AOS1 - nervous system functioning Flashcards
what are the three main functions of the nervous system?
receive info, process info and coordinate a response to information
what two things make up the central nervous system?
the brain and the spinal cord
what are the two functions of the spinal cord?
- receive sensory info from the body via the PNS and send those messages to the brain for processing
- receive motor info from the brain and send it to relevant parts of the body
what are the two functions of the PNS?
- carry info to the CNS from muscles, glands and organs
- carry messages from the CNS to the bodies muscles, organs and glands
what four NS’s make up the PNS?
somatic, autonomic –> sympathetic and parasympathetic
what is the function of the somatic NS?
carries sensory info TO the CNS and motor info AWAY from the CNS
(SAME: sensory afferent, motor efferent)
what is the function of autonomic NS?
connects the CNS to the body’s internal organs and glands, providing feedback to the brain about their activity
what is the function of sympathetic NS?
activates internal muscles, organs and glands to prepare the body for vigorous activity or to deal with stressful or threatening situations
what is the function of the parasympathetic NS?
helps to maintain the internal body environment in a steady, balanced state i normal functioning. restores the body to a state of calm and maintains homeostasis
what is a conscious response?
a reaction to a sensory stimulus that involves awareness, a voluntary reaction. controlled by the somatic NS
what is an unconscious response?
a reaction to a sensory stimulus that does involve awareness, an unintentional, automatic reaction. controlled by the autonomic NS
what are the six steps of the spinal reflex?
- receptor cells detect stimulus and send a neural message to a sensory neuron
- sensory neuron carries message to the spinal cord
- interneuron in spinal cord relays message to a motor neuron
- motor neuron carries message to muscles causing a withdrawal reflex
- while the spinal reflex, the message is sent to the brain through the spinal cord
- the message is received by the brain and the pain is interpreted
what is a neuron?
an individual nerve cell specialised to receive, process and transmit information
role of the dendrite?
detect and receive information from other neurons
role of the axon?
transmits neural information to other neurons
role of myelin/myelin sheath?
promote efficient transmission of information
role of axon terminals and buttons?
store and secrete neurotransmitter
what is a motor neuron?
an efferent neuron that carries messages from the CNS to skeletal and visceral muscles to stimulate activity or response
what is a sensory neuron?
an afferent neuron that received messages from both the bodies internal and external environments and transmits it to the CNS
what is an interneuron?
a neuron that sends messages sensory and motor neurons within the CNS
what is a synaptic gap?
a tiny space between the terminal buttons of one neuron and the dendrites of another where the neurotransmitter secreted from the buttons is received by the dendrite
what is a synapse?
the site where the communication occurs between adjacent neurons
what is neurotransmitter?
a chemical substance produced by a neuron that carries a message to other neurons or cells
what is glutamate?
the CNS’s main excitatory neurotransmitter. it increases the likelihood of the post-synaptic neuron firing
what gamma-amino butyric acid (GABA)?
the CNS’s main inhibitory neurotransmitter. it decreases the likelihood of the post-synaptic neuron firing
explain the lock and key process
as every neurotransmitter has a chemically distinct shape, it will search for the correctly shaped receptor site on the dendrites of the adjacent neuron
what is parkinsons disease?
a slow developing neurodegenerative disease that can affect both motor and non-motor functions.
list four motor symptoms of parkinsons
- tremors
- bradykinesia
- muscle rigidity
- postural instability
what is bradykinesia?
slowness or involuntary movements
list three non-motor symptoms of parkinsons
- sensitivity to temperature
- loss of sense of smell
- cognitive functioning issues such as slowed thinking, impaired problem solving etc.
what is believed to cause the motor symptoms?
degeneration and loss of neurons in the substantia nigra
where is the substantia nigra located?
in the basal ganglia found in the midbrain
what neurotransmitter does the SN produce?
dopamine