Biopsychology

• What components make up the central nervous system?

  the brain and spinal cord
• What is the function of the brain?

  - the brain is the centre of awareness

  - it controls perception and motor control

  - it is responsible for regulating bodily processes and maintaining homeostasis (e.g. maintaining temperature and hormone levels based on information from the peripheral nervous system)
• Describe the divisions of the nervous system.

  
• brain labelled

  
• What is the function of the spinal cord?

  Relays informationbetween the brain and bodyCoordinates reflexesvia reflex arc (automatic responses)Transmits sensory signalsfrom body to brainSends motor commandsfrom brain to muscles/glands
• What is the structure of the peripheral nervous system?

  - Made ofsensoryandmotor neurones

  Peripheral Nervous System (PNS): outside the brain and spinal cord

  Somatic Nervous System: controls voluntary movements; sensory & motor pathways

  Autonomic Nervous System (ANS): controls involuntary functions (e.g., heart rate, digestion)-> Sympathetic Nervous System: "fight or flight"; increases arousal->Parasympathetic Nervous System: "rest and digest"; calms the body after arousal
• What is the function of the peripheral nervous system?

  Connects CNS to the body(limbs, organs, etc.)Transmits sensory informationfrom body to CNSCarries motor commandsfrom CNS to muscles/glandsControls voluntary movements(somatic nervous system)Regulates involuntary functions(autonomic nervous system: heart rate, digestion)
• The peripheral nervous system has two divisions, what are they?

  autonomic nervous system and somatic nervous system
• What is the role of the autonomic nervous system?

  - Made ofsensoryandmotor neurones- Regulates involuntary functions(e.g., heart rate, breathing, digestion)- Maintains homeostasis(internal balance)- Divided into two branches:

  Sympathetic Nervous System: activates "fight or flight" response (increases heart rate, dilates pupils)

  Parasympathetic Nervous System: triggers "rest and digest" response (slows heart rate, promotes digestion)
• What is the role of the somatic nervous systems?

  - Made ofsensoryandmotor neurones- Voluntary body movement and sensing external stimuli- It inputs from sense organs (5 senses) and outputs to muscles, skin and joints by receiving a signal to respond to the changes detected.

  Example: catching a ball-your eyes detect the ball moving towards you, brain assesses info, then instructs the muscles of your arm to reach out and catch the ball.
• Which division of the Peripheral Nervous System contains the sympathetic and parasympathetic divisions?

  Autonomic
• What is the role of the sympathetic nervous systems?

  Made of motor neuronesActivates "fight or flight" responseduring stress or dangerIncreases arousal: raises heart rate, blood pressure, and breathing rateDilates pupilsfor better visionInhibits digestionto conserve energyReleases adrenalinefrom adrenal glandsRedirects blood flowto muscles
• What is the role of the parasympathetic nervous systems?

  Made of motor neuronesActivates "rest and digest" responseafter stressReduces arousal: lowers heart rate, blood pressure, and breathing ratePromotes digestion: stimulates saliva, increases digestive enzyme productionConserves energy: promotes relaxation and recoveryConstricts pupilsEncourages waste elimination(e.g., bladder function)
• Describe the structure of a neuron.

  Cell Body (Soma):Contains the nucleus and organellesIntegrates incoming signalsDendrites:Branch-like structuresReceive signals from other neurons or sensory receptorsAxon:Long, slender projectionTransmits electrical impulses away from the cell bodyMyelin Sheath:Fatty layer surrounding the axonIncreases speed of impulse transmission (saltatory conduction)Formed by Schwann cells in the PNS; oligodendrocytes in the CNSNode of Ranvier:Gaps in the myelin sheathFacilitates rapid signal conductionAxon Terminals (Synaptic Boutons):End of the axon branchesRelease neurotransmitters to communicate with other neurons or muscles

  
• What is the structure of sensory neurones?

  Long dendrites and short axons

  Receptor endings (e.g., skin, eyes)
• What is the function of sensory neurones?

  Transmit sensory information (e.g., touch, pain, temperature) from peripheral receptors to the CNS
• What is the structure of relay neurones?

  Short dendrites and axons

  Located within the CNS (brain and spinal cord)
• What is the function of relay neurones?

  Connect sensory and motor neurons

  Process and relay information between neurons
• What is the structure of motor neurones?

  Long axons and short dendrites

  Cell bodies located in the CNS, extending to muscles
• Which part of the central nervous system is in control of reflexes?

  Spinal cord
• Describe synaptic transmission.


  - transmission involvesimpulsescrossing aspaceor gap between an axon terminus and the adjacent neuron (the synapse/synaptic cleft)- neurotransmitters are chemicals released from vesicles on thepresynaptic neuron- electrical impulses (action potentials) reach thepresynaptic terminal- electrical impulses (action potentials) trigger release ofneurotransmitter- neurotransmitters cross thesynapsefromvesicles- neurotransmitters combine withreceptorson thepostsynaptic membrane- stimulation of postsynaptic receptors by neurotransmitters result in eitherexcitation(depolarisation) orinhibition(hyperpolarisation) of the postsynaptic membrane.
• What are excitatory neurotransmitters?

  neurotransmitters that make the post synaptic neuron is more likely to fire an impulse
• Are neurotransmitters excitatory or inhibitory?

