biopsychology Flashcards
what is the nervous system?
a specialised network of cells that is our primary mode of communication.
how does the nervous system communicate?
by electrical impulses that are quick acting and short lasting
what are the two main functions of the nervous system?
-collect, process and respond to stimuli from the environment
-co ordinate the working of different organs and systems in the body
what is the central nervous system and what is it made up of?
origin of all complex commands and functions, it processes info
made up of brain and spinal chord
what is the function of the brain?
centre of all conscious awareness
what is the function of the spinal chord?
extension of the brain responsible for reflex actions. Passes messages to and from the brain and connects nerves to PNS
what is a reflex action?
automatic response we cannot control
what is the function of the peripheral nervous system?
transmits messages through neurones to and from the CNS. Sends info from outside world to CNS and then from CNS to effectors in the body
what are the 2 divisions of the PNS?
autonomic nervous system (ANS)
somatic nervous system (SNS)
what is the function of the autonomic NS?
controls vital functions in the body that are involuntary e.g. breathing, heart rate, digestion
what is the function of the somatic NS?
controls conscious/ voluntary bodily functions (muscle movement)
what is the ANS further divided into?
The sympathetic and parasympathetic nervous system
what is the the function of the sympathetic nervous system?
prepares the body for fight or flight response in the face of stress
what is the function of the parasympathetic nervous system?
rest and digest state (regulates body’s functions to conserve energy)
what are some effects of activating the sympathetic NS (fight or flight) ?
-increased heart rate
-increased breathing rate
-increased blood pressure
-dilated pupils
-digestion stops
what are some effects of activating the parasympathetic nervous system (after fight or flight)?
-decreased heart rate
-decreased breathing rate
-decreased blood pressure
-constricted pupils
-digestion starts
what is the endocrine system?
controls vital functions in the body alongside the nervous system by instructing glands to release hormones into the blood stream which are carried to effector organs
compare the endocrine system vs nervous system?
chemical messengers vs electrical impulses
slow acting but more widespread powerful effects that are long lasting vs quick acting but short lasting effects
what are glands?
organs that produce hormones
what are hormones?
chemical messengers that circulate in the blood stream to affect target organs. Each hormone has a highly specialised function.
what is the master gland and where is it located?
the pituitary gland in the brain
what does the pineal gland do?
releases melatonin which helps you sleep
it is located in the brain
what does the adrenal gland do?
releases adrenaline and noradrenaline which are responsible for the activation of the fight or flight system
what is the fight or flight response defined as?
how an animal responds when stressed through the physiological arousal of the body to prepare to flight or flee an aggressor
the endocrine system and NS (ANS) work together
describe the process of fight or flight?
-amygdala detects a threat
-sends info to the hypothalamus
-activates sympathetic NS
-sends message to adrenal glands
-release of adrenaline and noradrenaline
-which causes the body responses of fight of flight
-once threat passes parasympathetic NS is activated and reverts body back to rest and digest.
what are neurons?
cells that make up the NS. they are the nervous system’s primary method of communication and process and transmit messages through electrical and chemical signals
what are the three types of neurons?
sensory, motor and relay
what is the function of the sensory neuron?
registers the input from the senses (PNS) and transports to the CNS
what is the function of the relay neuron?
decides what to do and passes the message on within the brain. connects sensory to motor neuron or another relay neuron
what is the function of a motor neuron?
tells muscles and glands what to do by connecting CNS to effectors
what are key points about the structure of relay neurons?
short dendrites and axons
what is a key point about the structure of sensory neurons?
cell body part way along the axon
what is a key point about the structure of motor neurons?
have the longest axons
using knowledge of neurons, explain how a reflex arc happens?
-stimulus is detected by sense organs in the PNS, which convey a message along a sensory neuron
-the message reaches the CNS where it connects with a relay neuron
-this then transfers the message to a motor neuron which carries a message to an effector e.g. muscle or gland
where do you find sensory, relay and motor neurons?
sensory- PNS
relay and motor- CNS
what is synaptic transmission?
how neighbouring cells communicate across the synaptic gap through chemical messengers (neurotransmitters) in order to pass on the electrical signal to the neighbouring neuron.
what are neurotransmitters?
brain chemicals that send signals from one neuron to the next through diffusing across the synapses. Can be exhibitory and inhibitory. Examples include serotonin and dopamine
describe the process of synaptic transmission?
-electrical impulses reach end of the presynaptic neuron which stimulates the release of neurotransmitters from vesicles
–neurotransmitters then diffuse across the synapse and bind to receptor sites on the postsynaptic membrane
-if the neurotransmitters reach threshold, excitation or inhibition can occur depending on the summed charge of the neuron
what does neurotransmitters being inhibitory or excitatory determine?
whether the post synaptic neuron fires an impulse or not (to pass on the message)
what is excitation?
when a neurotransmitter increases the positive charge of the post-synaptic neuron. This increases the likelihood that the neuron will fire and pass on the electrical impulse e.g. adrenaline
what is inhibition?
when a neurotransmitter increases the negative charge of the post-synaptic neuron. This decreases the likelihood that the neuron will fire and pass on an electrical impulse e.g. GABA or serotonin
what is summation?
the excitatory and inhibitory influences are summed.
If the net effect on the post synaptic neuron is inhibitory the neuron will be less likely to fire and pass on the signal
when is the action potential (electrical impulse) of the post-synaptic neuron triggered?
if the sum of the excitatory and inhibitory signals at one time reach the threshold.
explain why information can only travel in one direction at a synapse? (3)
-synaptic vesicles containing neurotransmitters are only released from the presynaptic membrane
-receptors for neurotransmitters are only present on the post synaptic membrane
-diffusion of neurotransmitters means they can only go from high to low conc
