Unit 3 AOS 1 Flashcards
Neuron definition
individual nerve cell that receives, transmits and processes information
SAME acronym
sensory, afferent, motor, efferent
Human nervous system definition
a communication subsystem that consists of networks of neurons that connects the brain, spinal cord, and different parts of the body to each other via electrochemical signals
What are the two main divisions of the human nervous system
peripheral nervous system, central nervous system
Central nervous system definition
a major division of the nervous system consisting of all the nerves in the brain and spinal cord
What is the CNS made up of
the brain and the spinal cord
What does the brain do (3 things)
1) regulates and guides all other parts of the nervous system. 2) Receives information via senses, processes it and co-ordinates appropriate response (via spinal cord). 3) It is responsible for higher order functions (planning, thinking, learning)
What is the spinal cord
a column of nerve fibres that extends from the base of the brain to the lower back.
What are the 2 functions of the spinal cord
1) to receive sensory information from the PNS and transmit it to the brain via afferent tracts, 2) and to receive motor information from the brain and transmit it to the PNS via efferent tracts
Where do afferent tracts begin
the spinal cord
Peripheral nervous system definition
network of neurons located outside the CNS, comprising of muscles, organs and glands
Functions of the PNS
transmit sensory information to CNS, transmit motor messages from CNS - i.e. receive and respond to sensory information
What are the two main divisions of the PNS
autonomic nervous system, somatic nervous system
Somatic nervous system definition
the division of the PNS that transmits sensory info received from sensory receptor cells inwards towards the CNS and motor messages from the CNS to the body’s skeletal voluntary muscles
The somatic nervous system is also known as
the skeletal nervous system
The 2 functions of the somatic nervous system
1) transmits information from receptor sites on sense organs to the CNS (via afferent pathways), 2) Carries information from the CNS to the muscles that control movement (via efferent pathways)
Autonomic nervous system definition
transmits motor messages from the brain to the body’s internal organs, muscles and glands which results in involuntary activity of these, and transmits messages to brain about these
Functions of the autonomic nervous system
1) carries neural messages between CNS and the internal visceral muscles, organs and glands, 2) and it regulates the internal functions of these organs/glands/muscles
Biofeedback definition
a process by which a person receives information about their autonomic physiological activity (instruments) in order to learn how to control these.
What are the two main divisions of the autonomic nervous system
sympathetic nervous system, parasympathetic nervous system
Sympathetic nervous system definition
branch of the ANS that alters the activity level of internal muscles, organs and glands to physically prepare our body for increased activity during times of high emotional or physical arousal e.g. stress.
Function of the sympathetic nervous system
activates internal muscles, organs and glands to prepare body for vigorous activity, or to deal with a stressful situation
Fight-flight-freeze response
a response triggered by the sympathetic nervous system that physiologically prepares the body during a stressful situation in order to optimise survival and involves either confronting the stressor (fight), running away (flight) or remaining stationary (freeze).
Fight-flight-freeze response involves what systems
nervous (autonomic and sympathetic) and endocrine
Parasympathetic nervous system definition
branch of ANS that maintains energy levels appropriate for normal bodily functioning and physically calms us after high arousal by reversing the changes in bodily functioning caused by the domination of the sympathetic nervous system
The 3 functions of the parasympathetic nervous system
1) Counterbalances sympathetic nervous system responses (returns body back to normal functioning/state of calm) through physically calming us after high arousal by reversing the changes in bodily functioning caused by the domination of the sympathetic nervous system, 2) and it maintains the body’s natural state of equilibrium (homeostasis). 3) This also allows resources to be saved for when needed and restoring depleted resources.
What are conscious responses
neural communication that involves conscious awareness and any somatic nervous system functions
What are unconscious responses
Neural communication involving unconscious awareness involves any autonomic nervous system functions such as breathing, digestion, blood pressure
What is a reflex action
simple automatic response that is hardwired into our nervous system e.g. blinking when dust goes into eyes
Spinal reflex definition
An automatic response that is initiated by interneurons in the spinal cord instead of the brain.
What is an interneuron
a specialised neuron that links sensory and motor neurons; located in the CNS
What happens in a spinal reflex
sensory neurons receive an intense sensation, this information travels to the spinal cord to interneurons, interneurons send motor information to withdraw,
When does a spinal reflex reaction occur
intense sensation, danger/threat/critical time
The spinal reflex is a ___ response
survival response
Why does the message bypass the brain initially
to get a quicker response, therefore less negative impact and more chance of survival
Why does the message then go to the brain after acted
to learn
What is pain
an unpleasant sensory or emotional experience associated with actual or potential tissue damage
Example of spinal reflex
burn, sting
Monosynaptic reflex
reflex response that involves one synapse and the interaction between a sensory neuron and a motor neuron
Example of monosynaptic reflex
patellar ‘knee jerk’ reflex
Monosynaptic reflexes do not involve…
interneurons
Polysynaptic reflexes definition
a reflex response that involves the activation of more than one synapse: it includes an interneuron making a connection between a sensory and a motor neuron
Example of polysynaptic reflex
withdrawal reflex, spinal reflex
Dendrite (function/structure)
neuron fibre that extends from the soma that receives incoming neural information from other neurons
Define soma
the main cell body of a neuron that contains the nucleus that is responsible for integrating information (receive from dendrites, pass on to axon)
Define axon
pathway down which neural message travels
Define myelin sheath
a fatty white tissue that coats the axons of some neurons - role is to protect the axon and assist with speed of transmission of neural message
Define axon terminals
Exit pathways for neural message to make their way to next neuron
Define terminal buttons
Releases neurotransmitters to a receiving neuron for communication purposes
Define glial cells
assist in structure of neurons/nutrition
Remember about neural transmission
neurons don’t move, message does
Neural transmission involves ____ energy
electrochemical energy
Resting potential is
positive on outside, negative on inside
Action potential is positive/negative outside/inside…
negative outside, positive on inside
Resting potential definition
the typical internal environment (negatively charged) of a neuron in comparison to the external environment (positively charged)
All or nothing means
no levels of action potential only there is or isn’t
What comes first polarisation/depolarisation/repolarisation
polarisation, then depolarisation then repolarisation
Define receptor sites (neuron)
areas on the cell membrane of the dendrites of post-synaptic neuron that are sensitive to specific neurotransmitters
Neurotransmitters definition
a chemical messenger synthesised within a pre-synaptic neuron and transmitted across a synapse.
Excitatory neurotransmitters definition
neurotransmitters that cause the post-synaptic neuron to fire/stimulate post-synaptic neuron
Inhibitory neurotransmitters definition
neurotransmitters that prevent the post-synaptic neuron from firing.
Glutamate is responsible for
high speed neural transmission and is necessary for memory and learning.
What is one receptor site for glutamate
NMDA
What does too much glutamate do
too much glutamate has been linked to neurodegenerative diseases such as motor neuron disease.
Is glutamate excitatory or inhibitory
excitatory
What does GABA stand for
gamma amino butyric acid
What does GABA do
calm and slow neural transmission, decrease anxiety
What are the receptor sites for GABA
GABAa, GABAb, GABAc
What is low levels of GABA linked to (2)
epilepsy (less inhibition) and anxiety
Is GABA excitatory or inhibitory
inhibitory
Other neurotransmitters (other than GABA and glutamate)
acetylcholine, epinephrine, dopamine, serotonin
What is acetylcholine responsible for and what happens without it
memory and without it Alzheimer’s
What is epinephrine responsible for
arousal
What is another name for epinephrine
adrenaline
What is dopamine responsible for and what happens without it
motivation, voluntary movement, without it Parkinson’s disease/depression