BIOPSYCHOLOGY - Neurons Flashcards
Name all the parts of the neuron
• Dendrite
• Cell body
• Nucleus
• Nodes of Ranvier
• Axon
• Myelin sheath
• Schwann cell
• Axon terminal
Describe the cell body and its role in a typical neuron
• Includes the nucleus which contains the genetic material of the cell
Describe the role of dendrites in the structure of a typical neuron
Receives signals from other neurons or receptor cells
Describe the axon and its role in the structure of a typical neuron
Carries impulses away from the cell body down the length of the neuron. Covered in a fatty layer of myelin sheath which protects the axon and speeds up electrical transmission of the impulse.
How and why is the myelin sheath segmented?
• Segmented by gaps called nodes of Ranvier
• If the myelin sheath was continuous then it would have the reverse effect and slow down the electrical impulse
• Nodes of Ranvier speed up transmission of impulse by forcing it to ‘jump’ across the gaps along the axon.
Describe the role of the axon terminals
Communicate with the next neuron in the chain across a gap known as the synapse
What are the three types of neurons?
Sensory, relay, motor
Describe the role of the sensory neurons.
Carry impulses from the PNS to the CNS (have long dendrites and short axons)
Describe the role of the relay neuron.
Connect the sensory neurons to the motor or other relay neurons (short dendrites short axons)
Describe the role of the motor neurons.
Connect the CNS to effectors such as muscles and glands. (Short dendrites long axons)
Nerve impulses always travel from _________ to _____.
Dendrites to axons.
Where are sensory neurons commonly found?
In receptors such as the eyes, ears, tongue and skin, and carry nerve impulses to the spinal cord and brain
Where are relay neurons commonly found?
Between sensory input and motor output. Found in the brain and spinal cord to allow sensory and motor neurons to communicate
How do motor neurons effect change?
When motor neurons are stimulated they release neurotransmitters that bind to the receptors on muscles to trigger a response, which leads to movement.
