Biopsychology Flashcards
Nervous system
Divided into 2:
- Central Nervous System (CNS)- consists of brain and spinal cord- this where all the complex processing of information is done and decisions are made
- Peripheral Nervous System (PNS)- brings information from the senses to the CNS and transmits information from the CNS to muscles and glands
Central Nervous System
Brain:
- At the centre of awareness and decision making
- Divided into 2 hemispheres: (right hemisphere- controls left hand side of body, left hemisphere- controls right hand side of body)
Spinal cord:
- Extension of brain
- Transports messages to and from the brain to the PNS
- Responsible for reflexes
Peripheral Nervous System
Somatic Nervous System (SNS):
- Receives information from the senses and transmits it to the CNS
- Also transmits information from the CNS to direct movement of muscles
Autonomic Nervous System (ANS):
- Responsible for vital functions- e.g heartbeat, breathing, digestion
- Transmits information from and to the internal body organs- e.g liver and lungs
- Operates automatically, involuntarily
Autonomic Nervous System (ANS):
Sympathetic Nervous System:
- Stimulates functions- e.g increasing oxygen to muscles and releasing energy
- Involved in “fight or flight” response
Parasympathetic Nervous System:
- Slows the heartbeat and reduced blood pressure
- Involved in “rest and digest”
Neurons
- Neurons carry neural information throughout the body
Sensory neurons
- Carry signals from sensory receptors to the spinal cord and brain
- Located in sensory organs- (e.g eyes).
- Some terminate in spinal cord allowing quick reflex actions
Relay neurons
- Allow sensory and motor neurons to communicate with each other
- Located in the the brain and spinal cord
Motor neurons
- Carry signals from the CNS to muscles (project from spinal cord to muscles)
Neurons (8 Points)
- Cell body contains nucleus
- Dendrites extend from the cell body
- They carry electrical impulses from other neurons towards the cell body
- The axon is an extension of the neuron, it carries the impulses away from the cell body
- It is covered by the myelin sheath, a fatty substance
- Main purpose of myelin sheath is to increase the speed at which impulses are carried
- There are breaks of between 0.2 and 2 mm in the myelin sheath- nodes of Ranvier
- At the end of the axon are terminal buttons which communicate with the next neuron in the chain
HOW TO LABEL A NEURON
How do neurons transmit signals?
- Neurons do not make direct contact
- There is a very small gap between neurons- SYNAPSE
- The signal needs to cross this gap to continue on its journey to, or from, the CNS
- This is done using chemicals which diffuse across the gap between 2 neurons
- Chemicals = neurotransmitters
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The synapse: Chemical transmission (5 points)
COME BACK TO!
- An electrical impulse travels along the axon of the transmitting neuron
- This triggers the nerve- ending of the pre- synaptic neuron to release chemical messengers called neurotransmitters
- These chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the next neuron
- The receptor molecules on the second neuron bind only to the specific chemicals released from the first neuron. This stimulates the second neuron to transmit the electrical impulse
- Reuptake: the neurotransmitter is reabsorbed in the vesicles of the pre- synaptic neuron after it has performed its function of transmitting a neural impulse
Inhibitory effect
- Some neurotransmitters act by making the neuron more negatively charged so less likely to fire
- E.g SSRIs- Increase Serotonin
- Nervous Systems “off switch”
Decrease likelihood neuron will fire
Excitatory effect
- Other neurotransmitters increase the positive charge so make the neuron more likely to fire
- E.g Noradrenaline- released during the fight or flight response- ready for action
- Nervous systems “on switch”
Increase likelihood that neuron will fire
Endocrine system
- Consists of glands which produce hormones which are released in the blood stream to the target organs which contain receptors for specific hormones
- Hormones work more slowly than nerve impulses but often together with the nervous system
Process of the Endocrine system and the Nervous System work together to produce the acute stress response
- Amygdala (scanning environment for threat)-> Hypothalamus (Activates Sympathetic Nervous System)
- SNS sends a signal (noradrenaline) to the Adrena Medulla
- Which produces Adrenaline
It causes: - Increased heart rate
- Increased blood pressure
- Faster breathing
- Mouth becomes dry
- Digestion stops
- Pale- blood diverted away from skin to muscles
- Shakes- muscles ready for action
- Body becomes ready for FIGHT or FLIGHT response
- Parasympathetic nervous system produces GABA and brings the body back to an optimum state by slowing down the heart rate and bringing the blood pressure back to a normal level
Evaluation of Endocrine System
- WEAKNESS: Over simplistic- at least one other response = freeze. Time to work out how to respond to stresser
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STRENGTH: Animal testing- can relate to humans, also only use males, females too messy, assure females respond same- Beta bias = males + females = same
In response to stresser, female produce adrenaline and oxytocin root for social bonds, to make sure others around are safe particularly children = tend and befriend reponse
Help us understand stress related illnesses
Long term consequence:
- IBS, Heart disease, etc
Pituitary gland
MALE
- Releases growth hormone
- Regulates growth
Adrenal gland
MALE
- Adrenaline and Noradrenalne
- Increases heart rate, blood pumping from heart, stress hormone
Pancreas
FEMALE
- Insulin and glucagon
- Help maintain blood sugar levels
Ovary
FEMALE
- Oestrogen and Progesterone
- Regulate development and function of uterus, menstruation
Localisation of function
- Refers to the principle that specific functions have specific locations within the brain
Motor cortex
- Responsible for voluntary motor movements
- Located in frontal lobe
- Both hemispheres of the brain have a motor cortex
- Regions are arranged logically next to one another
Somatosensory cortex
- Detects sensory events arising from different regions of the body
- Located in the parietal lobe
- Both hemispheres have a somatosensory cortex
- Using sensory information from the skin, the somatosensory cortex prroduces sensations of touch, pain etc, which it then localises to specific body regions
Visual centres
- Primary visual centre in brain located in visual cortex
- Visual processing begins in the retina, at the back of the eye, where light enters and strikes the photoreceptors (rods- darkness, cones- colour)
- Visual cortex spans both hemispheres (right hemisphere receiving its input from the left- hand side of the visual field, while the visual cortex in the left hemisphere receives its input from the right- hand side of the visual field)
Auditory centres
- Concerned with hearing
- Lies within the temporal lobes
- Auditory pathways begin in the cochlea, where sound waves are converted to nerve impulses, which travel via the auditory nerve to the auditory cortex
Language centres- Broca’s area
- Only in left hemisphere
- Problem with language production
- Broca’s aphasia- Understands language but can’t produce language