Post on 15-Jan-2016
The Endocrine The Endocrine SystemSystem
Honors Honors
Physiology Physiology
What are hormones?What are hormones? Hormones:Hormones:
send messages send messages act locally or at a distanceact locally or at a distance work quickly or slowly work quickly or slowly can be created/excreted by cells, tissues or can be created/excreted by cells, tissues or
organs, collectively known as “glands”organs, collectively known as “glands” secreted via epithelial cells secreted via epithelial cells extracellular fluid extracellular fluid
blood stream blood stream receptors on target cells receptors on target cells ducts are not used by endocrine systemducts are not used by endocrine system
Comparison to Nervous Comparison to Nervous SystemSystem
Fig. 13.2
Comparison to Nervous Comparison to Nervous SystemSystem
EntityEntity Nervous SysNervous Sys Endocrine SysEndocrine Sys
Cell typeCell type NeuronsNeurons EpithelialEpithelial
Chemical Chemical signalsignal
NeurotransmitterNeurotransmitter HormoneHormone
Specificity of Specificity of responseresponse
Receptors on Receptors on postsynaptic cellpostsynaptic cell
Receptors on Receptors on target cellstarget cells
SpeedSpeed MillisecondsMilliseconds Seconds to hoursSeconds to hours
Length of Length of effecteffect
Brief Brief Brief or longBrief or long
Example of Hormonal Example of Hormonal Regulation—Today’s LabRegulation—Today’s Lab
ThyroxineThyroxine Released from thyroid Released from thyroid
glandgland Target: cells all over bodyTarget: cells all over body Influences metabolismInfluences metabolism
Thyroid stimulating Thyroid stimulating hormone (TSH) hormone (TSH) Released from anterior Released from anterior
pituitary glandpituitary gland Target: thyroid glandTarget: thyroid gland Signal: “release thyroid Signal: “release thyroid
hormones!”hormones!”
Endocrine System—Relative Stability of Endocrine System—Relative Stability of Hormone ConcentrationsHormone Concentrations
Negative feedback Negative feedback maintains stable maintains stable hormone levels hormone levels Fig. 13.11
Endocrine System—3 Ways To Endocrine System—3 Ways To Control Hormonal SecretionsControl Hormonal Secretions
Fig. 13.8
Example: Negative Feedback Example: Negative Feedback Controls Blood Glucose LevelsControls Blood Glucose Levels What What
happens happens when your when your blood blood glucose glucose gets too gets too low?low?
Fig 13.36
Example: Negative Feedback Example: Negative Feedback Controls Blood Glucose LevelsControls Blood Glucose Levels What What
happens happens when your when your blood blood glucose glucose gets too gets too high?high?
Fig 13.36
Fig. 13.5
Steroid HormonesSteroid Hormones
Steroid HormonesSteroid Hormones
Lipid soluble Lipid soluble Receptor in the nucleus Receptor in the nucleus
binds hormone binds hormone gene transcription gene transcription
mRNA is then translated into a protein in the mRNA is then translated into a protein in the cytoplasmcytoplasm
ExamplesExamples estrogen, testosteroneestrogen, testosterone aldosterone, cortisolaldosterone, cortisol
Nonsteroid HormonesNonsteroid Hormones
Fig. 13.7
Nonsteriod HormonesNonsteriod Hormones
CannotCannot move through lipid bilayer move through lipid bilayer Instead they bind to receptors in cell Instead they bind to receptors in cell
membranemembrane Examples:Examples:
TSHTSH EpinephrineEpinephrine Glucagon Glucagon
HypothalamusHypothalamus Regulates other glands to tell them when Regulates other glands to tell them when
to release their hormonesto release their hormones
Fig. 13.9
Pituitary GlandPituitary Gland
Fig. 13.9
Anterior PituitaryAnterior Pituitary
Adrenocorticotropic hormone (ACTH)Adrenocorticotropic hormone (ACTH) Target: adrenal cortex, stimulates cortisol releaseTarget: adrenal cortex, stimulates cortisol release influences protein and fat metabolisminfluences protein and fat metabolism
GonadotropinsGonadotropins follicle stimulating hormone (FSH) follicle stimulating hormone (FSH)
egg or sperm maturation egg or sperm maturation For egg, stimulates release of egg from follicle mid cycleFor egg, stimulates release of egg from follicle mid cycle
luteinizing hormone (LH) luteinizing hormone (LH) Stimulates release of sex hormonesStimulates release of sex hormones
Anterior Pituitary cont.Anterior Pituitary cont.
