Anatomy and Physiology of the GI System: Clinical Work Application

This report provides a comprehensive overview of the gastrointestinal (GI) system, detailing its anatomy and physiology. It begins by explaining the structure and function of the GI tract, from the mouth to the anus, including the roles of various organs such as the esophagus, stomach, small and large intestines, pancreas, and gallbladder. The report emphasizes how these anatomical structures work together to facilitate digestion, absorption, and waste elimination. Furthermore, it explores the interaction between the GI system and other body systems, such as the skin. The report highlights the clinical relevance of understanding GI anatomy and physiology, emphasizing its importance for healthcare professionals in assessing and treating patients with gastrointestinal disorders. The report concludes by summarizing the key aspects of the GI system and its significance in maintaining overall health.

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9/29/2019

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Table of Contents
Introduction.................................................................................................................................................2
How the anatomy and physiology interact...............................................................................................2
Application in clinical work....................................................................................................................5
Conclusion...................................................................................................................................................6
References...................................................................................................................................................7

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Introduction
The human body is composed of different types of cells, these cells made up tissues and
the tissues makes organs which help in performing different types of functions in the body. The
system includes different organs that perform specific or several functions. The gastrointestinal
system is the organ system within the human body and other creatures (Shier, Butler & Lewis,
2015). It comprised of a hollow muscular duct which starts a person’s oral cavity where the food
enters the mouth, continuing to different other parts like esophagus, stomach and intestines, and
ends to the anus. The main purpose of this system is to break the food into small pats and absorb
the nutrition from it and utilized to produce energy (DeSaix et al., 2018). In this particular
assessment report how the anatomy and physiology interact in this system will be discussed. Use
of this information in my clinical work will also be mentioned in this report.
How the anatomy and physiology interact
First food should be ingested inside the mouth for mechanical process and to moisten.
Secondly, ingestion happens mostly in the stomach and the small intestine where components
like proteins, fats and the carbohydrates are broken down chemically into their basic building
blocks (Kim & Pritts, 2017). The Smaller particles are further absorbed crossways the epithelium
of SI and consequently enter the circulation. The large intestine is situated around SI and plays
an important role in the reabsorption of excess water. Lastly, undigested substances and secreted
waste material are expelled from the human body through defecation (passing of faeces) (Rizzo,
2015).
The gastrointestinal system is a tube that spreads from the mouth to the rectum. It has
usually the same structure all over. There is a hollow portion of the tube recognized as the

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lumen, a muscular coating in the middle, and a coating of epithelial cells. These coatings are
responsible for upholding the mucosal integrity of the GI tract. There are three different
functions of the gastrointestinal system: transportation, digestion, and absorption of the food
(Cheng et al., 2010). After chewing and mixing of the food with saliva in the month it is
swallowed and transports down towards the oesophagus. The oesophagus has the stratified
squamous epithelial coverings which safeguard the oesophagus from shock or trauma,
submucosa discharges mucus from the mucous glands which provide the pathway of food
towards the oesophagus. The oesophagus lumen is covered by the linings of the muscles
(Miranda-Bautista, Bañares & Vaquero, 2017).
The stomach is the J shaped bag-like structure, situated just left side of the midline
between the small intestine and oesophagus. It is separated into 4 different regions and has two
different borders named the greater and smaller curvatures. The first part is the named cardia
which surrounds another part called Cardiol orifice where the oesophagus goes into the stomach
(Kim & Pritts, 2017). The fundus is superior and dilated part of the human stomach that linked
with the diaphragm dome. The human body is the biggest area between the fundus and the
curved area of the J. this the part where the majority of the gastric glands are situated and where
the maximum mixing of the food happen the gastric content are then expelled into the proximal
duodenum through the pyloric sphincter. The inner lining of the stomach is contracted in to the
rogue which is the longitudinal folds the stomach has five main functions that are temporary
storage of the food, control of the rate at which the engulfed food enter the duodecimo, secretion
of acids and antibacterial action, stomach content fluidisation, and preliminary metabolism with
the pepsin, and lipases (Treuting, Arends & Dintzis, 2018).

