Biopsychology key terms

Types of neuron

Motor, sensory, relay

Motor neuron

Carries messages from CNS to muscles and glands

Sensory neurons

Carry messages from PNS to CNS

Relay neurons

Carry messages from sensory to motor neurons, or other relay neurons

Structure of neurons

Each neuron contains a cell body, dendrites which carry nerve impulses towards the cell body, an axon covered in myelin sheath to speed up the message, and terminal buttons that communicate with the next neuron in the chain

Synapse

Neurons do not physically touch each other but are separated by a gap called the synapse

Neurotransmitter

When the electrical signal reaches the end of a neuron synaptic vesicles release neurotransmitters which relay the signal across the synapse

Excitation

Makes it more likely that the next neuron will fire

Inhibition

Making it less likely that the next neuron will fire

Axon

Carries the impulses away from the cell body down the length of the neuron, is covered in a fatty layer of myelin sheath that protects the axon and speeds up electrical transmission of the impulse

Effector

Something such as a muscle or gland which produces a response

Neural networks

Groups in which neurons communicate with each other

Synaptic vesicles

Tiny sacs that release neurotransmitters

Postsynaptic receptor site

The dendrites of the next neuron

Serotonin

Neurotransmitter that causes inhibition in the receiving neuron

Dopamine

Neurotransmitter that causes excitation in the receiving neuron

Summation

The likelihood of the cell firing, calculated by adding up the excitatory and inhibitory synaptic inputs.

Nervous system

The nervous system id divided into the central nervous system (CNS) and the peripheral nervous system (PNS)

Central nervous system

The CNS is made up of the brain and the spinal cord

Peripheral nervous system

The PNS is made up of the autonomic nervous system (ANS) and the somatic nervous system (SNS)

Autonomic nervous system

The ANS is further split into the sympathetic branch and parasympathetic branch

Endocrine system

Consists of a number of glands that send chemical messages called hormones throughout the bloodstream

Fight or flight

During stress, the endocrine system and sympathetic branch of the ANS work together to product the fight or flight response (physiological changes such as increased heart rate)

Somatic nervous system

Information to and from the senses and to and from the nervous system

Sympathetic nervous system

Generally increases bodily activities

Parasympathetic nervous system

Generally maintains or decreases bodily activities

Spinal cord

Receives and transmits information to and from the brain

Brain

Maintains life, involved in higher functions and psychological processes

Cerebral cortex

The brains outer layer which is highly developed in humans, distinguishing our higher mental functions from that of animals

Glands

Organs in the body that produce and secrete hormones to regulate many bodily functions

Pituitary gland

The major endocrine gland located in the brain, which controls the release of hormones from all the other endocrine glands in the body

Adrenaline

Released in the adrenal gland, triggers the fight or flight response in a stressful situation

Testosterone

Released in the testes, causes the development of tested in the womb, as well as creating secondary sexual characteristics during puberty

Oestrogen and progesterone

Released in the ovaries, helps to regulate the menstrual cycle. Oestrogen is involved in repairing and thickening the uterus lining whilst progesterone maintains the uterine lining

Melatonin

Regulates the sleep-wake cycle. High levels of melatonin cause drowsiness when daylight is low.

Adrenal medulla

The inner core of the adrenal glands that releases adrenaline in a fight or flight response.

Localisation of function

Different areas of the brain are responsible for different behaviours, processes or activities

Motor area

Frontal lobe, involves in regulating movement

Somatosensory area

Parietal lobe, processes sensory information such as touch

Visual area

Occipital lobe, receives and processes visual information

Auditory area

Temporal lobe, analyses speech-based information

Language areas

Broca’s areas, frontal lobe in the left hemisphere, speech production.

Wernike’s area, temporal lobe in the left hemisphere, language comprehension

Auditory Cortez

In both hemispheres, receives information from both ears which is about what sound is and its location

Motor cortex

Generates voluntary motor movements, located at the back of the frontal lobe in both hemispheres

Somatosensory cortex

Lies next to the motor cortex in the brain, where sensory information from the skin is represented. The somatosensory cortex from one side of the brain receives sensory information from the opposite side of the body

Visual cortex

There are two, one in each hemisphere, in the occipital lobe. Each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex

Area V1

An area which seems to be necessary for visual perception. Individuals with damage to this area report no vision.

Hemispheric lateralisation

Certain mental processes and behaviours are controlled or dominated by one hemisphere rather than the other (such as language)

Split brain studies

Corpus callosum cut in patients with severe epilepsy, allowing researchers to investigate the extent to which brain function is lateralised

Procedures

Image/word is projected to the right visual field (RVF) or left visual field (LVF)

Describing what you see

Pictures shown to the RVF could be described but not those to LVF because there are no language centres in the left hemisphere

Recognition by touch

Could not describe objects projected to LVF but able to select a matching objectfrom a selection of different objects using their left hand

Corpus callosum

The bridge across the two hemisphere of the brain, so that the two hemispheres can exchange information

fMFI

Measures brain activity by detecting associated changes in blood flow

EEG

A record of the brain wave patterns produced by neurons, producing characteristic patterns

ERPs

Isolating specific responses of neurons to specific stimuli or tasks

Post mortem examinations

Correlating behaviours before death with brain structures after death

Plasticity

Brain’s tendency to change and adapt (functionally and physically) as a result of experience and new learning

Functional recovery

A form of plasticity, the brains ability to redistribute or transfer functions following damage through trauma

Synaptic pruning

As we age, rarely used connections are deleted and frequently used connections are strengthened

Axonal sprouting

Undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed

Recruitment of homologous areas

Regions on opposite sides of the brain take on functions of damaged areas

Axon sprouting

The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

Factors affecting recovery of the brain after trauma

Age

Gender

Physical exhaustion

Stress

Alcohol consumption

Biological rhythms

The natural cycle of change in our body’s chemicals or functions. These are governed by two things- the body’s internal body clocks (endogenous pacemakers) and external changes (exogenous zeitgebers)

Circadian rhythms

A cycle in biological or psychological activity that occurs over 24 hours. These include hormone production, the sleep-wake cycle and core body temperature

Infradian rhythms

Rhythms that last more than 24 hours, such as the menstrual cycle

Untraditional rhythms

Biological rhythms lasting less than 24 hours, such as eye blinking, heartbeats, sleep patterns, breathing, pulse, appetite

SCN

The superchiasmatic nucleus- a bundle of nerve cells located in the hypothalamus, plays an important role in maintaining circadian rhythms, such as the sleep/wake cycle

Examples of exogenous zeitgebers

Light, social cues