  They can be both but GABA is purely inhibitory.
• What is a neurotransmitter?

  Chemical substances that transmit signals across synapses from one neuron to another or to target cells (such as muscles or glands).
• What are inhibitory neurotransmitters?

  neurotransmitters that make the post synaptic neuron is more likely to fire an impulse
• What is the function of motor neurones?

  Carry motor commands from the CNS to effectors (muscles and glands)

  Control voluntary and involuntary movements
• Explain why neurons can only transmit information in one direction at a synapse.

  - thesynaptic vesiclescontaining the neurotransmitter are only present onthe presynaptic membrane- thereceptorsfor the neurotransmitters are only present on thepostsynapticmembrane- it is thebindingof theneurotransmitterto thereceptorwhich enables thesignal transmitted to the next neuron- diffusion of the neurotransmitters mean they can only go fromhightolowconcentration, so can only travel from thepresynapticto thepostsynapticmembrane.
• How do drugs affect synaptic transmission?

  Psychoactive drugs work by affecting (increasing or inhibiting) the transmission of neurotransmitters across the synapse
• Describe what is meant by summation.

  During synaptic transmission, 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 if the net effect is excitatory, the neuron will be more likely to fire.
• Example

  Stimulus --> receptor --> sensory --> relay --> motor --> effector ---> response.
• Outline the structures involved in synaptic transmission.

  The synaptic cleft, pre and postsynaptic membranes, postsynaptic receptor sites, neurotransmitters in vesicles in the presynaptic terminal
• What glands and hormones make up the endocrine system, and what do they produce?

  1. Pituitary gland --> HGH, TSH, ACTH, LH, FSH, ADH,

  2. Pineal --> melatonin

  3. Pancreas --> insulin, glucagon

  4. Adrenal gland -->. adrenaline

  5. Thyroid gland --> thyroxine

  6. Testicles --> testosterone

  7. Ovaries --> oestrogen
• What are the differences between the endocrine system and the nervous system?

  - Endocrine system gives chemical messengers vs nervous system giving electrical impulses.

  - Endocrine system has long-lasting effects whilst the effects of nervous system is short-lived.

  - Endocrine system takes much longer to work whilst the nervous system is very quick (e.g. reflexes)

  - Endocrine system has more permanent and wide effects whilst the effects of nervous system is more localised and temporary.
• When and how do endocrine and nervous system work together?

  - The endocrine and ANS often work in parallel with one another, e.g. a stressful event.

  - When a stressor is perceived, the hypothalamus triggers the sympathetic nervous system and the ANS changes from its usual resting state (the parasympathetic state).

  - Adrenaline is released from the adrenal medulla into the bloodstream, resulting in the physical arousal needed for fight/flight.

  - Once the threat has passed, the parasympathetic nervous system kicks in and returns the body to its natural resting state (decreases heart/breathing rate etc.)
• What is the fight or flight response?

  A sequence of activity within the body that is triggered whenthe body prepares itself for defending or attacking (fight) or running away to safety (flight). This activity involves changes in the NS and the secretion of hormones that are necessary to sustain arousal.
• What changes occur in the body during the fight or flight response?

  - increase heart rate

  - constricts blood vessels, increasing rate of blood flow and raising blood

  pressure

  - diverts blood away from the skin, kidneys and digestive system

  - increases blood to brain and skeletal muscle

  - increases respiration and sweating
• Why is adrenaline released?

  released from the adrenal medulla in response to activation of

  the sympathomedullary pathway
• What are the general effects of adrenaline?

  - prepare the body for action, fight or flight

  - increase blood supply/oxygen to skeletal muscle for physical action

  - increase oxygen to brain for rapid response planning
• Evaluate the flight or fight response (1): Limited explanation

  POINT:One issue with the fight or flight explanation is that human behaviour is not limited to just two response.

  EVIDENCE:Graysuggests that the first response to danger is to avoid confrontation altogether, which is demonstrated by a ‘freeze’ response.

  EXPLAINATION:During the freeze response, humans are hyper-vigilant while they appraise the situation to decide the best course of action for that particular event.

  EVALUATION:This suggests that the fight or flight explanation of behaviour is limited and doesn’t fully explain the complex cognitive and biological factors that underpin human response in stress/danger.
• Evaluate the fight or flight response (2): Androcentrism/Beta Bias

  POINT:Another issue with the fight or flight explanation is that it doesn’t fully explain the stress response in females.

  EVIDENCE:Taylorsuggested that females adopt a ‘tend to befriend’ response in stressful situations.

  EXPLAINATION:Women are more likely to protect their offspring and form alliances with other women, rather than an adversary or flee.

  EVALUATION:This is a limitation because it highlight’s the beta bias within this area of psychology as psychologists assumed that females responded in the same way as males until Taylor provided evidence. This has prompted more recent research which has provided an alternate explanation which is applicable to females