Describe the ionic basis of an action potential and be sure to include the role of...

Describe the ionic basis of an action potential and be sure to include the role of channels/gates within the cell membrane and how this relates to a positive feedback homeostatic mechanism.

Solutions

Expert Solution

There are many ion channels/gates located in the membrane. Some of it allows free movement while some need ATPs for their actions.

When a neuron is not conducting any impulse, i.e, resting, axonal membrane is comparatively more permeable to K+ ions and nearly impermeable to Na+ ions. The membrane is impermeable to negatively charged proteins too.

Consequently, the axoplasm inside the axon contains high concentration of K+ ions and low concentration of Na+ ions. In contrast, fluid outside the axon contains low K+ and high Na+ ions and thus form a concentration gradient.

These ionic gradient are maintained by NA+/K+ ATP pump. It pumps 3Na+ outwards and 2K+ into the cell. As a result, outer surface possess a positive charge while its inner surface are negatively charged and therefore polarised. The electrical potential difference across the resting plasma membrane is called as the RESTING POTENTIAL.

In neuron signalling, the cycle of rapid depolymerization during the action potential is positive feedback loop.

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Describe the steps of an action potential and synapse. Include the role of myelin.

Describe how an action potential is generated across the axon. Make sure to explain the role...

Describe how an action potential is generated across the axon. Make sure to explain the role of Na+ and K+ channels and pump in this process.

Discuss the steps in generating an action potential in a neuron. (Make sure to include which...

Discuss the steps in generating an action potential in a neuron. (Make sure to include which ion channels are activated and how, changes in membrane potential as a result of the movement of those ions, the different phases seen in an action potential, and the movement of the action potential in relation to the anatomy of a neuron.).

Describe in detail the action of insulin. Be sure to include a description of what it...

Describe in detail the action of insulin. Be sure to include a description of what it is (what kind of biomolecule/class of hormone), how its secretion is regulated, where specifically it is secreted from, its general effects on body cells, and finally each of its specific effects (if it has any) on: skeletal muscle, the liver, adipose tissue, and blood glucose levels.

What determines whether a neuron initiates an action potential? Include the role of resting membrane potential,...

What determines whether a neuron initiates an action potential? Include the role of resting membrane potential, threshold, sodium, graded potentials, and the axon hillock. (answer in short answer pragraph form)

Describe in detail the action potential of an SA nodal cell of the heart. Be sure...

Describe in detail the action potential of an SA nodal cell of the heart. Be sure to names the phases, include the main types of membrane proteins involved, how they are opened, the movements of ions, and the changes in membrane potential. Explain how this type of action potential is different from that seen in a skeletal muscle cell and why the difference(s) are significant.

Describe the net flow of ionic current during the phases of the action potential. During what...

Describe the net flow of ionic current during the phases of the action potential. During what phase of the action potential does positive feedback occur.

Describe in detail the action potential of myocardial contractile cells. Be sure to names the phases,...

Describe in detail the action potential of myocardial contractile cells. Be sure to names the phases, include the main types of membrane proteins involved, how they are opened, the movements of ions, and the changes in membrane potential. Explain how this type of action potential is different from that seen in a skeletal muscle cell and why the difference(s) are significant.

In your own words describe what is taking place during an action potential. Be sure to...

In your own words describe what is taking place during an action potential. Be sure to include the following terms: sodium ions Na+, potassium ions K+, Threshold, depolarization, repolarization, hyperpolarization, voltage gates. This is not an exhaustive list, you will need to use additional terms when necessary.

Describe the two stages of the Action Potential. Include (i) the names of the ion channels...

Describe the two stages of the Action Potential. Include (i) the names of the ion channels and whether they are active or passive, (ii) which of these ion channels open during the first stage and which open during the second stage, and the direction ions move, and (iii) the value in mV reached during the two stages.

Subjects