Flashcards in 16. Hormones Deck (14):
Hormondes are distributed by ...., bind to ....
Target cell receptors (target specificity depends on receptor equipment of cells)
Two examples of chemical signals that act locally, without entering blood stream?
Autocrine (acts on same cell that secretes them)
Paracrine (acts on neighbouring cells)
Three main chemical families of hormones?
1. Peptides and polypeptides (not lipid soluble)
2. Amino acid derivatives (most no lipid soluble)
3. Steroids (lipid soluble)
What is PTTH?
(Prothoracicotropic hormone) Brain hormone, peptide
- Stored/produced by brian
- Production influenced by environmental cues
- Controls activity of prothoracic gland
What is ecdysone?
- Produced by prothoracic gland
- Secreted into hemolymph
- Epidermis is target cells
- Response = ecdysis
- Brain responds by shutting off PTTH hormone (negative feedback)
2 hormones related to moulting in arthropods&
PTTH triggers periodic release of .... which ....
Declining release of ..... influences developmental stages of metamorphosis
Ways the nervous and endocrine systems work together
1. Neurons trigger hormone release (neurons in hypothalamus makes hormones released by posterior pituitary gland)
2. Hormones feedback onto nervous systems
1) Liver to convert glycogen to glucose
2) Heart to beat faster
3) Blood vessels to gut and skin to constrict, shunting more blood to muscles
4) Fat cells to release fatty acids (fuel) into blood
ADH (anti-diuretic hormone)
Trigger: increased salt concentration in bloods
Function: water is conserved & urine more concentrated
Action: increase reabsorption of water
- Target 1
- Action 1
- Target 2
- Action 2
1: smooth muscle of uterus, contractions
2: mammary glands, milk release
Hormones act by...
1. Affecting expression of gene
2. Altering activity of existing gene
3. Changing permeability of cell membrane