DO YOU WANT TO LEARN MORE ABOUT NUTRITION?
Nutrition is a valuable and important adjunct to many different job roles. This proficiency award is designed to upskill professionals who have already had some relevant experience, but want to develop and strengthen their knowledge of nutrition. This course would be perfect for:
- Personal trainers and fitness instructors
- People in health or food marketing or production
- Hospitality staff
- Weight loss consultants
- Wellbeing journalists
- Health professionals (massage therapists, nurses, and so on)
So, if you're looking to add to existing knowledge as a form of Continued Professional Development, or perhaps you need to refresh your knowledge to ensure it's up to date, then this course is a great opportunity to do just that.
Note that each module in the Qualification - Proficiency Award In Nutrition is a short course in its own right, and may be studied separately.
THE DIGESTIVE TRACT
The mouth, also know as the oral cavity, is the region encompassed by the lips and the cheeks. It has several functions, serving to:
The mouth is lined by a mucous membrane. Mucous membrane is a layer of specialised epithelial tissue. The roof (top) of the mouth is called the palate. The palate has two parts: the soft palate (i.e. soft tissue at the back) and the hard palate (i.e. a hard area of skin over the top of a layer of bone at the front of the mouth). When food is swallowed, the soft palate rises to block off the nasal passage at the back of the mouth. The hard palate provides a solid surface which the tongue can squash food against when chewing. This process requires saliva, which is secreted from salivary glands located in pairs in different parts of the mouth. These will be discussed further in the section on accessory organs.
The oesophagus is a thick and strong tube made up of cartilage rings and muscle, which connects the mouth to the stomach. It passes through the diaphragm (the partition between the chest and the abdomen). The tube is lined with mucous membrane and the walls are made up of involuntary muscle fibres.
Once the bolus has been forced into the oesophagus from the mouth by the process of swallowing (or deglutition) it is automatically pushed down the oesophagus by an action known as peristalsis. Peristalsis is an involuntary muscular contraction of muscles in the digestive tract. The bolus is forced along by the muscle behind the bolus contracting and narrowing the oesophagus, whilst the muscle in front of the bolus remains relaxed and widening the oesophagus. This squeezes the bolus forward into the area of relaxed muscle. This area of muscle now contracts and propels the bolus further forward. The whole process is like a wave-like motion. Once the bolus is in the oesophagus, it must travel down to the stomach.
There is no conscious control over this process, as the muscles are involuntarily controlled. Peristalsis defies gravity which allows for the movement of food along the digestive tract whilst the body is in motion or being held up-side-down.
The Simple Stomach
The stomach is a small muscular bag, the walls of which are made of involuntary muscle. The inside of the stomach is lined by a membrane of specialised cells. Food enters the stomach via the oesophagus. Once food has been processed it passes out of the stomach into the small intestine.
Both the entrance to the stomach (from the oesophagus) and the exit to the duodenum (the first part of the small intestine) are controlled by narrow rings of muscle called sphincters. These control the flow and passage of food into and out of the stomach. When the sphincter is contracted, it prevents the flow of food. When the sphincter is relaxed, food can pass through. The sphincter between the oesophagus and the stomach is the lower oesophageal sphincter. At the bottom of the stomach and the duodenum is the pyloric sphincter.
The lining of the inside of the stomach consists of numerous small folds which increase the surface area coming into contact with the food inside the stomach. In addition, the stomach lining contains many gastric glands (small pits). These glands are lined by three types of cells as follows:
Mucous cells: produce a thick, sticky fluid
Parietal cells: produce hydrochloric acid
Chief cells: produce enzymes
All these substances help in the process of food digestion. You should note the hydrochloric acid and the enzymes work in sync for some digestion to take place in the stomach. The complexities of this are not discussed here.
On leaving the stomach, the mixture of food and gastric juice is now referred to as chyme (pron. kyme).
The Small Intestine
The small intestine is a long, muscular tube leading from the stomach to the large intestine. Most of the digestion occurs here.
There are three sections to the small intestine:
1. The Duodenum
When food leaves the stomach, it moves through the pyloric sphincter and enters the duodenum. The duodenum is a c-shaped tube and is the shortest part of the small intestine, commonly about 25 cm long. Hormones are secreted in the duodenum to control the release of digestive enzymes from the pancreas, and bile from the gall bladder. The chyme (food released from the stomach) is vigorously mixed here also. The majority of digestion in the small intestine occurs in this small region.
