Nervous system
Central Nervous System
Periferial Nervous System
The Central Nervous system is composed by the brain and spine cord. This system is the one who makes the desicions.
Network of all the nerves in the body that sends the messages to and from the central nervous system.
Efferent neuron: Neuron that carries a message from the CNS.
• Afferent neuron: Neuron carrying the message to the CNS.
Brain
Meninges
Lobes
Layers of protective tissue that cover the brain and spinal cord
Frontal Lobe: send out planned voluntary skeletal muscle messages
Parietal Lobe: responsible for general senses like touch
Temporal Lobe: responsible for hearing sense
Occipital Lobe: responsible for vision.
Spine Cord
Commands are sent here by the brain. Consequently, the spinal cord activates particular muscles in each leg with the correct timing and strength creating a locomotion form that involves using both legs, which is called "gait".
SPINAL INTERNEURON CIRCUITS: interneurons send axons across the midline to allow crossed inhibition which allows muscle activation by alternating left-right muscle activation. This prevents muscles from both sides from contracting at the same time.
If they contract at the same time, the crossed inhibitory connections are weakened.
We have 4 muscle control circuits, one for each limb, and in order to control it, besides using the crossed inhibition, we use the inhibitory connection that exist between the upper and the lower parts
In both nervous systems, neurons communicate through a process called synapse.
During it, action potentials, which are electrical impulses, cross various neurons in a circuit activating the next neuron in the circuit.
The transference of information occures when a dendrite connects to a synaptic terminal.
As the transference occurs, channels in the synaptic terminal open allowing calcium mines into the nerve terminals, which at the same time activate packages of neurotransmitters that release their content into the gaps of the synapse.
Some of them difuse away, but others activate reseters on target neurons opening further channels whcih let sodium mines in, transmitting the information from one neuron to the next.
The nervous system works in a format similar to the Fourier analysis, which means breaking down wave forms into their different sensorial components because every sine or wave form can be described as the series of sum of sine and cosine waves.
The way neurons pass information is very important. In the video we can see how the information goes from one neuron to another, using the neurotransmitters. The signal travels along the axon to the synaptic knob. Then the neurotransmitters crosses the synapse and the receptor cells activate. This is how the information goes from one neuron to another.
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When we walk, the brain sends signals to our spinal cord which at the time activates some muscles in the legs with the correct timing and strength. This is a somatic movement because it is voluntary.