So that went well! I got 3rd place overall at the Dale half-marathon, organised very well by the Pembrokeshire Tri Club. I was the first back in my age group (17-39?) so was beaten by two vets and as such I was given the 2nd prize. Confusing? Winner was 1st vet but got overall 1st prize, 2nd place got 1st vet prize and in 3rd overall I got 2nd overall prize – this race has a method of making sure as many people as possible get a prize and that each gets the best prize possible.
It’s a very hilly race and I was very happy with my restrained pacing in the first half of the race and up the first hill. I felt pretty good, pulled some gaps on the descents and then stretched the gap between 3rd and 4th to something like 4 minutes. I caught sight of the runner ahead on the second main climb and chased hard to try and catch him on the descent. I didn’t quite make it but was chuffed with my strength and some decent gutsy running back to the finish. I feel the mental aspects of my running is still improving. 1:22:36 I think. I wonder if I can get a 1:21 next year.
It looks my lactate threshold has risen this year, and it was important that I ran on feel & not by numbers. If I’d run at the pace suggested by my lactate threshold heart rate of a few months ago I would have run unnecessarily slowly.
After Dale we stopped off at Wiseman’s Bridge to see family that had been staying there for the last week. We went there a few weeks ago for a week’s holiday so the kids loved going back to the beach and rockpools & getting to play with nana, uncles and aunt.
I’ve got the Devil’s Aquathlon this weekend, and although it’s a new race it sounds like there will be some quality competition so I’m hoping to recover for that, but also keeping the running up for the Cardiff half-marathon in a few weeks’ time. Tricky stuff. The Devil’s Aquathlon will include a 2km swim in the open air Lido in Cheltenham, a week after they switch the heating off (yipes!) followed by a 10km cross-country run up Leckhampton Hill to the Devil’s Chimney & back. I’m a little disadvantaged as I’ll struggle to pull back the time a good swimmer will take off me over 2km in the water in just 10km of running. It’s off road though, and has something like 250m of ascent so who know what might happen? I sounds like a lot of fun.
They’re raising money for the Lido itself and for Macmillan Cancer Support so if you can please sponsor me Â£1 or Â£2 on my JustGiving page: www.justgiving.com/Samuel-Webster.
Flickr – Dale Half-marathon 2010
Just Giving – Devil’s Aquathlon
Cheltenham Lido & the Devil’s Aquathlon
Week 103: Lung anatomy
On Monday we looked at some lungs. Plastic models, lungs in situ, lungs on their own, and lungs attached to the heart and great vessels. The main aim was to look at the differences between the left (2 lobes) and right (3 lobes!) lungs and develop a good understanding of the shapes of the lungs and their lobes. In this case 3D is quite different to 2D diagrams, however good they may be, and having a good sense of the shapes of the lungs and their positions within the thoracic cage will be very helpful in your clinical studies.
Beware that in some people the horizontal or oblique fissures may be incomplete or there may be an extra fissure, causing the arrangement of lobes to appear different, or to give an extra lobe.
We looked at the structures of the hilum of the lung: bronchus, pulmonary artery and pulmonary veins. Although tricky to identify which is which, relational anatomy is your friend here, so remember where these structures are in relation to the heart and that the airway is posterior to the heart and these blood vessels.
What we failed to do because we were having so much fun was to talk about the lymphatic drainage of the lungs and their nervous innervation. We can rectify that a little bit here.
A superficial lymphatic plexus drains the tissue of the lung to bronchopulmonary lymph nodes in or near to the hilum of the lung. A deep lymphatic plexus drains fluid from the structures of the root of the lung, and they drain to pulmonary lymph nodes around those structures and then to bronchopulmonary nodes. Lymph then drains to superior and inferior tracheobronchial lymph nodes around the carina of the trachea (where the trachea divides to form the main bronchi) and then to bronchomediastinal lymph trunks that usually pass to the subclavian veins on either side (or the thoracic duct on the left side) to pass the lymphatic fluid back into the systemic circulation.
Lymph on the right side of the lung generally follows the path on the right side, and lymph from the left lung generally follows the route on the left side, however lymph from the lower lobe of the left lung will also pass to the right superior tracheobronchial nodes and then on up the right side.
Tumour cells will metastasise to the bronchopulmonary lymph nodes.
Sympathetic, parasympathetic and visceral afferent (sensory fibres passing to the brain) nerve fibres will pass to and from the lungs via the pulmonary plexus near the roots of the lungs. The parasympathetic fibres are from the vagus nerve and the sympathetic fibres are from the nearby sympathetic trunk. The sympathetic fibres inhibit the smooth muscle of the bronchial walls causing bronchodilation but cause the smooth muscle of blood vessels to contract causing vasoconstriction. The parasympathetic innervation has the opposite effects. Parasympathetic innervation also increases glandular secretions in the airways.
