Biopsychology Flashcards
Nervous system
Complex network of nerve cells that carry messages to and from the brain and spinal cord to the different parts of the body
Central Nervous system
Receives info and processes it to bring about responses
Controls behaviour and the regulation of the body’s physiological processes
Spinal cord
Collection of nerves collected to the brain - relay signals from brain to body
Peripheral Nervous System
All nerves outside the CNS
Automatic nervous system
Actions without conscious control e.g. heart beating, digestion
This is necessary as these vital bodily functions would not work as efficiently if we had to think about them
Somatic Nervous System
Receives signals from CNS directly muscles to act
Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves
Sympathetic nervous system
‘Fight or flight’ Adrenaline released Heart rate increases Blood pressure increases Pupils dilate Digestion halted Inhibits saliva production
Parasympathetic Nervous system
‘Rest and digest’ - involved with energy conservation Heart rate slows Digestion increases Constricts pupils Stimulates saliva production Decreases breathing rate
Neurons
Specialised cells that carry electrical impulses to and from the CNS
What does action potential create
An electrical signal travelling down the axon of a neuron
What is the CNS made up of
Brain
Spinal cord
What is the PNS divided into
Somatic nervous system
Automatic Nervous system
What’s the ANS divided into
Parasympathetic Nervous system
Sympathetic nervous system
Sensory neurons
Carry nerve impulses from sensory receptors (PNS) to the spinal cord and brain (CNS) in the form of neural impulses
Some of these neurons only take info to the spinal cord
Relay neurons
Transfer impulses from the sensory to the motor neurons
These neurons all lie within the brain or spinal cord
Motor neurons
Originate in CNS and project their axons outside CNS
Deliver impulses from the CNS to the PNS
Form synapses with muscles to control contraction
When they are excited they cause contraction, when inhibited cause muscle relaxation
Cell body (soma)
Contains nucleus
Controls neuron
Dendrites
Receive signals from other neurons
Axon
Long thin extension of cytoplasm where the action potential travels down
Myelin sheath
Insulates axon (fatty layer) Speeds up electrical impulse
Nodes of Ranvier
Section of axon without myelin sheath
Impulse jumps along the nodes
Terminal button
End of neuron forms synapses with other neurons or an effector
When does an action potential occur
When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second, causing an action potential to occur
Synaptic transmission
Action potential arrives at the end of pre-synaptic neuron
Neurotransmitter in vesicles is released into synapse
Neurotransmitter diffuses across synapse
Neurotransmitter binds to specific receptors on the post synaptic neuron
A post synaptic potential is generated
Neurotransmitter is removed from synapse by enzymes or is taken back to be reused
Types of neurotransmitters
Excitatory or inhibitory
These generate either excitatory post synaptic potential (EPSPs) or IPSPs
What will a post-synaptic neuron often receive
Several presynaptic inputs. EPSPs increase the likelihood of the neuron firing an action potential, IPSPs decreases the likelihood
Types of summation
Spatial
Temporal
Spatial summation
Multiple pre-synaptic neuron firing
High conc. of neurotransmitter in synapse
Strong EPSP in post-synaptic neuron
Temporal summation
One pre-synaptic neuron with lots of action potential travelling down it
Examples of excitatory neurotransmitter
Acetylcholine
Noradrenaline
Examples of inhibitory neurotransmitters
Serotonin
GABA
What are inhibitory neurotransmitters reponsible for
Calming the mind and body
Inducing sleep
Filtering out unnecessary excitatory signals
Endocrine system
Network of glands throughout the body that manufacture and secrete chemical messengers (hormones)
Uses blood vessels to deliver hormones
Major glands of endocrine system
Pituitary
Adrenal
Ovaries
Testes
Hormones produced by anterior pituitary
Adrenocorticotropic hormone (ACTH) Luteinising hormone (LH) Follicle Stimulating hormone (FSH) Prolactin (PRL) Growth hormone (GH)
Hormones produced by posterior pituitary
Anti-diuretic hormone (ADH)
Oxytocin
Hormones produced by Adrenal cortex
Cortisol
Aldosterone
Both necessary for life
Cortisol
Release in response to stress
Suppressed immune system
Increases blood sugar
Aldosterone
Regulates Na, blood pressure and K levels
Hormones produced by Adrenal Medulla
Adrenaline
Noradrenaline
Fight or flight
Stressor —> amygdala —> (distress signal); Hypothalamus —> multiple responses via sympathetic nervous system
Response to acute stressors
Triggers SNS
SNS sends a signal to Adrenal medulla - releases adrenaline into the bloodstream
When the threat has passed PNS returns body to resting state
It works in opposition to the SNS
Response to chronic stressors
Hypothalamus - Releases CRH into bloodstream
Pituitary glands - CRH causes ACTH to be produced and released. Transported in bloodstream to target site
Adrenal glands - ACTH stimulates Adrenal cortex to release various hormones e.g. cortisol, can have -ve or +ve affects e.g. impaired cognitive performance or bursts of energy
The feedback system
Cortisol levels are monitored by the hypothalamus and pituitary gland. If it rises, a reduction in CRH and ACTH is initiated
Holistic theory
All parts of the brain were involved in the processing of thought and action
Localisation of function
Theory that the different areas of the brain are responsible to different functions
Cerebral cortex
Outer layer of both hemispheres - this covers the inner parts of the brain
Cortex found in frontal lobe
Motor cortex
Motor cortex
Controls voluntary movement in the opposite side of the body
Damage to frontal lobe
Loss of control over fine motor movement
Somatosensory cortex
Found in parietal lobe
Where sensory info from the skin is represented
Damage to parietal lobe
Loss of sense of touch, vibration and temperature
Visual cortex
Occipital lobe
Each eye sends info from the right visual field to the left and from the left visual field to the right
Damage to occipital lobe
Can produce blindness in the right visual field of both eyes
Auditory cortex
Temporal lobe
Analyses speech-based info
Damage to temporal lobe
Partial hearing loss
The worse the damage, the more extensive the loss
Broca’s Area
Frontal lobe (left hemisphere)
‘Language centre’
Critical for speech production and responding to demanding cognitive tasks
Damage to Broca’s area
Unable to speak nor express thoughts in writing
Wernicke’s Area
Left part of temporal lobe
Processes spoken lang. and helps understand speech
Broca’s aphasia
Frequently speak in short phrases
Omit small words, “is”, “and”, “the”
Typically understand speech of others fairly well
Wernicke’s aphasia
Speak in long sentences with no meaning, unnecessary words and create made up word
Difficult to understand them
Great difficulty understanding speech
Unaware of mistakes
What has split-brain research discovered
Left hemisphere is responsible for speech and language
Right hemisphere specialises in visual-spatial processing
Connectivity between different regions is as important as the different parts
Brain plasticity
Ability to change and adapt as a result of experience and new learning
Functional recovery
Moving functions from a damaged area of the brain after trauma to other undamaged areas
Spontaneous recovery - quickly after trauma
Rehabilitative therapy - several weeks or months later to further recovery
Hippocampus
Part of brain associated with the spatial and navigational skills
Maguire et al (2000)
Found hippocampus is 28% bigger in London taxi drivers that have taken ‘The Knowledge’
Michelli et al (2004)
Found bilinguals have a larger parietal cortex
Wall (1977)
‘Dormant synapses’ - synaptic connections that exist anatomically but their function is blocked
Increasing the rate of neural input to these synapses can open or unmask them
Structural changes that support opening ‘dormant synapses’
Axonal sprouting - growth of new nerve endings with other undamaged nerve cells to form new neuronal pathways
Reformation of blood vessels
Recruitment of homologous areas
