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Sport and Exercise Physiology - Coggle Diagram
Sport and Exercise Physiology
The Nervous System
Components of the nervous system
Neurons
AKA; Nerve cells
Communicate via travelling action potentials (nerve impulses)
Glial cells
Highly abundant cells
Help to protect neurons
Do not generate or transfer action potentials
Neurotransmitters
Chemical substances
(seratonin, dopamine, acetylcholine)
Facilitate synapses
Dopamine & seratonin involved in many brain processes (i.e. learning)
Acetylcholine important for
muscular contraction
Neuron structure
Cell body (soma)
Includes regular cell components e.g. nucleus, organelles
Dendrites
Extend from cell body
Receive information (e.g chemical messages)
Axon
Propagate
(transfer)
impulses
Axon terminals
Site of synapse
(communication between neighbouring cells)
Neurotransmitters stored
Types of neurons
Sensory (Afferent) 'Towards'
Monitor & provide information
Impulses received by brain - decides appropriate response
Examples
•
Proprioceptors
- Detect relative position of body parts
•
Baroreceptors
- Detect stretch of blood vessels
•
Mechanoreceptor
- Monitor physical stimuli (i.e. touch, pressure, vibration)
•
Chemoreceptors
- Monitor blood pH/blood gas
•
Nociceptors
- Detect pain related to pressure, temperature and chemicals
•
Thermoreceptors
- Monitor temperature
Motor (Efferent) 'Away from'
Command/instructions
Transfer impulses to active tissues (muscles and glands)
Triggers muscles to contract & glands to secrete
Nervous system arrangement
Central Nervous System (CNS)
Brain & spinal cord
Processes incoming sensory information
Decides necessary action
Peripheral Nervous System (PNS)
Autonomic nervous system (ANS)
Sympathetic
Helps to support emergency actions
'Fight or flight'
Parasympathetic
Takes care of quieter bodily functions
'Rest and digest'
Sensory neurons
Provide information from organs (i.e. lungs, heart)
Motor neurons
Send impulses from CNS to
smooth muscle, cardiac muscle & glands
Involuntary
Somatic nervous system (SNS)
Sensory neurons
Provide information from the periphery (e.g. limbs)
Motor neurons
Send impulses from CNS to
skeletal muscle only
Voluntary
What are action potentials?
An electrical impulse; primary method of communication in neurons
Originates in cell body
Transferred by axon terminals
Received by dendrites (if receiving from another cell)
Sends signals between neurons and from neurons to other cells (e.g. muscle)
Can occur in other excitable cells (i.e. cardiac muscle cells)
Communication - Action potentials
Changes in membrane potential (electrical charge)
- Due to movement of sodium
Rapid movement of sodium causes
depolarisation
Depolarisation leads to the generation of an action potential
Cells must
repolarise
before this process can repeat
Synapses
1) Action potential stimulates release of
acetylcholine
2) Acetylcholine diffuses over synaptic cleft & bind to receptor
3) Causes Na+ to flow into the muscle cell = initiating an action potential across the muscle membrane
Neuromuscular junction
= connection between motor neuron terminals and muscle cell membrane
