chap 2- Nervous System Flashcards
what is the nervous systems function
to communicate stimuli from the body and the outside world to the brain and then communicate commands for movements and other responses to the body.
What are the branches of the nervous system
Central nervous system and peripheral nervous system
what makes up the central nervous system
Brain and spinal cord
What is the central nervous system for
Where the information can travel
What is the Peripheral nervous system broken down into
Somatic nervous system and autonomic nervous system
What is the somatic nervous system also known as
skeletal nervous system
What is the somatic nervous system for
links body to CNS by carrying sensory info towards the brain and motor/movement info back to the body. For voluntary movement
What are afferent neurons for
Sensory information
What are efferent neurons for
motor movement information
Is the somatic nervous system for voluntary movement
Yes
What is the Autonomic nervous system for
The bodies internal environment and helps regulate basic life functions.
What is the Autonomic Nervous system broken up into
sympathetic and parasympathetic
What is sympathetic for
controls arousal, fight/flight response, fires us up, releases adrenaline, heart and breathing up.
What is parasympathetic for
calms back down, keeps at stable level, digestion, resting etc.
What is the autonomic branch connected to
internal organs
is the autonomic branch consciously controlled
No
What is the enteric nervous system for
controls activity of the digestive syste,
What are conscious responses controlled by
the brain
are conscious responses voluntary
Yes
Why do conscious responses occur
As a result of communication between brain and somatic nervous system.
Are unconscious responses important
Yes they are essential for survival.
What are unconscious responses known as
reflex actions
How do unconscious responses occur
automatically by somatic nervous system and the spinal cord. occur independently from the brain
What does the monosynaptic reflex arc involve
only one synapse where an affecter neuron brings a sensation from receptors in the body and effecter neuron carries motor messages to muscles of the body
What does the polysynaptic reflex arc involve
interneurons connecting the affecter and effecter neurons and therefore at least 2 synapses.
What is the spinal reflex also known as
A reflex arc
What is an example of the spinal reflex
withdrawal reflex
What is the spinal reflex and where does it occur
the simplest stimulus response that occurs in the spinal cord.
What is the soma
The cell body that determines whether neuron will be activated and thus transmit message to other neurons
What is a dendrite
short thin widely branching nerve fibre that is specialized to detect and receive neural info.
What is an axon
an extension that transmits messages from the soma to other cells in the body including other neurons, muscles, organs and glands.
what is the myelin sheath
a white fatty substance that coats the axon and helps to speed up transmissions.
What are the axon terminals
branches at the end of each axon
What is the terminal button / synaptic knob
small knob like swelling at the tip of each axon terminal
What are neurotransmitters
chemicals stored in the synaptic knob that assist in he transmission of neural info from one neuron to another
What is the synapse
the gap between neurons
What is the lock/key in the lock and key process
lock- receptors
key- neurotransmitters
what do excitatory synapses do
cause the post synaptic neuron to fire up
what do inhibitory synapses do
reduce or stop the likelihood of post synaptic neurons firing up
What are antagonists
substances that share a similar molecular structure to neurotransmitters
What do antagonists do
Inhibit neurotransmitters and their effects
why are antagonists inhibiters
they act as the key that fits with the receptor sites so the neurotransmitters cant
Are antagonists inhibiters
Yes
What are agonists
substances that act as a key to the lock so it mimics the action of the neurotransmitter
what do agonists do
produce an excitatory effect
What is glutamate
A neurotransmitter
What does glutamate do
excite neurons in the brain and the rest of the nervous system. speeds up neural transmission
Why is glutamate important
for learning and memory
What does GABA do
have an inhibitory effect on the brain
Why is GABA important
regulating anxiety and stress
What are neuromodulators
a subclass of neurotransmitters that alter the strength of neural transmission by increasing/decreasing the responsiveness of neurons to neurotransmitter signals
What is dopamine involved in
many nervous system functions. eg mood, pleasure, attention, mood, cognition and motivation
What affect does dopamine have
both excitary and inhibitary
What are dopamine and seratonin examples of
neuromodulators
is serotonin an inhibitory neurotransmitter
Yes, however it also acts as a neuromodulator
what does serotonin modulate
mood, perception, reward, anger, aggression, appetite, memory, sexuality and attention
What has impairment to the serotonin pathway been linked to
depression, anxiety disorders or Parkinson’s disease
What is the biological explanation of memory and learning
new memories are not stored in individual synapses but in the pattern of thousands of new interrelated connections
How many nerve cells are babies born with
100 billion
At birth how many nerve cells synapse with other neurons
2500
When is the most rapid development of synapse formation, and how many should there be
the first 2 years of life. there should be 15000
Why do synapse formations decrease to 8000 at adulthood
unused connections are destroyed
what is synaptogenesis
formation of new neural connections
what is synaptic pruning
removal of synaptic connections that are no longer needed
what is neural plasticity
the brain reorganizes the way neurons in different regions operate in response to experience or a deficit
what can cause neural plasticity
birth or brain damage
how can neural plasticity occur
synaptogenesis, synaptic pruning, rerouting and sprouting
what is rerouting
neurons near damaged area seek new active connections with healthy neurons
what is sprouting
new dendrites grow
What is LTP
the more frequently activated a neural connection is the more easily activated it becomes
What does LTP stand for
Long term potentiation
What are the three ways synapse strength can improve
- increased release of neurotransmitter
- increased number of receptor sites
- growth of new synapses
What is LTD
the less frequently activated a neural connection is the less easily activated it becomes. weakens the synaptic connection over time
What does LTD stand for
Long term depression
What may LTD play an important role in
forgetting
OR
pruning unused connections and enabling he brain to work more efficiently
