There are different types of Amino acids; but this article refers to the Amino acids needed for protein synthesis in the human body. Amino acids are the building blocks of polypeptide chains which are the building blocks of protein. The human body uses 20 different amino acids in our genetic code. In most cases, our bodies can manufacture 11 of the 20 amino acids used to build protein molecules, but we need to derive the other 9 amino acids from our diet. These 9 that cannot be synthesized without nutrients in our food are called Essential Amino acids. They include the following list with a selection of foods they can be found in. The list of foods is in no way to be considered comprehensive or exhaustive (as I am not a medical professional), but rather a sampling of the foods that these amino acids can be found in.

Isoleucine – found in eggs, soy protein, seaweed, turkey, chicken, lamb and cheese

Leucine – found in soy protein concentrate, peanuts, wheat germ, almonds, lentils, chick peas, corn and brown rice

Lysine – found in soy, red meat, lamb, poultry, cheese, certain fish and eggs

Methionone – sesame seeds, Brazil nuts, fish and cereal grains

Phenylalanine – dried egg white powder, dried whole egg powder, peanut flour, seeds, soy flour, soy meal, some fish, frozen tofu, and cheese. An important non-food source is Aspartame.

Threonine – cottage cheese, poultry, fish, meat and lentils

Tryptophan – chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, and poultry

Valine – cottage cheese, fish, poultry, peanuts, sesame seeds and lentils

Histidine – soy protein isolate,dried egg white, parmesean cheese, sesame flour, peanut flower, dried frozen tofu, defatted soy flour.

There are two provisionally needed amino acids that some people cannot manufacture without dietary sources. Tyrosine can be manufactured from Phenylalanine, but in individuals suffering from PKU – an inability to digest Phenylalanine, Tyrosine may be deficient. Secondly, Selenocysteine, is an unclassified Amino acid that may be deficient in some populations.

Lithograph of the Rotator Cuff group from Gray's Anatomy.

The Rotator Cuff is a group of four muscles that attach to the humerus and scapula to support the shoulder joint. The Glenohumeral joint (where the scapula and humerus meet, a.k.a. the shoulder) is a ball and socket style joint and due to the small surface area of each bone where they connect, it is the most moveable joint in the entire body. The Rotator Cuff along with deltoid, teres major and the coracobrachialis make up the 7 muscles responsible for the movement and stability in the shoulder.

The four muscles of the Rotator Cuff include the supraspinatus, the subscapularis, infraspinatus and teres minor all of which have their attachment and/or insertion points on the scapula bone and/or the humerus (the large bone connecting the shoulder to the elbow). The most commonly damaged muscles in the group are the supraspinatus and the infraspinatus.

A sudden, powerful movement of the shoulder joint can cause an acute tear. Bowlers, tennis players, boxers, and pitchers often suffer an acute tear. A chronic tear is caused by repetitive motion wearing down the muscle on or near the tendon. Chronic tears can lead to Impingement Syndrome; the condition where the inflammed muscles are squished under the acromial arch before they attach to the Humerus. Chronic tears occur most often in people over 40 years old.

Rotator Cuff tears have a 40-90% treatment success rate.

Smooth Muscle cells by Polarlys

The human body has three different kinds of muscle: smooth, skeletal and cardiac. Smooth muscle is the involuntary, non striated muscle that is found in your digestive tract, blood vessels, lymph system, bladder, respiratory system, uterus, skin – almost any part of the body you can think of that requires movement of some type that is automatically regulated without your conscious control. For example, smooth muscle lines your digestive tract and is responsible for moving the partially digested food through the small and large intestine by peristalsis, the systematic contraction and relaxation of muscle fibers that produces a squeezing effect. Peristalsis is what happens when you swallow food as well. Smooth muscle cells contain only one nucleus; whereas skeletal muscle cells contain multiple nuclei.

Skeletal muscle is under our conscious control and is involved in every movement the human body

Skeletal muscle structure by Raul654

makes; be it walking, talking, chewing, riding a bike, and so on. Skeletal muscle fibers are structurally different from smooth muscle in that they are striated – under a microscope, dark lines appear along their length. Each space between two striations in a skeletal muscle cell is called a sarcomere and is made up of actin and myosin proteins. When a muscle contracts or relaxes, actin and myosin fibers slide against one another becoming closer together or further apart. Thus the striations appear (if we could see this in action under a microscope) to come closer together or further apart.

