Biological Structures & Neurochemistry
- Biological psychologists recognise the importance of biological structures and neurochemistry in the body and the role it plays in behaviour
Endocrine system
- The endocrine system is a chemical messaging system that operates throughout the body
- The endocrine system releases hormones into the bloodstream
- Pituitary gland:
- It controls the release of hormones from other glands
- It is known as the master gland
- Adrenal gland:
- It releases adrenaline/ noradrenaline as part of the fight/ flight response
Reflex arc
- The reflex arc consists of a collection of cells that transmit information
- Sensory neurons:
- They send information from the senses e.g. touching a hot radiator, to the brain e.g. pulling hand off the radiator
- Relay neurons:
- They connect with other neurons
- They analyse sensations
- They decide which response to make
- They act between sensory and motor neurons
- Motor neurons:
- They send messages from axons in neurons to the muscles
Synapse
- A synapse is found at the end of the cell
- Synaptic transmission allows neurons to communicate by passing chemical signals/messages between them
- These chemical messengers released are called neurotransmitters
- There are two types of neurotransmitters
- Excitation: Excitatory neurotransmitters increase the likelihood of a new action forming in the postsynaptic cell When the receptors are detected, the electrical charge inside becomes more positive and likely to fire, known as depolarisation
- Inhibition: Inhibitory neurotransmitters decrease the likelihood of a new action forming the postsynaptic cell
- When the receptors are detected, the electrical charge inside becomes more negative and less likely to fire, known as Hyperpolarisation
- The Process of synapse transmission
- The action potential travels down the axon of the presynaptic neuron
- This forces vesicles containing neurotransmitters to merge with the cell membrane and release the neurotransmitter into the synaptic cleft
- Receptors on the postsynaptic neuron's dendrite membrane detect the presence of neurotransmitters, changing the chemistry of the postsynaptic neuron
- If the change inside the postsynaptic neuron passes a threshold, a new action potential is triggered and the message is passed on
- The neurotransmitters detach from the receptors and return to the presynaptic cell via transport proteins, (known as reuptake)
Nervous systems in the body
- The Nervous System
- The collection of nerve cells that sends electrical messages around the body
- Central Nervous System
- Contains the brain and spinal chord
- Receives information, processes it and makes decisions
- Peripheral Nervous System
- Information across the body to the brain
- Sends decisions from the brain to the body
The Brain
- The brain has different regions which perform different tasks for the body, this is known as localisation of brain function
- Brain Stem
- This connects the brain to the spine and rest of the body
- It regulates basic functions such as breathing, heart rate, eating and sleeping
- Temporal Lobe
- This controls hearing/ auditory perception
- It also controls speech comprehension, processing sounds and noise to speech
- Frontal Lobe
- This predicts future consequences
- It is linked to executive control e.g. not acting on impulses, thinking, reflecting
- Cerebellum
- This receives information from the spinal cord, sensory systems and other parts of the brain
- It regulates balance and motor movements
- Cerebral Cortex
- This is the largest area of the brain
- It controls; cognition, perception, consciousness, memory, attention, awareness, thought and language
- Occipital Lobe
- This processes visual stimuli, such as colour, orientation and shape
- Parietal Lobe
- This regulates sensory information from across the body
