What is a Hemorrhoid? | Minnesota
Believe it or not, everyone has had a normal hemorrhoidal tissue in their rectum and anus. Hemorrhoids are actually part of our normal anatomy. They are clusters of vascular tissue, smooth muscle, and connective tissue lined by the normal epithelium of the anal canal.
We used to believe that hemorrhoidal bleeding is venous. Now the evidence indicates that hemorrhoidal bleeding is arterial, which is supported by the bright red color and arterial pH of the blood.
There are two different types of hemorrhoids: internal and external hemorrhoids based on their anatomic origin and their position relative to the dentate line.
|Internal Hemorrhoids||External Hemorrhoids|
|Surface Epithelium||Columnar epithelium||Squamous epithelium|
|Nerve Supply||Not cutaneous nerves||Somatic sensory nerves|
|Position relative to the dentate line||Above the dentate line||Below the dentate line|
Internal hemorrhoids are not supplied by cutaneous nerves and therefore cannot cause sharp pain. hemorrhoids can be found at any position within the rectum, and many have 3 main cushions around the anal canal.
Under normal circumstances, hemorrhoids vascular tissue helps to assist in defecation during the bowel movement by providing important sensory information, enabling the differentiation between solid, liquid, and gas, and keeping some continence or control of our gas.
It’s only when your hemorrhoids enlarge and prolapsed that they’re considered abnormal or diseased.