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The small intestine is the part of the gastrointestinal system which is responsible for most
of the digestion (chemical and mechanical). It is the place where all the absorption process takes
place virtually. The complete small intestine is lined-up with the absorptive type of mucosal,
with certain advances for every part. The small intestine also comprises smooth muscle wall with
two different muscle layers: the rhythmical type of contraction force products of the metabolism
via the intestine also called peristalsis (Peate, 2018). The small intestine has 3 different sections
that are duodenum which works in neutralising the acidic gastric contents and starts the further
breakdown of food. The small intestine also contains jejunum and ileum which are the highly
coiled portions, works in increasing the surface area for absorption dramatically. The enzymes
secreted in the small intestine food digestion process are lipase, amylase, maltase, lactase,
sucrose, and dextrinase. The large intestine looks like a horseshoe, and extents nearby the small
intestine as a frame (Denbow, 2015). It contains an appendix, caecum, ascending, transverse,
descending, the sigmoid colon, and the rectum. It extends from the terminal ileum situated at the
ileocecal valve to the end part called rectum. Water absorption is the main part of the large
intestine, it absorbs nearly 1 and one and a half litres water every day. It also absorbs chloride,
potassium, and sodium. It also takes part in the accumulation of the unabsorbed material to
produce faeces, and some digestion by the bacteria which is responsible for the creation of
intestinal gas. The pancreas is the lobular, pinkish-grey part of the gastrointestinal system
situated behind the stomach (Miranda-Bautista, Bañares & Vaquero, 2017). The head of the
pancreas is attached with duodenum and tail extends to the spleen. It is nearly 15 cm long
cylindrical with head and tail. This organ of the GI system has both exocrine and endocrine
function in the body. The exocrine function means it helps in the production of essential
hormones which happen in the Langerhans islets. The secretory or exocrine function indicates

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that it makes up around 80 to 85 per cent of the pancreas (Shames, 2019). The pancreas
discharges the fluids with high carbohydrate and some inactive enzymes. Some of the enzymes
secreted by the pancreas are carbohydrases, lipases, nucleases and the proteolytic enzymes. The
gall bladder is pear-shaped and sac-like the organ of the GI system attached to the liver works in
storing the bile. When the meal rich in fat is engulfed, the nerve and chemical messages signal
the gallbladder to contract, which results in the release of bile into the digestion system. Bile has
three different main components: water, bile salts, and bile pigments. The bole salts help in the
absorption and emulsification of fats-soluble vitamins (Peate, 2018).
There is an important relationship between the GI tract and skin. Skin problems and gut
issues have a long history of interaction. It has been established that for healthy or reduce skin
issues like acne, it is important to consume healthy food. Both the gut and human skin plays an
important role in defending the body against the pathogens. The gut and the skin act together,
each one can affect the other via numerous pathways, especially the microbiome and its
metabolites (Lavrinienko et al., 2018). The GI wall near the lumen of the human GI tract is
composed of 4 different layers of particular tissues that are mucosa, submucosa, muscular layer,
and serosa. The epithelium is the highly exposed part of the mucosa which contains goblet cells
that helps in mucus secretion which perform lubrication of the food. Another link between these
two is If waste is left in the human lower bowel, the body might reabsorb some of the materials
to get rid of these substances. Later this reabsorbed material can be eliminated from the skin
which as we know can cause skin problems (Bowe & Logan, 2011).
Application in clinical work
Preforming clinical work needs complete information about human. It is important to
understand the anatomy and physiology of the GI system (gastrointestinal system) to assess the

