Stomach Anatomy and Cell Functions

Study Notes

Stomach Layers

Serosa/Visceral Peritoneum: The outermost layer of the stomach.
Muscularis: Responsible for stomach movement, with three layers: outer longitudinal, middle circular, and inner oblique.
Submucosa: Contains blood vessels.
Mucosa: The innermost layer of the stomach, containing:
- Rugae: Folds that expand the stomach when it fills with food.
- Gastric Pits: Openings for gastric glands.

Stomach Cells

Parietal Cells: Produce hydrochloric acid (HCI), which plays several roles:
- Activates the digestive enzyme pepsin.
- Breaks down proteins.
- Converts ferric ions into ferrous ions for hemoglobin synthesis.
- Contributes to nonspecific disease resistance.
- Intrinsic factor: A glycoprotein essential for vitamin B12 absorption in the small intestine, also crucial for hemoglobin synthesis.
- Ghrelin: A hunger hormone, regulating appetite.
Chief Cells:
- Pepsinogen: Precursor to pepsin, activated by HCI to digest proteins.
- Gastric lipase: Digests lipids.
Endocrine Cells: Produce regulatory hormones.

Liver Functions

Bile Production: Contains bile salts for fat emulsification and bilirubin, a pigment derived from broken red blood cells.
Storage: Stores glycogen, fats, vitamins, copper, and iron.
Nutrient Interconversion: Converts waste products into useful substances.
Cori Cycle: Converts lactic acid into glucose.
Detoxification: Hepatocytes neutralize toxic ammonia, produced by the breakdown of proteins, into urea.
Phagocytosis: Kupffer cells, the liver's phagocytes, remove dying white blood cells, red blood cells, and bacteria.
Synthesis: Produces essential proteins like albumin, fibrinogen, globulin, heparin, and clotting factors.

Stomach Layers

Serosa/ Visceral Peritoneum: Outermost layer of the stomach.
Muscularis: Responsible for stomach movement and mixing food.
- Outer Longitudinal: Runs lengthwise.
- Middle Circular: Runs around the circumference.
- Inner Oblique: Runs diagonally.
Submucosa: Contains blood vessels that provide nutrients and oxygen to the stomach lining.
Mucosa: Innermost layer of the stomach.
- Rugae: Folds in the stomach lining that expand to accommodate food.
- Gastric Pits: Openings for gastric glands that secrete digestive juices.

Stomach Cells

Parietal Cells: Secrete hydrochloric acid (HCl) and intrinsic factor.
- HCl: Makes the stomach acidic, activates pepsin (protein digestion), breaks down lingual lipase (fat digestion), and converts ferric ions to ferrous ions for hemoglobin synthesis.
- Intrinsic Factor: A glycoprotein needed for vitamin B12 absorption in the small intestine. Vitamin B12 is also essential for hemoglobin synthesis.
Chief Cells: Secrete pepsinogen and gastric lipase.
- Pepsinogen: Activated by HCl to form pepsin, which breaks down proteins.
- Gastric Lipase: Digests lipids.
Endocrine Cells: Secrete regulatory hormones, including ghrelin (a hunger hormone).

Liver Functions

Bile Production: Bile contains salts that emulsify fats and bilirubin (a pigment from broken down red blood cells).
Storage: Stores glycogen, fats, vitamins, copper, and iron.
Nutrient Interconversion: Converts waste products into useful substances.
- Cori Cycle: Converts lactic acid into glucose.
Detoxification: Liver cells (hepatocytes) convert ammonia (a toxic byproduct) into urea.
Phagocytosis: Kupffer cells within the liver remove dying white blood cells, red blood cells, and bacteria.
Synthesis: Produces essential proteins, including albumin, fibrinogen, globulin, heparin, and clotting factors.

Description

Explore the layers and cellular functions of the stomach in this quiz. Learn about the roles of serosa, muscularis, submucosa, and mucosa, along with various stomach cells like parietal and chief cells. Test your knowledge on their contributions to digestion and overall health.