Discuss the role of negative feedback in living organisms and how it benefits these living organisms? (25 marks) Negative feedback is the process by which changes occur to bring an organism’s internal environment back to the normal level. One example of negative feedback in a living organism is the ways humans regulate their blood glucose levels. I will firstly discuss the processes that occur as a result of blood glucose levels being too low. When blood glucose levels are too low the pancreas
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thyroid hormones thyroxine (T4) and triiodothyronine (T3) that increase the body’s metabolic rate. The thyroid is regulated by the hypothalamus gland in the brain that makes thyrotropin-releasing hormones that then stimulate the pituitary gland to make thyroid-stimulating hormone (TSH) which is what regulates the thyroid’s production of hormones. Both the hypothalamus and the pituitary gland
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Page 429 #’s 1-7 1. List the three major parts of the brain and describe their locations. A. cerebrum- constitutes about 83% of its volume and consists of a pair of half-globes called the cerebral hemispheres. B. cerebellum- lies inferior to the cerebrum and occupies the posterior cranial fossa. C. brainstem- that which remains of the brain if the cerebrum and cerebellum are removed. 2. Gyrus- a wrinkle or fold in the cortex of the cerebrum or cerebellum. Sulcus- a groove in the surface of
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Homeostasis is the maintenance of a steady state. With changes within and around living cells‚ conditions are maintained at a constant level. The ‘two major control systems‚ nerves and hormones‚ are mainly responsible for co-ordinating homeostatic mechanisms’ (Human Body) whilst using feedback. If a change in condition is detected a corrective mechanism is activated‚ conditions return to set point and the corrective mechanism is then switched off. The conditions are then at constant level. Some of
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obesity and the health problems associated with being fat are the most prominent features. Individuals with PWS have some but not all of the same features and symptoms. PWS is a birth defect. A defect in the hypothalamus‚ a region of the brain‚ is suspected to be the cause.The hypothalamus determines hunger and satiety.They can’t fell satiety‚so they always have a urge to eat.Some PWS cases are so out of control thay will eat bottlecaps‚glass‚pencils‚garbage‚bugs‚dogfood‚ and anything else they
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Otitis media is a common inflammation found most frequently in infants and young children. Otitis media is an inflammation of the mucous membrane of the middle ear. It occurs due to the obstruction of the eustachian tube permitting secretions and bacteria from the nasopharynx into the middle ear. Otitis media is categorized into two different sections‚ acute otitis media‚ and otitis media with effusion. Acute otitis media is present with a cold‚ allergy‚ or an upper respiratory infection. When bacteria
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temperature‚ which is the temperature in the center of your body. The temperature sensors in your skin and internal organs monitor your core temperature. Your control center is the hypothalamus in your brain where the sensors transmit signals to via nerves. If your core temperature rises above its set point the hypothalamus then sends fewer nerve impulses to blood vessels in the skin causing blood vessels to dilate. When it does this‚ it increases blood flow to the skin and promotes heat loss. It activates
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Infradian rhythms are biological rhythms that last for more than 24 hours. They are controlled by the hypothalamus‚ an endogenous pacemaker which requires input from exogenous zeitgebers so the rhythm can run correctly. An example of an infradian rhythms is the mentstrual cycle. This is controlled by the pituary gland which is an endogenous pacemaker. The pituary gland releases hormones which cause an egg in the ovaries to ripen and produce oestrogen. Whilst it is known to be biological due to its
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Hyperthyroidism‚ also known as Thyrotoxicosis‚ is a condition that is caused by the excessive release of thyroid hormones into the body. These thyroid hormones include thyroxine and triiodothyronine. Hyperthyroidism‚ while not a deadly disease‚ effects about 1.2% of the population‚ occurs mostly in women‚ and can have detrimental effects on the body. Generally‚ Hyperthyroidism arises as a symptom of other more prevalent diseases. An example of this is Graves disease. Graves disease is the number
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production 7 found in the upper thorax overlying the heart; 8 large during youth found in the roof of the third ventricle 9. Although the pituitary gland is often referred to as the master gland of the body‚ the hypothalamus exerts some control over the pituitary gland. How does the hypothalamus control
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