The need for communication

The need for communication

1. Receptors

   • Detect changes and signal the changes in the organism needed to respond and maintain safety
   • Photoreceptor - light
   • Olfactory receptor - Airborne chemicals
   • Chemoreceptors - CO2 and pH in blood
   • baroreceptors - blood pressure
   • Proprioreceptors - limb position

2. Effectors

   • Parts of the body that respond to change
   • muscles
   • glands

3. Cell signalling

   • One cell releases a chemical that is detected by another cell
     • Second cell responds depending on cell type and stimulus
   • Endocrine pathway
     • Hormones over long distances
     • Circulatory system
     • Long-term responces
   • Paracrine signalling
     • Intermediate distance
     • Acts on neighboring cells
   • Autocrine signalling
     • Cell produces and reacts to its own signal