CH25 Lect Final SG

What are the 4 tissue layers that most of the digestive tract has?

• Mucosa

• Submucosa

• Muscular layer

• Serosa

Which parts of the GI tract have stratified squamous cells for abrasion?

• oral cavity

• Throat

• esophagus

Which parts of the GI tract have simple columnar for secretion & absorption?

• stomach

• Intestines

What is lamina propia?

• Thin

• Located in the mucosa

• Deep to epithelium

• Contains blood & lymphatic vessels & nerve ending

How does the lamina propia hold capillaries?

• Loose (areolar) connective tissue

What components of the GI tract increase surface area for absorption?

• circular folds

• Villi

• Microvilli

What is the neural plexuses in the submucosa layer & how does it connect w/parasympathetic & symp NS?

• submucosal neural plexuses- innervate the mucosa

• (activate muscles, process motor command)

• Connects bc it has parasympathetic ganglia (relax)

• Connects bc it has symp postganglionic fibers (alert)

What is the neural plexus in the muscular layer & how does it connect w/parasympathetic & symp NS?

• myenteric neural plexus

• Network of parasympathetic ganglia (relax & digest)

• Sympathetic (alert) postganglionic fibers

What type of muscle tissue is in the muscular layer?

• smooth muscle tissue

What is the serosa?

• outermost layer of digestive system

• Lubricates to reduce friction

What is adventitia & where does it take place?

• connective tissue

• Stiff/tough

• Takes place on exterior of blood vessels

What is peristalsis?

• muscular layer propels a bolus (small mass of food) through digestive tract in a series of peristaltic waves

• Segmentation happens when food is churned and fragmented & at same time propelled through tract by contractions

What structure separates the oral cavity from the nasal cavity?

• roof of the mouth- consists of hard plate & soft plate

What is lingual lipase for?

• begins digestion of lipids (fats, chem digestion)

What is the salivary amylase in the saliva for?

• enzyme( protein that breaks down molecules)

• Partially digests carbs/sugars

What are mucous surface cells & why is so much mucus made?

• face the lumen

• Make so much mucus to protect lining of stomach from auto-digestion

What cells make hydrochloric acid in the stomach?

• Parietal cells

What cells activate pepsinogen?

-chief cells

What gets injected into the duodenum of small intestine & which organs it comes from?

• receives digestive enzymes from the pancreas

• Bile from the liver & gallbladder

What a is the function of the jejunum?

• most of digestion & absorption occurs here

What does the cecum do & what part of the small intestine attaches to it?

• Is the 1st part of L. Intestine

• House of bacteria

• Ilium connects to it

• Reservoir for chyme (partially digested food) received from small intestine

• Mixes w/bacteria, break down remaining materials, absorbs H2O

What is the function of the large intestine?

• absorbs H2O from chyme & acids

• Turns it into stool

• Absorbs vitamins produced by house of bacteria

What is the path through the large intestine?

• cecum

• Ascending colon

• transverse colon

• Descending colon

• Sigmoid colon

• Rectum

• Anus