Gastro Intestinal Tract – Small Intestine
The small intestine is split into three sections: duodenum , jejunum and ileum. It starts at the
Pyloric Sphincter and continues until it merges with the Jejunum. The function of the small
intestine is to digest and absorb (Slomianka, 2014).
According to Columbia CNMTL Histology Laboratory Manual and Tortora and Derrickson,
the Concentric coats of the small intestine, from the lumen out are:
o Lamina propria (a thin layer of loose Connective Tissue)
o Muscularis mucosa
o Dense Connective Tissue
o Connective Tissue containing nerves + Blood vessels sandwiched between a layer of
smooth muscle either side. With a outermost layer, Serosa. (General Biology Lab
Rutgers EDU. 2014)
o Connective Tissue
Connective Tissue Arrangement:
The connective tissue is in the submucosa, with the mucosa between it and
the lumen(Columbia CNMTL Histology Laboratory Manual, 2014).
Some Loose Connective Tissue is in the core of the Villi (The Human Protein
In the ileum division, in the submucosa there are Collagen Fibres, dense
connective tissue (A Website for Human Anatomy and Physiology, 2014).
Epithelial Tissue Arrangement:
The Villi are lined with columnar epithelial cells (The Human Protein Atlas,
2014). Villi projects into the lumen. This is part of the Mucosa, it is also made
o Goblet Cells – mucous secreting epithelial cells.
o As well as Enterocytes, Paneth cells, Enteroendocrine cells , M cells
and Undifferentiated cells. (General Biology Lab Rutgers EDU, 2014).
Other Tissues Relevant:
Smooth muscle Tissue makes up the muscularis. The muscularis has an
inner layer of circular smooth muscle and an outer layer of longitudinal
smooth muscle, and a outermost layer of visceral peritoneum or Serosa
(Connective tissue) (General Biology Lab Rutgers EDU. 2014).
Other Features Relevant:
Pilicae Circulares are fold of mucosa and submucosa which increase the
surface area(Slomianka, 2014).
Crypts: secrete intestinal juices, hold cells to regenerate the epithelium and
Paneth, which release antibacterial substances (Slomianka, 2014).
According to Tortora and Derrickson, submucosa secrete alkaline mucous to
combat the gastric acid in the chime from the duodenal glands.
How does the Structure of the cells/ tissues link to the function of the Small
The small intestine is adapted to absorb and digest as it is so long, (Tortora and Derrickson.
2013.) but to increase the surface area it has other features such as:
Villi and the Pilicae both provide extra surface area for the digestion and
absorption process. The Villi in the intestine are using in absorption, while in
the stomach they secrete mucous (Columbia CNMTL Histology Laboratory
The Epithelial Cell arrangement works with the function of the small intestine
of digesting an absorbing nutrients, as it creates a larger surface area for this
to occur (Tortora and Derrickson, 2013).
The Enterocytes are absorption cells, and absorbing is one of the functions of
the Small Intestine.
Connective Tissue in the Submucosa Layer:
The Collagen Fibres in the Submucosa give structural strength (A Website for
Human Anatomy and Physiology, 2014).
A Website for Human Anatomy and Physiology. 2014. Dense Irregular 1.
http://bioweb.uwlax.edu/aplab/Lab-Unit-02/Lab-02-10.html Viewed on the 11th of February
Columbia CNMTL Histology Laboratory Manual. 2014. Histology Laboratory Manual: Small
Intestine. http://histologylab.ccnmtl.columbia.edu/lab13/small_intestine.html Viewed on the
11th of February 2014
Gallik, S. 2014. Chapter 7, Page 11 – HistologyOLM 4.0.
.html Viewed on the 10th of February 2014
General Biology Lab Rutgers EDU. 2014. Tissues of the Small Intestine.
http://bio.rutgers.edu/~gb102/lab_9/904dm-amphiuma.html Viewed on the 11th of February
MD, E. 2014. Organ System Pathology.
http://library.med.utah.edu/WebPath/ORGAN.html#2 Viewed on the 11th of February 2014
My Virtual Medical Centre. 2006. Gastrointestinal System – myVirtual Medical Centre.
http://www.myvmc.com/anatomy/gastrointestinal-system/#C7 Viewed on the 11th of
Slomianka, L. 2014. Blue Histology – Gastrointestinal Tract.
on the 11th of February 2014.
The Human Protein Atlas. 2014. Dictionary Small Intestine.
http://www.proteinatlas.org/dictionary/normal/small+intestine Viewed on the 11th of
Tortora, G. J. and Derrickson, B. 2013. Principles of anatomy & physiology. Hoboken, NJ:
University of Michigan Medical School. 2014. Connective Tissue: Medical Histology
and Virtual Microscopy: University of Michigan.
http://www.med.umich.edu/histology/cellsTissue/connectiveTissue.html Viewed on the 12th
of February 2014
University of Ottawa Medicine Histology Course Web. 2014. The Small Intestine.
English/Gastrointestinal/gastro_small_intest.htm Viewed on the 10th of February
Wwwmgs.bionet.nsc.ru. 2014. Small Intestine.
http://wwwmgs.bionet.nsc.ru/mgs/gnw/trrd/thesaurus/Di/small.html Viewed on the 12th of