Download - Hormones
2006-2007 AP Biology
Endocrine SystemHormones
AP Biology
Regulation Why are hormones needed?
chemical messages from one body part to another
communication needed to coordinate whole body
homeostasis & regulation metabolism growth development maturation reproduction
growth hormones
AP Biology
Regulation & Communication Animals rely on 2 systems for regulation
endocrine system ductless gland which secrete
chemical signals directly into blood chemical travels to target tissue slow, long-lasting response
nervous system system of neurons, central
nerve system transmits “electrical” signal to
target tissue fast, short-lasting response
AP Biology
Regulation by chemical messengers
Axon
Neurotransmitter
Endocrine gland
Receptor proteins
Hormone carried by blood
Target cell
Neurotransmitters released by neurons Hormones release by endocrine glands
Receptor proteins
AP Biology
Classes of Hormones Protein-based hormones
polypeptides small proteins: insulin, ADH
glycoproteins large proteins + carbohydrate: FSH, LH
amines modified amino acids: epinephrine, melatonin
Lipid-based hormones steroids
modified cholesterol: sex hormones, aldosterone
AP Biology
How do hormones act on target cells Lipid-based hormones
hydrophobic & lipid-soluble diffuse across membrane & enter cells bind to receptor proteins in cytoplasm & nucleus bind to DNA as transcription factors
Protein-based hormones hydrophilic & not lipid soluble
can’t diffuse across membrane trigger secondary messenger pathway activate cellular response
enzyme action, uptake or secretion of molecules…
AP Biologynucleus
cytoplasm
plasma membraneDNA
mRNA protein
steroid hormone blood
proteincarrier2
3
5
4
S
S
S
1S
Action of lipid (steroid) hormones
receptor protein
AP Biology
Action of protein hormones
3
4
GTPactivatesenzyme
activatesenzyme
activatesenzyme
Receptorprotein
cAMP
Proteinhormone
ATP
1
2
cytoplasm Produces an action
proteinmessengercascade
G protein
AP Biology
adrenal gland
Action of epinephrine (adrenalin)
3
4
GTPactivates
protein kinase-A
activatesphosphorylase
activates adenylyl cyclase
receptorprotein
cAMP
epinephrine
ATP
1
2
cytoplasm
G protein
liver cell
glucoseglycogen
releasedto blood
AP Biology
Benefits of a 2° messenger system
Amplification!
Signal molecule Receptor protein Activated adenylyl cyclase
Amplification
Amplification
Amplification
Amplification
GTP G protein
2
1
3
4
5
6
7
Enzymatic product
Enzyme
Protein kinase
cAMP
Not yetactivated
2005-2006AP Biology
Negative Feedback Model
high
low
hormone 1
lowersbody condition
hormone 2
gland
specific body condition
raisesbody condition gland
2005-2006AP Biology
Body Temperature
high
low
nerve signals
sweat
nerve signals
brain
body temperature
shiver brain
dilates surfaceblood vessels
constricts surfaceblood vessels
FeedbackNervous System Control
2005-2006AP Biology
liver
pancreas
liver
Blood Sugar
blood sugar level
insulin
body cells takeup sugar
from blood
liver storessugar
reducesappetite
glucagon
pancreas
liver releases
sugartriggershunger
high
low
FeedbackEndocrine System Control
2005-2006AP Biology
nephron
low
Blood Osmolarity
blood osmolarityblood pressure
ADH
increasedwater
reabsorption
increasethirst
renin
increasedwater & saltreabsorption
high
FeedbackEndocrine System Control
pituitary
angiotensinogenangiotensin
nephronadrenalgland
aldosterone
AP Biology
Endocrine & Nervous system links Hypothalamus = “master control center”
nervous system receives information from nerves around body
about internal conditions regulates release of hormones from pituitary
Pituitary gland = “master gland” endocrine system secretes broad range
of hormones regulating other glands
AP Biology
Thyroid gland
Hypothalamus
Anteriorpituitary
Gonadotropic hormones:Follicle-stimulatinghormone (FSH) & luteinizing hormone (LH)
Mammaryglandsin mammals
Musclesof uterus
Kidneytubules
Posteriorpituitary
Thyroid-stimulating Hormone(TSH)
Antidiuretic hormone(ADH)
Adrenalcortex
Boneand muscle Testis Ovary
Melanocytein amphibian
Adrenocorticotropic
hormone (ACTH)Melanocyte-stimulating hormone(MSH)
OxytocinProlactin (PRL)
Growth
hor
mon
e (GH)
AP Biology
Homology in hormones
prolactin
mammals
milkproduction
birds
fatmetabolism
amphibians
metamorphosis& maturation
fish
salt &water
balance
growth& development
What does this tell you about these hormones?
