Menstruation

2018-12-10T09:33:02Z

180138397: Edited reference

Menstruation is the female body's monthly cycle in preparation to become [[Pregnancy|pregnant]]<ref>https://www.webmd.com/women/normal-period</ref>. If the egg isn't fertilised during a specific time during the cycle, pregnancy doesn't occur and the [[Uterus|uterus]] lining is shed in the form of a period. The length of the cycle is detemined by the number of days between the first full day of bleeding on one period to the first full day of bleeding on the next and the average cycle length for most women is 28 days although it ranges from about 24-35 days<ref>https://womeninbalance.org/about-hormone-imbalance/</ref>. 

The menstrual cycle is controlled by 3 main hormones: Folicle Stimulating Hormone (FSH), [[Oestrogen|Oestrogen]] and [[Luteinizing hormone|Luteinizing Hormone]] (LH)<ref>https://www.healthline.com/health/womens-health/stages-of-menstrual-cycle</ref>.

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Menstruation

2018-12-10T09:29:20Z

180138397: Created page

Antibiotics

2018-12-07T16:40:51Z

180138397:

Antibiotics are drugs which are used to treat infections. When they were first discovered they were thought to be a wonder drug that would eliminate all worldwide [[Infection|infection]]. However, it was soon realised that the [[Bacteria|bacteria]] they were treating would develop resistance against them. This resistance can be either intrinsic or acquired resistance. Acquired resistance is when the antibiotics are effective at treating the infection but over time they develop resistance<ref>H P Rang, M M Dale et al. (2007). Rang and Dale's Pharmacology. 7th ed. Spain: Elsevier. 609-37.</ref>. Intrinsic resistance is when the bacteria never respond to the antibiotics they have always had resistance. In response to the increase in antibiotic resistance new drugs keep being synthesized in an attempt to find new cures – however, the amount of new effective antibiotics being found is rapidly decreasing<ref>Yassin, Dawson (2007). Pharmacology. 3rd ed. China: Mosby. p201-210.</ref><ref>H P Rang, M M Dale et al. (2007). Rang and Dale's Pharmacology. 7th ed. Spain: Elsevier. 609-37.</ref>.

It was [[Alexander Fleming|Alexander Fleming]] who discovered the first known antibiotics. This was in the 1920’s when he saw [[Staphylococci|Staphylococci]] being inhibited by [[Penicillin|Penicillin]]. However discovering how to extract the penicillin and use it effectively did not occur until the 1940s<ref>Yassin, Dawson (2007). Pharmacology. 3rd ed. China: Mosby. p201-210.</ref>.

There are three different types of antibiotics; [[Bacterostatic|bacteriostatic]], [[Bactericidal|bactericidal]] and [[Bacteriolytic|bacteriolytic]]. Bactericidal antibiotics, on the other hand, kill all of the bacteria present, ridding the body of any present infection<ref>Yassin, Dawson (2007). Pharmacology. 3rd ed. China: Mosby. p201-210.</ref><ref>H P Rang, M M Dale et al. (2007). Rang and Dale's Pharmacology. 7th ed. Spain: Elsevier. 609-37.</ref>. If you were to plot this on a graph of log cell number vs time, the total number of cells would remain constant (dead cells count towards total cell number), but the number of viable cells would drop dramatically. Bacteriostatic antibiotics act by simply halting the growth and proliferation of bacterial cells, to give the body time to deal with the infection. On the same type of graph, both total cell count and viable cell count would remain the same. Bacteriolytic antibiotics act to lyse the bacteria, dramatically decreasing the total cell count and the viable cell count. Many common antibiotics such as [[Penicillin]] act in this way. Penicillin acts by irreversibly binding to and inhibiting the enzyme ([[Transpeptidase]]) that creates cross-links between the peptidoglycan in the cell wall. The cell wall is now not functional to protect the bacterial cell from [[Lysis]] via [[Osmotic action]]. Bacteriolytic antibiotics may not be favourable in bacteria that contain endotoxins which would release upon cell lysis as these can be very harmful to the body.

Antibiotics are used to treat [[Bacteria|bacteria]] that cause [[Infection|infection]]. The first antibiotic to be discovered was penicillin and was founded by [[Alexander Flemming|Alexander Fleming]].

=== '''How was Penicillin discovered?''' ===

Alexander Flemming discovered penicillin completely by accident. He was working with a strain of ''[[Staphylococcus|Staphylococcus]]'' [[Bacteria|bacteria]] and found that the Petri dishes became infected with [[Fungi|fungi]]. However, there was a ring around each colony where the [[Bacteria|bacteria]] had died. Flemming did some research into the [[Fungi|fungi]] and found it came from the Penicillium genus which is how penicillin got its name<ref>Sadava et al. (2012). Life, the Science of Biology. 10th ed. Sunderland: Sinauer Associates Inc. 608</ref>.

=== Why do antibiotics work? ===

[[Bacteria|Bacteria]] and [[Eukaryotes|eukaryotes]] form two different kingdoms meaning that there are many differences between them. These differences can be exploited when trying to beat an [[Infection|infection]]. Drugs can directly inhibit a process in [[Bacteria|bacteria without]] causing any disruption to a similar process in the host [[Organism|organism]]. Many antibiotics target the cell wall biosynthesis as [[Eukaryotic cells|eukaryotic cells]] don’t have cell walls making it an easy target<ref>Alberts et al. (2008). Molecular Biology of the Cell. 5th ed. New York: Garland Science. 1521-1522.</ref>.

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Menstruation

Menstruation

Antibiotics