,Introduction
As part of science studies I have been asked to write a report that provides clear information and
guidance on the anatomy and physiology of the digestive system and uses of various important
nutrients and associated symptoms of nutrient deficiency and treatment for diseases. Therefore, in
my report I must evaluate and explain different disorders that affect the normal functioning of the
digestive system. I must also explain the side effects of medical treatment on the human body. In
addition, I must explain any practical experiment to establish the nutritional content of a wide variety
of food such as starch, protein, lipids etc..
One of the most complex and difficult systems in the human body is the digestive system and also
where digestion and absorption take place. It is made up of the gastrointestinal system, which is
hollow organs which are connected from the mouth to the anus. Therefore, the accessory organs in
the digestive tract help to break down molecules of food into smaller ones that can be absorbed into
the bloodstream. Food is then broken down into smaller pieces until the molecules are extremely
small to be absorbed and any waste products removed from the body. The alimentary canal is
another name for the digestive system because it is composed of long and continuous tubes which
travel from the mouth to the anuns. This comprises the mouth, throat, oesophagus, stomach, small
and large intestines. Furthermore, the salivary glands, liver, gallbladder, and pancreas are important
because these organs are known to produce fluids into the digestive system which help in digestion
of food. Food that enters the body will go through three digestive processes such as: digestion,
absorption, and elimination. Once the food is digested the molecules will be absorbed in the
bloodstream which will be used in metabolism by the cell. The digestive system's six basic processes
are as follows:
➢ Ingestion of food
➢ Secretion of fluids and digestive enzymes
➢ Mixing and movement of food and waste through the body
➢ Food digestion into small molecules
➢ Nutrients absorption
➢ Excretion of waste
Ingestion
Ingestion, or food consumption is the initial activity of the digestive system. This is because the
mouth is the opening whereby all food enters the body, it is responsible for this function. The mouth
and the stomach controls the storing of food while it is being digestive in the body. This is because
the mouth breaks down food into smaller pieces so it can be absorbed in the bloodstream.
Secretion
The digestive tract secretes around 7 litres of fluids every day. Saliva, mucus, hydrochloric acid,
enzymes, and bile are examples of these fluids. Saliva helps by moisten the food which also include
enzymes that help with digestion of carbohydrates and lipids known as salivary amylase. Additionally,
inside the gastrointestinal tract the mucus acts as a protective barrier and lubricant. Hydrochloric
acid aids in the chemical digestion of food and protects the body by destroying microorganisms
found in the food. Moreover, enzymes are biological catalysts which help to break down
macromolecules such as carbohydrates, proteins and lipids into smaller molecules which are
,absorbed by the body. Finally, bile is utilised to emulsify huge quantities of lipids into small globules
that can be easily digested.
Mixing and movement
To transfer and absorb food molecules, the digestive system involves three major processes:
- Swallowing - Swallowing is the process which forces food to go down by using skeletal and
smooth muscles of the mouth, tongue and pharynx.
- Peristalsis - Peristalsis is defined as a muscle contraction which passes through the digestive
organs, as it transports digestive food molecules. Therefore, the food will travel from the
oesophagus down to the organs such as the stomach and intestines and finally in the GI
tract.
- Segmentation - The food is broken down by digestive enzymes which helps to increase the
absorption of the nutrient. This allows the nutrient to be absorbed into the bloodstream and
increase the interaction with the guts walls.
Digestion
Digestion is the process of breaking down big pieces of food into their constituent components. The
process of breaking down large pieces of food into smaller pieces is known as mechanical digestion
because it physically breaks down large bits of food into smaller pieces. Therefore, the digestion
begins in the mouth where the tooth starts chewing where the large piece of food is broken down
into smaller pieces. Once the food is broken into smaller pecice it will be forced down to the GI tract
which are digestive organs that help to break down food more into smaller pieces. For example, the
liver's bile is also utilised to mechanically break down lipids into much smaller globules. The food can
be chemical digested because chemical digestion is referred to digestive enzyme such as salivary
amylases in the the mouth that helps break down large complex molecules such as carbohydrates
and can be absorbed into the bloodstream much faster. Moreover, the chemical digestion is
continued in the stomach by enzymes and the acid, but the majority of chemical digestion occurs in
the small intestine due to pancreatic activity. The pancreatic juice contains enzymes such as:
trypsinogen, carboxypeptidase, elastase, pancreatic lipase, nucleases, chymotrypsinogen and
amylase. The food molecules will be broken down further by help of the digestive enzymes which can
then be absorbed into the bloodstream. This is because the food molecule is broken down into
components such as fatty acids, amino acids, monosaccharides, and nucleotides by the time it exits
the duodenum which is the first part of the small intestine.
