Nervous System Flashcards
CNS (Central Nervous System)
Processes information to and from the PNS
Includes the brain and spinal cord
PNS (Peripheral Nervous System)
Carries information to and from the CNS and sensory organs
Includes neurone that connect the rest of the body to the CNS
Voluntary response
Responses produced by the body which are conscious and involve the individuals thinking time
Involuntary Response
Responses subconsciously produced by the body usually to protect it
Mylein Sheith
Insulates electrical impulses across a nerve cell, (made of Schwann cells)
Dendrite
Extensions at the (front) end of a nerve cell which connect to other nerve cells to pass electrical impulses
Axon
Where electrical impulses are transported along a nerve cell
Axon terminal
The end of a nerve cell which connects to other nerve cells to receive electrical impulses
Synoptic end bulb
The tips of the axon terminal which inflates and connects to dendrites on other cells to receive electrical impulses
Node of Ranvier
gas between the myelin sheath that help assist faster impulses and allow substances to diffuse in and out the cell
Schwann cells
A spherical organelle which helps develop and regenerate peripheral nerves
Reflex Arc Pathway
Stimuli, Receptor, Sensory Nuron, Relay Neuron (spinal cord), Motor Neuron, Effector (muscle or gland), response
Synapse
A gap between two neurons
How impulses pass across a synapse
Electrical impulses diffuse into chemical signals, they then pass through the neuron and diffuse back into electrical signals in the neuron
Reflex Arc
A faster immune response subconsciously produced by the body to protect itself (from harm)
Pathway of a Reflex Arc
Stimulus
Receptor
Sensory neuron
Relay neuron (spinal cord)
Motor neuron
Effector (muscle/gland)
Response
Synaptic cleft
The space between the pre and post-synaptic cells
Synaptic vesicle
Clustered at pre- synaptic cell and contain neurotransmitters which are triggered by Ca+ to release (the neurotransmitters) by exocytosis
Action potential
The change in voltage of a (nerve) cell membrane during a nervous impulse
Cannabis
A drug which inhibits synaptic transmission,
It does this by stimulating the release of dopamine (at abnormally higher levels)
This leads to feeling high/happy
And once this falls a persons mood is lower leading to a cycle of addiction
Symptoms of Cannabis use
- Increased heart rate
- Dry mouth
- Reddening of eyes
- feeling sick
- hallucinating
Caffeine
A drug which increases synaptic transmission by triggering the release of acetylcholine (used during muscle contraction) which therefore leads to a higher heart rate
Effects of caffeine
- rising body temp.
- frequent urination
- anxiety
- dehydration
- irritability
- trembling hands
Prions
A disease caused by a misfolded protein which can transmit to other proteins and cells leading to more misfolded proteins and cellular death (and then death)
Kuru
An example of a prion disease, spread through open wounds or cannibalism (of the brain)
Symptoms of Kuru
- muscle twitching
- loss of coordination
- arm & leg pain
- muscle jerks
- fits of laughing
- not being able to swallow
Treatments/cures of Kuru
There is no cure/ treatments for Kuru and most people die with a year of being diagnosed/ having it
