Jennifer Ellison Brown: The digestive and absorptive system

first_img Digestion Digestion and absorption requires a large volume of blood in the capillaries in the walls of the intestine. If exercise is done too soon after eating, blood is moved from the digestive process to working muscles and the food is left undigested. It is important to keep physical activity to a minimum after eating. Generally, it is best to avoid exercising until at least three hours after a meal. By that time, the food would have entered the small intestine, where it passes quickly into the bloodstream and is stored around the body, ready to be converted to energy during physical activity. Digestion and exercise Digestion is the breakdown of food into simpler molecules (nutrients), which can be absorbed into the bloodstream and used by the cells of the body. The process begins in the mouth, where the food is chewed into smaller pieces and mixes with saliva that contains the digestive enzyme amylase. Amylase digests starch (e.g. bread, rice, pasta, yam, etc.). After chewing, the food is swallowed into the oesophagus, which leads to the stomach. Food moves through the oesophagus by a process called peristalsis, whereby muscles automatically contract, producing rhythmic waves. When food reaches the stomach, it is mixed with a number of acidic substances, collectively called gastric juices. This gastric juice kills any harmful bacteria that may have been ingested with the food. Some nutrients and water contained in the food are absorbed into the bloodstream. The enzyme pepsin starts the breakdown of protein. Food stays in the stomach for about two and a half hours, where it is churned into a liquefied state to form chyme. The chyme is released in small amounts into the first part of the small intestine, the duodenum. In the duodenum, a number of enzymes produced by the gall bladder, the liver and the pancreas are mixed with the food. The gall bladder stores bile, which neutralises the acid leaving the stomach. Bile also helps to break down fats in the small intestine. The liver produces bile, which also helps with the breakdown of carbohydrates and protein. It also acts as a filter, maintaining the balance of nutrients in the blood. The pancreas produces insulin and other enzymes, which help with the digestion of carbohydrates, fats and proteins. The end products of digestion (glucose, amino acids and fatty acids), along with minerals, vitamins and water are absorbed into the blood stream by hair-like projections (villi) on the inner surface. All the nutrients absorbed from the small intestine is carried to the liver first. The level of nutrients in the blood is adjusted to the best levels for the body to function. Excess glucose is converted to glycogen and fat. Glycogen is stored in the liver and muscles and fat is stored all over the body, but particularly beneath the skin. Excess fatty acid is also converted to fat, while excess amino acid is converted to glucose and the toxic waste urea. Urea is eventually excreted by the kidney. If glucose and fatty acids are in short supply, the liver reverses the processes described above and releases glucose from the glycogen stores and fatty acids from the fat stores. The body cannot store protein. Therefore, if amino acids are in short supply, the liver cannot produce more. After the liver has adjusted the amount of nutrients to the correct level in the blood, they pass on around the body. Glucose and fatty acids are used as energy sources. Amino acids are used to make the proteins necessary for growth and the repair of tissues; e.g. muscle tissue or as a source of energy, if necessary. The remaining undigested food passes into the large intestine (colon), where water is reabsorbed and the undigested food moves to the rectum and eventually passed out the anus as faeces. The digestive and absorptive system consists of the alimentary canal (mouth, oesophagus, stomach, small intestine, large intestine, rectum and anus), salivary glands, the pancreas, the liver and the associated blood vessels.last_img read more

Colin Murray and Friends – Wednesday, February 11

first_imgColin Murray was joined in the studio by Dietmar Hamann and Steve Bunce. On today’s show, Buncey tells the story of Buster Douglas v Mike Tyson on the 25th anniversary of the fight that stunned the boxing world and Murray Meets Roy Carroll.last_img

DONEGAL CHOSEN TO KICK-START SECURITY SEMINARS AFTER ATTACKS ON ELDERLY LOCALLY

first_imgDonegal has been chosen to kick-start a nationwide series of security seminars after the recent spate of burglaries on elderly people across the county.Organised in response to a growing fear among older people about security at home, the events are free and open to the public.The first seminar, which will be held on Thursday night, takes place at Letterkenny’s Station House Hotel and is expected to draw a large crowd. Over the next 12 months a total of 18 seminars will take place in 18 counties around the country attended by local Community Policing members of An Garda Síochána, security consultants and community representatives and organised by Bluebird Care.Marty Kelly, Director of Bluebird Care Donegal, said there is a responsibility on all of us to take a ‘community approach’ in terms of being aware of older people living around us.“This first security seminar in Donegal comes on the back on a dangerous spate of burglaries targeting older people in their homes and marks a very worrying time for them. We have already seen an increase in calls from family members for overnight care for their parents who may live alone.”Eddie O’Toole, Operations Director of Bluebird Care says, “There has been a 60% increase in calls to Senior Line – a freephone line for older people – worried about security at home. “And this is also reflected in our own network as we hear anecdotal evidence from the thousands of older people that we work with on a daily basis. We are inviting members of local communities, neighbourhood watch schemes, residents associations and other interested groups along.”The security seminar takes place at 7:30pm on Thursday 28th February in the Station House Hotel, Letterkenny.For more information contact Marty Kelly, Bluebird Care Donegal on 074-9129562 or email donegal@bluebirdcare.ie. You can also log onto www.bluebirdcare.ie/security-seminars for more information. DONEGAL CHOSEN TO KICK-START SECURITY SEMINARS AFTER ATTACKS ON ELDERLY LOCALLY was last modified: February 26th, 2013 by StephenShare this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)Click to share on Telegram (Opens in new window)Click to share on WhatsApp (Opens in new window)Click to share on Skype (Opens in new window)Click to print (Opens in new window) Tags:attacksBluebird Caresecuritylast_img read more