Transcript Anatomy - inoncology

CRC: ANATOMY OF THE GASTROINTESTINAL TRACT
Slides last updated: March 2015
The wall of the GI tract is composed of four layers1
GI tract wall
1. Mucosa
2. Submucosa
Lumen
3. Muscularis
4. Serosa
1. Tortora GJ, et al. Principles of Anatomy and Physiology. 11th Ed. Hoboken: John Wiley & Sons;2006:895-946.
The wall of the GI tract is composed of four layers1
1. Mucosa
•
Mucous membrane that lines the lumen of the GI tract
•
Further divided into the epithelium, lamina propria and muscularis
mucosa
2. Submucosa
•
Areolar connective tissue that binds the mucosa to the muscularis
•
Contains blood and lymphatic vessels that receive the absorbed
nutrients
•
Also contains glands, lymphatic tissue and an extensive network of
neurons
1. Tortora GJ, et al. Principles of Anatomy and Physiology. 11th Ed. Hoboken: John Wiley & Sons;2006:895-946.
The wall of the GI tract is composed of four layers1
3. Muscularis
•
Contains either skeletal muscle for voluntary control of movement, or
smooth muscle organised in two sheets of perpendicular fibres to
generate involuntary contractions
4. Serosa
•
Superficial layer of the GI tracts segments that are suspended in the
abdominopelvic cavity
•
Also called the visceral peritoneum
•
Composed of areolar connective tissue and simple squamous
epithelium
1. Tortora GJ, et al. Principles of Anatomy and Physiology. 11th Ed. Hoboken: John Wiley & Sons;2006:895-946.
Stage is determined by how far the cancer has spread1
Cancer progression
Stage 0
Cancer is in the
mucosa only
Stage
IA-B
Stage
IIA-C
Stage
IIIA-C
Stage
IVA-B
Cancer has
grown through
the muscularis
mucosa or
submucosa
Cancer has
grown through
the muscularis
propria, serosa,
or through the
colon or rectum
wall
Cancer has
grown through
at least the
muscularis
mucosa, and
has been found
in nearby
lymph nodes
Cancer has
grown through
at least the
muscularis
mucosa and
has spread to
distant organs
(metastasised)
1. American Cancer Society. Colorectal Cancer Detailed Guide, 2014. Available online from
http://www.cancer.org/acs/groups/cid/documents/webcontent/003096-pdf.pdf, last accessed on 17/03/2015.