A&p 2 Lecture - Digestive System

Front 1

How often are selected cells of the stomach epithelium replaced?

Back 1

Rapidly; Every few days!

Front 2

What are the names of the selected cells of the stomach epithelium?

Back 2

Parietal, Mucous, Chief, Enteroendocrine

Front 3

Name the selected cell of stomach epithelium: Secretes H+ (protons, literally) via ion pumps in the cell membranes, which combine with Cl- in the lumen to form HCL. Also secretes intrinsic factor (necessary for the absorption of vitamin B12)

Back 3

Parietal Cells

Front 4

Name the selected cell of stomach epithelium:
Make the protective mucus barrier that protects the gastric epithelium from the harsh, Acidic environment of the lumen.

Back 4

Mucous Cells

Front 5

Name the selected cell of stomach epithelium:
Secrete several enzymes, especially pepsinogen which is later converted to active pepsin by the HCl; pepsin is a protease (breaks down proteins.) This is the first location in the alimentary canal where some proteins are chemically digested by an enzyme

Back 5

Chief Cells

Front 6

Name the selected cell of stomach epithelium:
Secrete a variety of hormones and chemical messengers that regulate digestion.

Back 6

Enteroendocrine cells

Front 7

Function of the stomach: The stomach is a _____________ that breaks food down into very small particle; it also begins the _________ (________) digestion of ________ (with pepsin).

Back 7

mechanical mixer; enzymatic (chemical); proteins

Front 8

The end product of mechanical and chemical digestion in the stomach is a pastelike material called _______, which then moves into the ________ a little at a time (entry is controlled by the ________) for further digestion.

Back 8

chyme, duodenum, pyloric sphincter

Front 9

Very few materials are actually absorbed into the blood from the stomach. T/F? Name a few.

Back 9

T; ethyl alcohol, asprin, certain lipid-soluble drugs

Front 10

What makes the protective mucus barrier that protects the gastric epithelium from the lumen? What is the average pH of the lumen? What can damage the barrier and promote the formation of stomach ulcers? These ulcers can be worsened/caused by what type of bacteria? How is this type of bacteria treated?

Back 10

Mucous cells; 2; "barrier-breaking" agents such as NSAID's and ethyl alcohol; Helicobacter pylori; antibiotics

Front 11

Very special bacteria that have protective mechanisms against extreme acidity; may cause/worsen peptic ulcers

Back 11

Helicobacter pylori

Front 12

What largely secretes the enzyme pepsinogen, which is later converted to active pepsin? What is responsible for this conversion? Pepsin is a protease, which means what?

Back 12

Chief Cells, HCl, Breaks down proteins

Front 13

The first location in the alimentary canal where some proteins are chemically digested by an enzyme

Back 13

Chief cells

Front 14

Chief cells secretes ________ which is later converted to active _______ by the ______.

Back 14

Pepsinogen, Pepsin, HCl

Front 15

What secretes H+ via ion pumps in the cell membranes which combine with Cl- to form HCL, and also secretes intrinsic factor? Intrinsic factor is necessary for the absorption of? Persons who have had parts or all of the stomach removed often have to take this vitamin sublingually or by injection, why?

Back 15

Parietal cells, B12, they lack intrinsic factor and cannot absorb enough in the diet

Front 16

When a person has serious/chronic "Acid indigestion" or reflux due to excessive stomach acid production, several approaches in drug therapy can be taken. Drugs called "__________" like Pepsid or Zantac Block one subclass of receptors for _______ (a neurotransmitter of the enteric nervous system) on the parietal cell membrane. This causes?

Back 16

"H2 receptor blockers"; histamine; A reduction of stimulation of the parietal cells by histamine. The parietal cells then secrete fewer H+ into the stomach lumen, reducing acidity.

Front 17

When a person has serious/chronic "Acid indigestion" or reflux due to excessive stomach acid production, several approaches in drug therapy can be taken. The use of drugs called "____________" like Prilosec can reduce acid secretion by? Less H+ secreted = ?

Back 17

"proton pump inhibitors"; interfering with the ion pumps for H+ in the parietal cell membrane; less acidity in the lumen of the stomach.

Front 18

When a person has serious/chronic "Acid indigestion" or reflux due to excessive stomach acid production, several approaches in drug therapy can be taken. For minor or periodic acid indigestion, ________ (like Tums) which simply neutralize some of the acid are often a better approach.

Back 18

antacids