AQA A Level Psychology Biopsychology Questions and Answers Already Graded A

AQA A Level Psychology Biopsychology Questions and Answers Already Graded A What is the nervous system The nervous system is a specialised group of cells in our body and is our primary communication system, it collects processes and responds to different information and co-ordinates the working of different functions within the body. It is made up of both the central nervous system and the peripheral nervous system. What is the central nervous system (CNS) The CNS includes the brain and the spinal cord, the brain is the centre of all conscious awareness and it is the outer layer, the cerebral cortex, which distinguishes us from animals. The spinal cord is an extension o the brain and is responsible for our reflexes and movements. The spinal cords main function is to relay information from the brain to the rest of the body. The brain is made up of four main areas, the brain stem, the diencephalon, the cerebellum and the cerebral cortex. The brain stem regulates automatic functions such as breathing and swallowing. The diencephalon comprises the thalamus which takes nerve impulses from the senses to the brain and the hypothalamus that regulates body temp and hunger. The cerebellum that controls motor skills and balance co-ordinating muscles to work together. The cerebral cortex is divided into four lobes each with a different function: POFT The Parietal lobe for sensory information The Occipital lobe for the processing of visual information The Frontal lobe for thought and speech The Temporal lobe for auditory information and memory What is the peripheral nervous system (PNS) The PNS is divided into two main sections the first being the somatic nervous system. This is made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves, containing both sensory and motor neurons it is also involved in reflex actions. The autonomic nervous system is much more complex, it essentially regulates involuntary actions such as heart rate without any conscious awareness. It is made up of the sympathetic nervous system and the parasympathetic nervous system which have opposing effects on the body. The sympathetic nervous system helps us deal with emergencies (fight or flight), it increases the heart rate, blood pressure and dilates pupils. It can also shut down non essentials like digestion. The parasympathetic nervous system has the opposite effect of the fight or flight, as this response triggers homeostasis. This relaxes the individual after the emergency, slowing heart rate and non essentials back on. What are neurons and outline the three main ones Neurons are specialised cells designed for the transmission of information throughout the body, there are three types: Sensory neurons, these carry impulses from receptors to the spinal cord/brain. Relay neurons allow sensory and motor neurons to communicate with each other, located in the brain and spinal cord. Motor neurons from synapses with muscles and when an impulse travels down the motor neuron it causes the muscle to contract. Outline synaptic transmission Action potential is the electrical signal that travels down the neuron to the axon ready to be passed on. To cross a synaptic junction the end of an axon has many sacks of neurotransmitters known as vesicles which assist the message transfer. When the action potential reaches the synaptic vessels it causes them to release neurotransmitters, this is known as exocytosis. The neurotransmitter diffuses across the synaptic junction and binds to receptor sites on the post synaptic knob. Once these sites are activated it produces either an excitatory or an inhibitory effect on the post synaptic knob. This whole process takes a fraction of a second and is ended when the neurotransmitters are reabsorbed by the reuptake site. As stated before based on the neurotransmitter released it can cause either an excitatory or an inhibitory effect. Excitatory neurotransmitters such as noradrenaline make it more likely for an excitatory signal to be sent to the post synaptic knob. This results in an excitatory post synaptic potential meaning the knob is more likely to fire. The inhibitory neurotransmitters such as serotonin obviously have the opposite effect causing an inhibitatory post synaptic potential Outline the endocrine system The endocrine system works along side the nervous system and essentially is very similar in the sense that it controls vital functions in the body. However the endocrine system works much more slowly with much more powerful effects. Instead of using nerves to transmit information it uses blood vessels to deliver hormones. Endocrine glands produce and release hormones with the main ones being the pituitary gland and the adrenal glands. The adrenal glands are on top of the kidneys. The outer part is called the adrenal cortex and the inner is the adrenal medulla. The adrenal cortex releases hormones which are essential to life whereas the adrenal medulla are not. The adrenal cortex produces cortisol which regulates cardiovascular and anti-inflammatory functions. The adrenal medulla releases adrenaline, which increases heart rate and thus blood flow to the brain, and noradrenaline which constricts blood vessels causing blood pressure to go up. Outline the fight or flight response When a person experiences a life threatening or stressful situation the body responds with what is known as the fight or flight response. It is an evolutionary adaptive survival mechanism enabling us to react quickly to certain stimuli. However this response now days is activated too often to non life threatening situations such as exam stress. It works by as follows, when faced with a stressful situation the amygdala is activated a signal is then sent to the hypothalamus which uses the sympathetic nervous system to communicate with the rest of the body. It's response to acute stress takes the sympathomedullary pathw