Unit 3 (neurobiology) Flashcards
central nervous system
brain and spinal cord
what does the brain do?
processes and relays information
converging
impulses from several neurons group together to form a summation
diverging
an impulse from one neuron go into several neurons e.g fine motor movement (writing)
the brain is composed of…
many interconnecting neurons
parts of the brain
- medulla oblongata
- cerebrum
- cerebellum
- hypothalamus
medulla oblongata
The medulla oblongata is responsible for regulating several basic functions of the autonomic nervous system, including respiration, cardiac function, vasodilation, and reflexes like vomiting, coughing, sneezing, and swallowing
cerebellum
Coordination of voluntary movements. Most movements are composed of a number of different muscle groups acting together in a temporally coordinated fashion.
cerebrum
The cerebrum (front of brain) is composed of the right and left hemispheres, which are joined by the corpus callosum.
what is the outer layer of the cerebrum called?
the cerebral cortex
what is the cerebral cortex
it is the outer layer of the cerebrum
what do the left and right hemispheres of the brain do?
the left hemisphere processes information from the right side visual field and controls the right hand side of the body and the right hemisphere is for the right hemisphere processes information from the left visual field and controls the left of the body
corpus collosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
cerebral cortex functions
sensory
motor
association
higher mental processes
intelligence, language, processing, personality, creativity, imagination and conscience
3 levels of memory
sensory, short term and long term
glieal cells
they produce mylin sheaths and physically support neurons, they are usually found surrounding a neuron
myelin sheath function
the presence of the mylin sheath is to increase the speed at which impulses can be transmitted from node to node along the axon of a neuron. they develop around axon fibres of individual neurons.
myelination
the development of mylin. mylination lasts from birth to adolescence this means that in the first two years of life you’re not as coordinated as an older child would be
Synapse
gap between neurons
what does dopamine do?
it is produced in several regions of the brain when a survival related urge is satisfied e.g hunger, thirst and sexual needs
where are endorphins produced?
in the hypothalamus
what do neurotransmitters bind with?
receptors
what are the two types of receptors?
inhibitory and excitatory
short term memory (STM)
short term memory can only hold a limited amount of information — usually about 7 items at one time (memory span) and the items are only held for a short time.
what happens when information in short term memory isn’t needed?
it is either:
- transferred to LTM
- displaced (pushed out bu new info)
- decays
how do you improve short term memory?
rehearsal - repeating information over and over again
chunking - several units are pushed together to make one meaningful unit e.g 2341 could be remembered as 1234 which is easier to remember
Acetylcholine
A neurotransmitter that enables learning and memory and also triggers muscle contraction
what can recreational drugs do to someones neurochemistry and what is the effect of thus?
the alteration in someone’s neurochemistry may lead to changes in:
- mood
- cognitive thinking
- perception
- behaviour
what effect do recreational drugs have on neurotransmitters?
they can:
- stimulate the release of a natural neurotransmitters
- act as an agonist by initiating the action of a neurotransmitter
- act as a antagonist by binding with receptors and blocking the action of a neurotransmitter
- inhibit the reuptake of a neurotransmitter
- inhibit the breakdown of a neurotransmitter by an enzyme
contextual cues
memory triggers
what is the peripheral nervous system made of?
the somatic and autonomic nervous systems
autonomic nervous system
the part of the peripheral nervous system that controls not voluntary actions for example, the glands and the muscles of the internal organs (such as the heart). it is made of the sympathetic and parasympathetic nervous systems.
somatic nervous system
The somatic nervous system is the part of the peripheral nervous system associated with the voluntary control of body movements
sensory neurons
they are neurons which connect sense receptors to the CNS
inter neurons
(also known as relay, association or connector neurons) they are found in the CNS and and connect with sensory, motor and other inter neurons
inter neurons
(also known as relay, association or connector neurons) they are found in the CNS and and connect with sensory, motor and other inter neurons
Parts of a neuron
cell body, dendrites, axon, myelin sheath
gaps in myelin sheath are called…
nodes
what are neurotransmitters?
chemical messengers that cross synaptic clefts between neurons
what is elaboration (memory)?
analyzing the meaning of or building more detail around the item that has been memorized
serial position effect
we remember things at the start and the end of a list better than what is in the middle
ways to study the brain
EEG, accidents, scans and electrical simulation
Agonist
A chemical that mimics the action of a neurotransmitter.
motor areas
send impulses to glands to carry out responses
association areas
parts of the cerebral cortex that receive inputs from multiple areas; association areas integrate incoming sensory information, and also form connections between sensory and motor areas.
3 effects of an increase of adrenaline
increased heart and breathing rate
decreased peristalsis and secretions
decreased blood pressure and blood diverted to skeletal muscles
reverberating neural pathway
neurons later in the pathway link with earlier neurons. sending the impulse back through the pathway (this allows repeated simulation)
3 layers of the brain
central core (medulla and cerebrum limbic system (hypothalamus) cerebral cortex
cerebral cortex use
conscious thought/memories/ alters behaviours in light of past experiences
what types of information does the brain capture?
sights, sounds, smells, tactile sensations, emotions
how does enzyme degradation work in the removal of neurotransmitter?
enzymes break down neurotransmitters into nonactive products which are reabsorbed by the presynaptic neuron
what are 2 ways that neurotransmitters can be removed from the synaptic cleft?
enzyme degragation
decay
which structure ensures there is enough energy fir the resynthesising of neurotramsitters?
mitochondria provides energy through respiration
what happens to weak stimuli at a synapse?
they are filtered out
what is a summation?
where a series of weak stimuli can release enough neurotransimtter to meet the threshold
why are only some impulses transferred?
a threshold must be met - a minimum number of neurotransmitter molecules must bind to receptors
initial decision
voluntary action to take the drug for the first time
drug addiction
chronic disease that causes the suffer to seek out and use the drug regardless of consequences
sensitisation
an increase in number and sensitivity of receptors because of using antagonists. craving more of the drug.
drug tolerance
when reaction to a drug is lessened - a larger dose is required to bring about the original effect
desensitisation
decrease in number and sensitivity of receptors as a result of using agonists. leads to drug tolerance.
which 3 methods increases transfer of information between the short term and long term memory
rehearsal
elaboration of meaning
organisation
what is association (cerebral cortex)?
association - makes sense of/analyse the information received
what is sensory (cerebral cortex)?
receives information from body’s receptors
what is motor (cerebral cortex)?
motor - carry’s our orders by sending motor impulses to effectors
why are memories displaced?
they are displaced as short term memory can on average only hold 7 things at once.
what are endorphins?
Endorphins are neurotransmitters that stimulate neurones involved in reducing the intensity of pain.
what does the removal of neurotransmitters or reputake prevent?
The need for removal of neurotransmitters by enzymes or reuptake to prevent continuous stimulation of post-synaptic neurones.
where are neurotransmitters stored?
in vecsiles
what does the arrival of impulse cause?
Arrival of an impulse causes vesicles to fuse with membrane and release neurotransmitter
summation of weak stimuli can release…
Summation of weak stimuli can release enough neurotransmitter to fire an impulse
which direction do nerve impulses travel?
left to right…from cell body along the axon to the nerve endings
function of dendrites?
These receive incoming impulses from other neurones.
describe how an impulse is transmitted from one neuron to another
- Vesicle releases neurotransmitter.
- Neurotransmitter moves across the synaptic cleft
- Neurotransmitter binds to the receptor.
- Sufficient amount of neurotransmitter is required (to transmit impulse).