The other sensory fibres carry all that information that’s so useful to normal lung function, that I’ll leave to your physiology lectures (just remember them when you’re hearing about all those reflexes & autonomic controls).
Overview of the innervation of the lung. Belvisi, 2002.
Last year’s blog entry for week 103.
Bala (standard distance) triathlon, 2010
So that was an interesting weekend. Kim and I went to Bala for the last race of the triathlon season. It was great getting back to Snowdonia and fun to camp, although we don’t seem to be as slickly organised as I vaguely remember. Probably the best thing about Bala is that a whole bunch of Cardiff Triathletes go up to race, and it’s good to catch up with faces that I usually only recognise as email addresses or usernames.
Anyway, race day. The lake was cold! It’s nice swimming in a lake after all the sea swimming I’ve been doing. A much better taste. No sign of Teggy or Gwyniad in the black depths during the swim, but some twat did kick me hard in the chest when he switched to breaststroke to sight. What? Why? I came out of the swim in the top 25 in my wave, and yet I’m swimming next to a guy that breaststrokes? WTF? Not a good idea. We’re drafting in a tight group & kicking out hard unexpectedly isn’t nice. It’s akin to standing up quickly on the bike in a group climb and sending your bike backwards into the bloke behind you. If he’d kicked me a tad lower I’d have been winded & that would have ruined my race. I’m all for the tussle of the swim but that’s stupid.
The swim felt a bit crap but the time was OK. I’m getting faster but the numbers were about right. I’d borrowed a wetsuit that fits and it probably didn’t make much difference to my time but it felt great. Streeeeetchy!
Cold feet, swift through T1 and out on the bike, and almost bounced off the curb (not paying attention to where I was going). I passed Mike and Mark (didn’t notice Mike at the time) and kept my HR and effort high. I swapped places on the way out but got passed time and time again on the way back. It was pretty frustrating and I was feeling a bit negative in places. I kept giving myself a positive spin and kept pushing back to T2. I certainly didn’t ease up and was wondering how I was going to run after pushing so hard on such a flat course. A skinny guy like me is much better off in the hills, especially against these guys with big legs & lots of watts. The time was disappointing.
I struggled getting my feet in my running shoes in T2. It only took a handful of extra seconds but my cold feet made it hard to feel my way in past the stretchy bits holding the tongue in place in my Sauconys. I think I’ll swap those for something else next year.
Running out was hard but my pace seemed ok. Again I was swapping places, probably picking up more than I lost. The run is also very flat and largely on the straight road by the lake. As usual I felt a bit better after a mile or so but all the work I’d put into my biomechanics wasn’t paying off as I was moving a little craply. It seems I struggle to move efficiently when I’m tired. Into the camping park, around the tree (bleep-bleep over the mat), back out and back up the road.
Chasing a guy I kept trying to up my pace but squeezing it just a little I could feel the big fade coming on and had to ease back to my previous speed. I was definitely right on the edge! I couldn’t have breathed any harder. I almost caught a group of three on the line, but it wasn’t happening. I hit my target of 37 min 10k pacing (the run was 10.25km) proving that I can bike hard and still run hard.
So, during the race it all seemed a bit crappy, but if you’d been looking at my recent training data you’d probably have predicted the times I achieved, so that’s ok. I performed well, but there was no magic. There were just a lot of really fast boys out to put me firmly in my place. By my reckonings, if I’d been trying to qualify for the European Age-Groupers’ Champs next year I’d have officially missed out by 1 place.
Rather than being a negative experience it turned out to be a motivator. When I realised how flat this race was my first thoughts were to not bother entering next year, but after my effort I started thinking that if I could shave a couple of minutes off the bike, a minute off the run and a couple of minutes off the swim I could get down to 2 hours. I’d be around the top 10 then…..
We (Cardiff Triathletes) also won the team prize, so that helps! Go fast!
P.S. Jonathan Hotchkiss won this race. I just read on his website that when he first did Bala in 2003 it was his fourth olympic distance triathlon ever and he finished 86th overall. Bala in 2010 was my fourth ever olympic distance triathlon and I finished 41st overall. You might say I’m a little old, or you might say, “Yeah, but he’s a pro”. You guys are all cup-half-empty. I say, “Hmmm, maybe if I just…”
Bala standard distance triathlon 2010 results.
