Action potential potential, such as plant cells, muscle cells, and the specialized cells of the heart (in which occurs the cardiac action potential). However, the main excitable cell is the neuron, which also has the simplest mechanism for the action potential. Neurons are electrically excitable cells composed, in general, of one or more dendrites, a single soma, a single axon and one or more axon terminals. Dendrites are cellular projections whose primary function is to receive synaptic signals. Their protrusions, known as dendritic spines, are designed to capture the neurotransmitters released by the presynaptic neuron. They have a high concentration of ligand-gated
Evolution of the brain the structures responsible for basic behaviors. A long term human study comparing the human brain to the primitive brain found that the modern human brain contains the primitive hindbrain region – what most neuroscientists call the protoreptilian brain. The purpose of this part of the brain is to sustain fundamental homeostatic functions. The pons and medulla are major structures found there. A new region of the brain developed in mammals about 250 million years after the appearance of the hindbrain. This region is known as the paleomammalian brain, the major parts of which are the hippocampi and amygdalas, often referred