unit 3 AOS1 - nervous system functioning Flashcards
define the human nervous system
enables the brain and the body to exchange neural messages (electro chemical) and communicate with one another
what are neural messages communicated via
neurons
what are the three types of neurons
- Motor Nurons (efferent nurons)
2.sensory nurons (afferent nurons)
3.Interneourons
what is a motor nuron
transmits neural messages about motor movement from the central nervous system to the peripheral nervous system
what is sensory nurons
transmits neural messages about bodily sensations from the peripheral nervous system to the central nervous system
what is interneurons
transfer neural messages between sensory neurones and motor neurones. The central nervous system, including the brain and spinal cord, is made up of interneurons
what are the types of responses
Conscious response
unconscious response
Conscious response
are deliberate and voluntary actions that are intentionally initiated by the brain and performed by the body
- involves the central nervous system because the brain is involved
unconscious response
are automatic and involuntary actions that are performed by the body independently of the brain. they occur without conscious awareness in response to internal and external sensory stimuli.
what are the unconscious responses
- physiological responses to the autonomic nervous system (FFF)
- the spinal reflex
The brain is the control centre of the NS
- The brain receives sensory information
2.processes it, integrates it, and organises it - and then initiates a bodily response to the skeletal muscles to respond to stimuli
role of the Central nervous system
the spinal cord a cable of nerve tissue that extends from the brain, connecting to the peripheral nervous system.
ascending tracks
transmits sensory messages from the peripheral nervous system to the brain
desending tracks
transmits motor messages from the brain to the peripheral nervous system
role of the peripheral nervous system
- a major division of the nervous system comprisisingn every nuron in the body outside the central nervous system.
-transmits messages between the central nervous system and the body
the somatic nervous system
overview
is a division of the peripheral nervous system that transmits neural messages related to voluntary motor movement (skeletal muscles)
the autonomic nervous system
is a division of the peripheral nervous system that regulates visceral muscles organs and glands not connected to the skeleton that are predomanentley self regulated and do not require conscious control.
- transmits neural messages to the central nervous system about their activity
The somatic nervous system and how it works responding to sensory stimuli and initiating voluntary motor movements
sensory neural message travel from sensory receptors, which are the nerve endings that detect sensations, to the central nervous system via afferent neural pathways in the somatic nervous system.
motor neural messages travel from the central nervous system to skeletal muscles, which are muscles connected to the skeleton that carry voluntary motor movements, via efferent neural pathways in the somatic nervous system.
what are the two branches of the autonomic nervous system
- sympathetic nervous system
2.parasympathetic nervous system
describe the different between sympathetic nervous system and parasympathetic
becomes dominate when a person is confronted with threat or stressor were as parasympathetic nervous syetm becomes dominate during rest and physical inactivity.
what is the type of response of a sympathetic nervous system
physiological responses occur to energise the body, preparing it to confront or escape the threat or stressor
what is the response for a parasympathetic nervous system
physiological responses occur that maintain optimal and balanced functioning
example of behaviours that will occur for sympathetic
- heart rate increases to increases blood flow, enabling high levels of physical activity
- pupiles dilate, to allow more light to entree the eyes improving vision
-adrenal glands secrete stress hormones such as adrenilen to energise the body
- the body relies more glucose to energies the body
parasympathetic responses
- the heart beats are steady and regular that support optimal balance and functioning
- lung airways contract allowing spreading and regular breathing
- purples constrict according to external light levels allowing for an appropriate amount of light to enter the eye for adequate vision
-
spinal reflex definition
an unconscious response to sensory information that is initiated by internerouns in the spinal cord independently of the brain
purpose of the spinal refelx
to protect the body from injury or harm and increases chance of survival
- the spinal reflex is considered an adaptive response
the spinal cord involves three types of nurons
sensory (afferent) detecting sensations
interneurons or relay nervous (links motor and sneaky nurons in spinal cord)
moror nuron or effernt (enables responce)
how a spinal reflex works
the path along which the neural signal is transmitted as part of the spinal reflex is called the reflex arc. The sensory neural message travels from sensory receptors to the spinal cord. it then loops around the spinal cord, and now a motor mural message travels from the spinal cord to skeletal muscles, which completes the reflex arc.
Step by Step spinal reflex
- touches hot pan, painful sensation is detected by sensory receptors and ad transmitters via sensory neural pathways (afferent) to the spinal cord
- an interneuron in the spinal cord relays this message from a sensory nuron to a motor nuron, initiating an unconscious motor response to withdraw hand.
- skeletal mucles in persons hand automatically, carry out this unconscious response.
