For those that don’t know what embryology is; it is the growth of an animal after fertilisation of an egg (ovum) by sperm (or in the case of some species self-fertilisation). The sperm and egg fuse together with the haploid DNA contained in each combining to form diploid DNA within the nucleus. This single cell the goes on to rapidly divide multiple times with the number of cells doubling with each division (2-4-8-16 etc). Talking simply, this then folds in on itself (invaginates) to form a tube through the middle which will later become the digestive system. At this stage 3 different layers are formed; the ectoderm which is the outer later, the mesoderm which is the middle layer and the internal layer which is the endoderm. The cells in each of these layers are then differentiated to form different organs and structures related to that part of the body – for example the ectoderm forms the majority of the skin.
After embryology we then had the histology lecture that we had missed previously on the senses and today looked at the eye and ear. Personally I think the eye is amazing as the cells here are some of the fastest replicating cells within the body – most injuries to the surface layer heal within hours! The retina is the part of the back of the eye that is responsible for processing images into nerve pulses for the brain to understand and under the microscope looks like this…
Looking at it quickly the layer at the top which is thick forms the fibres that holds the eye together known as the choroid and is attached to the sclera. Under this we then have a layer of pigment before the layer of rods and cones with the associated ganglionic nerve structures.
We finished this afternoon with our Physiology lecture which was looking at the brain, this is something so complex that by the end of the lecture most of use had our head aches. As vets we need to understand how different signals are processed, and the areas of the brain that deal with different functions of the body. In fact if we wanted we could actually progress to become Veterinary Neurosurgeons…. Is that cool or what?!?!
Well today was another day of anatomy followed by horse riding, in anatomy we looked at the large intestine (intestinum crassum) of the horse and carnivores along with the Liver (hepar). Now this was interesting as the liver plays a crucial role in metabolism and stores the glycogen, fats and some of the protein. During the embryonic stages the liver also participates in haematopoiesis helping to form the blood of the body, and during life it also plays a role in removing old red blood cells from the body. The major role it plays in digestion is that it is responsible for the secretion of bile and is where the gall bladder is located within the body. The liver is an organ with anatomy that differs greatly between species and one which I think will be very interesting from a surgical perspective next year.
The size of the liver for one varies between species, and though not sure what they are I know there are special techniques for liver surgery as the tissue is very delicate. Also the number of lobes the liver has varies between species – carnivores have 6 lobes with distinct separation (one of which is in two separate parts) – whilst the ruminants have just 4 lobes with no obvious distinction between them.
This afternoon was time for horse riding again, today we went over the basic skills of tacking up and saddling the horse. Though I have some horse experience it is very limited and was mainly in a natural (or traditional) horsemanship setting where the focus was on establishing a bond with the horse. Whilst many people have horse experience it is generally taught in a more master-horse relationship focus than in actually working with the animal, and is where the rider forces the horse to do their will instead of asking.
Something I am very passionate about is cruelty to animals, and I personally believe that a good horseperson is one that forms a bond with their horse. I’ve had the pleasure of meeting Monty Roberts in the past who is a master of this, and through discussion have also heard other names mentioned. It’s hard to believe when you’ve not seen it yourself however with this bond you can do things like playing at liberty and actually have the horse choosing to run alongside you of its own free will. I will always advocate for animals to be treated as a person would like to be treated, if you would not like to be whipped or dragged by your nose or neck then what gives you the right to do this to an animal?