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Large Intestine Overview - Anatomy & Physiology (view source)
Revision as of 18:02, 10 December 2010
, 18:02, 10 December 2010no edit summary
[[Image:Colon fox lymphatic nodule.jpg|thumb|right|250px|Lymphatic Nodule - © RVC 2008]]
[[Image:Colon fox lymphatic nodule.jpg|thumb|right|250px|Lymphatic Nodule - © RVC 2008]]
Lymphatic nodules are present in the mucosa of the large intestine. Lymph nodes of the large intestine drain into one of two centres, the '''cranial mesenteric centre''' or the '''caudal mesenteric centre'''. The '''cranial mesenteric centre''' includes lymph nodes of the [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and the following lymph nodes of the large intestine The '''caecal''' - drains the [[Caecum - Anatomy & Physiology|caecum]]. The '''Colic''' - drains the ascending and transverse [[Colon - Anatomy & Physiology|colon]]. The efferent vessels of these lymph nodes converge to form the cranial mesenteric trunk which drains into the chyle cistern. The '''caudal mesenteric centre''' includes the lymph nodes of the descending [[Colon - Anatomy & Physiology|colon]], which are situated in the mesocolon. The efferent vessels of these lymph nodes converge to form the caudal mesenteric trunk which unites with the cranial mesenteric trunk to open into the chyle cistern.
Lymphatic nodules are present in the mucosa of the large intestine. Lymph nodes of the large intestine drain into one of two centres, the '''cranial mesenteric centre''' or the '''caudal mesenteric centre'''. The '''cranial mesenteric centre''' includes lymph nodes of the [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and the following lymph nodes of the large intestine The '''caecal''' - drains the [[Caecum - Anatomy & Physiology|caecum]]. The '''Colic''' - drains the ascending and transverse [[Colon - Anatomy & Physiology|colon]]. The efferent vessels of these lymph nodes converge to form the cranial mesenteric trunk which drains into the chyle cistern. The '''caudal mesenteric centre''' includes the lymph nodes of the descending [[Colon - Anatomy & Physiology|colon]], which are situated in the mesocolon. The efferent vessels of these lymph nodes converge to form the caudal mesenteric trunk which unites with the cranial mesenteric trunk to open into the chyle cistern.
==Histology==
[[Image:mucosal layer of colon.jpg|thumb|right|150px|Mucosal Layer of Colon (Fox) - © RVC 2008]]
*The mucosa of the large intestine is smooth; there are '''no villi or microvilli'''.
*Mucosal glands are much longer and straighter.
*The number of goblet cells in the mucosa is increased compared to the [[Small Intestine Overview - Anatomy & Physiology|small intestine]].
**Mucus is very important for lubrication of the ingesta as it passes through the intestine, particularly as more water is absorbed from the lumen making chyme drier.
*There are numerous scattered lymph nodules.
**The number of lymph nodules increases compared to the [[Small Intestine Overview - Anatomy & Physiology|small intestine]].
*The submucosa is much reduced in thickness.
*'''Taenia''' may be present.
**These are concentrations of the longitudinal muscle layer into long bands.
**When the taenia contract, they cause shortening of the large intestine, which produces saccualtions, or '''haustra'''.
***Haustra help to mix the content and to slow the transit time
*Many glands are present in the mucosa and skin of the anal region.
==Species Differences==
==Species Differences==
'''Test yourself with the [[Large Intestine - Anatomy & Physiology - Flashcards|Large Intestine Flashcards]]'''
'''Test yourself with the [[Large Intestine - Anatomy & Physiology - Flashcards|Large Intestine Flashcards]]'''
'''Click here for information on [[Intestines, Small and Large - Pathology|pathology of the Small and Large Intestine]]'''
'''Click here for information on [[Intestines, Small and Large - Pathology|pathology of the Small and Large Intestine]]'''