Week 202: Circle of Willis
Or the circulus arteriosus cerebri.
Although it seems that the circle of Willis was covered many, many times on Monday it was also part of my session. As I discovered this I shifted the session towards other aspects of the blood supply to the brain.
We looked at the internal carotid artery and followed its route up through the carotid canal and into the cranium (with, er, pipecleaners and skulls). We noted how the internal carotid artery lies upon the foramen lacerum, and how this is not a true foramen but more of a joining of bones in the skull, filled in living head by cartilage. We also noted how the internal carotid artery passes very closely to the structures that must be passing through the superior orbital fissure. Indeed, the internal carotid artery passes through the cavernous sinus (remember that?) and is surrounded by those motor cranial nerves passing anteriorly into the orbit.
We saw the internal carotid artery end just superior to the middle and anterior clinoid processes (and isn’t it funny how when you put a pipecleaner in there that those processes seem to help form a circle that holds the pipecleaner/artery?) Here the internal carotid artery becomes the anterior and middle cerebral arteries, and part of the circle of Willis.
You can see from the photo of one of our plastic skulls (on the right) that they get marked up by students poking around in them with pens. Please don’t! They cost Â£100’s & aren’t easily cleaned.
We also talked about the other arteries that contribute to the circle of Willis: the vertebral arteries. These guys are the first branches from the subclavian arteries, and pass posteriorly to reach the cervical vertebrae and then pass superiorly, up the neck, within foramen within the transverse processes of the cervical vertebrae. So that will be another way in which you can identify the upper 6 cervical vertebrae then.
The left and right vertebral arteries enter the cranium through foramen magnum and join to form a single basilar artery that runs between the pons and the clivus. This sends off smaller branches to the pons, medulla and cerebellum (worth looking at these as interesting things can happen with cerebrovascular accidents here).
A branch of the basilar artery also passes to the inner ear. The labyrinthine artery is a branch of the anterior inferior cerebellar artery, which is a branch of the basilar artery.
The basilar artery ends by dividing to form two posterior cerebral arteries. All our cerebral arteries are linked by communicating arteries, providing a key example of anastomoses that have evolved to try and ensure blood flow to the brain is uninterrupted. All these arteries combine to form the circle of Willis that you saw a dozen times or more on Monday morning, and so should be etched into (if not under) your brains.
Interactive skull images.
What is Cerebral Perfusion Pressure?
Sudden Deafness and Anterior Inferior Cerebellar Artery Infarction. (Lee et al, 2002).
Circle of Willis. Wikimedia Commons.
Last race of the season
Well, my last triathlon for 2010 anyway. I’ve still got a bunch of running races lined up (and a sneaky aquathlon).
This will be one of the few races this year that I hope to feel fresh for. I’ve spent most of the year trying to catch up my fitness (after breaking my foot) for the Windsor triathlon and this weekend’s Bala triathlon. I was knackered at Broad Haven for example, which fell part way through my highest volume week of the year. So on Sunday I’ll be very interested to see what I can do on a fast, flat course after some well organised training. If all goes well I should set myself a good benchmark for future years.
I’m also looking forward to going to Snowdonia again, as Kim and I used to visit North Wales regularly when mountain walking and climbing. We’re leaving the kids at home, driving up on winding roads and camping so it will be very much like old times! Thom has lent me a wetsuit that fits a lot better than my un-snug Snugg (the Snugg is a too-big-hand-me-down) so I’m up to set a new swim PB. The swimming in the pool this week has been the best I’ve swum all year.
As this is the last triathlon of my season my training changes radically after this weekend. For the next week there will be no plan, and I’ll allow myself to do what I like training-wise every day. After that I’ll run almost every day, dump most of the biking, and swim as I feel. I’m extending my racing season into October to make up for the lack of training in February, and will run the Dale half-marathon in Pembrokeshire and the Cardiff half-marathon, hence the run focus. I also like running, and would like to run more. Even with that much running the number of hours I spend training will drop radically, allowing me to do all the things I haven’t had time for. In late October and November I’ll probably try to swim 5 days out of 7 and dump the running and the biking, letting parts of my body and mind recover from 2010 while trying to improve a weaker area with little effort. Then, when the time comes to resume cycling I should be looking forward to it, not dreading more hours in the cold and rain. If I cut out the cycling for a bit I tend to get hungry for it again, and I’m an all-weather cyclist.
Oh, and I love the autumn.
So its a bit of an annual landmark weekend. Fun, racing and changes.
Week 201: The Otic Ganglion
Ouch! That wasn’t a nice way to start the second year of medical school was it?
