Chapter 6: Communication, Integration, and Homeostasis Flashcards
what are the two types of physiological signals for cell to cell communication?
- electrical
* chemical
what are the methods of cell to cell communication?
- local communication
2. long distance communication
what does local communication consist of?
- gap junctions
- contact-dependent signals
- paracrine signals
what does long distance communication consist of?
- passing along neurons
* chemical messengers transported through the blood
- cytoplasmic link between adjacent cells
- involve connexin proteins
- can function in synchronizing communication
gap junctions
where are gap junctions found?
- heart muscle
- smooth muscle
- some glands
- some neurons in -the brain
- A surface molecule on one cell binds a membrane protein on another.
- cell adhesion molecules (CAM’s)
- Play a role in the immune system as well as growth and development
contact-dependent signals
Chemicals that communicate with neighboring cells (must be close enough that once secreted into ECF it can reach the target cell by simple diffusion
paracrine signals
what are paracrine examples?
- Eicosanoids lipid derived signal molecules
- Cytokines peptides function in coordinating the body’s defense against infections
what do autocrine signals act on?
act on the cell that secreted it
what are hormones secreted by?
endocrine system
chemicals secreted into the interstitial fluid, where they diffuse into the blood and are distributed all over the body
hormones
which cells can respond to hormones?
Only cells possessing receptors specific for the hormone can respond (target cells)
this system is a combination of chemical and electrical signals
nervous system
how do the chemical and electrical signals of the nervous system work?
- Electrical signals travel down neurons
- Chemical signals secreted by neurons are neurocrine molecules
diffuse across narrow space to target cell (rapid onset effect)
neurotransmitter
signal acts as a paracrine signal
neuromodulator
chemicals
released by neurons into the blood
for action at distant targets
neurohormone
what do signal pathways include?
- ligand (1st messenger) binding receptor protein
- receptor activation
- activation of intracellular signal molecules
- response of cell by protein modification or synthesis
transmit their signals by binding to target cell receptors located either on the plasma membrane, in the cytosol, or in the nucleus.
chemical messengers
what is the location of binding dependent on?
- dependent on the properties of the molecule
- lipophilic molecules
- lipophobic molecules
receptors are cytosolic or nuclear (slower response)
lipophilic molecules
receptors on the cell membrane (rapid response)
lipophobic molecules
what does intracellular signal receptors involve?
- receptor in cytosol
- receptor in nucleus
- lipophilic signal molecules