Ironman flies!
academia.edu
Scary films on iTunes
Back on the bike!
Podcast - embryology of the ear
Schmap!! Brighton
Week 106 - development of the gut
October sea swimming
Olympic cycling star tells car drivers how it is
October 2008 Archives
October 27, 2008
Epiploic appendices!
In the last group of the anatomy teaching this morning I was struggling to think of the right name for the little fatty bits of peritoneum hanging off the large bowel. The textbook calls them omental appendices, which I know is correct but doesn't have the right feel. A quick search of the web turns up the other (older?) name: epiploic appendices. What an awesome sounding term. Say it out loud five times. I think the words link my memory back to my own anatomy learning by dissection.
Epiploic appendices. Nice.
October 26, 2008
October 24, 2008
October 23, 2008
Scary films on iTunes
Brilliant - iTunes have put up a collection of scary films on iTunes. I love the Halloween build up & I'll be downloading a few of these for the dark evenings of the next week. The Fly (Vincent Price!),The Bride of Frankenstein (fantastic trailer), Leprechaun 3. OK, maybe not Leprechaun 3. The actual Halloween list is quite short, but when you start clicking through the linked movies you find plenty of great, old horror films.
The older and more B-movie the better. For some reason stuff like The Saw makes me laugh on the sofa. This is a little unfortunate as I think that scares other people in the room more than the film.
Now, what can I scare Jack with?
October 17, 2008
Schmap!! Brighton
One of my photos got used in Schmap's guide to Brighton.
That's two of my pictures that have been found and published (with my consent) this year. Nice!
October 16, 2008
Week 106 - development of the gut
This week's embryology lecture attempted to link the processes that form the gastrointestinal (GI) tract with the anatomy that you're seeing in the lab. We started by recapping the end of the last lecture (gastrulation) and showing how the flat sheet of the early embryo can be rolled up to form a tube. We looked at the role of the yolk sac in this, and how the ectoderm, mesoderm and endoderm roll up and contribute to the different parts of the embryo.
We divided the simple gut tube into foregut, midgut and hindgut regions based on the attachment of the gut tube to the yolk sac. These regions each have their own artery branching from the aorta (coeliac trunk, superior mesenteric artery and inferior mesenteric artery respectively). This simple tube will dilate, lengthen and twist to form what we recognise as the adult GI tract.
The foregut forms the oesophagus, stomach, part of the duodenum, liver, gallbladder and pancreas. We talked about how each of these forms, and how a 90 degree left to right rotation moves these structures from a midline starting position to their final locations on the left or right side. Most of the tube will become closed by epithelial proliferation during development, and then cleared. Importantly we also looked at the mesentery, which starts as a very simple sheet of connective tissue running in the midline from the dorsal to ventral walls of the embryo's developing abdomen. With the twisting of the gut tube this simple sheet will form all the more complex connecting bits of peritoneum in the adult that tie these organs together, such as the lesser omentum, greater omentum, falciform ligament, gastrosplenic ligament, etc.
The midgut will form the rest of the small intestine and the large intestine as far as the transverse colon. It starts as a simple loop that becomes longer and rotates 270 degrees, again from left to right. As it lengthens it pushes out into the umbilical cord and then is pulled back into the abdomen. The simple mesentery initially holding the single loop of midgut in place has become much larger as the midgut lengthened, and now carries many branches of the superior mesenteric artery to all parts of the tube.
The hindgut will form the remainder of the GI tract and part of the urogenital system. The cloaca is an endoderm lined cavity at the anus end of the gut tube, and becomes split in two by the urogential sinus. The dorsal part will become the rectum and the superior parts of the anal canal, and the ventral part will help form the bladder and the urethra. The cloacal membrane that had closed off the tube up to this point ruptures, and two openings are formed (rectum and urethra). The last part of the anal canal is formed from the external ectoderm, explaining the two separate routes of blood supply to the anal canal in the adult (inferior mesenteric artery and internal pudendal artery).
With these normal developmental processes in mind, what could go wrong and what congenital defects would be observed?
Links:
Pyloric stenosis - kidshealth.org, emedicine.com
Gastroschisis & omphalocoele.
emedicine.com: imperforate anus
October 12, 2008
October sea swimming
Honestly, I took this photo today. This is a late October Sunday afternoon. Cool, eh? Well, except for the daft number of surfers. When the tide is this high there's no width to the bay so everyone gets crammed into a small section. People are playing in the sea or are trying to swim, so surfers dragging their boards out today mostly just sat around looking at each other. It's way too common around here and any beach with surf gets ridiculously busy.
