Unit 3 AOS 1 Flashcards
Structure of a neuron
- Dendrites
- Soma
- Nucleus
- Myelin sheath
- Axon
- Axon terminals
Role of dendrite
Detects and receives information from neighbouring neurons
Role of soma
Integrates information received from dendrites
Role of axon
Carries neural impulses to terminal buttons
Role of myelin sheath
Acts as an electrical insulator and increases speed of signals
Role of axon terminals
Acts as an exit for neural messages to make their way to the next neuron
Role of terminal buttons
- Release neurotransmitters into the synapse
Sensory neurons
Afferent and transmit information from the body to the brain
Motor neurons
Efferent and transmit information from the brain to the body
Interneurons
Communicate between sensory and motor neurons
Excitatory
Stimulates/activates post synaptic neurons to perform their functions
e.g. Glutamate
Inhibitory
Block/prevent post synaptic neurons from firing
e.g. Gaba
Neurotransmitters
- Chemical substance produced by a neuron that carries messages to other neurons
- Attach to receptor sites located on dendrites
CNS
- Consists of the brain and spinal cord
- Receives info from PNS, processes it and then responds
PNS
- Carries info from sensory organs and internal organs to CNS
- Conveys info from CNS to muscles, organs and glands
PNS: Somatic nervous system
- Within our conscious control
- Transmits info from receptor site to CNS and then to the muscle
PNS: Autonomic
- Unconscious control
- Regulates functioning of internal organs and glands
ANS: Sympathetic nervous system
- Releases adrenaline
- Activates fight, flight, freeze
ANS: Parasympathetic nervous system
- Returns body to a state of calm
- Maintains homeostasis
Spinal reflex
- Response initiated by neurons in the spinal cord instead of the brain
- While spinal reflex is taking place sensory messages continue to the brain
- Pain cannot be felt until the message reaches the brain
Neural communication
- Is an electro chemical process
Communication witin neurons
- Received by dendrites, initiated by the soma and travels along the axon towards the axon terminals
Communication between neurons
- A chemical process
- Terminal button releases neurotransmitters once excited by the impulse
- Travel across the synapse
- Received by the dendrite of the post-synaptic neuron
Role of neurtransmitter
- Binds with its specific receptor on neighbouring dendrites and works as a lock and key process
Type of neurotransmitters
Excitatory
- Excite the neuron to fire
Inhibitory
- To block/prevent the neuron from firing
Glutamate
- Excitatory
- Responsible for memory formation and learning
GABA
- Essential for normal neuron firing activity and motor movement
What causes neurotransmitter interruption?
- Imbalance in a particular type of neurotransmitter
- Alcohol and drugs
- Stress
Side effects of neurotransmitter interruption?
- Mental health disorders
- Weight loss/gain
- Immobility
- Addiction
What is parkinsons disease?
- Progressive degeneration of the nervous system
What causes parkinson?
- Low levels of dopamine causing movement problems
- Low levels of GABA
Dopamine
- Important for pleasure, motivation and motor movement
Seratonin
- Important for stabilising mood
