AP Biology
Homeostasis and Development
Signal Transduction Pathway
Kinases “turn on” processes (can amplify)
Phosphotases “turn off” processes
• Ligand• Hormone• Target tissue
Basic Hormone Pattern
Targeteffectors
Response
Simple endocrine pathway
Glycogenbreakdown,glucose releaseinto blood
Liver
Bloodvessel
Pancreassecretesglucagon ( )
Endocrinecell
Low bloodglucose
Receptorprotein
Stimulus
Pathway Example
3 parts of hormonal system
•Exocrine•Endocrine•Neurosecretory
Remember the “hands” on cell membranes? (In GREEN)
Local Hormones
• Growth factors• Nitric Oxide (NO)• Prostaglandins• Cytokines
LE 45-7
Mammary glands,uterine muscles
Hypothalamus
Kidney tubules
OxytocinHORMONE
TARGET
ADH
Posteriorpituitary
Neurosecretorycells of thehypothalamus
Axon
Anteriorpituitary
CytokinesIL 1 – Macrophage to Helper TIL2 – Helper T to B or Cytotoxic T
Polar versus Non-polar HormoneSignal Reception
SECRETORYCELL
Hormonemolecule
Signal receptor
VIABLOOD
VIABLOOD
TARGETCELL TARGET
CELLSignaltransductionpathway
OR
Cytoplasmicresponse
DNA
NUCLEUS
Nuclearresponse
Receptor in plasma membrane Receptor in cell nucleus
DNA
NUCLEUS
mRNA
Synthesis ofspecific proteins
Signaltransductionand response
Signalreceptor
Hormonemolecule
SECRETORYCELL
Examples of Negative Feedback Loops
Hypothalamus
TRH
Anteriorpituitary
TSH
Thyroid
T3 T4
Positive Feedback Loop
Tropic Hormones of the PosteriorPituitary
Mammary glands,uterine muscles
Hypothalamus
Kidney tubules
OxytocinHORMONE
TARGET
ADH
Posteriorpituitary
Neurosecretorycells of thehypothalamus
Axon
Anteriorpituitary
Tropic Hormones of the Anterior Pituitary
Neurosecretory cells of the hypothalamus
Endocrine cells of theanterior pituitary
Portal vessels
Pituitary hormones(blue dots)
Pain receptorsin the brain
Endorphin Growth hormone
BonesLiver
MSH
Melanocytes
Prolactin
Mammaryglands
ACTH
Adrenalcortex
TSH
ThyroidTestes orovaries
FSH and LH
TARGET
HORMONE
Hypothalamicreleasinghormones(red dots)
Tropic Effects OnlyFSH, follicle-stimulating hormoneLH, luteinizing hormoneTSH, thyroid-stimulating hormoneACTH, adrenocorticotropic hormone
Nontropic Effects OnlyProlactinMSH, melanocyte-stimulating hormoneEndorphin
Nontropic and Tropic EffectsGrowth hormone
• Most of the cells in the thyroid are called follicular cells, but there are others called parafollicular cells (or C cells) which produce another important hormone called calcitonin. The thyroid also has four teensy glands called the parathyroid glands, which are embedded in the back of the thyroid and produce the hormone creatively called parathyroid hormone. These two hormones, calcitonin and parathyroid hormone, work in tandem to keep your body's calcium level in check. We all know how important calcium is to prevent diseases like osteoporosis, but too much of a good thing isn't ideal either. That's where calcitonin comes in; it decreases how much calcium is in your blood, while parathyroid hormone works to beef those levels up.
• http://www.youtube.com/watch?v=-S_vQZDH9hY
• http://www.innerbody.com/image/endoov.html