Biopsych definitions

Peripheral nervous system

Sends information to the CNS from the outside world, and transmits messages from the CNS to muscles and glands in the body

Somatic nervous system

Transmits information from receptor cells in the sense organs to the CNS. It also receives information from the CNS that directs muscles to act

Sensory neurons

• Carry messages from the PNS to the CNS

• Long dendrites and short axons

Relay neurons

• Connect the sensory neurons to the motor or other relay neurons

• Short dendrites and short axons

Motor neurons

• Connect the CNS to effectors like muscles and glands

• Short dendrites and long axons

Excitation

When a neurotransmitter increases the positive charge of the postsynaptic neuron => this increases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Inhibition

When a neurotransmitter increases the negative charge of the postsynaptic neuron => this decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Localisation of function

The theory that different areas of the brain are responsible for specific behaviours, processes or activities

Hemispheric lateralisation

The 2 hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other

Plasticity

The brain’s tendency to change and adapt as a result of experience and new learning. This generally involves the growth of new connections

Functional recovery

A form of plasticity. Following damage through trauma, the brain’s ability to transfer functions usually performed by a damaged are to other undamaged areas

Biological rhythms

Distinct patterns of changes in body activity that conform to cyclical time periods. Bio rhythms are influenced by endogenous pacemakers as well as exogenous zeitgebers

Circadian rhythms

Bio rhythms, subject to a 24-hour cycle, which regulate a number of body processes such as the sleep/wake cycle and changes in core body temperature

Infradian rhythm

A type of bio rhythm with a frequency of less than one cycle in 24 hours, such as menstruation and seasonal affective disorder

Ultradian rhythm

A type of biological rhythm with a frequency of more than one cycle in 24 house, such as the stages of sleep (sleep cycle)

Endogenous pacemakers

Internal body clocks that regulate many of our biological rhythms, such as the influence of the suprachiasmatic nucleus (SCN) on the sleep/wake cycle

Exogenous zeitgebers

External factors that affect or entrain our bio rhythms, such as the influence of light on the sleep/wake cycle