AQA Psychology for A Level Year 2 - Student Bk

1. Name and briefly outline two divisions of the human nervous system. [4 marks] 2. Identify and describe two glands of the endocrine system. [2 marks + 2 marks] 3. Briefly outline two hormones and explain the function of each of these. [2 marks + 2 marks] 4. Using an example, explain what is meant by the fight or flight response. [3 marks] Check It Methods: Stress and illness Research has shown that people who get ill have often experienced major stressful life events in the previous few months and years, such as getting married, divorce, death of a loved one, etc. A researcher investigated this relationship between illness and life events. She gave 150 participants a questionnaire in which they had to indicate the number of major life events (from a list of 20) they had experienced over the past three years. This was compared to the number of days off work through illness the participants had had over the same period. The researcher found a positive correlation between the two co-variables. 1. In the context of the investigation above, what is meant by ‘a positive correlation between the two co-variables’? ( 2 marks ) (See page 63) 2. Suggest a suitable graphical display that the researcher could have used to show the relationship between the two co-variables. ( 1 mark ) 3. Explain one advantage of correlational studies . Refer to the investigation above in your answer. ( 2 marks ) 4. Explain the difference between correlations and experiments. ( 3 marks ) @ookx hs @ookx hs The endocrine system Glands and hormones The endocrine system works alongside the nervous system to control vital functions in the body. The endocrine system acts much more slowly than the nervous system but has very widespread and powerful effects. Various glands in the body, such as the thyroid gland , produce hormones . Hormones are secreted into the bloodstream and affect any cell in the body that has a receptor for that particular hormone. Most hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses. For example, the thyroid gland produces the hormone thyroxine . This hormone affects cells in the heart (increases heart rate). It also affects cells throughout the body increasing metabolic rates (the chemical processes taking place in the cells). This in turn affects growth rates. The main glands of the endocrine system are shown in the diagram on the right. The major endocrine gland is the pituitary gland , located in the brain. It is often called the ‘master gland’ because it controls the release of hormones from all the other endocrine glands in the body. Endocrine and ANS working together: Fight or flight Often the endocrine system and the autonomic nervous system work in parallel with one another, for instance during a stressful event. When a stressor is perceived (your friend jumps out to frighten you or you think about your upcoming exams) the first thing that happens is a part of the brain called the hypothalamus triggers activity in the sympathetic branch of the autonomic nervous system. The ANS changes from its normal resting state (the parasympathetic state ) to the physiologically aroused, sympathetic state (try it – think of having to learn all this for your exams).The stress hormone adrenaline is released from the adrenal medulla (a part of the adrenal gland) into the bloodstream. Adrenaline triggers physiological changes in the body (e.g. increased heart rate) which creates the physiological arousal necessary for the fight or flight response. All of this happens in an instant as soon as the threat is detected – an acute response – and is an automatic reaction in the body. The physiological changes associated with this sympathetic response are listed in the table below right. These changes explain why stress, panic, or even excitement, is often experienced as a ‘sick’ feeling (‘butterflies’ in your stomach – does that describe what you were feeling?). Finally, once the threat has passed, the parasympathetic nervous system returns the body to its resting state. The parasympathetic branch of the ANS works in opposition to the sympathetic nervous system – its actions are antagonistic to the sympathetic system. The parasympathetic system acts as a ‘brake’ and reduces the activities of the body that were increased by the actions of the sympathetic branch. This is sometimes referred to as the rest and digest response. Practical activity on page 53 Key terms Endocrine system – One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body. Gland – An organ in the body that synthesises substances such as hormones. Hormones – Chemical substances that circulate in the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful. Fight or flight response – The way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or, in some cases, flee. Adrenaline – A hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system – stimulating the heart rate, contracting blood vessels and dilating air passages. Biological changes associated with the sympathetic and parasympathetic response. Sympathetic state Parasympathetic state Increases heart rate Decreases heart rate Increases breathing rate Decreases breathing rate Dilates pupils Constricts pupils Inhibits digestion Stimulates digestion Inhibits saliva production Stimulates saliva production Contracts rectum Relaxes rectum Hypothalamus Pituitary Parathyroid Thyroid Adrenals Pancreas Ovaries (female) Testes (male) The main endocrine glands in the human body. the nervous system and the endocrine system 35 •