The nervous system Flashcards
What does the Central Nervous system consist of?
Brain and Spinal column
What does the peripheral nervous system consist of?
Consists of all the nerves that relay information between the central nervous system and the rest of the body
What is the function of a motor neurone?
Connects nerves to effectors such as muscles or glands
What is the function of sensory neurones?
Receive information of the environment from the senses
What is the function of interneurons?
Located entirely in the CNS, local and relay interneurons form circuits to regions in the brain that are responsible for complex behaviours
What is the typical resting potential of a neurone?
-70mv
Why is a neurone typically negative while at a resting state?
The intracellular fluid has a negative charge whilst the Extracellular fluid is positive
What does it mean if a neurone becomes hyperpolarized?
The charge becomes more negative (for example -80mv)
What does it mean if a neurone becomes depolarized?
The neurone receives a positive charge and becomes closer to 0 (for example -50mv)
What is a threshold of excitation?
A set point for depolarisation to trigger
Describe an action potential within an axon?
Rapid depolarization followed by rapid hyperpolarization
Where in the neurone does action potential occur?
At the very start of the axon to the end of the terminal buttons
What is an ion (located in the intra and extra cellular fluids)?
A molecule with an electric charge
What is the name given to an ion with a positive charge?
Cations
What is the name given to an ion with a negative charge?
Anions
Which Ion’s are more prominent in Extracellular fluid (think about salt water)?
Na+ and Cl-
Which ion’s are more prominent in intracellular fluid?
K+
What’s the name given to a chemical that attaches to a binding site?
Ligand
How does an action potential cause vesicles to release neurotransmitters?
By causing vesicles to fuse with the presynaptic membrane which in turn breaks them open and pours their contents into the synaptic cleft
