Unit 3, Aos 1, Dp 1 Flashcards
Main functions of NS
- receive information
- process information
- coordinate a response
CNS
a major division of the nervous system comprising the brain and spinal cord, which receives neural messages from and transmits neural messages to the peripheral nervous system
CNS functions
- processes information from the internal and external environment
- formulates responses to this information
Brain
a complex organ contained within the skull that coordinates
mental processes and behaviour, and regulates bodily activity
Brain functions
● Often considered to be the ‘control centre’
● Controls physiological and psychological processes
● Enables you to perceive, interact with, and respond to the world around you
Spinal cord
a cable of nerve tissue that extends from the brain, connecting
it to the peripheral nervous system
Spinal cord functions
● Encased by the spinal column (backbone/spine)
● If severed, all movement and sensation below is lost
● Composed of afferent tracts - transmitting sensory messages from the PNS to the brain
● Composed of efferent tracts - transmitting motor messages from the brain to the PNS
● Therefore is the route via which neural information travels between the brain and the body
Peripheral Nervous System
a major division of the nervous system comprising every
neuron in the body outside the central nervous system
Peripheral Nervous System functions
● Transmits neural messages between the CNS and the body
● These neurons are outside the brain and spinal cord - therefore in the periphery of your body
● Connects the CNS with your external world
Subdivisions of PNS
- Somatic
- Automatic
Somatic Nervous System
a division of the peripheral nervous system that transmits
neural messages related to voluntary motor movement
Somatic Nervous System Functions
● Comprises:
○ sensory neural pathways, which are made up of sensory
neurons.
○ motor neural pathways, which are made up of motor neurons
● Transmits neural messages between sensory receptors, the CNS and skeletal muscles
Autonomic Nervous System
a division of the peripheral nervous system that regulates visceral muscles, organs, and glands, and transmits neural messages to the central nervous system about their activity
Autonomic Nervous System functions
● The visceral muscles, organs and glands are predominantly self-regulating and do not require conscious control
● Involved in unconscious responses
● The visceral muscles, organs and glands that are controlled by the autonomic nervous system are →
○ However! Sometimes we can control these things too i.e. slowing your breathing down
Autonomic Nervous System subdivisions
- The Sympathetic Nervous System
- The Parasympathetic Nervous System
Sympathetic Nervous System
a division of the autonomic nervous system that activates
visceral muscles, organs, and glands, preparing the body to respond to a threat or stressor
Sympathetic Nervous System functions
● Dominates in emergencies and stressful situations i.e. fight-flight response
● Organs and glands are activated in specific ways help energise the body and be better able to deal with a threat or stressor or engage in high levels of physical activity
Parasympathetic Nervous System
a division of the autonomic nervous system that maintains the
optimal and balanced functioning of visceral muscles, organs, and glands
Parasympathetic Nervous System functions
● Dominates in a relaxed state i.e. rest and digest
● Two main functions
○ Responsible for maintaining optimal levels i.e. homeostasis
○ It also returns the body to balanced and ideal levels of
functioning after the heightened arousal of a sympathetic
response
Neuron
a nerve cell that receives and transmits neural information
Sensory neuron
(also known as afferent neurons) neurons that transmit information (sensory neural messages) about the body’s
sensations from the PNS to the CNS
Motor neuron
(also known as efferent neurons) neurons that transmit information (motor neural messages) about movement from the CNS to the PNS
Interneuron
neurons that transfer impulses between sensory and motor neurons → only in CNS