Absorption
Food is ready for the body to be absorbed once it has been broken down into smaller molecules. This
means that absorption takes place mostly in the stomach and small intestine, where the vitamin and
mineral is taken straight into the bloodstream. This is because the wall of the small intestine is folded
to increase surface area so the nutrient can be absorbed into the bloodstream, which is called villi as
it is finger-like projections that is flooded to increase surface area. Therefore, the food molecules will
be absorbed in the bloodstream which will be carried in capillary to the rest of the body. Also, before
faeces leave the body, the large intestine absorbs water as well as vitamins B and K.
, Excretion
The digestive system's main role is waste expulsion, which is known as faeces. Defecation discharges
indigestible substances from the body, preventing them from accumulating inside the stomach. Also,
the conscious portion of the brain controls the time of faeces, but it must be done on a regular basis
to avoid a buildup of indigestible materials.
Digestive system's functions
The digestive system is a process which breaks down large molecules of food into smaller ones by
help of digestive enzymes which will then be absorbed into the bloodstream and transported
through the body.
Therefore, the digestive system contain hollow organs that help with digesting food such as:
- Mouth
- Pharynx
- Oesophagus
- Stomach
- small intestine
- Large intestine
- Pancreas
- Liver
- Gallbladder
These digestive organs will mechanically break down the food, allowing the digestive enzymes to
reach all of the food components. The chemical digestion of food is carried out by enzymes that are
different to various substrates. The digestive process is divided into different stages, the first of which
begins in the mouth.
Mouth
The gastrointestinal tract's facial entrance is the
mouth. The tongue, palates, gums, and teeth are
located in the oral cavity, which is bounded
anteriorly by the lips, laterally by the cheeks, and
posteriorly by the oropharynx. As a result, the
primary function of the mouth is to break down
food molecules by chewing and also to produce
enzymes such as salivary amylase for further
digestion. Furthermore, the secondary function of
the mouth is sound generation, facial expression,
test which is known as gustation and most importantly, respiration which allows gas exchange. The
oral cavity is anatomically separated into the oral vestibule, which is the gap between the teeth and
the mucosa of the lips and cheeks. The oral cavity is the space bounded on both sides by teeth
anteriorly and laterally, and posteriorly by the oropharynx. Teeth are strong, calcified structures that
are used to produce sound as well as bite and chew food. The palate, which is divided into soft and
hard palates, separates the oral cavity from the nasal cavity.
As part of science studies I have been asked to write a report that provides clear information and
guidance on the anatomy and physiology of the digestive system and uses of various important
nutrients and associated symptoms of nutrient deficiency and treatment for diseases. Therefore, in
my report I must evaluate and explain different disorders that affect the normal functioning of the
digestive system. I must also explain the side effects of medical treatment on the human body. In
addition, I must explain any practical experiment to establish the nutritional content of a wide variety
of food such as starch, protein, lipids etc..
One of the most complex and difficult systems in the human body is the digestive system and also
where digestion and absorption take place. It is made up of the gastrointestinal system, which is
hollow organs which are connected from the mouth to the anus. Therefore, the accessory organs in
the digestive tract help to break down molecules of food into smaller ones that can be absorbed into
the bloodstream. Food is then broken down into smaller pieces until the molecules are extremely
small to be absorbed and any waste products removed from the body. The alimentary canal is
another name for the digestive system because it is composed of long and continuous tubes which
travel from the mouth to the anuns. This comprises the mouth, throat, oesophagus, stomach, small
and large intestines. Furthermore, the salivary glands, liver, gallbladder, and pancreas are important
because these organs are known to produce fluids into the digestive system which help in digestion
of food. Food that enters the body will go through three digestive processes such as: digestion,
absorption, and elimination. Once the food is digested the molecules will be absorbed in the
bloodstream which will be used in metabolism by the cell. The digestive system's six basic processes
are as follows:
➢ Ingestion of food
➢ Secretion of fluids and digestive enzymes
➢ Mixing and movement of food and waste through the body
➢ Food digestion into small molecules
➢ Nutrients absorption
➢ Excretion of waste
Ingestion
Ingestion, or food consumption is the initial activity of the digestive system. This is because the
mouth is the opening whereby all food enters the body, it is responsible for this function. The mouth
and the stomach controls the storing of food while it is being digestive in the body. This is because
the mouth breaks down food into smaller pieces so it can be absorbed in the bloodstream.
Secretion
The digestive tract secretes around 7 litres of fluids every day. Saliva, mucus, hydrochloric acid,
enzymes, and bile are examples of these fluids. Saliva helps by moisten the food which also include
enzymes that help with digestion of carbohydrates and lipids known as salivary amylase. Additionally,
inside the gastrointestinal tract the mucus acts as a protective barrier and lubricant. Hydrochloric
acid aids in the chemical digestion of food and protects the body by destroying microorganisms
found in the food. Moreover, enzymes are biological catalysts which help to break down
macromolecules such as carbohydrates, proteins and lipids into smaller molecules which are
,absorbed by the body. Finally, bile is utilised to emulsify huge quantities of lipids into small globules
that can be easily digested.
