foetal-development

An umbilical cord with a true knot. A true knot is exactly what is described, a knot that forms in the umbilical cord during the pregnancy, typically as a result of the foetus flipping and moving within the amniotic sac. True knots can, at times, be a risk to the developing foetus as it can lead to a reduction in circulation and this may result in the death of the foetus in utero - especially during labour. 

Prime Violinists Leave Baseball Game Cells

Insider Baseball by Joan Didion (New York Review Of Books): This essay just nails the ways in which politics is basically upmarket reality TV (in that almost everything about what most people see and read about politics is content which has been deliberately manufactured to fill in TV newstime), where the journalists and politicians have an unspoken knowledge of the rules of the game. All of which prevents outsiders (e.g., large swathes of the 99%) from having much of a say in the political process, and prevents important issues from being debated. And it’s exactly the same in Australia. [via Jay Rosen, who also has interesting/related things to say about coverage of the US Republican primaries]

Test of Time: In Defense Of A Game That Lasts Five Days by Wright Thompson (ESPN): The form of cricket called ‘test cricket’ is a very strange thing: a game lasts for five whole days, and quite often ends in a draw. And a game where, though the point is to score runs by hitting balls, there are batsmen who are earnestly praised for their ability to not hit the balls. Though for something so strange, it’s extremely popular right now in Australia - it’s more or less the biggest news story going between Christmas and mid-January. I was watching a test between Australia and India the other day, and where other games have cheerleaders and sirens and so forth, this game had artists stationed around the stadium, some of whom drew impressionist pieces of the game. Anyway, Thompson is an American who is baffled by the appeal of this very strange game (which I do love and have strong opinions about), and who goes to all five days of a test to try and understand how such a game could possibly survive into the 21st century. In the end, he seems to think that test cricket is basically a form of Zen.

Our Selves, Other Cells by Jena Pincott (Boing Boing): When you’re a foetus, inside your mother’s belly, you swap cells with your mother. By the end of pregnancy, about 6 percent of the DNA in your mother’s bloodstream comes from the fetus. And some of the cells in your body, to this day, actually have your mother’s DNA. Which is amazing when you think about it, and may well explain things like babybrain.

Anesthesia May Leave Patients Conscious - And Finally Show Consciousness In The Brain by Vaughan Bell (The Crux): Doctors assume that patients are unconscious if they do not respond to prodding or talking. This is not always the case - perhaps 1 in 1000 people who go under don’t actually go fully under. And such phenomena may say very interesting things about the workings of the mind. (Though the examples of people who are not fully unconscious that Bell gives here seem much more like people dreaming than people who are semi-conscious - or is that the idea?)

The Prime Minister Who Disappeared by Mike Dash (Past Imperfect): In 1967, an Australian Prime Minister named Harold Holt literally disappeared. He went for a swim on a beach (somewhat foolhardily, considering) and drowned; his body was sucked under the water and he was never seen again. Of course, there were conspiracy theories about him boarding a Chinese submarine. Sadly, Dash’s article forgets to mention the existence in Melbourne of the Harold Holt Swim Centre, a suburban public pool, named in somewhat poor taste (but possibly typical Australian humour).

Violinists Can’t Tell The Difference Between Stradivarius Violins And New Ones by Ed Yong (Not Exactly Rocket Science): Of course they can’t - it’s all placebo effect. I’m very curious to see if guitar nerds can actually tell the difference between the tones of the various electric guitars and amps that they talk about at such length. (Maybe I should do a study on this?) 

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The Brain During Development

The nervous system develops from embryonic tissue called the ectoderm. The first sign of the developing nervous system is the neural plate that can be seen at about the 16th day of development. Over the next few days, a “trench” is formed in the neural plate - this creates a neural groove. By the 21st day of development, a neural tube is formed when the edges of the neural groove meet. The rostral (front) part of the neural tubes goes on to develop into the brain and the rest of the neural tube develops into the spinal cord. Neural crest cells become the peripheral nervous system.

Texas doctor's consent form for women seeking abortions #1yrago

Redditor Mystharia terminated a pregnancy for medical reasons last week; her doctor gave her this consent form, mandated by – and scathingly attacking – the Texas legislature, which requires the doctor to enumerate an eye-wateringly detailed account of the foetal development before termination. (Icon: Kevin Dooley/CC-BY)

http://boingboing.net/2015/08/28/texas-doctors-consent-form-f.html

Neural tube defects

Defects of the neural tube are the most common birth defects; one in 1,000 live births in the United States are affected. Adding folic acid to women’s diets reduces neural tube defects by 50-70% (Dukes Centre of human genetics).

Various neural tube defects are caused when different regions of the neural tube fail to close:

-       Failure of the posterior region to close at day 27:  Spina Bifida

-       Failure of the anterior region to close: Anencephaly

-       Failure of entire neural tube to close along entire body axis: Craniorachischisis

Spina bifida leaves some of the spinal cord exposed, the severity of the condition depends on how much of the spinal cord remains exposed. Anencephaly on the other hand leaves the forebrain exposed to amniotic fluid causing it to degenerate - interrupting fetal brain development and preventing the skull form forming. Anencephaly is fatal.
 

Foetal brain development, artwork. During the 4th week (25 days) the neural tube begins to differentiate into a spinal cord, forebrain, midbrain and hindbrain. These areas continue to develop over the 5th week (35 days). During the 6th week (40 days) the forebrain differentiates into the telencephalon and diencephalon. The telencephalon develops into the hippocampus, basal ganglia, amygdala and the cerebral cortex. The diencephalon develops into the thalamus and hypothalamus. By the 8th week (50 days) the cerebral hemispheres have formed and the brain is growing rapidly. By the 15th week (100 days) the cerebellum and medulla oblongata have formed from the hindbrain.

Foetal brain. Ventral (bottom) view of the brain of a 24-week-old foetus, the front of the brain is at top. The foetus’ developing spinal cord (lower centre) can be seen protruding from the brain. Below the spinal cord is the cerebellum, which controls motor function and maintenance of balance. The small organ at centre is the pituitary gland. This is an endocrine gland whose overall role is to regulate growth and metabolism. At this stage of development the foetal brain shows active auditory and visual responses.