Growth Hormone (GH)Growth Hormone (GH) bone growth/osteogenesisbone growth/osteogenesis
Melanocyte Stimulating Hormone (MSH)Melanocyte Stimulating Hormone (MSH) skin color, includes tanningskin color, includes tanning
Prolactin (PRL)Prolactin (PRL) lactationlactation
Thyroid Stimulating Hormone (TSH)Thyroid Stimulating Hormone (TSH) stimulates thyroid secretionsstimulates thyroid secretions
Robert P. WadlowRobert P. Wadlow8’ 11”8’ 11”
AgeAge HeightHeight
88 6’6’
1414 7’5”7’5”
1818 8’4”8’4”
2222 8’11”8’11”
Yikes, his anterior pituitary released too much growth hormone!
Anterior Pituitary cont.Anterior Pituitary cont. How am I going to remember all of How am I going to remember all of
this???this??? AA GGreen reen GGiant iant MMakes akes PRPRetty etty
TThingshings AACTHCTH GGonadotropins (FSH, LH/ICSH)onadotropins (FSH, LH/ICSH) GGHH MMSHSH PRPR TTSHSH
Posterior PituitaryPosterior Pituitary
Antidiuretic Hormone (ADH)Antidiuretic Hormone (ADH) decreases urine formationdecreases urine formation when you are dehydrated, your body says when you are dehydrated, your body says
“don’t lose water!”, so ADH is increased“don’t lose water!”, so ADH is increased increased ADH = concentrated urineincreased ADH = concentrated urine
Oxytocin Oxytocin smooth muscle contractions in the uterus smooth muscle contractions in the uterus
during childbirthduring childbirth Recent studies = “bonding” hormoneRecent studies = “bonding” hormone
Posterior Pituitary cont.Posterior Pituitary cont.
Why do you urinate more when you drink Why do you urinate more when you drink caffeine? caffeine? Your body recognizes caffeine as a toxin Your body recognizes caffeine as a toxin
that it needs to expel from the bodythat it needs to expel from the body Caffeine is a Caffeine is a diureticdiuretic – – it makes you urinateit makes you urinate
it it inhibitsinhibits secretion of ADH secretion of ADH you don’t get the “don’t lose water!” signalyou don’t get the “don’t lose water!” signal so you expel more water to try and flush out the so you expel more water to try and flush out the
toxintoxin
Pineal GlandPineal Gland
MelatoninMelatonin Helps regulate circadian rhythms (sleep-Helps regulate circadian rhythms (sleep-
wake cycle)wake cycle)
ThyroidThyroid
Thyroxine or tetraiodothyronine (TThyroxine or tetraiodothyronine (T44)-and )-and
Triiodothyronine (TTriiodothyronine (T33)) regulate your food metabolism (break down regulate your food metabolism (break down
glucose, fat & protein to create energy)glucose, fat & protein to create energy) increase temperature, growth and increase temperature, growth and
developmentdevelopment
Fig. 13.16
Thyroid & ParathyroidThyroid & Parathyroid
Thyroid releases Thyroid releases CalcitoninCalcitonin lowers calcium levels lowers calcium levels
in the bloodin the blood
Parathyroid releases Parathyroid releases Parathyroid Hormone Parathyroid Hormone (PTH) (PTH) increases calcium increases calcium
levels in the bloodlevels in the bloodFig. 13.24
PancreasPancreas
InsulinInsulin GlucagonGlucagon Islets of Islets of
LangerhansLangerhans regulate blood regulate blood
glucose levelsglucose levels Both hormones Both hormones
created in the…created in the…
Fig. 13.34
Pancreas cont.Pancreas cont.Islets of LangerhansIslets of Langerhans
Alpha CellsAlpha Cells Make GlucagonMake Glucagon Released when your Released when your
blood sugar levels get blood sugar levels get lowlow