2. The Jejunum
This is about 2.5 metres long and is the middle section of the small intestine. The lining of the intestine changes here, to one specialised for the absorption of protein and carbohydrates from the chyme.
3. The Ileum
This is the lowest section of the small intestine, measuring approximately 3.6 metres long. The lining here is specialised for the absorption of water, fats and a component of bile, bile salts. At the end of this section, the ileocecal sphincter (valve) controls the passage of material into the large intestine.
Most of the absorption of food which occurs happens in the small intestine. Food comes into the small intestine through the pyloric sphincter in the stomach and is pushed along by peristalsis. This is the same muscular action that pushes food down the oesophagus. Peristalsis is entirely involuntary so a person has no control over it at all.
If someone is unwell, the passage of food can either speed up resulting in improper digestion and nutrient uptake; or conversely, if the process is slowed, a person may end up constipated. The lining of the small intestine contains many mucus producing glands. Mucus is produced in order to lubricate the food. The glands also produce enzymes that are required for the further digestion of food that has passed from the stomach.
In addition, the lining contains many small finger-like projections called villi (singular = villus). Digested food diffuses through the villi on its way from the small intestine into the bloodstream. Digested carbohydrates and proteins pass into the bloodstream while digested fats pass through the villi into the lymphatic system.
The Large Intestine
The large intestine is also known as the colon. It serves to move eliminated waste received from the small intestine (via the ileocecal sphincter) to the rectum ready for elimination, while water absorption takes place. The diameter of the large intestine is much greater than the small intestine.
There are four main parts:
1. The Caecum (sometimes spelled 'cecum')
In humans the caecum is a pouch in the colon about 6cm long with a closed end. Its function in humans is mainly to absorb fluids and salts, while secreting thick mucus and mixing it with the waste product it receives. Attached to the caecum is a coiled tube called the vermiform appendix. The mesentery of the appendix (i.e. mesoappendix) attaches to the lower part of the ileum.
2. The Colon
The open end of the caecum merges into the colon, which is divided into 4 parts:
Ascending Colon: Ascends on right side of the body to the bottom of the liver.
Transverse Colon: Runs from right to left side of body, horizontally.
Descending Colon: Descends on left side of body to the point of the iliac crest.
Sigmoid Colon: Starts near the left side of the iliac crest and runs towards the middle of the body finishing at the rectum.
The ascending and transverse colon continue the process of absorption of both water and salts. As this occurs, waste becomes more solid and firm. The sigmoid colon has the special job of contracting to produce high pressure, which forces the solid waste products into the rectum. One of the effects of some infections and also laxative medicines is to prevent the absorption of water into the colon, causing people to pass a very watery fluid (diarrhoea). It is also very important that humans have access to plenty of fresh, clean water so lost fluids can be replaced.
3. The Rectum
This is commonly about 20cm long forming the final section of the digestive tract. Its function is to store the solid waste until it is eliminated from the body, by a process known as defecation.
4. The Anal Canal
This is 2-3cm long. The opening of this canal is called the anus. There are two sphincters that control defecation. Signals received from this region are what give us the ‘urge’ to go to the toilet.
WHY STUDY WITH ACS?
There are lots of reasons to study with us, these are just a few of them:
- As professionals we should never stop learning, continuing our professional development is important to keep our mind active and knowledge up to date, this course offers that opportunity
- Learning more about the impact of nutrition can help us in many different ways, whatever profession we are working in. Expanding this knowledge will have a knock on impact on those around you, and those you work with
- Doing this course will help to consolidate theory, knowledge and practice through opportunities for you to apply you learning to practical situations
- Our courses are designed to be studied flexibly, meaning that this can be done alongside your existing work commitments
- Throughout the course you will be supported by subject specialist tutors who will be there to answer questions and share their industry knowledge and experience
TAKE THE NEXT STEP, AND ENROL NOW!
You can enrol on the course now, but if you have any questions about the content of the course or studying with ACS, then please get in touch with us today - use our FREE COURSE COUNSELLING SERVICE to get in touch with our expert tutors. They will be pleased to help you!