Question

1.Briefly compare and contrast ion channels of the cell body and dendrites to the ion channels of the axon. *2 points

1.If a neuron is at rest, would diffusion drive sodium ions towards the inside or outside of the neuron?   If a neuron is at rest, would electrostatic forces drive sodium ions towards the inside or outside of the neuron? *2 points

2.If a neuron is at rest, would diffusion drive potassium ions towards the inside or outside of the neuron?   If a neuron is at rest, would electrostatic forces drive potassium ions towards the inside or outside of the neuron? *2 points

3.If a neuron is at rest, would diffusion drive chloride ions towards the inside or outside of the neuron?   If a neuron is at rest, would electrostatic forces would drive sodium ions towards the inside or outside of the neuron? *2 points

Answer 1

Dendrites emerge from neuron cell body. Synaptic inputs are recieved by the synaptic inputs and thus large surface area is occupied by them. In order to transport ion channel which are voltage gated from soma to the dendrites various specific molecules are involved in their transport.

Axon ion channel plays an important function in the neuron. There is the polarity change across the membrane when action potential generates in the axon as a result of which signals recieve from other neuron sodium and potassium ions channel get open up as membrane approaches its threshold potential as sodium channel opens it gets pushed inside axon which causes depolarization nd as potassium channel open as a result of which potassium ions move out of axon caused repolarization.

Ans1-)When neuron is at rest, the sodium ions will move inside the neuron. The two forces will attract the sodium ions towards inside of the cell, The concentration of sodium ions outside the cell is much higher which will push these sodium ions towards inside the cell down through concentration gradient. Also, the electrostatic pressure will push the sodium ions to inside of the cell as inside of the neuron is negatively charged which will attract the sodium ions.

Ans2-)When neuron is at rest, the potassium ions will move outside of the neuron. The concentration of sodium ions are much higher to the inside of the cell. As the potassium ions will move freely across the membrane of neuron, so these ions will have much higher tendency to move out of the cell down through their concentration gradient. As more negative charge inside the cell will induce the electrostatic pressure which will attract the potassium ions to inside the cell.

Ans3-)When neuron is at rest, the chloride ions will move freely across the membrane of neuron. As negative charge is much higher inside the cell, so the electrostatic pressure will cause the chlorine ions to move out of the neuron. When the concentration of chlorine ions will increase outside the cell they will then Flow back to inside of the neuron down the concentration gradient.