Individual smooth muscle cells are fusiform in shape and flatten out in their relaxed state and fatten up in their contracted state. Individually, these cells have more elasticity than skeletal muscle cells.

Heart Muscle fibers by Dr.S. Girod, Anton Becker

Cardiac muscle cells are striated, involuntary cells found in the heart. They differ from skeletal and smooth muscle in many ways, but two are key: cardiac muscle fibers appear branched under the microscope, but still have a striated appearance and the chemical mechanisms that activate their contraction or relaxation are different from those of skeletal or smooth muscle.

Cow Pox pustules on a Cow's Udder

Both viruses and bacteria cause diseases in plants and animals. It’s important to note, though, the vast majority of bacteria are harmless to humans, and a great number of bacteria are essential to our survival. Viruses, bacteria, prions and fungus that cause disease are known as pathogens. Pathogens are simply infectious agents; as the word origin suggests in this case: “pathos” means suffering and “gen” means the generation of.  A virus is an interesting entity that hovers on the cusp of being life. It is basic genetic material boiled down to the most essential elements: genes, protein and sometimes, a lipid outer shell, built using the host’s cellular material. That’s it. Bacteria are prokayotic cells, of which there are many, many varieties. Prokaryotes lack a nucleus and have very few (if any) membrane bound organelles (cellular organs wrapped in their own individual coating).

A virus cannot multiply on its own; it needs to be inside a cell in order to divide. Typically, a virus is proliferated in the following manner: first, it attaches to the outer shell of a cell and either through diffusion or chemical messenger channels, is absorbed. Next, the protein covering protecting the viral DNA or RNA (there are both DNA and RNA viruses) dissolves, releasing the virus’ genetic material. The plant, animal, or fungi cell then combines its own DNA with the viral DNA and begins making copies. Since the viral DNA is actually combined with the host’s DNA, any host cell division will also make a copy of the virus. Viruses can also proliferate by cellular lysis: the host cell completely fills up with copies of the virus, causing the cell to burst and spew out viruses which can then infect other cells in the body. The perfect parasite!

Now the biggest, medically relevant difference between viruses and bacteria is how they are treated when infecting a body. Antibiotics only treat bacterial infections; not viral ones; like the Common Cold or Influenza. Your body needs to just batten down the hatches and kill the viral invaders on its own. It has only been very recently that drugs have been developed to treat a virus once it has become symptomatic: Tamiflu and Relenza are but a few. The main defense against viruses is still vaccines: altered forms of the virus introduced to the body to create an immunity “memory”. Our body then recognizes subsequent exposures to the same virus and can mobilize an immune attack accordingly. The etching at the right is Cow Pox, the much less dangerous form of a similar strain called Small Pox. It was discovered that those who were exposed to Cow Pox, did not succumb to Small Pox as the Cow Pox created an immunity memory.

Alzheimer’s Disease is a neurodegenerative disease characterized in its early stages by the difficulty in acquiring new memories, diminished language capacity, depression, irritability, apathy, aggression, inability to concentrate, long term memory loss, and/or loss of motor control (no, we don’t all have it even when it feels like it sometimes . This combination of symptoms combined with an examination of a patient’s brain post mortem, confirms a diagnosis of Alzheimer’s Disease. Dementia can include all of these symptoms and more, but can have a number of different causes such as stroke, physical injury or substance abuse. Dementia is not a specific diagnosis, but a description of a collection of symptoms that has or has not necessarily been attributed to a specific cause, like injury, etc. The word dementia, although referring to a completely different host of symptoms, is used similarly to the word colic in that they both describe manifestations of a symptoms, but are not a specific diagnosis (colic describes extended periods of crying and irritability in infants between 2 weeks and 3 months old).

In summary, Alzheimer’s Disease is a specific diagnosis, named after a the guy who discovered it – Alois Alzheimer in 1906, whereas dementia describes a collection of symptoms that have a number of possible causes. Alzheimer’s Disease is confirmed by cognitive – behavioural assessments and brain scans, and is confirmed post mortem by an autopsy.

