4)
All glands that produce steroid hormones have enzymes that produce ______
- Dietary consumed, Synthesized by Liver
- LDL’s
- endocrine
- hormone binds to LDL receptor
- internalized (receptor mediated endocytosis), liberated
- Pregnenolone
- Testosterone, Estradiol, Cortisol, Aldosterone
All steroid hormones produce pregnenolone
Cholesterol’s Biosynthesis Pathway
- Ch_____ -> P_____ -> I_____ -> ___ points (4)
- Each step sideways or down requires an _____ -> someone with a deficiency of one of these enzymes -> not able to produce ___ hormone and overproducing an ______
- ex) In utero masculinazation =
- Cholesterol -> Pregnenolone -> Intermediates -> End points (aldosterone, cortisol, testosterone, estradiol)
-
Enzyme, end, intermediate
- masculinaztion of external genitalia by a female baby’s deficiency of enzyme that produces cortisol so results in too much androgens/testosterone (ambiguous gender)
Peptide Hormone Action: Two Mechanisms
- Example of Second Messenger Systems
- Hormones bind to receptor -> cascade of reactions triggered -> rise in either ____ or ____ -> change in ____ of protein or enzyme
- Two common second messengers
- 1)
- 2)
- Second Mesenger System
- cAMP or Ca -> change in function
- 2 common second messengers
- Cyclic AMP (cAMP)
- Intracellular Ca+
When using cAMP phosphorlyated protein that is produced either stimulates or inhibits response
Components of Lipid Soluble Hormones
Which are (2)
- Can ____ cross membrane and tend to have a
- _____ receptor (R) = receptor found inside ____ that is bound to a region of ___ called the
- _____ region = where gene ____ is c_____
Steroid Hormone and thyroid hormone
- easily
- Nuclear Receptor = nucleus, DNA
- Promoter Region = gene expression is controlled
AKA Steroid and Thyroid hormones can trigger the expression of a gene - ex) thyroid hormone -> enters cell and binds to receptor on nucleus -> triggers transcription and translation and production of a lot of protein including Na/K+ pumps -> cell consumes ATP at a high rate -> metabolism goes up
Control of Hormone Secretion
Via what loop?
What type of control?
Negative Feedback Loop
Hierarchal Levels of Control
- All of the glands are receiving feedback on hormone 3*
- ex) Hypothalamus (gland 1), Anterior pituitary (gland 2), peripheral thyroid gland (gland 3) -> thyroid hormone (hormone 3) provides negative feedback control to hypothalamus and pituitary*
- Many hormonal loops act this way*
Control of Hormone Secretion (Notes)
- Negative feedback loop = glands _____ the amount of hormone in the ____, as hormone levels rise, gland will ____ production rate
- Hierarchal Control = control of hormonal secretion is so ____ regulated that often more than ___ or more glands are involved in releasing hormones which then eventually releases the last hormone that carries out the re_____
- monitor, bloodstream, decrease
- tightly, 2 or more glands, response
Central Endocrine Glands
Found at center of ____ and connected by the ____ _____
-
_________
- Neurosecretory cell bodies located in this structure move down its axons through the connecting stalk and end at axon terminals located in the (1)
-
_________
- ______ _______ = ______ of endocrine gland, rich in endocrine cells, true endocrine structure
- ______ ______ = ____ portion of gland that really is just an _____ of the hypothalamus
Brain, connecting stock
-
Hypothalamus
- posterior pituitary
-
Pituitary
- Anterior pituitary = majority
- Posterior pituitary = tiny, extension
Relationships between Hypothalamus + Anterior or Posterior Pituitary
- ____ bodied neurons make (2) and transport these hormones down their axons to the ____ pituitary for relase
- ____ bodied nuerons make releasing hormones, transport down their axons and secrete them into primary ____ plexuses.