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patient with gastrointestinal illnesses accurately. To maintain the health of the patient it is
essential to understand the mucosal integrity associated with the gastrointestinal tract and the
working of its addition organs (Liao, Zhao & Gregersen, 2009). The position of the organs can
be separated into four different quadrants: the right upper side quadrant, the left-sided upper
quadrant, the left lower sided quadrant, and the right lower positioned quadrant. The health and
wellbeing of every patient are dependent upon the health care worker's understanding of the
human structure (Kramer, 2019). For example, for the registered nurses, they must learn the
fundamentals of the human organ systems, different tissues and associated cells so that they
know what to search for inpatients as each of these deliver signs as the individual's relative
health. To reduce medication errors, it is important for every health care provider that they have
proper information or knowledge about the gastrointestinal system. For example, the older adults
have weakened GI tract functioning, therefore, they need to prescribe medicine accordingly
which will enhance the recovery chances (Johnston et al., 2015).
Conclusion
There are different types of system in the human body such as nervous system; skeleton
system, and gastrointestinal system. All the systems perform different types of function in the
body. The gastrointestinal system is the tube-like structure starts from mouth to the anus. It
contains different organs such as oesophagus, stomach, small intestine, large intestine, pancreas,
gall bladder etc. the each has specific function such as abortion, breakdown of food, moistening
of food, secretion of enzymes etc. the food is ingested from the mouth where mechanical
breakdown takes place, the ingestion process happen In the stomach and small intestine. Then
the food is moved into the large intestine where the waste material is converted into faeces and

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excreted from the anus. There are different enzyme are secreted to facilitate the whole process
such as amylase, carbohydrases, Lipase, maltase, lactose, sucrose etc. knowing the anatomy and
physiology of the system help the health care providers to perform the clinical work, and to
assess the patient with GI problems easily. The link between the skin and GI system important as
these both can affect each other and cause health issues like acne.

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References
Bowe, W. P., & Logan, A. C. (2011). Acne vulgaris, probiotics and the gut-brain-skin axis-back
to the future?. Gut pathogens, 3(1), 1.
Cheng, L. K., O'Grady, G., Du, P., Egbuji, J. U., Windsor, J. A., & Pullan, A. J. (2010).
Gastrointestinal system. Wiley Interdisciplinary Reviews: Systems Biology and
Medicine, 2(1), 65-79.
Denbow, D. M. (2015). Gastrointestinal anatomy and physiology. In Sturkie's avian
physiology (pp. 337-366). Academic Press.
DeSaix, P., Betts, J. G., Johnson, E., Johnson, J. E., Korol, O., Kruse, D. H., ... & Young, K. A.
(2018). Anatomy & Physiology: OpenStax.
Johnston, A. N. B., Hamill, J., Barton, M. J., Baldwin, S., Percival, J., Williams-Pritchard, G., ...
& Todorovic, M. (2015). Student learning styles in anatomy and physiology courses:
Meeting the needs of nursing students. Nurse education in practice, 15(6), 415-420.
Kim, Y., & Pritts, T. A. (2017). The gastrointestinal tract. In Geriatric Trauma and Critical
Care (pp. 35-43). Springer, Cham.
Kramer, J. A. (2019). Diseases of the Gastrointestinal System. In The Common Marmoset in
Captivity and Biomedical Research (pp. 213-230). Academic Press.
Lavrinienko, A., Tukalenko, E., Mappes, T., & Watts, P. C. (2018). Skin and gut microbiomes of
a wild mammal respond to different environmental cues. Microbiome, 6(1), 209.

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Liao, D. H., Zhao, J. B., & Gregersen, H. (2009). Gastrointestinal tract modelling in health and
disease. World Journal of Gastroenterology: WJG, 15(2), 169.
Miranda-Bautista, J., Bañares, R., & Vaquero, J. (2017). The Gastrointestinal System: Anatomy
and Sources of Oxidative Stress. In Gastrointestinal tissue (pp. 3-20). Academic Press.
Peate, I. (2018). Anatomy and physiology, 9. The gastrointestinal system. British Journal of
Healthcare Assistants, 12(3), 110-114.
Rizzo, D. C. (2015). Fundamentals of anatomy and physiology. Cengage Learning.
Shames, B. (2019). Anatomy and Physiology of the Duodenum. In Shackelford's Surgery of the
Alimentary Tract, 2 Volume Set (pp. 786-803). Content Repository Only!.
Shier, D., Butler, J., & Lewis, R. (2015). Hole's essentials of human anatomy & physiology. New
York: McGraw-Hill Education.
Treuting, P. M., Arends, M. J., & Dintzis, S. M. (2018). Lower gastrointestinal tract.
In Comparative Anatomy and Histology (pp. 213-228). Academic Press.