In the 15th century when disease was such a big part of daily life; this type of artwork was commonplace.

Generally, the difference between pandemic and epidemic is one of concentration and geographic reach. Epidemics occur in a specific area which can be a city, state or even an entire country as long as the incidence of the disease remains relatively constant with no exponential growth, and localized. Pandemics are more widespread, and affect a larger amount of people – an entire continent or world wide. HIV, the virus causing AIDS is considered a pandemic. As was the Bubonic plague and small pox.

Colloquially, when the word epidemic refers to a high rate of infection – higher than you would normally expect to be the case. There are frequent epidemics of Dengue fever in the tropics; a virus spread by infected mosquitoes. Seasonal flu is not considered to be an epidemic, even though it has a high rate of occurrence, because it is expected that many people will contract the flu. It can become an epidemic, however, if the number of cases is many more than is historically usual for the seasonal flu. This can become a pandemic if the cases start increasing exponentially and spreading to new populations and geographic locations unexpectedly.

Shin splints is the general term given to pain experienced in the shin area of the leg and is not a specific diagnosis, but rather a convenient term to describe a number of possible physical processes at work; most commonly associated with the tibia. The tibia and fibula are the two leg bones between the knee and foot; the fibula is on the outside of the leg and much thinner than the tibia which sits on the inside of the leg. Pain in this area is most commonly caused by stress to the muscles, tendons or ligaments connected to the tibia. This stress can be caused by an increase in intensity or duration of exercise, or in athletes who endure a lot of shock to the legs; for example, marathon runners. Pain associated with this condition is called medial tibial stress syndrome, the attachment point on the tibia for the soleus and tibialis posterior muscles. This is half way between the knee and the foot on the inner surface of the tibia. In addition to marathon running, and dramatic exercise increases, the shape and locomotion of your foot can cause this syndrome. If you overpronate; your foot flattens out too much when standing upright, your foot will roll inwards placing stress on the muscles and tendons attaching to the tibia.

Another cause of shin splints is a stress fracture in the tibia.  Unlike acute fractures that happen with impact stress and are instantaneous – breaking a leg skiing or falling; or breaking a bone in a car accident – large, instant traumas, stress fractures are usually caused by low forces acting on a bone over a long period of time. Also known as fatigue fractures, these breaks occur in athletes who do a lot of running and jumping on hard surfaces; dancers and runners.

Undiagnosed shin pain can be caused by Compartment syndrome. If you look at a cross section of the muscles and bones below the knee, you will see different pockets with the various muscles that make up the lower leg – these pockets, or compartments can contain one or several different muscles wrapped in fascia. Think of fascia like connective tissue shrink wrap surrounding your muscles. If, in the course of training, one of these muscles becomes too big for its compartment, it will cause stress and pain in the surrounding tissue. This is one cause of compartment syndrome. Another cause is swelling or bleeding resulting from a traumatic event.

Permanent treatment usually involves surgery – splitting the fascia; followed by careful rehabilitation. Short term treatments involve rest, physiotherapy and possibly orthotics.

My standard disclaimer – I am not a doctor, nor should any of the above information be taken as medical advice. I provide the above for informational interest. If your reaction to the above is “huh”, or “interesting”, my job is done.

Shingles is caused by the Varicella zoster virus, the same virus that causes chicken pox. A typical case of shingles starts out as chicken pox as a child. You will contract the virus, break out in the spots, and hopefully in two weeks, be symptom free, but the VZV can lie dormant in your nervous system and 10-20% of people who have had Chicken Pox will go on to develop shingles.

What are the symptoms of shingles?

In the prodromal stage, between 2 and 5 days before a rash breaks out, you feel like you are getting the flu – fever, chills, nausea. You may also feel numbness, tingling, itching or pain on one side of your body or face. The VZV lies dormant in your nerve cells. The symptoms you feel on your body follow nerve pathways.

