Introduction to bone and the human skeleton!

What is bone?


We all know we have a skeleton, but what is bone and why do we need it?

• Bone is used for: Support, Protection, Leverage and as a Chemical storehouse
• Bone is made up of two components: Organic (collagen) and Inorganic (calcium phosphate)
• Bone formation involves three cells: Osteoblasts (bone forming) which produce the basic materials and proto-collagen upon which minerals are deposited, Osteocysts which are mineralised osteoblast on it's way to becoming bone and Osteoclasts (bone removal) which are cells that absorb bone by resorbing it.
• This formation and removal processes allow bones to maintain or change their shape or size during growth: modelling - bone sculpting during growth and remodelling - continuous removal and replacement of bone through life. This can be from functional adaptation and wear and tear during life.

Bone development

• Bone starts out as an ossified centre (where mineralisation of organic matrix begins)
• These form the diaphysis ie. the shaft of bones such as the tibia or humerus
• Secondary ossified centres also occur, which form the epiphyses, such as the ends of long bones
• A cartilage growth plate separates these two, and deposits bone and continues to make cartilage, making the bones grow longer. 
• So basically, bone starts off small and continues to grow by gradual formation as bone is continually deposited!

Anatomy of bone at the macro-level

• Compact or cortical bone is dense and solid, but at the macro level, it is porous due to the penetration of many tiny blood vessels that carry nutrients into bone.
• The inner surface of bone is filled with cancellous, which saves weight, bone mass and makes it flexible rather than brittle! This cancellous bone is formed from trabeculae with collagen filling in the spaces.
• Each bone is covered with a layer called the periosteum, with the endoseum on the inside. These layers are made up of collagen with fibres that enter the bone.
• Nutrient arteries enter the bone through nutrient foramen, which supplies the marrow cavities with blood. Some bones have a larger supply of blood going through them, depending on where they are situated in the skeleton. For instance, the femur has a major blood supply through it. In an archaeological sense, if this bone was broken, the individual would have bleed to death as it would not have been possible to stop the flow of blood.

The Human Skeleton


206 bones form the adult skeleton and 300 - 350 form an infants skeleton at birth.

• Skull: 28 (8 Cranial, 14 Facial and 6 Ear Bones)
• Vertebra: 26 (7 Cervical or neck, 12 Thoracic or back and 5 Lumbar or lower back.
• Ribs: 24 (Plus the sternum or breast bone, 2 scapula or shoulder blades and 2 clavicles or collar bones)
• Pelvic Girdle: Pelvis is formed of three fused bones called the Os Coxae: Pubis, Illium and Ischium

                     Sacrum (base of the vertebral column)
                     Coccyx or vestigial tail (3-5  variably fused segments)

• Arms: 3 bones in each side (Humerus, Radius and Ulna)
• Hand: 27 in each side

          8 Carpals (Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Trapezoid, Capitate, Hamate)
          5 Metacarpals
          14 Phalanges (5 Proximal, 4 Intermediate and 5 Distal)

• Legs: 4 bones in each side (Femur, Tibia, Fibula and patella)
• Foot: 7 Tarsals (Talus, Calcsneum, Cuboid, Navicular, and Medial, Intermediate and Lateral Cuneiform)

         5 Metatarsals
         14 Phalanges

A new start!

Right.....

So I have been very neglectful of this blog and have mainly been focusing on my other blogs, so I have kept writing, but mainly creatively in poems and working on my first book! I suddenly thought today however, that I need to start getting back into my osteology work, as I don't want to forget all the wonderful knowledge that I learnt last year. Since my life changing accident three months ago, I have this new found thirst for life and want to do so much, but all at the same time! So I am starting somewhere I know I can focus on fully, and that is this blog, as well as carrying on with my other writing!

So here goes, a new start to the blog I want to work on...and to show you all what osteology can really show us!

Enjoy!

My very major and very traumatic accident....but oddly related to my area of interest!!!!

Well it's now 2010 a new year and a new start for me, as I'm now living back in Exeter after completing and graduating with my MA degree....yay!! I'm a whole year older too, but so far, being 27 hasn't been all that fun, and my new start in 2010 hasn't been all that I had hoped for. This new year was going great for me, until the 15th February, when things went from bad to worse in a matter of minutes!!!

