The many layered follicle

The hair follicle is a challenge to draw and I have tried a number of different methods. This time I have concentrated on using Object>path>offset path. The hair shaft & follicle consist of concentric rings of epithelial cells so it lends itself to this Ai command.

First I drew the hair shaft (brown) with the pen tool then offset the path 1mm for the inner root sheath (yellow) and 4mm for the outer root sheath (purple). I used the pencil tool to shorten the tops so that they don’t surround the hair shaft completely. I then offset -1.5mm to created the hair shaft cortex (dark brown), using the blend tool to merge it into the bulb of the hair follicle. So then all I needed was to draw the skin surface and sebaceous gland which I did with the pencil tool (fidelity 4 pixels; smoothness 34%).

Lecture engineering

This year’s lecture to the Tissue Engineering undergraduate module (Cardiff University, Biosciences) is approaching. My job is to introduce the students to skin structure and function with a focus on normal wound healing. This year, I finally have time to improve the presentation, combining Ai and powerpoint, and have just spent six hours redoing the wound healing sequence of slides.

Wound healing is a very complex process and is normally divided into four stages; immediate, inflammatory, proliferation and resolution phases which overlap considerably. Careful planning and layer discipline in Ai to export the drawings with and without certain parts visible to build up the animation in powerpoint were the main considerations rather than drawing techniques. However, there was one thing that frustrated me; the erythrocyte. I had to laugh when the first Ai effect I tried, extrude and bevel, converted my red blood cell into something more reminiscent of a blood vessel. The one marked erythrocyte below is the original and the others have had various effects applied to them. As you can see I am still looking for a perfect RBC but otherwise the whole animation is so much better than the previous one I had created.

Purple Creative Streak

Digesting a beautiful Madhur Jaffrey fish dish with fenugreek and fennel I became intrigued by the patterns on the cover of her recipe book Curry Easy, wondering how I could achieve the same effect in Ai. Object>path>offset path draws a border around an object but I wanted to have different brush strokes on the outer edge and inner edge. It turned out to be easy; just a couple of snips with the scissor tool (under the eraser) cuts the line into two bits that can be manipulated separately. The flower is just a case of rotating and copying by 30 degrees around a central point.

The idea inspiring this design is that I often wonder (in July/August) how many purple hairstreak butterflies are above the oak canopy, flying in the sun as I walk underneath in the shade. I have only seen these wonderful creatures three times at eye level. And the little brown jobs? They are meant to be the caterpillar. The flower is based on part of the plumage of the under-wing.

Cell Biology Symbols

This week I have finally completed lesson 14 in the Ai ‘Classroom in a book.’ I wonder if I could have completed my e-card for bumblebee conservation before Christmas much more quickly if I’d done this sooner. Creating a symbol allows you to place an object repeatedly with a single click instead of copy>paste>move. However, I also realised from this lesson that it is possible to drag an object with the Alt key to copy and paste it to your chosen position. So easy! So, having discovered this, is there any benefit for creating symbols? Well there are two I can think of: 1) spraying symbols all over the place with a flick of the index finger over the mouse-pad (great for a quick immune infiltrate perhaps?) 2) creating a library of diagram components frequently used in cell biology that can be used between documents and between lab members. So here is a diagram showing some of my symbol library, so far. It never ceases to amaze me how busy the cell membrane must get with all those receptors! It is also possible to make a brush stroke library which is also useful to transfer between documents.