Showing posts with label Body. Show all posts
Showing posts with label Body. Show all posts
The Neanderthal's brain was bigger than yours is.
On average, a person has two million sweat glands
Domestic animals have apocrine glands at the base of each hair follicle but eccrine glands only in foot pads and snout. Their apocrine glands, like those in humans, produce an odorless oily milky secretion evolved not to evaporate and cool but rather coat and stick to hair so odor-causing bacteria can grow on it. Eccrine glands on their foot pads, like those on palms and soles of humans, didn’t evolve to cool either but rather increase friction and enhance grip.
Both apocrine and eccrine sweat glands contain myoepithelial cells (from Greek myo– ”muscle”), specialized epithelial cells located between the gland cells and the underlying basal lamina. Myoepithelial cell contractions squeeze the gland and discharge the accumulated secretions. The secretory activities of the gland cells and the contractions of myoepithelial cells are controlled by both the autonomic nervous system and by the circulating hormones.
The slowest growing finger nail is on the thumb nail and the fastest growing is the finger nail on the middle finger
In humans, nails grow at an average rate of 3 mm (0.12 in) a month. Fingernails require three to six months to regrow completely, and toenails require 12 to 18 months. Actual growth rate is dependent upon age, sex, season, exercise level, diet, and hereditary factors. Nails grow faster in the summer than in any other season. Contrary to popular belief, nails do not continue to grow after death; the skin dehydrates and tightens, making the nails (and hair) appear to grow.
In mammals, the length and growth rate of nails is related to the length of the terminal phalanges (outermost finger bones). Thus, in humans, the nail of the index finger grows faster than that of the little finger; and fingernails grow up to four times faster than toenails.
In mammals, the length and growth rate of nails is related to the length of the terminal phalanges (outermost finger bones). Thus, in humans, the nail of the index finger grows faster than that of the little finger; and fingernails grow up to four times faster than toenails.
Every day 2,700 people die of heart disease
Currently practiced measures to prevent cardiovascular disease include:
- A low-fat, high-fiber diet including whole grains and plenty of fresh fruit and vegetables (at least five portions a day)
- Tobacco cessation and avoidance of second-hand smoke;
- Limit alcohol consumption to the recommended daily limits; consumption of 1-2 standard alcoholic drinks per day may reduce risk by 30% However excessive alcohol intake increases the risk of cardiovascular disease.
- Lower blood pressures, if elevated, through the use of antihypertensive medications;
- Decrease body fat (BMI) if overweight or obese;
- Increase daily activity to 30 minutes of vigorous exercise per day at least five times per week;
- Decrease psychosocial stress. Stress however plays a relatively minor role in hypertension. Specific relaxation therapies are not supported by the evidence.
Routine counselling of adults to advise them to improve their diet and increase their physical activity has not been found to significantly alter behaviour, and thus is not recommended.
The human heart can create enough pressure that it could squirt blood at a distance of thirty feet
Blood flows through the heart in one direction, from the atria to the ventricles, and out of the great arteries, or the aorta for example. Blood is prevented from flowing backwards by the tricuspid, bicuspid, aortic, and pulmonary valves.
The heart acts as a double pump. The function of the right side of the heart (see right heart) is to collect de-oxygenated blood, in the right atrium, from the body (via superior and inferior vena cavae) and pump it, via the right ventricle, into the lungs (pulmonary circulation) so that carbon dioxide can be dropped off and oxygen picked up (gas exchange). This happens through the passive process of diffusion.
The left side (see left heart) collects oxygenated blood from the lungs into the left atrium. From the left atrium the blood moves to the left ventricle which pumps it out to the body (via the aorta).
On both sides, the lower ventricles are thicker and stronger than the upper atria. The muscle wall surrounding the left ventricle is thicker than the wall surrounding the right ventricle due to the higher force needed to pump the blood through the systemic circulation. Atria facilitate circulation primarily by allowing uninterrupted venous flow to the heart, preventing the inertia of interrupted venous flow that would otherwise occur at each ventricular systole.
Starting in the right atrium, the blood flows through the tricuspid valve to the right ventricle. Here, it is pumped out of the pulmonary semilunar valve and travels through the pulmonary artery to the lungs. From there, blood flows back through the pulmonary vein to the left atrium. It then travels through the mitral valve to the left ventricle, from where it is pumped through the aortic semilunar valve to the aorta and to the rest of the body. The (relatively) deoxygenated blood finally returns to the heart through the inferior vena cava and superior vena cava.
Women are four times more likely to have foot problems than men
Due to their position and function, feet are exposed to a variety of potential infections and injuries, including athlete’s foot, bunions, ingrown toenails, Morton’s neuroma, plantar fasciitis, plantar warts and stress fractures. In addition, there are several genetic disorders that can affect the shape and function of the feet, including a club foot or flat feet.
This leaves humans more vulnerable to medical problems that are caused by poor leg and foot alignments. Also, the wearing of shoes, sneakers and boots can impede proper alignment and movement within the ankle and foot. For example, High-heeled footwear are known to throw off the natural weight balance (this can also affect the lower back). For the sake of posture, flat soles with no heels are advised.
Andropause is the male menopause
Andropause or male menopause, sometimes colloquially called "man-opause", is a name that has been given, in some parts of the English-speaking world, to a set of effects that appears in some aging men, and which have some superficial similarities to menopause effects in women.
Andropause may be related to the slow but steady reduction of the production of the hormones testosterone and dehydroepiandrosterone in middle-aged men, and the consequences of that reduction. It is also associated with a decrease in Leydig cells. A steady decline in testosterone levels with age (in both men and women) is well documented.
Unlike "menopause", the word "andropause" is not currently recognized by the World Health Organization and its ICD-10 medical classification. While the words are sometimes used interchangeably, hypogonadism is a deficiency state in which the hormone testosterone goes below the normal range for even an aging male.
Andropause may be related to the slow but steady reduction of the production of the hormones testosterone and dehydroepiandrosterone in middle-aged men, and the consequences of that reduction. It is also associated with a decrease in Leydig cells. A steady decline in testosterone levels with age (in both men and women) is well documented.
Unlike "menopause", the word "andropause" is not currently recognized by the World Health Organization and its ICD-10 medical classification. While the words are sometimes used interchangeably, hypogonadism is a deficiency state in which the hormone testosterone goes below the normal range for even an aging male.
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