Unit 3 AOS 1: Nervous system & Stress Flashcards
The Nervous System
A communication system between the body’s in eternal cells and organs and the external word.
What does the NS control?
Both voluntary and involuntary responses.
How does the NS function?
- Receives sensory information from the external and internal environment.
- Processes information and coordinates.
- Organises a response to information.
What are the major divisions of the NS?
Central nervous system (CNS) and the Peripheral nervous system (PNS)
Sensory neurons (in PNS)
Afferent pathways, receives and carries sensory information to the CNS. ( PNS - CNS )
Motor neurons (in PNS)
Efferent pathways, carries messages from the CNS to the skeletal muscles, organs and glands to stimulate activity. ( CNS - PNS )
Interneurons (in CNS)
Relay messages between sensory and motor neurons.
What is the CNA comprised of?
Brain and Spinal cord
The Brain
- an organised network of neurons where certain areas and structures have specialised functions.
- receives and processes sensory information from the environment, controlling all bodily actions and functions.
Spinal cord
- the long, thin bundle of nerve tissue that extends from the base of the brain to the lower back ( links brain to PNS )
- receives sensory information from the body and sends these messages ( via the peripheral NS ) to the brain for processing.
- receive motor information from the brain and send these messages to relevant parts of the body to control muscles, glands and internal.
What is the peripheral NS comprised of?
- All the nerves and neurons within the body that are outside of the CNS.
- The nerves and neurons the brain and spinal cord, and connect with muscles, organs and glands.
- has 2 subdivisions, Somatic NS and Autonomic NS ( ANS )
Main functions?
- carries sensory information to the CNS from the body’s muscles, organs and glands (internal) and from the sensory organs (externals).
- carries motor information from the CNS to the body’s muscles, organs and glands.
Somatic Nervous system
initiates skeletal muscle movement and allows us to perform conscious or voluntary movement.
Comprised of?
neurons that carry sensory information to the CNS and motor information from the CNS
Main functions
- carries sensory information detected by sensory receptors in the body ( skin ), along sensory pathways via to the CNS.
- carries motor information from the CNS, along motor pathways to skeletal muscles to control voluntary movements.
TEMPLATE RESPONSE
Sensory receptors in the ______ ( sense organ ) detect the ________ ( stimulus ) and transfer the sensory information to sensory neurons in the peripheral nervous system ( somatic NS ) to the brain ( in the CNS ), via the spinal cord. The brain processes the sensory information and coordinates/initiates a motor response to _______ ( voluntary behaviour ) which is relayed to motor neurons in the peripheral nervous system ( somatic NS ) to the skeletal muscles/effector in ___________ ( body part ), causing them to contract/relax and allowing the conscious/voluntary action of ____________________.
What are neurons?
Individual nerve cells that are specialised to receive, process and/or transmit information.
What is the function of dendrites?
Contain receptor sites which receive specific neurochemicals from the pre-synaptic neuron and transmits it to the cell body.
What is the role of the cell body (soma)?
Integrates information received from the pre-synaptic neurons and generates an action potential.
What does the axon do?
Conveys the neural impulse away from the cell body towards the axon terminals.
What is the function of the myelin sheath?
Speeds up neural transmission and protects the axon.
What are axon terminals?
Contains synaptic vesicles that hold neurochemicals.
What is the synaptic gap?
Space between pre and post synaptic neuron where neurochemicals are released into.
What is a synapse?
Includes axon terminal of pre-synaptic neuron, synaptic gap, and dendrites of post synaptic neuron.
What are neurochemicals?
Chemical messages that transmit information within the nervous system.
What is an excitatory neurotransmitter?
Makes the post synaptic neuron more likely to fire an action potential.
Example: glutamate, which is involved in learning and memory.
What is an inhibitory neurotransmitter?
Makes the post synaptic neuron less likely to fire an action potential.
Example: GABA, which fine tunes neurotransmission in the brain.
What are neuromodulators?
Neurochemicals that are released into the neural tissue in brain regions, which alter the strength of the signal transmission, and affect entire brain regions.
What is dopamine?
A neuromodulator primarily responsible for voluntary motor movement, the experience of pleasure, reward-based learning, and motivation.
