ANAT20006 Lecture Notes - Lecture 20: Serous Membrane, Smooth Muscle Tissue, Peristalsis

• School: University of Melbourne
• Department: Anatomy and Neuroscience
• Course: ANAT20006
• Professor: Junhua Xiao

Document Summary

Viscera are organs that regulate the internal environment. Involved in secretion, excretion, digestion and absorption. Hollow viscera are typically cylindrical and have a lumen. These have lots of folds which increase sa. Smooth muscle producing waves of contractions called peristalsis. Connective tissue which spits out fluid into the cavity around the viscus minimises friction. Serosa covers the external surface of viscera. They minimise friction by spitting out fluid outside. The serosa (membranes) can be continuous with a mesentery (connecting stalks to the body wall) keeps the organ suspended in the body cavities. Muscularis are usually both circular + longitudinal (contraction both ways) smooth muscle. They provide motility (peristalsis) and expansion (for increased storage in the associated organ) When the stretch occurs, there is no change in force of contraction. At the critical point of storage (stretch) reflexes (using sensory nerves) are initiated to cause micturition (pee) or defecation (poo)