Biopsychology Flashcards
What is the nervous system?
A specialised network of human cells in the human body.
Our primary internal communication system
What is the CNS made of?
Brain and spinal cord
What is the role of the CNS?
Processes info from the PNS and sends out signals to the PNS via the spinal cord
What is the role of the spinal cord?
Reflex actions
What is the PNS?
Made up of Autonomic and somatic nervous system
What is the role of the PNS?
Gathers information and sends to the CNS and to receives info from the CNS
What is the role of the Somatic nervous system?
Govens muscle movement
Responsible for carrying sensory and motor info to and from the spinal cord
Is the somatic nervous system under conscious or unconscious control?
Conscious- as receives signals via motor neurons from brain to initiate skeletal muscles
What is the role of the autonomic nervous system?
Governs vital functions-breathing, heart rate, digestion
Is the autonomic nervous system under conscious or unconscious control?
Unconscious control-automatic
What is the endocrine system?
One of the body’s major info system that instructs glands to release hormones into bloodstream. These can be carried to larger organs.
Describe the Pineal Gland
Involved in our circadian s/w cycle, produces melatonin and serotin to keep us drowsy/ awake
Describe the Adrenal Medulla
Involved in the sympathetic state, above the kidneys.
Releases adrenaline
Describe the thyroid gland
Located in the neck
Releases hormone thyroxine, that affects metabolic rate.
What is the role of the nervous system
To collect, process and respond to information in the environment
To coordinate the working of different muscles and cells
What is the function of Sensory neurons?
Carry messages from the PNS to the CNS.
What is the structure of a sensory neuron?
Found in PNS
Long dendrites, short axons
What is the structure of a Relay neuron?
Found in CNS
Short dendrites, short axon
What is the structure of a motor neuron?
Short dendrites, long axon
Found in PNS
What is the function of Relay neurons?
These connect sensory neurons to motor or other relay neurons
What is the function of motor neurons?
These connect CNS to effectors (muscles/glands)
Describe the reflax action that would occur after touching a hot pan.
Heat detected in skin receptors in hand, the signal is sent via sensory neurons (in PNS) to the CNS). The signal is passed onto relay neurons in the spinal cord. Once in the spine the signal is immediately sent out of the CNS via the relay neurons to the motor neurons (PNS). The motor neurons then connect to muscles to initiate hand movement off the pan.
Outline the process of synaptic transmittion
An electrical impulse travels along the axon of the transmitting neurone
This triggers the nerve-endings on the pre-synaptic neuron to release neurotransmitgters from vesicles
These chemicals diffuse across the synapse and bind to receptor sites on the membrane of the post-synaptic neuron
The receptor molecules on the post-synaptic neuron bind only to specific chemicals released from the first neuron. This stimulates the post neuron to transmit the electrical impulse.
The neurotransmitter is reabsorbed in the vesicles of the pre-synaptic neuron after it has performed its function of transmitting a neuronl impulse.
What is meant by excitatory?
When a neurotransmitter increases the positive charge of the post synaptic neuron. This increases the likelihood that the post-synaptic neuron will fire.
What is meant by inhibitory?
When a neurotransmitter increases the negative charge of the post-synaptic neuron. This decrease the likelihood that the neuron will fire.
Name an excitoray neurotransmitter
Adrenaline
Explain summation of charge
The total charge on the post-synaptic neuron. This excitary + inhibtory influences are summed: If the net effect on the post-synaptic neuron is inhibitory, the neuron won’t fire. If the net effect is excitorty, the neuron will fire.
Therefore the AP of the post-synaptioc neuron is only triggered if the sum of the E+I signals at any one time reaches the threshold.
Name a inhibitory neurotransmitter
Serotonin
Describe what is meant by an action potential
When a neuron is in a resting state the inside of the cell is negatively charged. When a neuron becomes actived by a stimulus the inside of the cell becomes positively charged for a spilt sec causing an ap occur
Why are action potentials unidirectional?
- Synaptic vescicles containing neurotransmitters are only presnt on presynaptic membrane
- receptors for neurotransmitter only on post-synaptic
- Can only diffuse from high to low concentration (only pre–>post)
Describe an EEG
a record of the tiny eletrical impulses produced by the brains activity. It works by measuring the eltrical activity in the brain via electrodes that are fixed to an individuals scalp using a skull cap. The scan recording represents the brains wave pattern that are generated from the action of thousands of neurons providing an overall account of brain activity.
What is a strength of an EEG? (AO3)
High practical value, used to diagnose epilepsy/sleep disorders
What is a limitation of an EEG? (AO3)
EEG signal not useful in pinpointing the exact source of neural activity, doesn’t allow researcher to distinguish between activities originating in different but adjacent locations- low spatial resolution
Describe an ERP
The electrophysical response of the brain to specific sensory, cognitive or motor event that can be isolated through the statistical analysis of an EEG. ERPs emerge only after many individual presentations of the stimulus of intrest are averaged together
What is a strength of an ERP (AO3)?
Cancels out noise + enhances the voltage response to the stimulus making it out clearly from the averaged out background
What is a limitation of an ERP (AO3)?
Lack of standardisation, methodogly differs between research studies so hard to confirm findings
Describe an FMRI
A method used to measure brain activity while s person is performing a task. It works by detecting the changes in blood oxygenation + flow that occurs as a result of neural activity in specific parts of the brain. When a brain area is more active it consumes more O2 + to meet this increased need, blood flow is redirected to the active area(haemodynamic response) allowing researches to detect specific brain regions.
What is a strength of a FMRI scan? (AO3)
Non-invasive, risk free, no radiation
What is a limitation of a FMRI scan(AO3)?
Poor temporal resolution due to 5 second time lag behind image on screen +initial firing of neural activity
Describe Post-mortem Examinations
The brain is analysed after death to determine whether certain observed behaviour during the persons lifetime can be linked to structural abnormalities in the brain when compared to a neurotypical. Carried out in a typical cases, may measure/ weigh/ look under microscope
What is a limitation of Post-mortem Examination(AO3)?
Issues with cause and effect as any observed damage cant be determined conclusively as a cause of any deficits
What is a strength of Post-mortem Examinations(AO3)?
Vital for early understanding of the brain-Broca/ Wernicke established links relaying on the method
What are biological rythms?
Distinct pattens of changes in the body activity that conforms to cyclical time periods
What is an ultradian rhythm?
a type of biological rhythm with a frequency of more than one in 24hours
Sleep cycle
What is an infradian rhythm?
A type of biological rhythm with a frequency of less then one cycle in 24hrs.
SAD
What are exogenous zeitgebers?
external cues in the environment that may affect or entrain our biological rhythms