Flashcards in Arthropods II: Metamorphosis Hormones Deck (64)
Wigglesworth's experiment using
a blood sucking insect moults after blood meal
Hormones are secreated by
Hormones are distrubted by the ____ and bind to ___ ____ _____
blood; target cell receptors
some chemical signals act locally meaning they can...
act without entering the blood stream
How do hormones work?
1. affect the expression of a gene
2. alternate the activity of an existing enzyme
3. change the permeability of a cell membrane
what are the three chemical families of hormones
1. peptides and polypeptides
2. amino acid derivatives
what is the hormone involved in Arthropod moulting?
PTTH: ProThoracicoTropic Hormone
where is PPTH produced and stored?
in the brain
PTTH controls the activity of what gland?
What does the prothoracic gland produce?
Where is the ecdysone secreted?
into the blood
What cells does the ecdysone targe?
what releases ecdysone?
what determines when its time to moult?
pulses in the brain
What are the two body control systems?
endocrine system and nervous system
What is the endocrine system?
- diffuse via blood
- slower, longer term
What is the nervous system?
- action potentials
- electrical signals along neurons
- quicker: shorter term
what happens when both systems work together?
- neurons trigger hormone release
- neurons in hypothalamus make hormones released by the posterior pituitary gland
- hormones feed back onto nervous system
what are the responses of nervous and endocrine system to stimuli?
1. brain detects danger and signals an action
2. brain signals adrenal gland to release epinephrin
3 epinephrine causes:
- the liver to convert clycogen to glucose
- the heart to beat faster
- Blood vessels to gut and skin to constricut - shunting more blood to muscles
- fat cells release fatty acids (fuel) into blood
The Hypothalamus integrates ...
information about the state of the body
ADH stands for
what triggers ADH?
Increased salt concentration in the blood
what is the function of ADH?
water is conserved and urine is more conentrated
what does ADH target?
what does ADH do?
Increases the absorption of water
Eating a bag of chips
- Sodium levels go up
- body tries to flush out some of the Na (this requires water)
- body loses water
- if you lose too much you'll shrivel up
- hypothalamus releases hormone to the kidney so it reabsorbs the water so you don't shrivel up
Oxytocin's 1st targe
the smooth muscle of the uterus
First action of Oxytocin