2 Neurons Flashcards
Sensory neurons
Carry information from body to CNS. They gather information such as light, sounds and odour.
Inter neurons
They link sensory and motor neurons
Motor neurons
Carry information from the CNS to the body. They control the contraction of muscles.
Describe the structure of a neuron
Long and thin axon with myelin sheath over it. At one end there is the soma and dendrites, at the other end there are terminal buttons.
What are the 3 types of glia?
Astrocytes
Oligodendrocytes
Microglia
What is the ratio of glia to neurons
1:1
What do astrocytes do?
They provide structural support and nutrients to neurons. Astrocytes receive glucose from capillaries and break it down into lactate which they release into extracellular fluid for the neurons to take up.
What do oligodendrocytes do?
Produce myelin sheath that insulates axons. 1 cell can produce 50 segments of myelin sheath
Microglia function
Smallest supporting cells. They clear away dead or dying neurons whilst attacking any foreign tissues.
What type of process is a transmission within a neuron?
An electrical process
What is the cell membrane made up of?
Two layers of phospholipid molecules. The head of the molecules are phosphate and the tail is a fatty acid
Cations
Positively charged molecules
Anions
Negatively charged ions
What molecules are in intercellular fluid
Potassium+ ions and Anions
What molecules are in extracellular fluid
Sodium+ and chlorine-
Membrane potential
The difference in electrical potential inside and outside of the cell
How is the membrane potential balanced?
By diffusion and electrostatic pressure
What is the resting potential of a neuron?
-70mV
Why is maintaining the resting potential important
So that the neuron can respond rapidly to a stimulus
What is an action potential?
The reversal in potential and is how information is sent through an axon