I actually got Jack into the sea and we were bashing through the waves. I think my right ear is ringing from all his screaming.
October 11, 2008
Olympic cycling star tells car drivers how it is
In an interview with the Times, "Victoria Pendleton has a sharp warning for drivers who tear past cyclists at close quarters - watch out, you might kill a British Olympic medallist."
"For starters, many motorists could at least stop being offensive as well as dangerous, says Pendleton. I have to train on the road daily. It's crucial for endurance work. But the abuse I get from drivers ... 'Get off the effing road', and 'Buy an effing car', are typical. I'm usually dressed in the Team GB kit, but drivers take no notice of that."
"It does my head in that people have no regard for my safety. If someone cuts me up, I will sometimes catch up and have a go at them. It's not like their journeys are so important. They're usually off to the shops to waste some more money. Honestly, what's a few seconds in their pointless life for the sake of not killing me?"
"Her fears are sadly justified. Her British teammate and fellow Manchester cyclist, Emma Davies-Jones, was left with a broken back after being knocked off her bike on the way to train at the city's Velodrome in 2005."
You'll have read very similar comments on this blog. Everybody loved the Olympic cycling on the TV this summer but will it change anyone's attitude to us cyclists? Or do I still have to look forward to the broken bones that I'm bound to receive from an ignorant motorist? Club mates have been smashed up after being clipped by cars, yet sometimeshttp://simbryo.stanford.edu the driver neither noticed or stopped. Or cared.
Read the full article on the Times online.
October 10, 2008
Week 105 - the first 18 days of human development
In this second embryology lecture we looked at how we develop from a zygote (fertilised ovum) to a simple embryo with the three germ layers that will form all parts of the adult.
Cells of the zygote divide until a mass of smaller cells forms a morula. The cells inside will form the embryo and are called the embryoblast, and the cells on the outside will form part of the placenta and are called the trophoblast. Next, a fluid-filled space forms inside the morula. The morula has become a blastocyst, and the embryoblast has been pushed to one end. The blastocyst will continue its journey along the uterine tube to the uterus, and begin to implant in its wall. This all occurs in the first week post-fertilisation.
Implantation is the major event of the second week. The blastocyst will begin to penetrate the uterine epithelium and stroma at the end holding the embryoblast. The cells of the blastocyst trigger the process of decidualisation, which gives the formation of the placenta from both maternal and blastocyst derived cells. The embryoblast cells differentiate to form the epiblast and hypoblast layers. The trophoblast cells differentiate and take part in the formation of the placenta. By the end of the second week the blastocyst is fully implanted within the uterine wall, and the syncytiotrophoblast (the developing placenta) is producing human chorionic gonadotrophin (hCG).
Gastrulation occurs in the third week and describes (in the case of human embryos) the process by which the epiblast becomes the three germ layers: ectoderm, mesoderm and endoderm. Cells of the epiblast move to the midline of the sheet of epiblast and dive down through the primitive streak to form the new layers beneath.
October 8, 2008
October 7, 2008
Week 5: the salivary glands
In this week's anatomy session we looked at the 3 pairs of salivary glands: sublingual, submandibular and parotid glands. We noted their locations, nearby structures, how they duct into the oral cavity and their nervous innervation. You can review this in your favourite anatomy textbook. Remember that these glands are encapsulated in connective tissue, causing pain on swelling of the parotid glands with mumps.
Remember that these glands receive parasympathetic autonomic innervation to instruct the cells to secrete saliva. The sublingual and submandibular glands receive this innervation from the facial nerve, also known as CN VII. The nerves leave the facial nerve in a fine nerve called the chorda tympani, pass to the lingual nerve, join it and pass beneath the tongue and floor of the mouth and reach the glands there. The parotid gland receives parasympathetic innervation from the glossopharyngeal nerve (CN IX). (Fibres from this nerve pass via the otic ganglion, by the way).
Interestingly the facial nerve passes through the parotid gland on its way to innervating the muscles of facial expression, but doesn't innervate the gland itself. Within the gland the nerve splits into 5 branches: temporal, zygomatic, buccal, marginal mandibular and cervical.
Also within the region of the parotid gland the external carotid artery splits into the maxillary and superficial temporal arteries. The retromandibular vein draining blood from the deep parts of the face forms here, and will drain to the jugular veins. So the parotid gland is an important landmark and is used for locating a number of structures.
MedlinePlus & salivary gland disorders (lots of links on this page).
Glands of the GI system - serous or mucous?
October 5, 2008
