Homeostasis refers to the ability of the body to maintain an optimal internal environment by acting to restore any changes that take the body away from this optimal state. Many examples of homeostasis will be familiar, such as those concerning temperature where your body acts to return to an optimal temperature when faced with a deviation from this. (A)Thus, when your body starts to overheat as in a sauna, sweat will soon appear on the body surface. Sweating serves to lower the body temperature. Conversely in a cool environment, we start to shiver.
Hormones may play a role in this process, for example the hormone arginine vasopressin. This hormone (B) is secreted from a gland located at the base of the brain, the pituitary gland, in response to dehydration (Toates, 2006). From here ‘it is transported in the blood to the kidney, where it slows up the production of urine’ (Toates, 2006). By contrast, if the body is over-hydrated, secretion of the hormone is reduced or stopped and the excretion of water is high. It is through this process that levels of water can be returned to the ideal level.
1 (A) i) PLAGIARISED
(A) Is plagiarism because is copied exactly from a passage of text without the use of quotation marks or an in text reference to the writer, or book. (B) is plagiarism, this is because it does not have quotation marks. This shows little about the students’ level of understanding. ii) CLOSELY PARAPHRASED
This is very closely paraphrased from book 1, page 21. There are only a few words that are different and is considered plagiarism. This shows little about the students’ level of understanding. iii) QUOTED FROM TEXT
This is quoted from the text correctly as indicated by the use of both quotation marks and an in text reference to the author. This shows little about the students’ level of understanding. iv) WRITTEN ABOUT TOPIC IN OWN WORDS.
This might be considered to be a paraphrase of text as it’s very similar, however, it would be very difficult to define homeostasis without paraphrasing the definition supplied. I believe that the rest of the answer is written about in the writers own words, the grammar is similar to that of the first part and the sentence flows well. This shows that the student does have a basic understanding of homeostasis and understands an example of it, the information written should have been much richer.
(199 words)
1 (B)
As the hypothalamus is concerned with homeostasis the hypothalamic neurons are activated when responding to deviations from homeostasis, activations will occur in order to regulate food and liquid intake and body temperature (Romero, 2006), the responses on the body that these neurons induce can be altered heart rate, changing the movement of food along the gut, and goose pimples (Romero, 2006). The pituitary gland is connected to the hypothalamus, it secretes hormones into the bloodstream, this process is controlled by the activity of the hypothalamic neurons (Romero, 2006). The responses to the activated neurons may trigger the sympathetic and parasympathetic branches of the ANS into either activity or reduced activity, a great example of this is when we are faced with danger and must ‘fight or flight’, the sympathetic branch of the ANS will be activated and hormones such as adrenaline and noradrenaline will be released in order to prepare the body for ‘fight or flight’. While the ‘fight or flight’ sympathetic response is occurring the pituitary gland will be induced into activation by the hypothalamic neurons and will release the hormone ACTH into the blood (Romero, 2006), which, when it reaches the adrenal will continue the production of adrenaline and as such the appropriate internal responses. This example shows how the hypothalamic neurons can indeed compliment the ANS.
Question 2
2 (A)
The putamen, globus pallidus, subthalamic nuclei and substantia nigra are all
