Showing posts from March, 2014

Science: Central Nervous System

Central Nervous System – contains the brain and the spinal cord. It serves to connect the sensory and motor fibers within the nervous system thus considered as the "integrating center" for all behavior and bodily functions.

Spinal Cord – is the large rope-like segment of nerve tissue extending down the vertebral column, which is approximately as thick as a person’s little finger. Its principal function is to distribute motor fibers to the effector organs of the body and to collect somato-sensory information to be passed on to the brain. Spinal cord is 2/3 as long as the vertebral column and the rest is spinal roots composed of caudal equina.

Brain – has an average weight of 3 lbs. and contrains at least 15 billion nerve cells called neurons
Major Parts of the Brain1. Hindbrain
Closest to the spinal cordIt performs a series of reflex actions such as blinking of the eye and some processes like breathing, heart rate and blood pressure.Parts of Hindbrain
Medulla Oblongata – or "…

Components of the Nervous System - Neurons

What is Neuron/Nerve Cell The basic structural unit or building block of the nervous system The smallest nerve cell is less than a millimeter in size while the largest may be more than a meter in length Nerve cell holds the secret how the brain works Nerve cell has two specialized functions: [1] to receive signal [2] the longer extension is for transmitting signals Acethylcholine – is a neurotransmitter or chemical substance that travels across synaptic gap, stimulates the next neuron, carrying the impulse from one neuron to another
Glial cells – are non-neural cells that hold the neurons in place

Myelin Sheath – is the covering on the axons of neurons, which insulate them, making the transmission of impulses faster Parts of a NeuronDendrites – receive impulses and carry them toward the cell bodies. These are short branches of fibers branching out like roots from the cell body Axon – carries impulses away from the cell body toward other neurons. These are the longer branches / fibers…