- the person registers the painful sensation that caused them to withdraw hand as this sesnory mesage reaches the brain
describing the neural pathway
two neourons in a neural pathway meet at the neural synapse, which is the region that includes. The axon terminal of presynaptic neuron, the synaptic gap and the dendrites of the post synaptic gap.
the presynaptic neuron
the presynaptic nuron is the neuron that releases nourochemicals into the neural synapse.
axon terminal are the ends of neuron that release neourchemicals into the neural synapse.
synaptic gap
this is the space between presynaptic nuron and poststyaptic neuron
nerochemicals in nerotransmission
the process of synaptic transmission is:
- neourochemicals are produced in the axon terminals of the presynaptic neuron
- neourochemicals are released from the axon terminals of the presynaptic neuron into the synapse
- neourcchemicals bind to receptor sites on the dendrites of the postsynaptic neuron.
- neourochemicals affect the postsynaptic neuron, ethethir triggering or inhibiting a response
definition of nurochemicals
nurochemicals are chemical substances that transmit neural information within the nervous syetm.
what are neurochemicals
- Neourotransmitters
2.Neouromodulators
Neurotransmitters
are chemical molecules that have an effect on one or two postsynaptic nurons.
- this type of neurochemical enables rapid communication between two nurons across the neural synapse
what are the two category’s of Neurotransmitters
excitatory: more likely to fire action potential
Inhibitory: less likely to fire action potential
Neourmodulators
are chemical molecules that have an effect on multiple postsynaptic nurons
- have wider spread modulatory effects as they can influence large areas of the brain.
produces relatively long-lasting effects, as they modulate neural activity more slowly than neurotransmitters.
what are the two types of Nurotransmitters
Glutamate
GABA
Glutamate as a neurotransmitter
-Type: excitatory neurotransmitter
-effect: increases the chance for the postsynaptic nuron firing action potential
role: has an important role in learning and memory. Specifically the exitotory effects of glutamate form and strengthen synaptic connections bettwen nurons that are repeativley activated during learning.
glutamate enables synaptic plasticity.
GABA role neurotransmitter
- inhibitory neurotransmitter
decreases likelihood for postsynaptic nuron firing an action potential
role in regulating postsynaptic regulation in neural pathways, preventing the overexitation of nurons in this way GABA reduces anxiety which is physiological and psychological response that involves general feelings worry.
- prevents seizures
what are the nuromodulator
- dopamine
-serotonin
dopamine nuromodulator effect
can have an excitatory and inhibitory effect of the postsynaptic nuron. depends on the type of receptor sites present at the particular brain location
role of dopamine nuromodulator
- coordinating voluntary motor movement,
- read based learning associated with the experience of pleasure
- motivation, to behave in reward based learning
nuromodulator serotonin pathways
there are pathways along the brain were serotonin is transmitted
these pathways originate from the raphe nuclei, which are masses of nurons in the brainstem that produce serotonin
effect of serotonin
inhibitory effect on post styptic nuron
role of serotonin
role in regulating moods and stabilisation. - positive stable mood promoting well-being
role in regulating sleep wake cycle
quality and quantity of sleep
feelings of alertness wakefulness during the day
appetite digestion and arousal
synaptic placidity definition
is the ability of synaptic connections to change over time in response to activity or experience. changes include the formation, strengthening or seeking of synaptic connections.
what are the two forms of synaptic placidity
- long term potentiation
- long term depression
definition of long term potentiation
is the long lasting and experience-dependent strengthening of synaptic connections that are regualy activated at high intensity simulation.
long term potentiation structural changes
structural changes occur to the synapse as a result of the increased release of neurotransmitters, specifically glutamate.
- increases number of receptor sites on the dendrites of postsynaptic nuron
- bushier dendrites on the postsynaptic nuron due to sprouting
- increased number of synaptic connections bettwen nurons due to sprouting
long term depression definition
is the long lasting and experienced-dependent weakening of synaptic connections between neurons that are not regally coactivated.
how does LTD work
by wearing the memory traces that are not regulary activated, LTD enables the brain to accommodate more necessary memory reaches that present more relevant information, and are consequently activated more frequently.
LDT structure changes
-decress number of receptors sites on the dendrites of th post synaptic nuron
-decress number of dendrites on the posynaptic nuron due to pruning
-decress number of synaptic connections due to pruning
LTD and LTP modifying connections
these are mechanisms for synaptic placidity
- sprouting
-rerouting
-pruning
sprouting
is the ability of dendrites or axons to develop new extensions or branches
pruning -LTD
is the elimination of synaptic connection that are not aequetley activated
this is necessary to accommodate stronger and more essential synaptic connections, consequently enhancing the efficiency of the brain functioning
rerouting
is the ability fof a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron.
