Neurons and neurotransmitters Flashcards
Lecture 5
What is the main function of the brain??
The brain interprets and predicts.
Explain brain activity.
All our experiences, thoughts and actions are the direct reflection of the activity of the brain. The brain is a physical system operating according to physical laws. The mid is a product of brain activity.
Explain the nervous system and its parts.
The ns has 2 main parts. The central ns is made up of the brain and spinal cord. The peripheral ns is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
Name the 4 lobes of the brain.
Frontal lobe, parietal lobe, occipital lobe and the temporal lobe.
What are the brain’s processing units?
These are called neurons.
What are the main components of a neuron.
A neuron has a cell body, which includes the cell nucleus and special extensions called axons and dendrites. Bundles of axons called nerves, are found throughout the body. Axons and dendrites allow neurons to communicate, even across long distances.
What is a bundle of axons called?
Nerves
Is the inside of a neuron negatively or positively charged compared to the outside?
Negatively
These neurons transmit messages from the brain to the rest of the muscles to generate movement.
Motor neurons.
What are the 2 different types of neurons that control/perform different activities?
Motor and sensory neurons.
What are sensory neurons?
They detect light, sound, odor, taste, pressure, heat and send messages about those things to the brain.
Explain the process of how a neuron sends a message to another neuron?
- It sends an electrical signal down the length of its axon.
- At end of axon that signal turns into a chemical signal.
- the axon releases the signal with chemical messengers called neurotransmitters into the synapse
- the neurotransmitters move the signal through the synapse to the neighboring dendrite which converts the chemical signal back into an electrical signal.
- That signal then travels through the neuron and goes through the same conversion process as it moves to neighboring neurons.
What is a synapse?
This is the space between end of an axon and the tip of the dendrite from another neuron.
What is a dendrite?
A dendrite (tree branch) is where a neuron receives input from other cells..
What is the axon?
This cable, several times thinner than a human hair, is called an axon, and it is where electrical impulses from the neuron travel away to be received by other neurons.
What is resting membrane potential?
RMP is the difference in electrical potential across the plasma membranes when the cell is not stimulated or when the cell is in a state of relaxation. Info is transmitted within the cell by transient alterations in the membrane.
What is action potential?
When a neuron is stimulated enough it fires an electrical impulse that zips down its axon to its neighboring neuron. They only have 1 signal they can send and it only transmits 1 uniform strength and speed. That nerve impulse is called action potential.
Integration of info can occur in the dendrite by the … or …
Spatial or temporal summation of graded potentials
Within axons this “pulse” is ..
All or none
Explain temporal summation…
Multiple neurotransmitters are released from one presynaptic terminal.
Explain spatial summation…
Multiple presynaptic terminals release neurotransmitters to generate a postsynaptic action potential.
What is the RMP electricity?
The resting potential of electrically excitable cells lies in the range of -70mV.
What is an ion channel?
These receptors are usually multimeric proteins located in the plasma membrane. Each of these proteins arranges itself so that it forms a passageway or pore extending from one side of the membrane to the other.
What is an axon hillock?
The axon arises from the cell body at a small elevation called the axon hillock.
What is the initial segment?
The proximal part of the axon, adjacent to the axon hillock is the initial segement.
How is info transmitted within the cell?
It is transmitted within the cell by transient alterations in the membrane potential.
Define a neuron and neurotransmitters.
A neuron is cells of the nervous system specialized to transmit ‘messages’. A neurotransmitter is chemicals used by neurons to communicate to each other.
