PAPER 2- TOPIC 2 BIOPSYCHOLOGY ✅ Flashcards
define the nervous system
- specialised network of cells in body, that is our primary internal communication system
- based on electrical and chemical signals
role of nervous system
- collect, process and respond to information in the environment
- communicates with and co-ordinates the different organs and cells
two sections of the nervous system
central nervous system
peripheral nervous system
Describe what makes up the Central Nervous System
•brain
- centre of conscious awareness (makes all decisions)
- controls every process (e.g. thoughts, emotion hunger)
- cerebral cortex wraps around whole brain
•spinal cord - passes messages to and from brain - connects nerves from brain to the peripheral nervous system - responsible for reflex arc (effectively an extension of the brain)
role of central nervous system
controls all complex demands and decisions
define the peripheral nervous system
- connects CNS to organs, limbs and sensory receptors
- transmit messages from the outside world to the CNS
- transmit messages from the CNS to the effector cells
describe the two sections of the peripheral nervous systems
•somatic nervous system -transfers info from receptors to CNS ----> and CNS to effectors ......????? -controls voluntary muscle movement
•autonomic nervous system
- important in homeostasis (vital involuntary processes)
- transmits info from CNS to organs (and from organs to CNS) automatically
- –> allows automatic responses and vital functions to occur
- splits into parasympathetic and sympathetic
describe the two sections of the autonomic nervous system
and examples of what occurs
•sympathetic
- prepares the body for a fight or flight response during stressful events
e. g. ——increases heart and breathing rate
•parasympathetic
- restores body to normal resting state after stressful event
- works as an antagonist to the sympathetic nervous system (opposite)
e. g. ——-slows heart rate, resumes digestion
way to remember sympathetic and parasympathetic
S sympathetic = S cared
P arasympathetic = P revent
define a neuron
an specialised nerve cell that carries neural information around the body through electrical and chemical impulses
describe the route that each neurone takes
sensory- info from stimuli in receptor cells in PNS to the CNS
relay- connect sensory and motor neurons, or between other relay neurons, form part of reflex arc (mostly in brain and spinal cord)
motor- from the CNS to effector cells (muscles and glands)
outline the role of the different structures in a neuron
nucleus- control centre for activity and contains genetic material
cell body- contains information being carried, contains nucleus
axon- carry impulse away from cell body across the neuron
dendrite- carries message from other neurones towards cell body
axon terminal (terminal buttons)- where axons communicate with other neurons across a synapse - releases neurotransmitters into synaptic cleft
myelin sheath- insulates and protects axon, to speed up transmission
nodes of ranvier- small gaps in the myelin sheath that speed up transmission (as impulse must “jump”)
describe the structure of a sensory, relay and motor neuron
sensory: long dendrites . cell body . short axons
relay : short dendrites . cell body (majority of neuron) . short axons . (no myelin sheath)
motor: short dendrites . cell body . long axons
define neurotransmitters
2 features
chemicals which diffuse across synapses to relay impulses to the next neuron
—-> electrical impulses trigger their release from synaptic vesicles
- every NT has its own specific structure and so fits into specific receptor sites like a lock and key
- either have an excitatory effect or inhibitory effect on neighbouring neurons
define a synapse
extremely small gap between neurons that allow them to communicate through chemical impulses
define synaptic transmission
how neurons communicate with other neurons (& rest of body) by sending chemical impulses across a synapse
describe the process of synaptic transmission of neurons
- electrical impulse is converted to a chemical impulse (neurotransmitters)
- neurotransmitters are released from synaptic vesicles in the pre- synaptic terminal , diffuse into the synaptic cleft
- they are absorbed by the specific post synaptic receptor sites in the dendrites of the next neurone
- and converted back to electrical impulse
describe the stages of electrical transmission of neurons
- when a neuron is at a resting state, the cell body is negatively charged
- when the neuron is activated by a stimulus, the cell body becomes positively charged for a split second
- causes action potential
- which causes an electrical impulse to travels down axon towards end of neuron (neuron is fired)
describe the idea of summation
• decides whether post-synaptic neurone fires or not
- post synaptic neurons can receive both excitatory and inhibitory neurotransmitters simultaneously
- these influences are summed and the net effect is what charge the post synaptic neuron will have
• if reaches positive threshold, the action potential is triggered, the cell body is momentarily positively charged, causing an electrical impulse to travel down the neuron’s dendrites
describe the excitatory effect a neurotransmitter can have on a neuron
example
- increases the neuron’s positive charge and makes it more likely to fire
- e.g adrenaline makes the neuron and more positively charged and more likely to fire
describe the inhibitory effect a neurotransmitter can have on a neuron
example
- increases the neuron’s negative charge and makes it less likely to fire
- e.g serotonin makes the more neuron negatively charged and less likely to fire
define localisation of function in the brain
idea that specific areas of the brain are responsible for certain tasks, behaviours or processes
- if a certain part of the brain gets damaged then the associated area and the function of this area will also be affected
what was the historic view of the brain
- holistic theory that all parts of brain were responsible for all thoughts and actions
describe the research that changed the view of the brain as holistic to localised
• Phineas Gage
- metal pole was projected through his eye and through his frontal lobe and out his skull
- survived, but friends said he now was more quick tempered and rude
- his change in personality then led to suggestions that the frontal lobe is associated with mood regulation
• Broca
-responsible for speech production, and damage to this area causes Broca’s aphasia (laborious speech)
• Wernicke
-responsbile for speech comprehension, damage to this area causes Werncike’s aphasia (unmeaningful speech)