The story is quite simple, but it ends up being complex due to the severity of the accident and the trauma that I suffered. But I am writing this in my blog, as oddly, it fit's in with my area of interest and I can explain it well in osteological terms!

Okay, so picture the scene....it's Monday 15th of February, I had just left my first shift at work and decided to sit by the quay in Exeter to make a phone call before I walked home through town to get some food. I sit on a concrete step by the river and make a phone call. I suddenly feel very hot and get flashing black lights, almost as if I'm going to faint. I think I remember standing up (why, I really do not know...as if I felt like I was going to faint, why would I make things worse by standing up?!), then I remember stumbling..........the next thing I remember is waking up, lying flat on my back in what appears to be a moving box, with a lady asking me questions. This totally spins me out as I have a vague memory of trying to figure out if it was reality or a dream, and if it was reality, what the hell was actually going on! But the moving box turned out to be an ambulance, racing me (with blue and twos) towards A&E with the paramedic asking me questions. The only question I remember is her asking me what the date was, to which I replied march 2008. Great! I had been unconscious and was now experiencing my first taste of amnesia!! What I can figure out is basically I had blacked out and completely collapsed (what's called a syncopal episode) and smashed my head on said concrete step I was sat on! Apparently according to the paramedic, passers by had seen me collapse and smash my head and had called 999, to which I am very pleased about as I wouldn't like to think of what the outcome may have been if not!

I was in Exeter RD+E Monday night, Tuesday and Wednesday of that week, but none of which I remember. My best friend came to visit me and so did my mum, as I must have given the doctors her number as my next of kin, but I vaguely remember any of that. I don't even recall the amount of pain I was in or the amount of tests that the doctors did, which is probably a good thing! I finally had a CT scan on my head on Wednesday 17th and the result showed a blood clot, basically between my skull and the surface of my brain. This was caused from the fall and trauma of the accident, which showed I must have gone down like a lead weight and smashed my head quite dramatically. I was transferred to Derriford Hospital in Plymouth in the evening, as this is the neurological centre for the South West, and was an emergency case for theatre the next day. The CT scan revealed I had a haematoma to the left temporoparietal area of my skull, so basically a blood clot behind my left temple area, just above my ear (shown in the photo by the larger red square). I had to fall and smash my head on the thinnest part of the skull!!! This was obviously the part of my head that had smashed the floor first. I also managed to fracture the left petrous temporal bone, which is basically the ear canal (shown on the photo by the smaller red square).

So, I needed surgery to remove the blood clot and relieve the pressure from my fall, as if not, the outcome would have not been good. I still don't really know what they did in the operation, apart from what is written on the discharge letter I got before I left hospital on Monday 22nd. I had a left craniectomy and evacuation of extradural haematoma (extradural means the skull side of the dura, which is the sack the brain is housed in). The operation lasted a few hours, but wont go into the nasty details of that! Except that when I came out of surgery and back up to the ward, it looked like I had numerous spaghetti junctions coming out of me, due to the drips, drains and various tubes going in and out of me!

This is what I was left with after the surgery; half a shaved head and a scar the length of my hand held together with metal staples. Having my hair shaved off was worse for me than the operation I think, as to me, my hair means a lot and my hair is a big part of me, as I have had long hair for years....I wouldn't be me without my hair! But I know it will grow back and the scar will heal, hopefully beyond recognition! It's just the memories and horrific time I had will be with me forever. I know I had to have this done to save my life, so I suppose I got off quite lightly as I could quite easily be 6 feet down!

So yes, this does relate to osteology, as undoubtedly my skull will have amazing pathology even though I don't know what actually happened in the operation. The fracture to the petrous area of my left temporal bone will have remodelled healing from where the fracture will heal, and my skull will have some crazy pathology going on, once bone healing is complete. I have had comments from my fellow osteo's about the pathology that will be left on my skull; mostly about imagining the crazy pathology that I will have and the excitement that a 23rd century osteologists will have when they find my skull....haha! Oh I have so much love from friends!

So now the major pain has subsided, and the staples have been removed and all seems to be healing....I can finally laugh and joke about the whole thing. Obviously not about the seriousness of the situation, or the major trauma that I suffered, or the damn awful few weeks that was this nightmare of a situation. But now I'm safely in recovery, I can but keep positive by laughing and joking to try and keep a smile on my face :o)