Human nutrition

Protein intake

Extraterrestrial life
On the other hand, humans in the past century have made considerable efforts to reduce negative impacts and provide greater protection for the environment and other living organisms, through such means as environmental law, environmental education, and economic incentives. It is the discipline searching for a general understanding of values and reality by chiefly speculative means. A mechanism that allows trade is called a market. For treatment of established anaemia, doses of mg of iron and 10 mg of folate are suggested. The Diet for Human Beings is the way humans are built to eat, what we evolved eating, therefore, the foods we require most.

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Animals and Ethics

Order lunch from your computer without getting up. Eat at your desk while simultaneously browsing the Internet and preparing that memo. Sit for another few hours. Get back in the car. Drive half hour to the gym. Spend an hour working out. Grab a snack and sit on the couch to catch up on your favorite series. While it might feel more comfortable to kick back in an armchair than take a walk around the neighborhood, living a sedentary lifestyle has a direct, negative effect on our health and wellness.

The human body was designed to move. Much of it was for survival: We moved to gather food, escape predators and migrate to more forgiving land. Even as humans advanced, our bodies were in motion.

Long days of farm work, trudging into town for school or supplies and other factors of everyday living meant there was little time for our ancestors to rest on their laurels. In the mid th century, however, technological advances, a rise in car culture and a shift from physically demanding work to office jobs began chipping away at our physical activity.

Today, at a time when we have more choices than ever in almost every aspect of our lives, most of us choose to be stationary. But how does not moving regularly take a toll on our health? The World Health Organization estimates that a lack of physical activity is associated with 3. Researchers found the highest level of frailty experienced the most severe impact. A study of more than 80, people found each hour they spent watching TV increased their risk of developing diabetes by 3.

Remaining stationary for too long slows blood circulation to the legs, which can lead to swollen ankles, blood clots , swelling and pain. At the scarier end is deep vein thrombosis , when a blood clot forms in your legs.

The clot can eventually break free and obstruct other parts of your body, including your lungs. Ironically, sitting down to work can actually lead to trouble concentrating.

This slows down our cognitive functions and leads to brain fog. We need our bodies to maintain lean muscle tissue so we can perform our daily tasks without hurting or taxing our bodies. With a sedentary lifestyle, that all changes. Ordinary events, like grocery shopping or picking things up, become much more difficult.

This becomes especially important in older adults, who are already losing muscle mass and bone strength. The kicker with our sedentary lifestyles is that even if you exercise regularly, it might not be enough to combat all those hours you spend sitting at work or in the car. Are you standing yet? The good news is that you can prevent the effects of a sedentary lifestyle, even if you do work in an office environment — and none of them include exercising more.

Use your smartphone for good, not evil. Glands contributing digestive juices include the salivary glands , the gastric glands in the stomach lining, the pancreas , and the liver and its adjuncts—the gallbladder and bile ducts. All of these organs and glands contribute to the physical and chemical breaking down of ingested food and to the eventual elimination of nondigestible wastes.

Their structures and functions are described step by step in this section. Little digestion of food actually takes place in the mouth. However, through the process of mastication , or chewing, food is prepared in the mouth for transport through the upper digestive tract into the stomach and small intestine, where the principal digestive processes take place. Chewing is the first mechanical process to which food is subjected.

Movements of the lower jaw in chewing are brought about by the muscles of mastication the masseter, the temporal, the medial and lateral pterygoids, and the buccinator. The sensitivity of the periodontal membrane that surrounds and supports the teeth, rather than the power of the muscles of mastication, determines the force of the bite. Mastication is not essential for adequate digestion. Chewing does aid digestion, however, by reducing food to small particles and mixing it with the saliva secreted by the salivary glands.

The saliva lubricates and moistens dry food, while chewing distributes the saliva throughout the food mass. The movement of the tongue against the hard palate and the cheeks helps to form a rounded mass, or bolus , of food. The lips, two fleshy folds that surround the mouth, are composed externally of skin and internally of mucous membrane , or mucosa. The mucosa is rich in mucus-secreting glands, which together with saliva ensure adequate lubrication for the purposes of speech and mastication.

The cheeks, the sides of the mouth, are continuous with the lips and have a similar structure. A distinct fat pad is found in the subcutaneous tissue the tissue beneath the skin of the cheek; this pad is especially large in infants and is known as the sucking pad.

On the inner surface of each cheek, opposite the second upper molar tooth, is a slight elevation that marks the opening of the parotid duct, leading from the parotid salivary gland , which is located in front of the ear. Just behind this gland are four to five mucus-secreting glands, the ducts of which open opposite the last molar tooth.

The roof of the mouth is concave and is formed by the hard and soft palate. The hard palate is formed by the horizontal portions of the two palatine bones and the palatine portions of the maxillae, or upper jaws. The hard palate is covered by a thick, somewhat pale mucous membrane that is continuous with that of the gums and is bound to the upper jaw and palate bones by firm fibrous tissue. The soft palate is continuous with the hard palate in front. Posteriorly it is continuous with the mucous membrane covering the floor of the nasal cavity.

The soft palate is composed of a strong, thin, fibrous sheet, the palatine aponeurosis, and the glossopalatine and pharyngopalatine muscles.

A small projection called the uvula hangs free from the posterior of the soft palate. The floor of the mouth can be seen only when the tongue is raised. In the midline is a prominent, elevated fold of mucous membrane frenulum linguae that binds each lip to the gums, and on each side of this is a slight fold called a sublingual papilla , from which the ducts of the submandibular salivary glands open. Running outward and backward from each sublingual papilla is a ridge the plica sublingualis that marks the upper edge of the sublingual under the tongue salivary gland and onto which most of the ducts of that gland open.

The gums consist of mucous membranes connected by thick fibrous tissue to the membrane surrounding the bones of the jaw. The gum membrane rises to form a collar around the base of the crown exposed portion of each tooth. Rich in blood vessels, the gum tissues receive branches from the alveolar arteries; these vessels, called alveolar because of their relationship to the alveoli dentales, or tooth sockets, also supply the teeth and the spongy bone of the upper and lower jaws, in which the teeth are lodged.

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