- 1 What is the role of Axolemma?
- 2 What is Axoplasmic resistance?
- 3 Which channel are present within the plasma membrane of Axon?
- 4 What is difference between Axoplasm and Axolemma?
- 5 What is a Neurilemma?
- 6 Does depolarization mean more positive?
- 7 What happens when the membrane is hyperpolarized?
- 8 What is the node of Ranvier?
- 9 Is sodium negative or positive?
- 10 What are channel proteins?
- 11 What is the major role of the Na +- K+ pump in maintaining the resting membrane potential?
- 12 What is Cytoplasms?
- 13 What is a synapse?
- 14 Is sodium found inside or outside the cell?
What is the role of Axolemma?
The axolemma conveys signals between the neuron and its Schwann cells that control the proliferative and myelin-producing functions of the Schwann cells and partly regulate axon size.
What is Axoplasmic resistance?
Axoplasm is the cytoplasm within the axon of a neuron (nerve cell). The electrical resistance of the axoplasm, called axoplasmic resistance, is one aspect of a neuron’s cable properties, because it affects the rate of travel of an action potential down an axon.
Which channel are present within the plasma membrane of Axon?
Voltage-gated calcium ion channels are located at axon terminals. All gated channels are closed at the resting membrane potential. As the channels open, ion movement across the plasma membrane increases and the membrane potential is changed.
What is difference between Axoplasm and Axolemma?
The axolemma is the cell membrane of an axon. The similar term axoplasm refers to the cytoplasm of an axon. The axolemma is responsible for maintaining the membrane potential of the axon, and contains ion channels through which ions can flow rapidly.
What is a Neurilemma?
: the plasma membrane surrounding a Schwann cell of a myelinated nerve fiber and separating layers of myelin.
Does depolarization mean more positive?
Action potential in a neuron, showing depolarization, in which the cell’s internal charge becomes less negative ( more positive ), and repolarization, where the internal charge returns to a more negative value.
What happens when the membrane is hyperpolarized?
Hyperpolarization is when the membrane potential becomes more negative at a particular spot on the neuron’s membrane, while depolarization is when the membrane potential becomes less negative (more positive). The opening of channels that let positive ions flow into the cell can cause depolarization.
What is the node of Ranvier?
Nodes of Ranvier. These are the gaps formed between the myelin sheath where the axons are left uncovered. Because the myelin sheath is largely composed of an insulating fatty substance, the nodes of Ranvier allow the generation of a fast electrical impulse along the axon.
Is sodium negative or positive?
Because there are many more sodium ions on the outside, and the inside of the neuron is negative relative to the outside, sodium ions rush into the neuron. Remember, sodium has a positive charge, so the neuron becomes more positive and becomes depolarized.
What are channel proteins?
A channel protein, a type of transport protein, acts like a pore in the membrane that lets water molecules or small ions through quickly. Water channel proteins (aquaporins) allow water to diffuse across the membrane at a very fast rate. Ion channel proteins allow ions to diffuse across the membrane.
What is the major role of the Na +- K+ pump in maintaining the resting membrane potential?
What is the major role of the Na+-K+ pump in maintaining the resting membrane potential? K+ ions can diffuse across the membrane more easily than Na+ ions. Imagine you changed the concentration of K+ outside a neuron such that the resting membrane potential changed to -80 mV (from the normal resting value of -70 mV).
What is Cytoplasms?
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. In eukaryotic cells, the cytoplasm includes all of the material inside the cell and outside of the nucleus.
What is a synapse?
The synapse, rather, is that small pocket of space between two cells, where they can pass messages to communicate. A single neuron may contain thousands of synapses. In fact, one type of neuron called the Purkinje cell, found in the brain’s cerebellum, may have as many as one hundred thousand synapses.
Is sodium found inside or outside the cell?
The sodium and chloride ion concentrations are lower inside the cell than outside, and the potassium concentration is greater inside the cell. These concentration differences for sodium and potassium are due to the action of a membrane active transport system which pumps sodium out of the cell and potassium into it.