Types of Digestion and Absorption

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Questions and Answers

What is the primary purpose of mechanical digestion?

To secrete digestive juices

To absorb nutrients into the bloodstream

To reduce food particle size (correct)

To chemically transform food into nutrients

Chemical digestion occurs only in the mouth.

False

What is formed when food is mixed with saliva during the process of insalivation?

Bolus

The liquid mush produced in the stomach is known as __________.

chyme Signup and view all the answers

Which process enables the bolus to travel through the pharynx to the stomach?

Deglutition Signup and view all the answers

Villi in the small intestine significantly increase the surface area for nutrient absorption.

True Signup and view all the answers

What are the three main types of juices that act in the small intestine?

Intestinal juices, bile, pancreatic juices Signup and view all the answers

The __________ wall has a large surface for absorption, approximately 200 metres squared.

intestinal Signup and view all the answers

Match the digestive process with its description:

Mastication = Chewing and grinding food Insalivation = Mixing food with saliva Deglutition = Swallowing of the bolus Chyme = Half-liquid mush in the stomach Signup and view all the answers

What are microvilli?

Tiny folds of plasma membranes in intestinal cells Signup and view all the answers

What is the main role of saliva during the digestive process?

To break down carbohydrates Signup and view all the answers

Chyme is produced in the small intestine.

False Signup and view all the answers

What is the term for the half-liquid mush created in the stomach?

chyme Signup and view all the answers

The process of __________ consists of tearing and grinding food in the mouth.

mastication Signup and view all the answers

Match the digestive processes with their corresponding definitions:

Mastication = Mixing food with saliva Deglutition = Moving the bolus to the stomach Chemical digestion = Transforming food into nutrients Absorption = Uptake of nutrients into the bloodstream Signup and view all the answers

Which of the following structures is essential in increasing the absorption surface area in the small intestine?

Villi Signup and view all the answers

The small intestine has a larger absorption surface compared to the stomach.

True Signup and view all the answers

What are intestinal villi and why are they important?

Intestinal villi are small projections on the inner wall of the small intestine that increase the surface area for nutrient absorption. Signup and view all the answers

Nutrients absorbed in the small intestine reach the body's cells via the __________.

blood Signup and view all the answers

Which digestive juices act specifically on proteins in the stomach?

Gastric juices Signup and view all the answers

Study Notes

Types of Digestion

Mechanical Digestion: Reduces food particle size for easier transport.
- Mastication: Chewing, tearing, cutting, and grinding food in the mouth using teeth and jaw movements.
- Insalivation: Mixing chewed food with saliva using the tongue, forming a bolus.
- Deglutition: Using peristaltic movements to move the bolus through the pharynx and esophagus to the stomach.
Chemical Digestion: Breaks down food into nutrients using digestive juices.
- Mouth: Saliva acts on carbohydrates, breaking them down into simpler substances during bolus formation.
- Stomach: Gastric juices (with pepsin) act on proteins, creating chyme.
- