Lec 3 - Chemical Signals in Animals Flashcards
Regulatory Mechanism
- Nervous system
- Endocrine system
conveys high-speed electrical signals along specialized cells
Nervous system
Specialized cell in nervous system
Neurons
secretes hormones that coordinate slower but longer-acting responses
Endocrine system
are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
(Animal) Hormones
Hormones which regulated insect metamorphosis
- Steroid 20-hydroxyecdysone
- Lipid juvenile hormone
Two types of glands
- Exocrine Glands
- Endrocrine Glands
secrete chemicals into ducts and the effect is where the duct empties
- Exocrine glands
secrete chemical messengers (hormones) into the blood for distribution throughout the animal’s body and bind to specific hormone receptors
Endocrine Glands
Conclusion of Arnold Adolph Berthold’s study
Hormones in testes is responsible for crown phenotype
Regulates developments in humans
Signaling Pathways
Activates the signaling pathways
Specific chemical signaling molecules
Only target cells respond to the signal, because it bears receptors for the hormone
Target Cell concept
3 types of intercellular communication
- Endocrine signaling
- Paracrine signaling
- Direct signaling
- secreted molecules diffuse into the bloodstream
- Trigger response in target cells anywhere in the body
Endocrine signaling
special type of endocrine signaling
Nueroendocrine signaling
neurohormones diffuse into the bloodstream and trigger responses
Neuroendocrine signaling
secreted molecules diffuse locally and trigger a response in neighboring cells
Paracrine signaling
Special types of paracrine signaling
- Autocrine signaling
- Synaptic signaling
secreted molecules diffuse locally and trigger a response in the cells that secrete them
Autocrine signaling
neurotransmitters diffuse across synapses and trigger responses in cells of target tissue
Synaptic/neuronal signaling
for some signals to be received, the cells must be in direct contact.
Direct Signaling
signaling that is relative slow
Endocrine signaling
signaling that has quick response
Paracrine signaling
Types of secreted signaling molecules
- Local regulators
- Neutrotransmitters
- Neurohormones
- Phermones
- Hormones
chemical signals that travel over short distances by diffusion
Local regulators