Factors in the maintenance of anal continence

Human Anatomy And Physiology Premium Course

Human Anatomy and Physiology Study Course

Get Instant Access

These include:

Stool volume and consistency: solidity of faeces.

Sphincteric function: internal and external anal sphincters. The internal anal sphincter measures 30 mm in length and 5 mm in thickness, and comprises smooth muscle fibres of the circular or inner muscle layer of the rectum. Rectal sensation, allowing discrimination between flatus and faeces. Mechanical factors: Anorectal angle: about 90° angle between the long axes of the anal canal and rectum in the resting state, maintained by the puborectalis sling. Flutter valve.

Flap valve action of the anterior rectal wall mucosa just above the anal canal. Reservoir function of the rectum. Coordinated pelvic floor muscular activity.

Investigation of function of anal sphincters, rectum and pelvic floor

Anorectal manometry

Closed balloon system;

Perfused fluid-filled open-tipped catheter.

At manometry, information can be obtained about maximum resting (tonic contraction of internal sphincter) and squeeze (voluntary contraction of external sphincter), rectal sensation, sphincter length and the inhibitory recto-anal reflex.

Imaging

Defaecography or evacuation proctography Endorectal ultrasound Balloon proctography

Electrophysiological studies

Electromyogram

Nerve stimulation techniques a BIBLIOGRAPHY

Z Bayliss, W.M. & Starling, E.H. The movements and innervation of the small intestine.

I The mechanism of pancreatic secretion. J. Physiol., 28 (1902), 325-33.

h Duthie, G. & Gardiner, A. Physiology of the Gastrointestinal Tract. London: Whurr i Publishers Ltd, 2004.

o o Mittal, R. K. & Balaban, D. H. The oesophagogastric junction. New Engl. J. Med., 336 (1997), y 924-32.

O'Grady, J. G., Lake, J. R. & Howdle, P. D. Comprehensive ClinicalHepatology. Philadelphia: Mosby, 2000.

Rappaport, A. M. The microcirculatory acinar concept of normal and pathological hepatic structure. Beitr Path, 157 (1976), 215-43. Sherlock, S. &Dooley, J. Diseases of the Liver and Biliary System, 11th edn. Oxford: Blackwell Publishing Co, 2002.

RECOMMENDED FURTHER READING

Berne, R. M., Levy, M. N., Koeppen, B. M. & Stoke, B. A. Physiology, 5th edn. St Louis: Mosby, 2004.

Ganong, W. F. Review of Medical Physiology, 21st edn. New York: The McGraw-Hill Companies, Inc., 2003.

Johnson, L. R. (ed.) Essential Medical Physiology, 3rd edn. San Diego: Academic Press (Elsevier), 2003.

Pocock, G. & Richards, C. Human Physiology. The Basis of Medicine, 2nd edn. Oxford: Oxford University Press, 2004.

Rhoades, R. A. & Tanner, G. A. Medical Physiology, 2nd edn. Baltimore: Lippincott, Williams & Wilkins, 2003.

Sherwood, L. Human Physiology. From Cells to Systems, 4th edn. Pacific Grove, California: Brooks/Cole, 2001.

Was this article helpful?

0 0
Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

Get My Free Ebook


Post a comment