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
- 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
- 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 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 asympathetic 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
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-
axon- carry impulse away from cell body across the neuron
dendrite- carries message from other neurones towards cell body
axon terminal- 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
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
define neurotransmitters
2 features
chemicals which diffuses across synapses to relay impulses to the next neuron
- 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 and the rest of the body
describe the process of synaptic transmission of neurons
- occurs through release of neurotransmitters into the synapse
- electrical impulse is converted to a chemical impulse (neurotransmitters)
- neurotransmitters are released from the axon terminal, diffuse into the synaptic cleft and absorbed by post synaptic receptor sites in the dendrites of the next neurone
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
describe the idea of summation
- 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 positive, action potential would be triggered and the electrical impulse would travel down the neuron’s dendrites)
define the role of the endocrine system
- major information and communication system that regulates hormonal levels and instructs glands to secrete hormones into the blood stream, where they are carried to target organs
- works on a feedback system: communicates amount needed to be produced
- works in parallel to nervous system
define hormones
-biochemical substance that is secreted by glands that can affect any cell in the body with the specific receptor
- disappear quickly
- very powerful
- can affect cells in many different organs
name all the glands (7) and describe their function/ function of their secreted hormone (4)
•pituitary
- master gland
- controls release of hormones from every endocrine gland
•thyroid
- secretes thyroxine
- —-> increases heart rate, metabolism and growth
•adrenal
- secretes adernaline
- —–>changes in cardiovascular system (e.g. increased heart rate, )
•hypothalamus
- brain structure that controls and informs pituitary gland to which hormones are needed and when
- links nervous system to endocrine system
- testes
- ovaries
- parathyroid
where is the pituitary, adrenal and thyroid gland located
pituitary = base of brain
adrenal = on top of kidneys
thyroid = in front of trachea