OK, so most of the session was about the tongue and salivary glands, which seem simple enough until you start trying to hook them up. Then you get into cranial nerves and the intricacies of head and neck anatomy. How many cranial nerves does it take to work the tongue properly? And how on earth do those fibres get to those different parts of the tongue? Fun stuff.
I talked about the otic ganglion in far too much detail, so here is what you need to know:
The glossopharyngeal nerve (CN IX) sends a bundle of preganglionic parasympathetic nerve fibres across the floor of the middle cranial fossa and into the petrous part of the temporal bone.
Those fibres find their way through the middle ear and out of the skull into the infratemporal fossa.
Meanwhile, the third branch of the trigeminal nerve (CN V) known as the mandibular nerve (CN V3) drops through the foramen ovale to leave the skull and also enters the infratemporal fossa. It sends a branch of general sensory nerve fibres called the auriculotemporal nerve out towards the ear and the temporal region.
The otic ganglion is found beside the mandibular nerve inferior to the foramen ovale. The preganglionic parasympathetic nerve fibres from the glossopharyngeal nerve synapse here and postganglionic parasympathetic nerve fibres pass with the auriculotemporal nerve out to the parotid salivary gland. They will convey secretomotor signals to cause the parotid gland to secrete saliva.
I also mentioned the other parasympathetic ganglia of the head: the ciliary ganglion, pterygopalatine ganglion and submandibular ganglion. We talked about their associated cranial nerves, but you’ve met some of them and will meet them again.
The other point of note was that sympathetic nerve fibres pass up into the head by following the major arteries, and sympathetic fibres jump from the middle meningeal artery (passing through the foramen spinosum and therefore really close to the foramen ovale and the otic ganglion) to the otic ganglion and also pass with the auriculotemporal nerve to the parotid gland. Probably. Mostly. These fibres have vasoconstrictive effects. The sympathetic fibres are already postganglionic, and do not synapse in the otic ganglion.
Want to review your cranial foramina (and bone and suture) knowledge? Check out my interactive skull.
Above image from: commons.wikimedia.org/wiki/File:Gray783.png
Maybe I’m a bit Wilbur
My mum has a dog called Wilbur. He’s the big black setter spaniel cross in the grass at the top of my blog pages. He’s a lovely dog and he loves chasing balls. There is nothing he loves more than chasing balls and running. Not even food. See ball! Ball thrown! Run! Chase ball! Finditfinditfindit! Got it! Run back! Run run run! Throw ball for me!
It’s a very simple thing and he takes a very simple (but huge) enjoyment from it. You can imagine how dogs like Wilbur have evolved to end up enjoying running and chasing.
I think I’m a lot like Wilbur.
Triathlon has been a lot of fun this year. I’ve really enjoyed trying to link together swimming, cycling and running fast in racing and in training, and the good results have been an added bonus. Go fast! Fun!
I love running and running races. Duathlons (run, bike, run) are fun but are missing something. Aquathlons (swim, run) are massive fun. And triathlons seem to be the most fun, with the most challenging mix. I’m sure I’ll have a go at testing myself with adventure racing one day if I get the chance but I’m not sure inline skating will add much for me (kayaking, orienteering and the huge distances might though). The simple trick is to try it. You might like it.
The enjoyment is in the movement, in the time spent alone, in the paths travelled, the distances covered, the speed and competition of races, the shocking levels of fitness developed by the human body in short periods of time, in the experimentation, in the thinking up future challenges, and in putting one foot in front of the other and getting outside.
Chase the ball.
Small time exploration
One of the best things about being fit is in having the confident ability to get lost and explore, to find and see places you wouldn’t otherwise see. Running, cycling, swimming, walking, climbing – most of the things I do let me explore. From the tops of (or sometimes partway up) cliffs you see obvious views, but from the sea you also see new perspectives on the coast. The different paces of running and cycling let you see different things. It’s very different to driving speed.
I’m bad at travelling but I’m good at getting lost. I don’t get lost by making navigational mistakes, more I intentionally lose myself as best as I can. I enjoy the feeling. I’m good at exploring and finding my way out. At the very least I can backtrack and follow the breadcrumbs. My son Jack hates this and it’s taking me a while to convince him that sometimes, when you have the time, getting lost is a good thing.
Away on holiday these skills tend to come to the fore. Cycling down the coast I can take the time to pick random turns, following a general sense of direction if not the map itself, often with a general idea of a roughly planned out route that usually takes too long because of unexpected hills or sightseeing. Or maybe because I got lost.