The Brain
Where is Broca's area located
left hemisphere of the frontal lobe
Explain how an impulse travels.
What are the two areas responsible for language in the brain?
Brocas Area & Wernickes Area
What is the main job of a neuron?
They are the basic unit of the nervous system and their purpose is to transmit information throughout the brain
What is myelin sheath and why is it important?
Myelin sheath is the white fatty substance that covers the axon, it speeds up neural conduction
It is important because it saves energy for the neuron, speeds up transmission and helps regenerate damaged axon
Where is Wernicke's area located in the brain?
the left temporal lobe
What is action potential?
Action Potential is the change in electrical potential that occurs when the cell membrane is stimulated enough to permit ion exchange
What is Broca's Area responsible for?
expressive language
What are the nodes of ranvier?
Areas between the myelinated segments of an axon, they are important in conduction
What band of fibers connect the two language centers of the brain?
Arcuate fasciculus
What is the all or nothing theory?
This states that once a message is released it cannot be stopped
What is responsible for receptive language?
Wernicke's area
Describe the dendrites.
Describe the axon terminal.
They are long, thin projections at the end of the axon with terminal buttons at the end
What does the arcuate fasciculus do for language comprehension?
What is the absolute refractory period?
This states that a neuron can only release one message at a time.
What does Broca's aphasia look like?
Slow speech, non-fluent, full of stops and starts, imprecise articulation and a decreased ability to produce grammatically correct sentences
Patients are aware and frustrated by their deficits
What does the axon do?
The axon conducts information away from the cell body
Describe terminal buttons.
The structures at the end of the axon, containing vesicles
Stroke, TBI
How does action potential occur?
At baseline the neuron is in a state of polarization, positive on outside negative on the inside, ready to receive message.
Action potential then begins when an impulse is received and depolarization, sodium enters the channels that are filled with Potassium, begins.
The message travels down the axon and cannot stop.
Repolarization begins to occur due to the outward flow of Potassium.
Depolarization spreads forward, causing action potential. This process repeats.
What does Wernickes aphasia look like?
Articulation, prosody and rate are normal but word choices do not make sense, fluent
patients have decreased awareness of their deficits
What is the junction of the axon and cell body?
What do synaptic vesicles contain?