Role Of The Neuron + Parkinson’s Flashcards
Dendrite
An EXTENSION of a neuron that DETECTS RECEIVES incoming neural messages FROM other neurons.
Soma
The body of the neuron, contains the nucleus with the genetic material for the neuron
Axon
Single, tubelike extension that TRANSMITS NEURAL INFORMATION to other neurons (or cells in muscles and glands)
Myelin sheath
Fatty tissue that ENCASES AND INSULATES the AXON to aid in the SPEED of transmission and PREVENT INTERFERENCE from surrounding neurons
Axon terminals
Exit pathways for neural messages to make their way to the next neuron
Terminal buttons
Releases a chemical substance known as NEUROTRANSMITTERS to a receiving neuron for communication purposes
Neurons
A neuron is an INDIVIDUAL CELL that is specialised to RECEIVE, PROCESS and or TRANSMIT information to other cells within the body
Fixed positions
Specialised cells
What is a Neurotransmitter:
CHEMICAL substance PRODUCED by a neuron that CARRIES a message to other neurons or cells in muscles, organs or other tissue.
Works by BINDING to RECEPTOR SITES of POST SYNAPTIC NEURONS that are specialised to receive that specific neurotransmitter
Synapse
The state where COMMUNICATION occurs between ADJACENT neurons.
Excitatory effect
Stimulates or activates post synaptic neurons to perform their functions.
Inhibitory effect
Block or prevent post synaptic neurons from firing.
Glutamate
PRIMARY EXCITATORY neurotransmitter in the CNS.
ENHANCES information transmission by making post synaptic neurons MORE LIKELY TO FIRE.
Involved in most aspects of normal brain function. Associated with enhanced learning and memory.
GABA
PRIMARY INHIBITORY neurotransmitter in the CNS.
makes post synaptic neurons less likely to fire
Fine tune neurotransmission in the brain and maintain it at an optimal level.
Without GABA activation of post synaptic neurons make get out of control
GABA and glutamate
Inhibitory action of GABA counterbalances the excitatory activity of glutamate and vice versa.
Both have important roles in regulating central Nervous System arousal
Lock and Key process
ACTION POTENTIAL causes VESICLES to RELEASE NEUROTRANSMITTERS into SYNAPTIC GAP, they then BIND to RECEPTORS on POST SYNAPTIC NEURON
A neurotransmitters shape must MATCH the shape of the RECEPTOR SITE on the POST SYNAPTIC neuron’s DENDRITES in order to BIND to its receptors.
The binding ‘UNLOCKS’ the post synaptic neurons RESPONSE so that the neurotransmitter causes CHANGES to the neuron, resulting in an EXCITATORY OR INHIBITORY effect.
Effects of interference of neurotransmitter function
Too LITTLE or too MUCH of a specific NEUROTRANSMITTER can have an impact on how we THINK, FEEL, or BEHAVE because of its effect on NS FUNCTIONING
Abnormal levels of specific neurotransmitters have been linked to various problems with mental processes and behaviour. Eg. Dopamine in Parkinson’s disease
Parkinson’s Disease
IDIOPATHIC PROGRESSIVE NEURODEGENERATIVE DISEASE = LOSS OF DOPAMINE NEURONS in the SUBSTANTIA NIGRA.
SUBSTANTIA NIGRA is DISEASED OR DAMAGED = DOPAMINE available for MOTOR ACTIVITY RECDUCES as neurons gradually die.
SN sends dopamine to PRIMARY MOTOR CORTEX and BASAL GANGLIA which is involved in planning , co ordinating and initiating voluntary movements. Fewer neurons in substantia nigra= less dopamine produced. receive slower/fewer dopamine messages about motor activity.
Symptoms of Parkinson’s Disease
Variety of MOTOR SYMPTOMS appear after extensive loss of dopamine producing neurons in the substantia nigra.
TREMOR- continuous, involuntary shaking
MUSCLE RIGIDITY- muscles seem unable to relax and are tight, even when at rest. Difficulty performing automatic actions.
SLOWNESS OF VOLUNTARY MOVEMENT- difficulty starting new movements or stopping an ongoing movement, lack of facial expression.
POSTURAL INSTABILITY, BALANCE PROBLEMS, WALKING DISTURBANCES- Inability to maintain a steady, upright posture or perform corrective action, taking short, shuffling steps and reduced arm swing