- Large, AVP (argenine vasopressine) and Oxytocin, posterior
- Small, capillary plexuses
Relationship btwn Hypothalamus + Anterior and Posterior Pituitary (Notes)
- Posterior Pituitary
- Neurosecretory cells in hypothalamus release hormones through its axon ____ located in the posterior pituitary straight into _______
- Anterior Pituitary
- Connection btwn hypothalamus and anterior pituitary is very different = _______ control -> hypothalmic cells release ______ hormone right into ____ _____ in the connecting stalk -> hormones travel to anterior pituitary and act on pituitary cells to release _____ hormones into body
- Posterior
- terminals, bloodstream
- Anterior
- Hierarchal -> hypothalmic hormone -> blood vessels -> pituitary hormones
Hormones Released by Posterior Pituitary
(2)
Released by what?
- Vasopressin (ADH) - released by Paraventricular Nucleus (PVN)
- Oxytocin - released by Supraoptic Nucleus (SON)
Anterior Pituiitary Hormone Flow
- _______ neurons in the Hypothalamus release H_______ hormones
- Hormones released into Hypothalmic -h_____ p____ system through the systemic ____ inflow
- _____ ______ hormone then released through system ____ outflow
- Neurosecretory, Hypophysiotropic
- hypophyseal portal system, arterial
- Anterior pituitary, venous outflow
Hormones Released by Anterior Pituitary
(5)
TSH
ACTH
Prolactin
Growth Hormone
LH, FSH
Hormones of Anterior Pituitary
-
TSH
- Acts on the? To release? that effects?
-
ACTH
- Acts on the? to release? that effects?
-
Prolactin
- Acts on the? to release?
-
TSH
- thyroid gland -> T3, T4 -> metabolic rate
-
ACTH
- Adrenal cortex -> Cortisol -> Metabolic actions; stress response
-
Prolactin
- EXOCRINE** mammary glands -> breast growth and milk secretion
Hormones of Anterior Pituitary
-
Growth Hormone
-
Act on
- _____ to release S____ that acts on both ____ and soft ____ to stimulate G_____
- Many t____ to effect _____ actions
-
Act on
-
Growth Hormone
-
Acts on
- Liver -> Somatomedins -> Bone and Tissue -> Growth
- Tissues -> metabolic
-
Acts on
Anterior Pituitary Hormones
-
LH and FSH
- Acts on _____ (___ in females, ___ in males)
- LH -> ____ hormone secretion (2) in female, (1) men
- FSH -> G____ production (1) in female, (1) in male
- Gonads (ovaries, testes)
- sex, estrogen/progesterone, testosterone
- Gametes, ova, sperm
Hypothalmic and Pituitary Hormones and Their Target Organs
Hypothalamic Hormone Overview (Notes)
-
Hypothalamic hormones stimulate release of (1) hormones
- __ types of cells in anterior pituitary release different pituitary hormones
-
Unique Pituitary Hormones
-
______
- _____ Releasing Hormone
-
D______
- Dominant most of the time and ____ production of prolactin)
- Only during ___ where dopamin declines and prolactin reaches peak -> prolactin produces breast milk
-
_____ Hormone
- G____ Hormone Releasing Hormone = _____ to GH
-
S______ = _____ to GH
- Note: GH acts both d____ on tissue throughout the body and also acts on ____ to release another set of growth enhancing hormones
-
______
- Anterior pituitary
- 5
-
Unique Pituitary Hormones
-
Prolactin
- PRH Prolactin
-
Dopamine
- inhibits
- birth
-
Growth Hormone
- GHRH stimulates
-
Somatostatin inhibits
- directly on tissue, liver
-
Prolactin
Connection between Hypothalamus and Anterior Pituitary
-
In Conclusion, the connection between Hypothalamus and Anterior Pituitary (the central endocrine glands) is involved in controlling so many body functions
- Basic S____ Response
- All R_____ function
