Nervous Control of Muscular Movement
The two divisions of the nervous system are the Central Nervous System and Peripheral Nervous
The central nervous system contains brain and spinal cord.
The two division of the Peripheral Nervous System is the Afferent Division and Efferent Division.
The Afferent System is the signals sending from the sensors ex joints and skin, to the Central
Nervous System. Efferent System is separated into two sections, Somatic Nervous System
controlling skeletal muscle and Autonomic Nervous System which controls cardiac muscle and
smooth muscle. (sympathetic division and parasympathetic division)
Forebrain(Cerebrum and Diencephalon), Cerebellum and Brainstem.
If a person have bad diet it will affect their circulation system this will affect their brain capacity
because although the brain is a small organ compared to the body it require a large amount of
good blood supply for it to be able to function properly.
The Peripheral Nervous System contains 12 pairs of cranial nerves and 31 pairs of spinal nerves.
Sympathetic is for fight or flights, located in the thoraces and lumbar area. Parasympathetic
comes out the cranial nerves, this is for normal usages such as sleeping. They comprise about 90% of the cells within the Central Nervous System. They serve as a
connective tissue that supports the neurons both physically and metabolically.
Neurons are nerve cells that conduct electrical signals. Their main role is to pass messages from
one part of the body to another.
A neuron is consist of cell body (which have all the typical organelles), axon are long fiber that
carry the electrical signals away from the cell body, and dendrites are short projections from the
cell body that carries the signals towards the cell body.
Myelin sheaths are discontinuous sheath around the axon. They mainly contain lipid and
protein. The purpose of having myelin sheath so the electrical signal can travel down the axon
faster because between the sheath it have Node of Ranvier which have sodium and potassium
A synapse is where the end of the axon connects to the beginning of a dendrite.
-Afferent neuron that carry impulses from the sensory receptors into spinal cord or brain.
-Efferent neuron transmit impulses from the Central Nervous System out to the muscle or
-Interneurons lies within the CNS. Nerve trunk contains hundreds of individual afferent and efferent nerve fibers that are bound
together by connective tissue sheaths.
Action potential is when the inside of the axon turns from negative to positive because of the
sudden rush of sodium at the same time the outside is now negative because of the rush of
potassium from the inside of the axon to the outside. Once the action potential is started, it
spreads along the entire length of the nerve fiber.
Nervous information is relayed across the synapses cleft by mean of a chemical transmitter
substance. This is either excitatory or inhibitory.
Spatial summation is when a lot of axon is coming into the cell body until it reaches threshold
and action potential happens. Temporal summation is when there is an increase of the firing
frequency until it reaches threshold and a