unit 3 aos 1 - key knowledge Flashcards
Role of central nervous system
Receives sensory information from peripheral nervous system
Sends motor information to peripheral nervous system
Role of brain
Command centre of central nervous system responsible for receiving panel processing information and generating responses to it
Role of spinal cord
Connects peripheral nervous system to brain
Controls reflex arc (spinal reflex)
Communicates neural information in two ways:
- carries sensory messages along ascending tracts from peripheral nervous system to brain for processing
- motor messages are sent along descending tracts from brain to muscles via peripheral nervous system
Roles of peripheral nervous system
Sends sensory messages to central nervous system
Receives and carries out instructions sent from CNS
Made up of both somatic nervous system and autonomic nervous system
Role of somatic nervous system
Controls muscles attached to skeleton, involved in voluntary movement
Two major functions:
- transmits sensory information from receptors in sensory organs to central nervous system => sensory (afferent) neurons transmit neural messages about bodily sensations from PNS to CNS
- control voluntary skeletal muscle movement via messages sent from CNS => motor (efferent) neurona transmit neural messages about motor movement from CNS to PNS
- Interneurons => transfer neural messages between sensory neurons and motor neurons
Role of autonomic nervous system
Relays messages between CNS and involuntary muscles
Operates without conscious awareness
Consists of sympathetic & parasympathetic nervous system
responsible for bodies internal environment
Role of sympathetic nervous system
Activates tight-flight-freeze response
Releases Adrenalin and monadrenalin to cause some body functions to speed up
Dominates under threat
Assists in physiological changes assisting in survival
roles of the Parasympathetic nervous system
Dominates normal day to day when we are relatively calm
Returning body to calm state after threatening/stressful situations
Autonomic functioning - sympathetic nervous system responses
Pupils dilate
Bronchioles relax
Heart rate increases
Digestion is inhibited
Bladder relaxes
Gull bladder stimulates glucose levels
Autonomic functioning - parasympathetic nervous system
Constricts pupils
Constricts bronchioles
Decreases heart rate
Enables digestion
Gall bladder stimulates bile production
Bladder contracts
Steps of conscious response
- Sensory stimulus (cold water) comes into contact with sensory receptors (on persons hand) detect internal sensations in body and external sensations from environment (cold sensation)
- Sensory neural (cold sensation) is transmitted via afferent pathways in somatic nervous system, and then spinal cord, to brain
- Brain processes (receives and processes cold sensation) sensory information, coordinating and initiating a conscious motor response (turn on ‘hot’ tap to increase water temperature)
- Motor neural message is transmitted via efferent pathways in spinal cord, and then somatic nervous system, to skeletal muscles
- Skeletal muscles carry out conscious motor response to sensory stimuli (skeletal muscles move person’s hand towards ‘hot’ tap to increase water temperature)
Unconscious response - physiological responses of autonomic nervous system
Breathing, digestion, blinking, spinal reflexes
Steps of spinal reflex
- Dangerous or harmful sensory stimulus (extremely hot pan) is detected by sensory receptors, which transmit sensory message via sensory neurons in somatic nervous system to spinal cord
- Interneuron in spinal cord immediately relays sensory neural signal from sensory neuron to motor neuron as a motor neuron signal, initiating automatic and unconscious motor response (quickly withdraw hand from hot pan)
- Motor message is transmitted via motor neurons in somatic nervous system to skeletal muscles, which carry out unconscious motor response to dangerous or harmful sensory stimulus
- Sensory message continues to travel via afferent tracts in spinal cord to brain. Brain independently registers sensation that triggered spinal reflex
Process of synaptic transmission.
- Neurochemicals produced in ancon terminals of presynaptic neuron
- Neurochemicals are released from axon terminals of presynaptic neuron into the synaptic gap
- Neurochemicals bind to receptor sites un dendrites of postsynaptic neuron
- Neurochemicals affect postsynaptic neuron, either triggering or inhibiting a response
Glutamate - type, effect, role in functioning
Type - excitatory neurotransmitter
Effect - increases likelihood of postsynaptic neuron firing an action potential
Role in functioning - important role in learning and memory. Strengthens synaptic connections between neurons that are repeatedly activated during learning.