Small, clear fluid filled blisters appear in the eruptive stage. These blisters resemble chicken pox and follow the same nerve pathways where you may have already experienced itching, numbness, tingling and/or pain. These blisters can range from somewhat irritating to incredibly painful. They tend to appear in bands or clusters called dermatomes; an area on the skin where a single nerve cell provides sensation. Dermatomes are sort of like a road map of which nerves supply which areas of the body with sensation. In about 2 weeks, the blisters will become pus filled – your white blood cells hard at work – eventually dry up to form scabs. At this point, the blisters no longer contain the active virus. The blisters and inflamed area surrounding them can be uncomfortable for 3 to 5 weeks; most symptoms are resolved within 5 weeks with no lasting scars – unless the blisters were scratched open to become infected. Most healthy people don’t experience complications from shingles. The course of the illness may even be shortened if you manage to see your doctor and are started on a course of antivirals within the first 3 days of the rash appearing.

Complications

Elderly people and those with compromised immune systems may experience complications. Postherpetic neuralgia (the VZV is in the herpes family of viruses) occurs when pain associated with the rash persists for months or years following an outbreak. Nerves can be damaged from a shingles outbreak. Damaged nerves can send faulty messages that they body interprets as pain. Nerve damage is incredibly difficult to heal. Patients over the age of 50 seem to be most at risk for developing PHN.

Hutchinson’s Sign in a shingles outbreak is a rash appearing on the tip of your nose. This sign indicates VZV infection of the ophthalmic nerve. Temporary blindness and eye swelling and should be seen by a doctor immediately. Ramsay Hunt Syndrome occurs when the VZV invades the facial nerve. Intense pain in the ear combined with dizziness, hearing loss and blisters in and around the face, ear, neck and scalp should also be seen by a doctor right away.

Bacterial skin infections can result from scratching your skin open; creating a doorway for bacteria to get into the body. In an already weakened immune system, your body may not be able to fight off these additional pathogens.

Infections in your internal organs may occur in patients with compromised immune systems.

My little disclaimer…

I am not a doctor or medical professional. This article is meant for informational interest only and should not be used in place of a physician’s diagnosis.

Major elements of the urinary system

The urinary bladder, as it is referred to anatomically to distinguish it from meaning “pouch or flexible enclosure”, sits atop your pelvic floor: protective layers of muscles and connective tissues designed to hold you internal organs in place. The bladder is the final internal destination for urine that has been collected and concentrated by the kidney and transported via the ureters – one for each kidney.

The urinary bladder; like the design of many other internal surfaces of your body, like the small intestine and the stomach is lined with folds of tissue. In the stomach and bladder, these folds are called rugae and they stretch and flatten in response to increased pressure – if you have just eaten a big meal or haven’t urinated in a long time. Our wonderful bodies follow this design because internal bladder expansion takes the pressure off the surrounding pelvic and abdominal organs. In contrast, if the bladder filled outwards like a balloon, our pelvic and abdominal muscles would be continually squashed.

We start feeling the urge to pee when our bladder is about 25% full. For most people; this pretty easy to ignore. Nerves on and near our bladder, when stretched, trigger the parasympathetic nervous system (the rest and digest part of our nervous system as opposed to the sympathetic fight or flight part of our nervous system) to signal us to go pee. As the bladder stretches, the PNS becomes more insistent that we go pee. If the bladder reaches 100% capacity you will expel urine involuntarily. The flow of urine is controlled by two muscles; an internal involuntary muscle called the detrusor muscle and an external voluntary Kegel muscle.

OK, a brief aside to explain involuntary and voluntary muscle: involuntary muscles are controlled directly by our nervous system without conscious input from us. They are made up of smooth muscle fibres. Skeletal muscle, under our voluntary control is also regulated by our nervous system, but we are the ones sending the signals to the brain to move or not move. Skeletal muscle is striated. Microscopically, they look very different from each other. Smooth muscles are working away in your body all the time; like for example, in your small intestine as the smooth muscles push food along the digestive tract towards the large intestine (or colon) and out the anus.

