I was started off on this MMPR jag because early early one morning I was cooking chapattis - The Beloved likes them and we had company. They are real simple and close to instant gratification. This is what you do:
- Mix flour, a pinch of salt and enough water to make a stiff but pliable dough
- Work it between your hands
- Leave to allow the wheat to absorb the water
- Pinch off a child's fistful and roll between palms
- Heat a dry cast-iron skillet - not too hot
- Roll out your doughball - not too thin ?3mm? keeping it roughly circular
- Slap it onto the dry spit-hot skillet for a few seconds
- Toss over before the top starts to blister
- The outsides are now sealed and the insides can start to steam cook
- After 'a while' flip the chapatti directly onto the gas flame
- It will blow up like a football
- Flip it over and over with your fingers until each side is just short of charring
In my human physiology course (yours, if you are lucky enough to get one, will differ), I start off with a glance at the Central Dogma of molecular biology which was first put out by Francis "DNA-structure" Crick in 1958 and can be summarised as
- DNA makes RNA
- RNA makes proteins
- Proteins make everything else
- Enzymes are the biological catalysts of all the cellular activities on which we depend: alcohol dehydrogenase to de-toxify the booze; lipase to make other things out of the lard in which we fry the chips; phenylalanine hydroxylase which is banjaxed if you are born with PKU; acetylcholinesterase which is inhibited by the nerve gas sarin. Notice, I say to my students, that all those enzymes end in -ase.
- Receptors otoh sit in the membrane of particular cells and recognise specific chemicals as they pass by. When those chemical 'ligands' dock with the receptor then a cascade of events happens inside to produce an appropriate response: allowing glucose across the membrane when insulin meets the insulin receptor; producing anti-microbial peptides when a Toll-Like Receptor TLR detects a pathogen; propagating nerve signals across a synapse when acetylcholine meets its receptor on the downstream neuron.
- Meissner's or tactile corpuscles consist of a single raw, unmyelinated neuron embedded in layers of supportive cells and connective tissue that are exquisitely sensitive to light touch, they are concentrated on the pads of the fingers and on the lips. They allow you to feel and be annoyed by the least particle of sand in your beach-picnic ham sandwich. You have about 4x more of them at menarche than you do at menopause (blokes ditto for equivalent ages). So I guess snogging isn't so much fun as you get older.
- Merkel's Disks are found, like Meissner's, where the dermis meets the epidermis especially the furry parts of the skin. They are sensitive to low frequency vibrations.
- Pacinian or lamellar corpuscles are located deeper in the dermis and look like 1mm-sized onions with the central neuron surrounded by layer upon layer of connective tissue. They are sensitive to vibration and pressure and help us pick up eggs - where just the right amount of pressure is needed to prevent either crushing or dropping. With their help you achieve this on a daily basis without the least conscious thought.
- Ruffini or bulbous corpuscles are located deeper than M&Ms but not as far buried as Pacinian, they are located particularly around the finger-nails and are sensitive to skin stretch and joint bending.Their structure is rather different from Pacinian corpuscles with more, subdivided, neuron and less surrounding connective tissue. They are thus also important in getting just enough muscle activity to hold things and move them from one place to another. They are also sensitive to heat.
Georg Meissner (1829-1905) anatomist from U Göttingen;
Friedrich Merkel (1845-1919) also U Göttingen;
Filippo Pacini (1812-1883) anatomist U Firenze;
Angelo Ruffini (1864-1929) embryologist from U Siena.
If they were women I'd write more about each one.