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Introduction
For this assignment, my focus will be on exploring the structure and components of the
digestive system. Additionally, I will delve into the various nutrients that are essential for
our optimal health, as well as nutrition deficiencies and dietary related disease, which
can impact our body’s normal functioning. Furthermore, I will discuss the treatment that
is available for these diseases to address their effects on our overall health and well-
being.
Explain the role and location of organs involved in digestion
The organs that make up the digestive system include: the mouth, pharynx, oesophagus,
stomach, liver, gall bladder, pancreas, small intestine, duodenum, jejunum, ileum, large
intestine, rectum, anal canal, and anal sphincter. (National Institute of Diabetes and
Digestive and Kidney Diseases, 2017)
Structure and features of the digestive system
Organ Role
Mouth The mouth, which is a rounded opening within the skull, serves two
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(mechanical primary purposes which are both eating and speaking. It consists of
digestion) various components, including the lips, vestibule, mouth cavity,
gums, teeth, hard palate, soft palate, tongue, and salivary glands.
(Better Health Channel, n.d.) The digestive process begins in the
mouth. When you chew food, the salivary glands secrete saliva,
which aids in the breakdown of food particles, making it easier for
the food to pass through the oesophagus. Saliva also contains an
enzyme called amylase, which initiates the breakdown of starch
present in the food. (National Institute of Diabetes and Digestive and
Kidney Diseases, 2017)
Pharynx The pharynx, a muscular tube located in the neck, is a hollow
(mechanical structure which begins behind the nose and extends to the openings
digestion) of the larynx (voice box) and oesophagus (food pipe). It is divided
into three sections also known as the nasopharynx, oropharynx, and
hypopharynx. (NCI Dictionary of Cancer Terms, n.d.) The pharynx
delivers both drinks and food to the oesophagus and from the
oesophagus to the stomach when the food is swallowed. It also plays
a protective role by ensuring that food does not enter the trachea or
lungs, thereby preventing the risk of chocking. (Cleveland Clinic,
2023)
Oesophagus The oesophagus is a lengthy tube. The upper part of the oesophagus
(mechanical is positioned behind the windpipe, also known as the trachea. As for
digestion) the lower part, it extends through the chest, running between the
spine and the heart. (NHS Choices, n.d.) Once you start swallowing
your food, signals from your brain prompt the muscles present in the
oesophagus to contract, initiating a process known as peristalsis.
(National Institute of Diabetes and Digestive and Kidney Diseases,
2017)
Stomach The stomach is located in the upper abdomen on the left side of the
(chemical digestion) bod. It is connected to the oesophagus through a valve also known
as the oesophageal sphincter, which is a muscle located at the end of
the oesophagus. The lower part of the stomach connects to the small
intestine. (Cleveland Clinic, n.d.) Upon the entry of food in the
stomach, the muscular wall of the stomach starts to mix the food
with hydrochloric acid. This mixture, known as chyme, is the result of
the mechanical and chemical breakdown of food in our stomach.
Subsequently, the stomach empties what’s left of the food into the
small intestine for further digestion and absorption. (National
Institute of Diabetes and Digestive and Kidney Diseases, 2017)
Pancreas The pancreas, resembling a leaf in shape, is situated beneath the
(chemical digestion) liver, in close proximity to the gallbladder, stomach, and bowel. It
spans across the body, positioned just behind the stomach, and it is
approximately 15 centimetres in length. (Cancer Research UK, 2023)
The pancreas produces enzymes which aid in the digestion of fats
and sugars present in food. These enzymes play a crucial role in
breaking down these nutrients into smaller molecules, facilitating
their absorption and usage by the body to break down fats and
sugars from foods. (Johns Hopkins Medicine, 2019)
Liver The liver is positioned in the upper right-hand area of the abdominal
(chemical digestion) cavity, situated below the diaphragm and above the stomach, right
kidney, and intestines. It has a conical shape and appears as a dark
reddish-brown coloured organ. It also weighs an approximate of 1
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kilogram. (Johns Hopkins Medicine, 2019) The liver is responsible for
producing and releasing bile, which aids in the digestion and
absorption of fats. Additionally, the liver processed blood that carries
absorbed nutrients from the small intestine. This process allows the
liver to metabolise and store nutrients, as well as detoxifying harmful
substances before the blood circulates throughout the body.
(University of Michigan Health, n.d.)
Gall bladder Situated on the right side of your abdomen, just below the liver, the
(chemical digestion) gall bladder is a small organ with a pear-like shape. (Mayo Clinic,
n.d.) The gallbladder stores and releases bile, which is essential for
the digestion and breakdown of fats in the digestive system.
(Cleveland Clinic, 2021)
Small intestine The small intestine is intricately coiled within the lower region of the
(chemical digestion) abdominal cavity, positioned beneath the stomach. Circling it, the
large intestine forms a border around the edges of the abdominal
cavity. The small intestine is a long, folded tube with a width
comparable to a pointer finger. It is the longest part of the
gastrointestinal tract, stretching about 22 feet. The lining of the small
intestine is highly folded, resulting in a large surface area. The small
intestine is composed of multiple layers of tissues and muscles,
containing nerves, blood vessels, immune cells, and lymphatic
glands. (Cleveland Clinic, n.d.) Villi are small projections in the small
intestine which help with absorption. They have thin walls and
numerous microvilli on their surface. Villi increase the surface area
for absorption and have a rich blood supply. They move to improve
absorption and have digestive enzymes on their surface. Capillaries
in the villi collect nutrients for transport into the bloodstream. The
structure of villi allows for efficient absorption of nutrients from the
intestine. (byju, n.d.) The small intestine is responsible for breaking
down food and absorbing the nutrients that our body requires. As
well as this, it gets rid of unnecessary components from out body.
(Collins, et al., 2023)
Duodenum The duodenum is the primary part of our small intestine. It’s situated;
(chemical digestion) it’s found between our stomach as well as the middle part of our
small intestine also known as the jejunum. (MedlinePlus, 2022) The
duodenum mixes food with enzymes and bile, to help the process of
digestion. It also helps break down nutrients from food, making them
more accessible for absorption into the bloodstream. This ensures
that the body can effectively extract and use the essential
components of the food we consume. (Christiansen, 2024)
Jejunum The jejunum is the middle part of our small intestine. It is situated;
(mechanical it’s found between the ileum which is the last part of our small
digestion) intestine, and the duodenum which is the first part of our small
intestine and the ileum which is final part of our small intestine.
(National Cancer Institute, n.d.) The jejunum helps to further digest
the food, as it absorbs important nutrients and water, so that the
body can use them. (NCI Dictionary of Cancer Terms, n.d.)
Ileum The ileum is the final part of our small intestine and it’s height can
(chemical digestion) reach up to three metres tall. (Collins, et al., 2023) The ileum plays a
crucial role in the further digestion of food, as it receives partially
digested food the stomach and small intestine. (National Cancer
Institute Dictionaries, n.d.)
Large intestine The large intestine is the final part of our gastrointestinal tract; it’s a
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