Kegel muscle a.k.a. the Pubococcygeus muscle

It is our voluntary muscle we contract to “hold pee in” You can strengthen this muscle by doing Kegel exercises – for women, flexing the little ring of muscles, inside your vaginal opening. Doing about 25 flexes of this muscle every day well help to prevent urinary incontinence problems when you are older. Men also have a Kegel muscle that allows their penis to stay erect, and controls their ejaculation and of course, help with incontinence. Men can isolate and strengthen this muscle by stopping and starting the flow when urinating. This is the same for women.

What can go wrong? Well it all boils down to incontinence, but for many different reasons. If you have damaged nerves, you may not be able to receive the PNS’s signals urging you to urinate as is the case with some Parkinson’s and Multiple Sclerosis patients. Your detrusor muscle (involuntary) is controlled by the PNS. If your PNS is damaged, this muscle may not function properly, and the only protection you have is your external muscle; which is likely not strong enough to hold back small outputs of urine. Prostate cancer can damage pelvic nerves resulting in incontinence.

Sometimes (mostly in women), if you laugh, sneeze or cough, the pressure it creates overcomes both sets of muscles resulting in little spurts of urine coming out. This is called Stress Incontinence and happens mostly in older women – over the age of 60, but can happen younger; say if you have a genetic predisposition to urinary incontinence.

Overactive bladder is diagnosed when you have to pee 8 or more times a day, and are up 1 or 2 times a night. Based on this definition approximately 1 in 6 people in the U.S. have this problem. OAB can be treated with antimuscarinic drugs or through a really cool sounding procedure whereby physicians insert an electrode near the tibial nerve in your leg. An electrical impulse travels to your sacral plexus via your tibial nerve. Recall, that your tibia is a bone in your lower leg. Your sacral plexus is a bundle of nerve fibers responsible for controlling parts of your pelvis and lower extremities. The treatment takes place once a week for 12 weeks. Some patients need more or ongoing treatment. I myself have an overactive bladder, but it doesn’t badly interfere with my life – excepting 11 hour long bus rides in Central Turkey with only one bathroom stop; I have just lived with it without treatment. Please understand, I am not a medical professional and I am not advocating any procedure or treatment, but just seek to educate people about our bodies and how they work. Peace out.

Your appendix is located in your lower right abdomen, attached to the large intestine. Just past the ileocecal valve; the gateway between the small and large intestine, is the cecum; a bulbous mass located at the bottom of the ascending colon. The appendix is a vermiform (worm shaped) organ that hangs off the end of your cecum. In most people it is about 10 cm long. At one time; the appendix was thought to be a vestigial organ; left over from the days of eating large amounts of plant matter, we now understand the appendix probably plays an important role in our immune system due to its rich supply of lymphocytes; better known as B-cells, T-cells and natural killer cells.

There are many different types of T-cells, but one of the best known to us are memory T-cells; as their name suggests, they are responsible for our immunity to certain diseases through vaccinations. B-cells make the antibodies that fight  antigens (foreign cells). In short, T-cells have the recipe and B-cells are the cooks. Natural killer cells attack viruses and tumor cells.

Although, current knowledge of the role of our appendix is based on well educated guesses, here is what we know:: our appendix may have played a role in helping our distant relatives digest plant matter; a mainstay of their ancient diet; by storing additional digestive enzymes. Scientists base this knowledge on the comparison between the human appendix and the koala bear appendix. The appendix is rich in lymphocytes as stated above. Finally, the appendix may play an important role in repopulating natural bacteria to our large intestine that are wiped out by diarrhea and other similar illnesses.

Why do so many people undergo an appendectomy?

Partially digested food and foreign antigens can become stuck in the appendix because of its remote location. Your appendix is a closed tube, making it difficult for your body to clear away debris, should any infection causing bacteria or other matter become stuck. It used to be routine practice to remove the appendix during any abdominal surgery due to its propensity for becoming infected and the deadly consequences that could result from this infection. If an infection continues without treatment, your appendix could rupture, spewing out bacteria laden materials into your peritoneum and abdominal cavity, possibly resulting in sepsis and death. Rather than take this risk, doctors used to routinely remove the appendix, but current medical practices include giving IV antibiotics to treat appendicitis (“citis” means inflammed), that can lead to a full recovery. It is worth noting, however, that most people don’t notice any difference in their body’s immune functioning after having their appendix removed.