Chapter 16 The Human Nervous System- Impulse Conduction In The Neuron Flashcards
Neurons are involved in what processing of human behaviour?
Thinking learning watching feeling planning or action
Where do neurons get the stimuli from and how is it relayed
Messages are relayed from the sensory organs that are stimulated by information from the environment and where this stimuli is converted into energy that can be relayed to neurons
What is impulse conduction
It is the process by which messages are relayed in neurons and from one neuron to the next.
Explain What are the 2 processes of impulse conduction
The electrical process where the nerve impulse begins in the first segment of the axon and travels down the axon to the terminal because of electrical event at the cell membrane.
The chemical process is the passage of the nerve impulse from one neuron to the next where the synapse between the structures of one neuron and another which determines whether or not the impulse will be conducted across the synapse to the next neuron.
What is potential difference with regards to neurons
It is the uneven distribution of positive and negative ions inside and outside the neuron causing it to have an electric charge
What is the resting membrane potential
It’s an electric charge brought about by the difference between the positive and negative ions inside and outside the neuron where the fluid inside the neuron is negative and outside positive
Give four mechanisms that create the resting membrane potential
Ions move from a high concentration to a low concentrations
Ions with opposite charge attract each other while those with similar charges repel each other
The cell membrane is selectively permeable to ions
The cell membranes contain pumps for sodium and potassium.
What is an action potential
Ashort termchange in the electrical potential that travels along a cell such as a nerve
What is the threshold potential
It’s when the resting membrane potential for an action potential is greater than the resting potential.
What is depolarisation
When the charges on the outside and inside of the cell membrane even out as there is no potential difference between inside and outside of axon
When does hyperpolarisation occur
The state where the axon is more polarised than in its resting phase
What is the refractory period
Where the membrane returns the na and k ions to their original states pumping na to the outside and k back inside.
What is the absolute refractory period
The beginning of the refractory period where the neuron doesn’t respond to any stimulus.
What is the relative refractory period
When an intense stimulus can trigger an impulse
What are the nodes of Ranvier
They are the gaps between myelinated sheaths that contain na and k channels required for impulse conduction
