Psyc CH2 - The nervous system

Glossary Terms

Nervous system

Nervous system

Consists of:

• Central nervous system CNS (brain, spinal cord)

• Peripheral nervous system PNS (Somatic nervous system, Autonomic nervous system [Enteric division-digestive, Sympathetic, Parasympathetic)

Central nervous system (CNS)

A major division of the nervous system comprising of the brain and spinal cord, which receives neural messages from and transmits neural messages to the peripheral nervous system.

Brain

A complex organ contain within the skull that coordinates mental processes and behavior, and regulates bodily activity.

Spinal cord

A cable of nerve tissue that extend from the brain, connecting it to the peripheral nervous system.

Peripheral nervous system

A major division of the nervous system comprising every neuron in the body outside the central nervous system.

Somatic nervous system

A division of the peripheral nervous system that transmits neural messages related to voluntary motor movement.

Skeletal Muscles

Muscles connected to the skeleton that carry out voluntary motor movements

Autonomic nervous system

A division of the peripheral nervous system that regulates visual muscles, organs, and gland and transmits neural messages to central nervous system about activity

Visceral muscles, organs, and glands

muscles, organ and glands not connected to the skeleton that are predominantly self-regulating and do not require conscious control

Sympathetic nervous system

a division of the automimic system that activates visceral muscles, organs and glands preparing the body to respond to a threat or a stressor (flight, fight, freeze)

Parasympathetic nervous system

A division of the autonomic nervous system that maintains the optimal and balanced functioning of visceral muscles, organs, and glands (homeostats)

Neuron

A nerve cell that receives and transmits neural information

Motor neurons (efferent neurons)

Neurons thar transmits neural messages about motor movements form the central nervous system to the peripheral nervous system

Sensory neurons (afferent neurons)

Neurons that transmit neural messages about bodily sensations from the peripheral nervous system to the central nervous system.

Interneurons

Neurons that transfer neural messages between sensory neurons and motor neurons.

Conscious responses

A deliberate and voluntary action that is initiated by the brain and the performed intentionally by the body

Sensory receptor

A nerve ending that detects internal sensations in the body and external sensations from the environments

unconscious responses

An automatic action that is performed by the body independently of the brain

Spinal reflex

An unconscious response to sensory stimuli that is initiated by interneurons on the spinal cord independently of the brain

Reflex arc

The path along which the neural signal is the transmitted as part of the spinal reflex

Glutamate (excitatory)

Helps the formation and retrieval of memory hence enables learning as a result

GABA Gamma-Amino Butyric Acid (Inhibitory)

It is associated with calming feelings of stress anxiety or fear

Serotonin

A neuromodulator that is involved in mood stabilization

Dopamine

A neuromodulator primarily responsible for voluntary movement, the experience of pleasure, and reward based learning

Synaptic Plasticity

The ability of synaptic connections to change over time in response to activity or experience

Sprouting

The ability of dendrites or axons to develop new extensions or branches

Rerouting

The ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron

Pruning

The elimination of synaptic connections that are not adequately activated

Long-term Potentiation

The long lasting and experience dependent strengthening of synaptic connections that are regularly activated

Long-term Depression

The long lasting and experience dependent weakening of synaptic connections between neurons that are not regularly activated

What happens when you step on a pin

Spinal reflex - unconscious response

Sensory receptors - Detect sensory stimuli, neural information travels to spinal cord

Spinal cord - transmits neural information from sensory to motoneurons via interneurons

Motorneural - information is transmitted to the muscle of the leg, results in a flinch

Roles of Serotonin as a neuromodulator

• modifies the effects on neural transmitters

• Slow release with long lasting effects

• controls the release of neural transmitter