Biopsychology Flashcards
What is the nervous system
- the body’s main communication system which is very fast acting
- complex network of speacialised nerve cells which passes information around the body
Draw the diagram of the nervous system
|———————————NS———————————|
CS. PNS
|. |——————|————|
Brain & spinal cord. Autonomic. Somatic
|————|
Sympathetic. Parasympathetic
What does CNS (or CS) stand for
Central Nervous System
What is the CNS made up of
Brain and the spinal cord
What is the function of the CNS
To pass messages from the brain to other parts of the body and receive information from the peripheral nervous system
What is special about the brain
- centre of the conscious awareness
- the cerebral cortex is highly developed in humans and distinguishes our higher mental functions from other animals
What is the spinal cord
- it is an extension of the brain
- responsible for reflex actions
What does PNS stand for
Peripheral nervous system
What is the PNS made up of
Nerve fibres (axons)
What is the peripheral nervous system
- sends information to the CNS from the outside world
- transmits messages from the CNS to muscles and glands in the body
What is the somatic nervous system
- receives instructions from the CNS for muscle movements
- controls conscious movement
- transmits information from the receptor cells in sense organs to the CNS
What is the somatic nervous system made up of
Axons and myelinated neurons
What is the autonomic nervous system
- responsible for control of the bodily functions not consciously directed
- transmits information to and from internal bodily organs
- acts slower than the SNS
What is the autonomic nervous system made up of
- unmyelinated nerve fibres
- sympathetic nervous system
- parasympathetic nervous system
Sympathetic nervous system =
Gets the body prepared for flight or fight
Parasympathetic nervous system =
Returns the body to its normal resting state
What is a neuron
Nerve cells which are part of the nervous system
How do neurons transmit information
- electrically (through action potential)
- chemically (using neurotransmitters)
What do neurons consist of
- cell body
- dendrites
- an axon
What are dendrites and what do they do
- receive signals from other neurons or sensory receptors
- connected to the cell body
What is the function of cell bodies
Control centre of the neuron which contains all the genetic information of the cell
What is the axon
Carries the impulse from the cell body to the terminal
What is the axon terminal
The end of the axon where the neurotransmitters are
What is a myelin sheath
- a fatty coating that forms around the axon
-allows nerve impulses to transmit more rapidly along the axon - if damaged impulses slow down
What size dendrites and axons does a sensory neuron have
Long dendrites
Short axons
What is a sensory neurons function
Carry messages from the sense receptors in the PNS to the CNS
Do all messages from the sensory neuron go to the brain
- no
- some terminate in the spinal cord to allow reflex actions to occur quickly
What size dendrites and axons does a motor neuron have
Short dendrites
Long axon
What is the motor neurons function
Connect CNS to effectors such as muscles and glands
Where is the motor neuron’s cell body and axon located
Cell body = in the spinal cord the fibre (axon) projects outside the spinal cord directly or indirectly control effector organs
What size dendrites and axon does a relay neuron have
Short dendrites
Short axon
What is the function of a relay neuron
Connect the sensory neurons to the motor or other relay neurons
Where are relay neurons ONLY found
Spinal cord and brain
What is the endocrine system
- a communication system that instructs glands to release hormones directly into the bloodstream
- these hormones are carried in the blood towards target organs in the body
- it works alongside the NS to control vital functions in the body
What speed does the endocrine system pass messages compared to the nervous system
It acts much more slowly than the NS but still has powerful effects
What is a hormone
A chemical substance that circulates in the bloodstream and affects target organs
What effects do hormones have
Hormones can affect cells in several organs leading to a diverse range of responses
What is released from the Adrenal gland and what impact does it have
Adrenaline and noradrenaline
- key role in fight or flight
What is released in the Adrenal cortex and what impact does it have
Cortisol
- triggers the release of glucose to provide the body with energy and suppressing the immune system
What is released in the testes and what impact does it have
Releases testosterone which is responsible for male sex characteristics during puberty and muscle growth
What is released from the ovaries and what impact does it have
Release oestrogen which regulates female reproductive system
What is the fight or flight response
A sequence of activity within the body that is triggered when the body prepares itself for defending or attacking (flight) or running away to safety (flight)
What phrase must you always use in this topic
‘Make the body prepared’
How are threats today different to the past
- Today the threats are more psychological than physical
- today the threats are more long term
What is the role of the amygdala
- Body’s “threat” sensor
- if it alerts that there is a threat then it will activate a sequence of events
Which 2 communication systems work together
Nervous system and endocrine system
What is the process of the SAM pathway
Amygdala
| alerts
Hypothalamus
|activates
Sympathetic Nervous System
|triggers
Adrenal Medulla
|releases
Adrenaline and noradrenaline
| facilitates
The fight or flight response
What is the role of adrenaline
- increased heart rate pushing blood to the muscles
- breathing becomes more rapid to take in more oxygen to provide to the muscles
- blood sugar and fats are released into the bloodstream to provide energy
- diversion of blood away from the digestive system by constructing blood vessels
- increase sweating
Fight or flight response - AO3 - LIMITATION
P- negative consequences
EE- the response is activated in conditions that are not life threatening and isn’t particularly helpful
L- we do not need the physical response in the modern world
Fight or flight response - AO3 - LIMITATION
P- gender differences in acute stress response which are ignored and thus presenting beta bias
E- Taylor (2000) suggests females display a different pattern to men
E- males = protective alliances Females = protect themselves & young
L- linked to primary caregiver
Fight or flight response - AO3 - LIMITATION
P- incomplete explanation
E- Gray (1988) argues first step is the ‘freeze’ response not fleeing or fighting
E- advantages of this for humans is that ‘freezing’ focuses attention
L- shows original theory of fight or flight is only partial explanation to how bodies react to immediate danger short term danger
What is synaptic transmission
The process in which one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse
What is the synapse
The gap between neurons
What is an action potential
An electrical impulse
- when a neuron is in a resting state it is negatively charged compared to the outside
- when a neuron is activated by a stimulus it becomes positively charged for a split second causing an action potential
What are the stages of synaptic transmission
1- an action potential travels down the axon of the presynaptic neuron
2- when the impulse reaches the terminal buttons it causes vesicles to migrate and bind with the presynaptic membrane triggering the release of the neurotransmitters
3- neurotransmitters diffuse across the synapse and bind with postsynaptic receptors like a lock and key
4- once activated the receptors produce either excitatory or inhibitory effects on the postsynaptic neuron
5- neurotransmitters are then released back into the synapse and go through either: 1= the process of reuptake or 2 = get metabolised
What is the function of serotonin
To regulate mood
- we think it is involved in depression, OCD & anxiety when levels are low
What is the function of dopamine
Pleasure
- can be lead to addiction
What is the function of GABA
- calming effect on the brain
- it is always inhibitory, never excitory
What is special about GABA
It’s the only inhibitory neurotransmitter
What is meant by inhibition
- “off switch”
- a negative charge at the post synaptic membrane will create an inhibitory post synaptic potential
—> less likely to fire an action potential
What is meant by excitation
- “on switch”
- a positive charge at the post synaptic membrane will create a negative charge at the post synaptic potential
—> more likely to fire an action potential
What is meant by summation
The net sum of the total IPSP’s and EPSP’s which determines whether or not the cell fires
- the threshold is -60v for an action potential to be created
