AQA A level psychology summary notes- biopsychology & QUIZLET ACCESS

Biopsychology
THE NERVOUS & ENDOCRINE SYSTEM
Central Nervous System
 Made up of the brain and spinal cord which
are connected by the brain stem
 Controls involuntary functions
Brain
 Provides conscious awareness and is involved
in all psychological processes
 Occipital Lobe
o Processes visual information
 Temporal Lobe
o Auditory information
 Parietal Lobe
o Information from different senses & for
spatial navigation
 Frontal Lobe
o High order functions
 E.g. planning, abstract reasoning & logic
Spinal cord
 Transfers messages to & from the brain and rest of the body
 Responsible for simple reflex actions

Peripheral Nervous System
 Transmits messages (via millions of neurons) to & from CNS
 Divided into Autonomic and Somatic Nervous System
Somatic NS
 Maintains communication between CNS and outside world
 Controls muscle movement and receives information between sensory receptors
 Sensory Receptors
o Carry information to spinal cord & brain
 Motor Pathways
o Allows brain to control movement
Autonomic NS
 Important for homeostasis
 Governs vital functions
o E.g. breathing, digestion, sexual arousal
 Consists of only motor pathways
 Sympathetic NS
o Involved in responses that prepare body for fight or flight
 E.g. increases heart rate, blood pressure
 Parasympathetic NS
o Returns body to normal state after fight or flight response
o ‘rest and digest’ response

,The Endocrine System
Hypothalamus
 Connected to pituitary gland
 Responsible for stimulating/controlling the release of hormones from pituitary gland
 Control system which regulates the endocrine system
Pituitary Gland
 Releases hormones which control and stimulate the release of hormones from other glands in
the system
 Anterior Lobe (front)
o Releases adrenocortical trophic hormone (ACTH)
o Stimulates the adrenal cortex and the release of cortisol
 Posterior Lobe (back)
o Releases oxytocin
o Responsible for uterus contraction during childbirth
Pineal Gland
 Releases melatonin
o Responsible for important biological rhythms e.g. sleep-wake cycle
Thyroid Gland
 Releases thyroxine
o Responsible for regulating metabolism
Adrenal Gland
 Adrenal Medulla
o Releases adrenaline & noradrenalin (key role in fight or flight)
 Adrenal Cortex
o Releases cortisol (stimulates release of glucose while suppressing the immune system)
Testes
 Releases androgens (including testosterone)
 Responsible for development of male sex characteristics during puberty & muscle growth
Ovaries
 Releases oestrogen
 Controls regulation of reproductive system (including menstrual cycle & pregnancy)

Fight or Flight System

Amy (amygdala)
Hit (hypothalamus)
Sam (SAM pathway)
Sophie (SNS)
Made (Medulla)

Awful (adrenaline)
Noise (Noradrenaline



What does Adrenaline do?
 Body goes into sympathetic state (physiological arousal)
 Increases heart rate
o Increases blood flow to organs & increases movement of adrenaline around the body.
 Increases breathing rate
o To increase oxygen intake.
 Pupil dilation
o To increase light intake and vision (especially in the dark).
 Sweat production

, o To regulate temperature.
 Reduction of non-essential functions (e.g. digestive system, urination, salivation)
o To increase energy for other essential functions.

AO3 PARAGRAPHS
P- One issue with the fight or flight explanation is that human behaviour is not limited to just two
responses.
E- For example, Gray (1988) suggested that the first response to danger is to avoid confrontation
altogether, which is demonstrated by a ‘freeze’ response.
E- During the freeze response humans are hyper-vigilant while they appraise the situation to decide
the best course of action for that particular threat.
L- Therefore, the fight or flight explanation of behaviour is limited and doesn’t fully explain the
complex cognitive and biological factors that underpin the human response to stress/danger.

P- A final issue with the fight or flight response is that it can have a negative/detrimental effect on
health, especially in modern day life.
E- While the fight or flight response may have been a useful survival mechanism for our ancestors
who faced genuinely life-threatening situations (e.g., from predators), modern day life rarely requires
such an intense biological response.
E- Therefore, the activation of the fight or flight response can increase blood pressure and cause
damage to blood vessels and contribute to heart disease.
L- This suggests that the fight or flight response is a maladaptive response in modern-day life.

NEURONS & SYNAPTIC LINKS
Sensory Neurons
 Found in receptor cells e.g. eyes & skin
 Carry messages from PNS to CNS
 These impulses are translated as ‘sensations’
e.g. touch
 Not all sensory neurons reach the brain, some
stop at the spinal cord resulting in reflex actions

Relay Neurons
 Found between sensory input and motor
output/response
 Found in brain and spinal cord
 Allow sensory and motor neurons to communicate

Motor Neuron
 Found in CNS
 Control muscle movement
 When stimulated they release neurotransmitters that
bind to the receptors on muscles to trigger a response


Structure of a Neuron
Dendrites: receive signals from other neurons/sensory receptor cells, connected to the cell body
Axon: long fibre which carries nerve impulses, in the form of electrical signal (action potential)
Myelin Sheath: surrounds most axons, insulating it so electrical impulses travel faster along the axon
 Segmented by gaps called nodes of Ranvier, if continuous, it would slow impulses down
because the gaps force the impulse to ‘jump’ across gaps
Axon terminal: connects neurons to other neurons (or directly to organs) using synaptic transmission