Nervous system Flashcards
What is the Spinal reflex. How is it triggered
An autonomic, involuntary response to a certain stimulus.
It is triggered by cells in he spinal cord rather than the brain
This enables an organism to respond faster
Define conscious response
A voluntary, intentional response to sensory stimuli
What is the receptor site
A protein molecule found in the dendrites of neurons which receive chemical signals from neurotransmitters
Define unconscious response
An involuntary, automatic, unintentional response to sensory stimuli
What is a motor neuron
Neuron that sends information away from the CNS to mussels and glands. Eg sends information to hand to make it move.
What is an interneuron
Neurones that send information between sensory and motor neurons. Most are located in the CNS
What is a sensory neuron
A neuron that sends information form the sensory receptors towards the CNS
Define neuron
A specialised nerve cell that receives, processes and/or transmits information
What is the spinal cord
A bundle of nerve fibers that connects the Brian and PNS
What’s the role of axon terminals
Stores chemicals called neurotransmitters which assists in the transmission of neural information form one neuron to another
What’s the role of the axon
Single tube like structure that carries neural impulses away from the cell body towards the axon terminals
Role of the soma (cell body)
Responsible for keeping the neuron alive and controls whether the neuron will be activated. Contains the nucleus
Role of the dendrites
Detects and recieves neural information from neighbouring neurons
What is another name for efferent neurons and what is their role
Also known as motor neurons. They carry signals away from the CNS in order to initiate an action.
What is the myelin sheath and role
White fatty substance on the axon that acts as an electrical insulator which increases the speed of neural signals down the axon. Not present on all cells
What is the sympathetic nervous system
Prepares the body for action by activating the flight, fright, freeze response. Increases responsiveness of muscles and organs during activity, stress or when threatened
What is the autonomic nervous system
The division of the PNS responsible for involuntary unconscious activity. It transmits motor messages from the Brian to the body’s internal organs and glands. Eg controls heart beat
What is the somatic nervous system
The division of the PNS that is responsible for voluntary movement. Eg moving an arm
Parasympathetic nervous system
Counteracts the actions of the sympathetic nervous system by calming the body once the cause of stress or threat is over. It responsible for homeostasis
Peripheral nervous system
Contains all the nerves outside the CNS. Contains two sub divisions autonomic nervous system and somatic nervous system.
Central nervous system
Contain the brain and spinal cord.
What are afferent neurons and their role
Sensory neurons. Carry signals from sensory receptors towards the CNS
Examples of what the sympathetic nervous system does to the body and why
Dilates pupils- for better sight
Dry mouth- conserving energy
Accelerates heart rate- for more oxygen to muscles
Increases breathing - for more oxygen
Decreases digestion- for conserving energy
Examples of what the parasympathetic nervous system does to the body and why
Contracts pupils
Produces more saliva
Decreases heart rate
Decreases breathing
All to return the body back to homeostasis
Define synapse
The gap between the axon terminals of the pre synaptic neuron to the dendrites of the post synaptic neuron.
Define pre synaptic neuron
Neuron before synapse
Define post synaptic neuron
Neuron after synapse
Communication betweeen neurons is …… energy
Electrochemical energy which is electrical and chemical energy
Define action potential
Getting a neuron to fire (release electrical energy.
Process of the message sending down the neuron
When a neuron is activated to fire, the inside of the neuron changes charge temporarily (Pos goes inside)
As change returns to normal state the change releases electric energy.
This happens to a small section at a time and moves along the axon
Define resting potential
When the axon membrane returns to resting potential after action potential
When a message is sent across the neuron is it ……… energy
Chemical
Steps across the synapse
- Vesicles containing neurotransmitters release into synapse
- the complementary neurotransmitter binds with specific receptor (lock and key process)
- the signal is sent to the soma which decides to fire or not depending on amount of the type of neurotransmitter.
Define reuptake
The process where the receptor on the post synaptic neuron recieves the information from the neurotransmitter
Define neurotransmitter
A chemical substance made of small molecules that uses chemical energy to pass the information across a synapse
Define excitatory neurotransmitters
Cause a POST SYNAPTIC neuron to fire, reaching axon potential and cause a response
Examples of excitatory neurotransmitters
Glutamate- essential for memory and learning
Dopamine- motivation and motor movement
Define inhibitory neurotransmitters
Decreases likelihood of neuron from firing and inhibits a response
Examples of inhibitory neurotransmitters
GABA- essential for decreasing anxiety
Serotonin- important for stabilising mood
Define gyrus and sulcus in the brain
The raised part between the sulculs
The groves in the brain
What’s the four lobes of the brain and their functions and their cortex
Frontal lobe- personality, problem solving and decision making (primary motor cortex)
Parietal lobe- sense of touch(primary somatosensory cortex)
Temporal lobe- processing auditory( primary auditory cortex)
Occipital lobe- processing visual info( primary visual cortex)
Broca’s area location and function
Located in the frontal lobe of left hemisphere
Movement required to produce speech and grammar with writing .
Wernickies area location and function
located in the temperal lobe of left hemisphere
Interpretation of speech or written language.
Define chronic
Long term, and recurring. A disease that gradually worsens over time
What is neurotransmitter interruption
Can occur from an imbalance or deficiency in a neurotransmitter
What causes neurotransmitter interruption
Alcohol and drugs
Diet and nutrition
Stress
Genetics
Treating neurotransmitter interruption
Drugs and medication that can mimic the neurotransmitter.
However this is not natural and can make the disease worse
Define Parkinson’s disease
A progressive degenerative neurological condition that affects a persons ability to control their body movement
Symptoms of Parkinson’s disease
Tremors
Involuntary movement
Restless sleep
Depression
Location of Parkinson’s disease
Midbrain in the substia niagra- contains neurone that realese dopamine and GABA
How does GABA affect Parkinson’s disease and examples
Without GABA more neurone fire
There is more muscle movement because GABA is not calming neurones
Involuntary muscle contraction occurs
Examples tremors and restless leg syndrome
How does dopamine affect Parkinson’s and examples
Without dopamine
Reduction of firing neurons
There are gaps in coordination
Examples- there is not efficient motor function when trying to move eg picking up a drink bottle will contain muscle rigidity
