The Nervous System Flashcards
What are the divisions of the nervous system?
The Central Nervous System and the peripheral nervous system
What are the divisions of the central nervous system?
The brain and the spinal cord
What is the function of the brain?
Controls thoughts, feelings and actions
What is the function of the spinal cord?
Connects the brain and the PNS
What are the divisions of the peripheral nervous system?
The autonomic nervous system and the somatic nervous system
What is the function of the somatic nervous system?
Communicates messages from the PNS to the skeletal muscles
What are the divisions of the autonomic nervous system?
Sympathetic and Parasympathetic nervous systems
What is the function of the sympathetic nervous system?
Prepares the body for action (activates FFF)
What is the function of the parasympathetic nervous system?
Calms body after action and returns it to and maintains homeostasis
What is the nervous system?
A complex and highly organised network that enables the brain to receive stimuli from both inside and outside the body
How does the nervous system work?
It serves as a communication system between internal cells and organs to the outside world.
What are the main functions of the nervous system?
- Receive information
- processes information
- coordinate a response
How is information transmitted between the CNS and PNS?
- afferent neurons detect external stimuli
- information travels along the afferent tracks to the spinal cord
- information is passed through the interneurons in the spinal cord
- brain receives information and formulates a response
- information passes back down to the interneuron
- response travels down the efferent tracks to the motor neurons
- muscles respond to external stimuli
Which hormone is released during FFF?
Adrenaline
What does adrenaline do during FFF?
- increases heart rate and blood pressure to allow more blood to larger muscle groups
- increases breathing rate to help oxygen levels
- releases sugar and fat from storage for energy
- dilates pupils to increase vision in low light
- increases production of sweat glands to cool the body
- slows digestion
What is a neuron?
An individual cell involved in the reception and transmission of information across the synapse
What is a dendrite and what is its function?
- an extension of a neuron
- detects and receives information from other neurons
What is the soma and what is its function?
- cell body
- integrates information from dendrites
What is an axon and what is its function?
- extension of the soma
- transmits received neural information down the neuron
What is the myelin sheath and what is its function?
- a fatty substance that surrounds and insulates the axon
- prevents interference from the activity of other surrounding axons
What is a terminal button and what is its function?
- the end of an axon
- secretes neurotransmitters into the synapse
What is the synaptic gap and what is its function?
- the space between one neuron and another
- where communication occurs
How does information travel through a neuron?
- an electrical signal is received by the dendrite on the presynaptic neuron and sent to the soma
- the action potential travels down the axon and to axon terminals
- this stimulates the release of the neurotransmitter into the synapse where they bind to the dendrite of the postsynaptic neuron
What is a conscious response?
A voluntary response that involves the awareness of the brain
What is an unconscious response?
An involuntary response that doesn’t involve the awareness of the brain
What is a spinal reflex?
An unconscious response to certain stimuli without any involvement of the brain
How does a spinal reflex occur?
-the signal from the sensory neuron reaches the internueron and bypasses the brain, moving straight back down the motor neuron
What is the purpose of a spinal reflex?
An adaptive response which enables a faster response time
What is a neurotransmitter?
a chemical substance produced by a neuron that carries messages to the other neurons in the body
What is the primary excitatory nuerotransmitter?
Glutamate
What does glutamate do?
enhances information transmission by making postsynaptic neurons more likely to fire
What is the primarry inhibitory neurotransmitter?
GABA
What does GABA do?
makes post synaptic neurons less likely to fire
What is the lock and key process?
- each type of neurotransmitter has a chemically distinct shape
- when released by the presynaptic neuron, the neurotransmitter (key) searches for the correctly shapded receptor site (lock) on the postynaptic neuron where it then binds
- this binding unlocks the postsynaptic neuron’s response
What happens to neurotransmitter which cannot bind to a receptor site?
They are reabsorbed into the presynaptic neuron by a process called reuptake
What is Parkinson’s disease?
a neurodigenerative disorder characterised by both motor and non-motor symptoms caused by a lack of dopamine in the substantia nigra
What is the role of dopamine?
Inhibitory neuron that coordinates fine muscle movement of the skeletal muscles
What are the main motor symptoms of Parkinson’s?
Tremors, muscle rigiditiy, slowness of voluntary movement and postural instability
What are some of the non-motor symptoms of Parkinson’s?
Increased sensitivity to temperature, fatigue, depression, anxiety, slowness of thinking and impaired decision making
What are some of the functions of medications used to treat Parkinson’s?
Can be converted into dopamine by neurons or mimic dopamine
