Biopsychology

Specification The divisions of the nervous system: central and peripheral (somatic and autonomic). The structure and function of sensory, relay and motor neurons. The process of synaptic transmission, including reference to neurotransmitters, excitation and inhibition. The function of the endocrine system: glands and hormones. The fight or flight response including the role of adrenaline. Localisation of function in the brain and hemispheric lateralisation: motor, somatosensory, visual, auditory and language centres; Broca’s and Wernicke’s areas, split brain research. Plasticity and functional recovery of the brain after trauma. Ways of studying the brain: scanning techniques, including functional magnetic resonance imaging (fMRI); electroencephalogram (EEGs) and event-related potentials (ERPs); post-mortem examinations. Biological rhythms: circadian, infradian and ultradian and the difference between these rhythms. The effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle.

The nervous system Biopsychologists assume that behaviour and experiences are caused by activity in the nervous system The nervous system is a specialised network of cells in the human body and is our primary internal communication system It has two main functions: To collect, process and respond to information in the environment To co-ordinate the working of different organs and cells

The major sub-divisions of the human nervous system

CNS Brain and spinal cord

The central nervous system (CNS) The CNS is made up of the brain and the spinal cord The brain is the centre of all conscious awareness. The brain’s outer layer, the cerebral cortex, is highly developed in humans The brain is divided in two hemispheres The spinal cord is an extension of the brain. It is responsible for reflex actions The CNS passes messages to and from the brain and connects nerves to the PNS

The brain Section 1: (The Brain) The Cerebral Cortex, which is involved in a variety of higher cognitive (conscious thought), emotional, sensory, and motor (movement) functions is more developed in humans than any other animal. It is what we see when we picture a human brain, the gray matter with a multitude of folds making up the outer layer of the brain. The brain is divided into two symmetrical hemispheres: left (language, the ‘rational’ half of the brain, associated with analytical thinking and logical abilities) and right (more involved with musical and artistic abilities). These are further divided up into four distinct lobes, which you will learn more about later. Under the cerebral cortex is the area of the brain which is more primitive and are concerned with vital functioning and instinctive behaviour.

The spinal cord The spinal cord is a white bundle of nerves, which runs from your brain down a canal in your backbone. It's roughly 40cm long and about as wide as your thumb for most of its length. Like the brain, your spinal cord is part of your central nervous system. Its main function is to relay information about what's happening inside and outside your body to and from your brain. It is also involved in reflex actions, such as the startle response.  

Complete the section A exam questions on the CNS Test yourself… Complete the section A exam questions on the CNS

PNS

The peripheral nervous system (PNS) The PNS transmits messages via millions of neurons (nerve cells), to and from the central nervous system The PNS is further sub-divided into: the somatic nervous system (SNS) the autonomic nervous system (ANS)

The somatic nervous system (1) The Somatic Nervous System is part of the PNS that is concerned with the interaction of the outside world. It is responsible for carrying sensory and motor information to and from the spinal cord. It controls the voluntary movement of skeletal muscles. It also consists of the nerves that carry messages from the eyes, ears, skeletal muscles and the skin to give the CNS experience of its environment.

The Autonomic Nervous System (1) Is the part of the PNS that controls involuntary movement from non-skeletal muscles, for example, the ‘smooth muscles’ that control the intestines, bladder, pupil size etc. and the cardiac muscle (the heart). It governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses The ANS is spilt into two further systems: the sympathetic and parasympathetic systems.

The two main divisions of the ANS The two main divisions of the autonomic nervous system are: The sympathetic nervous system The parasympathetic nervous system Their actions are mostly antagonistic - that is they usefully work in opposition to each other

The two main divisions of the ANS Section 1a: The Sympathetic Nervous System Is activated in situations requiring arousal and energy. When we feel threatened or under stress, the sympathetic branch of the ANS is activated which starts the instinctive reaction of ‘fight or flight’, aiding survival (you have more detail later). It produces increased heart and respiratory (breathing) rate, increasing blood flow to the muscles and pupil dilation (bigger pupils)   Section 1b: the Parasympathetic Nervous System This is activated soon after the threat of danger has passed. This has the opposite effect of the Sympathetic Nervous System and allows for the body to return to homeostasis (balance). Here the person’s heart and respiratory rate decrease to normal levels and blood flow decreases. The pupils return to normal size. This system is vital for the individual to conserve energy and not to become exhausted

Complete the section B exam questions on the PNS Test yourself…. Complete the section B exam questions on the PNS

Draw out the full diagram Are you ready…. Draw out the full diagram

The major sub-divisions of the human nervous system

Exam practice 1. Briefly distinguish between the central nervous system and the peripheral nervous system (3 marks) 2. Jenny has heard a loud bang and experienced the startled response. Which part of the nervous system is responsible for this and describe one bodily action in relation to the noise (1 + 2 marks) 3. Outline the main functions of the central nervous system (3 marks)

a) Briefly distinguish between the central nervous system and the peripheral nervous system (2 marks) The central nervous system (CNS) consists of the brain and the spinal cord, whereas the peripheral nervous system (PNS) consists of the somatic and autonomic nervous system (1 mark). The CNS is responsible for all conscious awareness and experience as well as some reflex actions, whereas the PNS is responsible for sending messages to and from the CNS to organs and muscles and the involuntary fight or flight response (2 marks).

b) Jenny has heard a loud bang and experienced the startled response b) Jenny has heard a loud bang and experienced the startled response. Which part of the nervous system is responsible for this and describe one bodily action in relation to the noise (1 + 2 marks) The sympathetic nervous system (1 mark). One bodily action is that her heart rate increases (1 mark) to increase the flow of blood to the muscles (1 mark)

c) Outline the main functions of the central nervous system (4 marks) The Central Nervous System consists of the brain and the spinal cord. The brain is involved in a variety of higher cognitive, emotional, sensory, and motor (movement) functions. The brain is divided into two symmetrical hemispheres: the left is linked to language and is considered the ‘rational’ half of the brain, associated with analytical thinking and logical abilities. The right hemisphere is more involved with musical and artistic abilities. The brain also contains many structures responsible for regulating actions which keep us alive. The main function of the spinal cord is to relay information about what's happening inside and outside your body to and from your brain. It is also involved in reflex actions, such as the startle response.

Plenary: You will be given a card by your teacher who is the nervous system. Read it through it carefully and try to work out which bit of the nervous system it is referring to. Don't discuss and don't look at notes. The classroom has now been split in half- cns and pns. You have one minute to decide which half of the nervous system you belong in and get to that side. Does your side agree you should be there? Now the tables in your half have been named either brain, spinal cord, somatic, autonomic, sympathetic and parasympathetic. Where do you belong? Go to your table and share your card with your group. Are you in the right place?