growthhormone
same gene family
AP Biology
Regulating metabolism Hypothalamus
TRH = TSH-releasing hormone
Anterior Pituitary TSH = thyroid stimulating hormone
Thyroid produces thyroxine hormones metabolism & development
bone growth mental development metabolic use of energy blood pressure & heart rate muscle tone digestion reproduction tyrosine
iodinethyroxine
AP Biology
GoiterIodine deficiency causes thyroid to enlarge as it tries to produce thyroxine
AP Biology
Regulating blood calcium levels
Increased blood Ca++
Thyroid
ParathyroidsLow blood Ca++
Parathyroidhormone (PTH)
Increased absorptionof Ca++ from intestine due to PTH activation of Vitamin D
Reabsorption of Ca++ &excretion of PO4
Osteoclasts dissolve CaPO4crystals in bone, releasing Ca++
–Negativefeedback
2005-2006AP Biology
corpusluteumovary
Female reproductive cycle
pregnancy
maintainsuterus lining
no
yes
Feedback
estrogenegg
matures &is released(ovulation)
builds up uterus lining
FSH & LHprogesterone
progesterone
fertilized egg(zygote)
HCG
corpus luteum breaks downprogesterone drops
menstruation
corpusluteum
maintainsuterus lining
GnRH
pituitarygland
hypothalamus
2005-2006 AP Biology
Any Questions??
2005-2006 AP Biology
Animal Reproduction&
Development
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Oogenesis
Meiosis 1 completedduring egg maturation
Meiosis 2 completedtriggered by fertilization
ovulation
What is the advantage of this development system?
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Fertilization
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Fertilization Joining of sperm & egg
sperm head enters egg
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Cleavage Repeated mitotic divisions of zygote
1st step to becoming multicellular unequal divisions establishes body plan
different cells receive different portions of egg cytoplasm & therefore different regulatory signals
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Cleavage zygote morula blastula
establishes future development
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Gastrulation Establish 3 cell layers
ectoderm outer body tissues
skin, nails, teeth, nerves mesoderm
blood, bone & muscle endoderm
inner lining digestive system
ectoderm
mesoderm
endoderm
protostome vs. deuterostome
gastrulation inprimitive chordates
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Neurulation 1st organ to form is notochord &
nerve chord develop into nervous system
Neural groove
Notochord
Neural tube
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OrganogenesisUmbilical blood vessels
Chorion
Amnion
Yolksac
AllantoisFetal blood vessels
Maternal blood vessels
Bird embryo
Mammalian embryo
Placenta
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Placenta Materials exchange across membranes
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Human fetal development
7 weeks4 weeks
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Sex determination
XY
XX
TestesY
Sperm Zygote
Zygote
Ovum
Sperm
Ovum
X
X
X
Indifferentgonads
SRY
No SRYOvaries
(Follicles do notdevelop until
third trimester)
Seminiferoustubules
Develop inearly
embryo
Leydig cells
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Human fetal development10 weeks
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Human fetal development
12 weeks 20 weeks
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Human fetal development The fetus just spends much of the 2nd & 3rd
trimesters just growing …and doing various flip-turns & kicks inside amniotic fluid
Week 20
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Human fetal development 24 weeks (6 months; 2nd trimester)
fetus is covered with fine, downy hair called lanugo. Its skin is protected by a waxy material called vernix
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Human fetal development 30 weeks (7.5 months)
umbilical cord
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Getting crowded in there!! 32 weeks (8 months)
The fetus sleeps 90-95% of the day & sometimes experiences REM sleep, an indication of dreaming
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Birthpositive feedback
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Intestine
Placenta
Umbilicalcord
Wall ofuterus
VaginaCervix
Birth (36 weeks)
Bladder
2005-2006AP Biology
The end of the journey!