What I learnt this week part 3 (Guest blog by Elinor Bridges)

Elinor BridgesHi everyone, I’m back – which fortunately means I wasn’t crushed under a growing pile of books last week in an effort to finish my coursework on time. Lucky for you, this past week of essays and a brief tryst with some early revision have taught me a lot. Now, it is time for me to pass the fruits of my laborious week onto yourselves. Please enjoy these seeds of knowledge, and let us hope your metaphorical mind is awash with lichen so that they may germinate.

I’m lichen the side of this mountain

Yes, it is pronounced lie-ken, not lich-in.

Lichen are a symbiosis between two types of organism, as I rediscovered during an optimistic, yet ultimately short-lived, revision session for Microbes, Man and the Environment. Lichen are made up of two components: a photosynthetic alga and a fungus. Each organism has something to offer its partner – rather like any partnership. The alga provides the fungus with sugars, while the fungus attaches to a surface for the lichen to live on and protects the alga from desiccation. While this might sound likeLichen-covered_tree,_Tresco something of a fragile being, these little guys are extremely hardy. They can live in incredibly harsh environments, and as alluded to above, are the only known organism type that can colonise bare rock. It is a testament to their toughness that they can survive on mountains for over 4000 years.

Colonisation by lichen is vital for ecosystems in certain areas, with lichen also making homes on tree bark and rooftops. When the lichen colonises a new substrate, it brings organic molecules into the area. When the lichen dies, it breaks down and forms a basic soil. If a lucky, wind-dispersed seed drifts in the right direction, it might just find itself landing on a spot that used to be a lichen. The presence of the soil means it is possible for the seed to germinate in that particular place, leading to a plant growing on the previously bare surface. This can begin a chain reaction which eventually leads to a whole community of organisms living in a place that was once as barren as the library during the Easter break.

(Foxg)love hearts

Despite the enduring chill, its undeniable that spring is in the air – a time associated with flowering plants and new love. While this post may be rather heavy on the plants, the closest we get to love is rather symbolic – hearts. For an essay exploring the influence of herbal remedies on modern medicine, I found myself learning an awful lot about hearts and the common foxglove.

Digitalis purpurea2 by Kurt StüberThis plant has been used as a herbal remedy for centuries, intended as a cure for a huge variety of illnesses. It has even been used to encourage vomiting in patients as it was sometimes believed that this would help them – because all you need when you’re under-the-weather is a poisonous plant rubbed onto your skin to make you vomit. Fortunately, the wonderful William Withering published something that could be recognized as a scientific study into foxglove in 1785. Here, he discussed use of foxglove in helping those with heart problems. As it turns out, he was onto something. Today, a compound from the foxglove is used in the treatment of cardiac arrhythmias – irregular beating of the heart. In just the right quantities, the compound alters the behaviour of the sodium-potassium pump in cell membranes to encourage a stronger and steadier heart rate.

Unlike in Withering’s time, the doses given today are highly researched and unlikely to poison you, but if you see a foxglove when you’re out and about I wouldn’t recommend giving it a try!

 

Thus concludes another summary of what I learnt this week. I am now preparing to delve into the darkest, messiest and most incomprehensible lecture notes ever scrawled in an attempt to make some sense of them. Hopefully I will be able to tease some interesting stories out of them for my final instalment on this blog. Until next week!