10.5 Overview of the Digestive System Flashcards
What are catabolic reactions?
reactions that breakdown molecules to supply energy
What are anabolic reactions?
synthesis of macromolecules
What is a basic overview of digestion?
breakdown of polymers into their building blocks
What is the primary and secondary function of the digestive system?
primary = digestion and absorption
secondary = protection from disease
What are all the names for the GI tract?
GI tract
digestive tract
alimentary canal
gut
What is the GI tract?
long muscular tube extending from the mouth to the anus
What is the GI lumen?
inside of the gut that is continuous with the outside of the body
What is the apical surface of the GI epithelium?
surface of the epithelial cell that faces into the lumen
What is the purpose of tight junctions in the GI epithelium?
separates the apical surface from the remainder of the cell surface
What is the basolateral surface of the GI epithelium?
sides and bottom of an epithelial cells that form the surface of the opposite of the lumen
What type of muscle is GI muscle?
smooth muscle
What are the two layers of smooth muscle in the GI tract?
longitudinal layer
circular layer
What is GI motility?
refers to the rhythmic contraction of GI smooth muscle
What are the five factors that determine GI motility?
- GI smooth muscle exhibits automaticity
- GI smooth muscle is functional syncytium
- enteric nervous system
- GI motility is affected by hormonal input
- parasympathetic causes relaxation of sphincters and sympathetic causes contraction of sphincters
What does automaticity mean in relation to GI motility?
GI smooth muscle will contract periodically without external stimulation
