Organisation of the nervous system



Biological Psychology: Organisation of the nervous systemOrganisation of the nervous systemKey Terms:Central nervous system (CNS) - Major part of the nervous system, made up of the brain and the spinal cord.Spinal nerves- Nerves are bundles of neuronal processes, mainly axons, travelling around the body. The spinal nerves radiate from the spinal cord. They carry sensory information into the central nervous system, and motor commands out the muscles and glands. The spinal nerves make up the peripheral nervous system (PNS).Sensory pathways- Pathways in spinal nerves running from sensory receptors into the central nervous system, carrying sensory information.Motor pathways- Pathways in spinal nerves carrying commands from the brain out to muscles and glands.Autonomic nervous system (ANS)- Part of the peripheral nervous system concerned with the regulation of internal structures and systems. It is vital in maintaining physiological regulation of the body.Brainstem - Collectively, the pons, medulla and midbrain regions of the brain. The brainstem controls vital physiological functions, and contains autonomic nervous system centres.Homeostasis - Regulation of a constant internal environment. The best example is our constant body temperature. Homeostasis is heavily reliant on the autonomic nervous system.Sympathetic nervous system- One of the two branches of the autonomic nervous system. Sympathetic dominance leads to a pattern of bodily arousal and preparation for energy expenditure.Parasympathetic nervous system- One of the two branches of the autonomic nervous system. Parasympathetic dominance leads to a pattern of physiological calm.Hypothalamus- Part of the diencephalon in the forebrain. Controls the HPA and SAM pathways involved in responses to stress.Hindbrain- Division of the brain, containing the medulla, pons and cerebellum.Forebrain- Largest division of the brain, containing the systems controlling higher cognitive and emotional functions. Key components are the diencephalon, limbic system, basal ganglia and cortex.Cerebellum- Large structure in the hindbrain, involved in coordination of movement. Damage results in a loss of motor coordination.Diencephalon- Component of the forebrain, containing the thalamus and the hypothalamus.Thalamus- Large structure in the diencephalon of the forebrain. Relays sensory pathways on to the cortex.Pituitary-adrenal system- One of the two key pathways involved in the body’s response to stress. The hypothalamus stimulates release of adrenocorticotrophic hormone (ACTH) from the pituitary gland into the bloodstream. ACTH travels to the cortex of the adrenal gland and triggers release of cortisol and other corticosteroids into the bloodstream.Sympathomedullary pathway- One of the two key components of the body’s response to stress. Activated by the hypothalamus, nerve pathways of the sympathetic branch of the ANS stimulate the adrenal medulla to release adrenaline and noradrenaline into the bloodstream.Limbic system- Interconnected structures in the forebrain, with major roles in emotion and memory. Key structures include the hippocampus, amygdala, septum and cingulated gyrus.Hippocampus- Major structure of the limbic system. Important in memory and emotional processing.Amygdala- Limbic system structure in the forebrain. Important in emotional processing.Basal Ganglia- System on interlinked structures in the forebrain with important functions in controlling movement. Damage can cause movement disorders such as Parkinson’s disease.Parkinson’s disease- Movement disorder characterised by tremor of hands and arms. This is a progressive disorder caused by damage to the basal ganglia.Motor cortex- Region of the cortex vital in controlling movement. Damage can cause motor paralysis.Sensory cortex- Regions of the cortex where input from our sensory receptors is analysed. Complex sensory systems such as vision and hearing have their own specialised cortical areas.Association cortex- Regions of the cortex where high level cognitive and emotional functions are organised. The largest area of association cortex is in the frontal lobe of the brain.Cerebral asymmetry- Sensory and motor functions are found on both sides of the brain. Some functions of association cortex are confined to one side or the other, i.e. they are asymmetrical.2081937545795There are billions of nerves which make up the nervous system and they are organised in systematic ways. We have the central nervous system, which is made up of the spinal cord and the brain. We also have spinal nerves radiating from the spinal cord... this is basically how the CNS connects with the rest of the body.BrainBrainstemPaired spinal nervesSpinal cordThe brain needs to receive sensory information which is carried in sensory pathways. They are carried from the sensory receptors to the CNS. The brain must be connected to muscles in the body, to basically control movement & it also controls the internal organs so the brain is connected through motor pathways. The peripheral nervous system is made up of spinal nerves. It contains millions of pathways connecting the brain to our body, the outside world and our responses. The autonomic nervous systemThis is important in terms of arousal due to stress and they are located in the brainstem. The go down the spinal cord and are spread through the body by spinal nerves. It controls vital functions such as body temperature, heart rate and blood pressure. The ANS has two separate divisions, the sympathetic branch and the parasympathetic branch, usually these two branches balance however in certain circumstances, the balance shifts and one becomes more dominant.Sympathetic arousal leads to a pattern of bodily arousalParasympathetic dominance leads to the opposite pattern, one of psychological harmThe BrainInitially, the brain is divided into hindbrain, midbrain and forebrain. The hindbrain is made up of the medulla, pons and cerebellum; these are classified together as the brainstem. The forebrain in the largest part of the brain, and is also divided into major components.The diencephalon contains two main structures, the thalamus and the hypothalamus. The thalamus relays sensory information from pathways coming from the spinal cord and brainstem. The hypothalamus is involved in many of the body’s physiological functions which include stress-related arousal, hunger, thirst and sexual and reproductive behaviours.Cerebral HemispheresThis contains the structures mostly linked to psychology as high level cognitive and emotional processes are controlled from these areas. Three major systems make up cerebral hemispheres:The limbic system is a set of interconnected structures: the hippocampus, amygdala, septum and cingulated gyrus. They are involved with memory, learning and emotionsThe basal ganglia have functions related to movement and motor control. Damage to this results in disorders such as Parkinson’s disease.The cerebral cortex is the most recently evolved part of the brain. It is a thin layer of neurons covering the forebrain, however thin it still contains 90% of the neurons in the forebrain. It is involved in cognitive functions such as planning, problem-solving, language, consciousness and personality.BrainstemMedullaPonsMidbrainSpinal CordCerebellumCerebral Hemisphere1345996368300 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download