Biopsychology Flashcards
what is the Nervous System?
a specialised network of cells in the body that has two main functions: - to collect, process and respond to information from the environment
- to coordinate the working of different organs and cells in the body.
what are the two sub-systems of the nervous system?
- the central nervous system
- the peripheral nervous system
what is the central nervous system?
it is made up of the brain, which is responsible for all conscious decisions and awareness. and the spinal cord, which is responsible for reflex arcs. the CNS passes messages to and from the brain and orchestrates complex demands and decisions.
what is the peripheral nervous system?
sends information from the outside world to the CNS and from the CNS to the body. it is divided into the atonomic nervous system (ANS) and the somatic nervous system (SNS)
what is the somantic nervous system?
transmits information from receptor cells in organs such as the eyes to the CNS it also receives information that instructs the muscles to act (from the CNS) - a conscious process
what is the autonomic nervous system?
it governs vital functions in the body such as breathing and heart rate. it is automatic and operates involuntarily. it consists of the sympathetic nervous system and the parasympathetic nervous system.
what is the endocrine system?
one of the bodies major information systems that instructs glands to release hormones directly into the bloodstream. these hormones are carried toward target organs in the body.
what is a gland?
an organ that synthesises and releases substances such as hormones.
what is the fight or flight response?
the bodies stress response - when a threatening stimulus is detected the body enters a state of physiological arousal in order to fight or flee.
what is adrenaline?
a stress hormone produced in the adrenal gland that causes an increased heart rate, dilated pupils, diverted bloodflow to muscles etc.
what happens during the fight or flight response?
the bodies normal state is the parasympathetic state - when triggered by a stimulus the hypothalamus triggers the sympathetic branch of the ANS. This causes the adrenal medulla to release adrenaline into the bloodstream which readies the body for action.
what is a neuron?
nerve cells which transmit chemical and electrical messages. there are 100 billion in the human nervous system and 80% of these are in the brain.
what are the three types of neuron?
motor neuron, sensory neuron and relay neuron.
what is a sensory neuron?
carry messages from the PNS to the the CNS. they have long dendrites and short axons.
what is a relay neuron?
connect sensory neurons to motor neurons - they have short axons and short dendrites.
what is a motor neuron?
connect the CNS to effectors such as muscles or glands to cause a response. they have short dendrites and long axons.
what is the structure of a neuron?
dendrites carry signals to the cell body or soma that contains the nucleus of the cell. the axon then carries the signal away towards other neurons. the axon is covered by an insulating myelin sheath that speeds up transmission. gaps in the myelin sheath called nodes of ranvier also speed up transmission. terminal buttons at the end of the axon connect to the dendrites of other neurons.
what is action potential?
the inside of a neuron is usually negative. when a neuron fires it becomes positive for a split second - this is an action potential and is what generates the electrical impulse.
what is synaptic transmission?
the process by which neurons communicate with each other by passing chemicals across a synapse. from the pre synaptic terminal to the post synaptic receptor sites.
what is a neurotransmitter?
brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another. neurotransmitters can be broadly divided into those that perform excitatory functions and those that perform inhibitory functions.
what is excitation?
when a neurotransmitter such as adrenaline, increases the positive charge of a neuron, increasing the likelihood that it will fire.
what is inhibition?
when a neurotransmitter such as seratonin makes the charge of the post synaptic neuron more negative. this decreases the likelihood that the neuron will fire.
what is holistic theory?
that all parts of the brain are responsible for all behaviour, thoughts and actions.
what is localisation of function?
the theory that different parts of the brain are responsible for different behaviours.
what is the basic structure of the brain?
two hemispheres, left and right (in general the left hemisphere controls the right side of the body and vice versa) the outer layer of the brain is called the cerebral cortex, which is around 3mm thick.
what are the four lobes of the brain?
the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.
where and what is the motor area?
an area at the back of the frontal lobe in both hemispheres that controls voluntary movement in the opposite side of the body.
where and what is the somatosensory area?
an area at the back of the parietal lobe that processes sensory information such as touch.
where and what is the auditory area?
an area in the temporal lobe that is concerned with the analysis of speech based information.
where and what is the visual area?
a part of the occipital lobe that processes visual information.
where and what is Broca’s area?
an area of the frontal lobe in the left hemisphere that is responsible for the production of speech.
what can damage to Broca’s area do?
it means that patients fully understand speech but cannot produce it - such as ‘Tan’ named so because he could only produce the word tan.
what and where is Wernicke’s area?
an area of the temporal lobe (encircling the auditory cortex) in the left hemisphere responsible for language comprehension.
what can damage to Wernicke’s area do?
it results in Wernicke’s aphasia where speech is fluent but nonsensical as the patient can produce language but not comprehend the meaning of language.
what is the brain scanning evidence for localisation?
- Petersen et al. used brain scans to show that Broca’s area was active during reading tasks and Wernicke’s area was active during listening tasks.
- Tulving’s study of memory found that semantic memories were stored in the left prefrontal cortex whereas episodic memories were stored in the right.
what is the neurosurgical evidence for localisation?
- lobotomy such as cingulotomy (severing the cingulate gyrus) is still sometimes used to treat severe OCD or depression. Dougherty studied 44 patients who had undergone the procedure and found that a third had achieved successful results.
how does the case of Phineas Gage support the theory of localisation?
he had an accident where a piece of metal was driven through his frontal lobe - he survived but his personality was greatly changed - therefore we can assume that the frontal lobe is responsible for regulating personality.
what counter argument to localisation of function does Lashley provide?
he suggested that higher cognitive processes such as learning were holistic. to test this he systematically removed parts of rats cortex as they were learning a maze - he found that no single area had a greater effect than any other.
what is plasticity?
this describes the brains tendency to change and adapt as a result of experience and learning.
what is functional recovery?
a form of plasticity, following damage through trauma, the brains ability to redistribute or transfer functions usually performed by the damaged area to other, undamaged areas.
what is synaptic pruning?
when we are 2-3 the amount of synaptic connections we have in our brain peaks at 15,000 - adults have around half this so as we grow the less used synaptic connections are deleted and frequently used ones are strengthened.
what is some research that has been done into plasticity?
- maguire et al. took images of taxi drivers brains and compared to a matched control group found that the grey matter of their hippocampus was enlarged. this is the area involved with spatial processing and navigational skills.
- Draginski et al. took images of medical students brains before and after medical exams. they found changes in the parietal cortex and posterior hippocampus - as a result of the exam.