- Basic _____ function
- G___ and Reg____
- R____ function
- Stress
- Reproductive
- Metabolic
- Growth and Regulation
- Renal
Regulation of GH Release
- Neurosecretory cells in the _____ nucleus secrete GHRH, a 43 amino acid peptide that reaches the _____ via the hypophyseal portal _____ supply
- Cells in the p______ region release _____ a hormone that is a potentent inhibitor of GH secretion, into the portal blood supply
- GHRH causes _____ to synthesize and release GH
- Somatostatin _____ the release of GH by somatotrophs
- aurate, somatotrophs, blood
- periventricular, somatostatin
- somatotrophs
- inhibits
Somatotrophs = type of pituitary cells that release GH
Pic bottom right - GH is being released by somatotroph and can either bind to GHRH or somatostatin, if binds to somatostatin you can see it inhibits GHRH pathway by blocking entry of Ca
Somatotrophs Secrete Growth Hormone in Pulses
- GH is primarily released at ___ dt association with stage 2 ___-___ sleep (deep sleep)
- Why sleep is so important! bc GH is important for a variety of things such as tissue turnover (organ renewing itself), break down stored muscle, increase lean muscle mass
- Somatostatin released mostly during ___
- night, NON-REM sleep
- day
GH Direct and Indirect Effects on the Body
- Directly acts on _____ on body to enhance g____ and cell ____
-
Indirectly acts by acting on _____ to produce (2) -> which functions to
- Increased l____ growth of b____
- Increased _____ size
- Decreased ad_____
- Increased lean ____ mass
- GH and IGF 1 and 2 have opposite effects on Blood sugar
- GH _____ blood glucose, how?
- IGF _____ blood glucose, how?
- tissue, growth and cell function
- liver -> IGF 1 and 2 (insuline like growth factor)
- length of bone
- organ size
- dec adiposity
- inc muscle
- Effects on blood glucose
- GH increases, by stimulating liver to release glucose and blocks cells rom taking up glucose (GH = anti-insulin effects)
- IGF decreases, by allowing cells to take up glucose in order to grow and divide
Peripheral Endocrine Glands
-
Thyroid gland
- Found over _____, looks like a bowtie (left, right, and connecting lobe)
- Function -> ___ stimulating hormone -> controls _______
-
Parathyroid glands
- ____ little glands behind thyroid gland
- Function: ____ hormone -> controls _____
-
Thyroid
- trachea
- TSH -> metabolism
-
Parathyroid
- two glands
- PTH -> calcium
Structure of the Thyroid Gland
-
Follicles =
-
Colloid =
- Thyroglobulin =
-
Colloid =
- Follicular cells =
- Parafollicular cells (C cells) =
- hollow structures that make up thyroid tissue
-
pro-protein material inside follicle cells where thyroid hormone is STORED*
- water soluble substrate that fat soluble thyroid hormone needs to attach to, to be stored inside colloid
-
pro-protein material inside follicle cells where thyroid hormone is STORED*
- cells that line the follicles
- cells that release Calcitonin and also help control calcium in the body
Histological Look at the Thyroid Structure
Flow of Thyroid Hormone
- ______ controls thyroid function
- Hypothalamus releases ____ that acts on
- ______ to release ____ that acts on
- ______ to release _____
- This flow and release of hormones TRH, TSH, T3 and T4 is ______ and designed to maintain normal lvls of T3 and T4 - > only limiting factor is the (1)
- There are things that enhance or decrease this system ie Chronic Stress _____ the system, when infant gets cold it ____ the system but overall is a pretty steady system .