Mixing and movement
To transfer and absorb food molecules, the digestive system involves three major processes:
- Swallowing - Swallowing is the process which forces food to go down by using skeletal and
smooth muscles of the mouth, tongue and pharynx.
- Peristalsis - Peristalsis is defined as a muscle contraction which passes through the digestive
organs, as it transports digestive food molecules. Therefore, the food will travel from the
oesophagus down to the organs such as the stomach and intestines and finally in the GI
tract.
- Segmentation - The food is broken down by digestive enzymes which helps to increase the
absorption of the nutrient. This allows the nutrient to be absorbed into the bloodstream and
increase the interaction with the guts walls.
Digestion
Digestion is the process of breaking down big pieces of food into their constituent components. The
process of breaking down large pieces of food into smaller pieces is known as mechanical digestion
because it physically breaks down large bits of food into smaller pieces. Therefore, the digestion
begins in the mouth where the tooth starts chewing where the large piece of food is broken down
into smaller pieces. Once the food is broken into smaller pecice it will be forced down to the GI tract
which are digestive organs that help to break down food more into smaller pieces. For example, the
liver's bile is also utilised to mechanically break down lipids into much smaller globules. The food can
be chemical digested because chemical digestion is referred to digestive enzyme such as salivary
amylases in the the mouth that helps break down large complex molecules such as carbohydrates
and can be absorbed into the bloodstream much faster. Moreover, the chemical digestion is
continued in the stomach by enzymes and the acid, but the majority of chemical digestion occurs in
the small intestine due to pancreatic activity. The pancreatic juice contains enzymes such as:
trypsinogen, carboxypeptidase, elastase, pancreatic lipase, nucleases, chymotrypsinogen and
amylase. The food molecules will be broken down further by help of the digestive enzymes which can
then be absorbed into the bloodstream. This is because the food molecule is broken down into
components such as fatty acids, amino acids, monosaccharides, and nucleotides by the time it exits
the duodenum which is the first part of the small intestine.
Absorption
Food is ready for the body to be absorbed once it has been broken down into smaller molecules. This
means that absorption takes place mostly in the stomach and small intestine, where the vitamin and
mineral is taken straight into the bloodstream. This is because the wall of the small intestine is folded
to increase surface area so the nutrient can be absorbed into the bloodstream, which is called villi as
it is finger-like projections that is flooded to increase surface area. Therefore, the food molecules will
be absorbed in the bloodstream which will be carried in capillary to the rest of the body. Also, before
faeces leave the body, the large intestine absorbs water as well as vitamins B and K.
, Excretion
The digestive system's main role is waste expulsion, which is known as faeces. Defecation discharges
indigestible substances from the body, preventing them from accumulating inside the stomach. Also,
the conscious portion of the brain controls the time of faeces, but it must be done on a regular basis
to avoid a buildup of indigestible materials.
Digestive system's functions
The digestive system is a process which breaks down large molecules of food into smaller ones by
help of digestive enzymes which will then be absorbed into the bloodstream and transported
through the body.
Therefore, the digestive system contain hollow organs that help with digesting food such as:
- Mouth
- Pharynx
- Oesophagus
- Stomach
- small intestine
- Large intestine
- Pancreas
- Liver
- Gallbladder
These digestive organs will mechanically break down the food, allowing the digestive enzymes to
reach all of the food components. The chemical digestion of food is carried out by enzymes that are
different to various substrates. The digestive process is divided into different stages, the first of which
begins in the mouth.
Mouth
The gastrointestinal tract's facial entrance is the
mouth. The tongue, palates, gums, and teeth are
located in the oral cavity, which is bounded
anteriorly by the lips, laterally by the cheeks, and
posteriorly by the oropharynx. As a result, the
primary function of the mouth is to break down
food molecules by chewing and also to produce
enzymes such as salivary amylase for further
digestion. Furthermore, the secondary function of
the mouth is sound generation, facial expression,
test which is known as gustation and most importantly, respiration which allows gas exchange. The
oral cavity is anatomically separated into the oral vestibule, which is the gap between the teeth and
the mucosa of the lips and cheeks. The oral cavity is the space bounded on both sides by teeth
anteriorly and laterally, and posteriorly by the oropharynx. Teeth are strong, calcified structures that
are used to produce sound as well as bite and chew food. The palate, which is divided into soft and
hard palates, separates the oral cavity from the nasal cavity.
