2012-1-1433
17 SEPTEMBER 2013
1. The function of a neuron is to convey or process signals. Discuss how the specific parts of a neuron allow this general function to occur.
Neurons has four distinct zones that has each of their specialization in the transmission of signals across the body.
The first zone is for signal reception, it consists the dendrites and the cell body. The dendrites receive the signals and be converted into electrical signals that will be transmitted in the cell body. The cell body also detects some signals but works more on “understanding” the signals received by the dendrites. The cell body is responsible for the metabolic functions such as synthesizing and degrading proteins, providing energy, and helping to maintain the structure and function of the neuron.
The second zone is for singal integration, it consists of the axon hillock. The signals transmitted from the first zone is integrated in this region. If the signal is strong enough, an action potential would be initiated.
Third zone is specialized for signal conduction, it consists of the axon. The axon carries the information, usually from action potentials, from the cell body to the axon terminal.
The fourth zone of a neuron is for signal transmission to target cells, it consists of the axon terminals. These axon terminals form the synapse. This is where the signal is converted into a chemical signal in a form of a chemical neurotransmitter. The neurotransmitter then diffuses across the synapse and binds to a receptor that would initiate the signal transmitted.
2. Explain the effect of the following on the membrane potential:
a. Open sodium gated ion channels
Open sodium gate ion channels result to entry of more sodium ions into the intracellular membrane and therefore would lead to a more positive membrane potential. This is due to increased permeability of the membrane to sodium ions. Once the membrane potential reaches its threshold,