New News Biology #40

Nervous System & Reflex Arc

Different parts of body need to communicate with each other to coordinate behaviour and respond to their surroundings. So they use these two organ systems to communicate: the nervous system & the endocrine system. Today is about the nervous system.

Structure of nerve cell (also known as the neuron);

Electrical impulses are carried along them

They are long & thin & have a lot of branched connections

Are the biological equivalent to a wire or data cable.

Have synapses at the very ends; these synapses temporarily convert electric signals to chemical then back to electric once its bridged the gap and continued travelling in another neuron.

Nervous system;

CNS (Central Nervous System); It consists of the brain & spinal cord. The ‘thinking’ happens here. It is basically a gathering of impulses & information which is evaluated by the brain. The brain then gives a response, which is sent out back through the neurons.

Reflex Arc (A nerve pathway for reflexes);

Auto, rapid, unconscious behavior is what we call a ‘reflex’

By touching a stimuli (like a hot stove), the receptor cells pick up info. That info is sent to the sensory neurons. It then travels up the spinal cord. The CNS generates a response, which is sent through a relay neuron to a motor neuron to an effector (like our bicep), and finally we have a reaction: We pull back our hand!