Increases blood Increases blood glucose levels by glucose levels by breaking down breaking down glycogen (storage glycogen (storage form of glucose in the form of glucose in the liver) and liver) and noncarbohydrates noncarbohydrates into glucoseinto glucose
Beta CellsBeta Cells Make InsulinMake Insulin Released when your Released when your
blood sugar levels get blood sugar levels get highhigh
Tells your body cells Tells your body cells to take sugar in, and to take sugar in, and decreases blood decreases blood glucose levels by glucose levels by stimulating the liver to stimulating the liver to form glycogenform glycogen
Pancreas cont.Pancreas cont. Diabetes- can’t regulate your blood glucoseDiabetes- can’t regulate your blood glucose
Type I - JuvenileType I - Juvenile Islets of Langerhans don’t work properly & cannot create Islets of Langerhans don’t work properly & cannot create
sufficient insulin (or glucagon)sufficient insulin (or glucagon) usually need insulin injections (why not glucagon usually need insulin injections (why not glucagon
injections?)injections?) usually inheritedusually inherited
Type II - Adult onsetType II - Adult onset Insulin Insulin receptorsreceptors throughout body don’t work properly throughout body don’t work properly usually can use oral treatmentusually can use oral treatment related to weight gainrelated to weight gain
About 17 million people in the US have diabetes!About 17 million people in the US have diabetes!
Adrenal GlandsAdrenal Glands
Adrenal MedullaAdrenal Medulla epinephrine/adrenalinepinephrine/adrenalin norepinephrine/noradrenalinnorepinephrine/noradrenalin
Increases blood glucose, heart rate, Increases blood glucose, heart rate, etc.etc.
Blood vessels constrict in digestive Blood vessels constrict in digestive tract and kidneys, dilate in blood tract and kidneys, dilate in blood vessels of the musclesvessels of the muscles
Fig. 13.28
Adrenal Glands cont.Adrenal Glands cont.Adrenal CortexAdrenal Cortex
AldosteroneAldosterone Target cells in kidneysTarget cells in kidneys Maintain NaMaintain Na++ and K and K++ balance balance
CortisolCortisol Glucose, protein and fat metabolismGlucose, protein and fat metabolism Anti inflammatoryAnti inflammatory
AndrogensAndrogens supplement gonad sex hormones supplement gonad sex hormones
Reproductive OrgansReproductive Organs
OvariesOvaries EstrogenEstrogen
stimulates egg maturation stimulates egg maturation secondary female sex characteristicssecondary female sex characteristics
ProgesteroneProgesterone maintains uterine lining in case of implantationmaintains uterine lining in case of implantation
TestesTestes TestosteroneTestosterone
regulates spermatogenesisregulates spermatogenesis secondary male sex characteristicssecondary male sex characteristics
Adrenal Glands cont.Adrenal Glands cont. Addison diseaseAddison disease
Cortisol hyposecretionCortisol hyposecretion low Nalow Na++, high K , high K ++, dehydration, low glucose, , dehydration, low glucose,
can be very serious can be very serious Cushing syndromeCushing syndrome
Cortisol hypersecretion (usually Cortisol hypersecretion (usually by too much ACTH)by too much ACTH)
High NaHigh Na++, low K+, high glucose, , low K+, high glucose, water retentionwater retention
Thyroid cont.Thyroid cont.
Grave’s diseaseGrave’s disease too much hormonetoo much hormone
HyperHyperthyroidismthyroidism
Hashimoto’s diseaseHashimoto’s disease too little hormonetoo little hormone
HypoHypothyroidismthyroidism