- Hypothalamus
- Thyrotropin Releasing Hormone (TRH)
- Anterior pituitary -> TSH
- Tyroid gland -> T3 and T4
- continuous, negative feedback loop
- inhibits, stimulates
Effects of Thyroid Hormone on Cells
- T3 and T4 are ____ soluble so easily crosses membrane
- _______ = Enzyme that most cells have that converts to T4 to T3
-
____ = the one that enters the nucleus and binds to thyroid hormone receptor and triggers transcription of many diff genes ie) it makes more
- (5)*
- ^all of these consume energy -> which is why thyroid function is connected to ____ rate
- lipid
- Monodeiodinase
-
T3
- Na K+ pumps
- Gluconeogenic enzymes that produce glucose
- Respiratory enzymes
- Myosin heavy chains (imp for muscle contraction)
- B adrenergic receptors
- metabolic
Test Question: most metabolic energy goes to producing heat -> how we measure basal metabolic rate (why hypothyroidism = cold, hyperthyroidism = hot)
Adrenal Glands
Sits on top of each kidney, is actually 2 glands
-
Adrenal Medulla
- location?
- Hormones released?
-
Adrenal Cortex
- location?
- Hormones released?
- Medulla
- center gland
- Catecholamines (epi, norepi) part of SNS
- Cortex
- outside gland
- Steroid hormones (cortisol, corticosteroids, aldosterone), including Reproductive Hormones (testosterone, estrogen, progesterone)
Histology of the Adrenal Gland
- Adrenal Medulla
- Is part of what system?
- Adrenal Cortex Layers that each produce different _____ hromones
- Zona _______
- Zona _______
- Zona _______
- Which is the only layer that produces Aldosterone?
- Sympathetic nervous system
- steroid
- Glomerulosa
- Fasciculata
- Reticularis
- Glomerulosa = Aldosterone
3 Categories of Hormones produced by Adrenal Cortex
-
________
- (3)
-
________
- (1)
-
________
- Masculinizing hormones (2)
- Feminizing hormones (2)
-
Glucocorticoids (blue block) named bc can cause elevation if blood glucose
- Corticosterone, Cortisol, Cortisone
-
Mineralcorticoids - named by effects Na, K, Ca..ish (specifically Na retention, K loss)
- Aldosterone
-
Sex Hormones
- Adrogens, Testosterone
- Progesterone, Estrogen and its intermediates
Steps in Glucocorticoid Production
- Hypothalamus releases _____ hormone which acts on
- ______ to release _____ hormone which then enters the _____ and acts on
- ______ to release glucorticoids (we mainly focus on _____)
- Cortisol
-
______ pattern = constantly produced more during ___ than at night, lowest lvl during ___ hours, highest just before waking
- Heart attack and stroke rates happen more commonly in the morning when cortisol lvls are highest bc tends to cause ______
- Natural rise in cortisol in the _____ helps wake you up
- Also stimulated by _____ response (neurohormonal response by the body to perceived threats)
-
______ pattern = constantly produced more during ___ than at night, lowest lvl during ___ hours, highest just before waking
- CRH (Corticotropin releasing hormone)
- Anterior pituitary, ACTH (adrenocorticotropic hormone), bloodstream
- Adrenal cortex, Cortisol
-
Diurnal = most during day, lowest evening
- vasoconstriction
- morning wakes you up
- stress
Glucorticoid (Cortisol) Flow
Actions of Cortisol
(5)
Acts on almost every system in the body -> designed to mobilize energy and effort, as part short lived response to stress
Gives immune system a day off and use all our energy to fight
- Elevates blood glucose by acting on the liver and enhancing glycogen breakdown and glucose release
-
Muscle breakdown and release of amino acids (which can be used by liver to drive gluconeogenesis)
- Therefore Cortisol works hard between liver and muscle to increase glucose
- Bone micro-breakdown to release Ca -> needed to drive muscle contraction/limits Ca excretion by kidneys
- Immunosuppressant and a strong Anti-inflammatory bc energy being rerouted
- Increases Neuro-excitability (“thinking on your toes during stress”)
Which is why in CHRONIC stress: cortisol levels are too high for too long -> you start getting sick, vulnerable to osteoporosis, prone to anxiety disorders
Pancreas
a cells produce _____
B cells produce _____
Pancreatic B cells release _____ -> destruction of B cells = ____ in insulin (what disease?)
glucagon
insulin
insulin -> deficiency (type 1 DM)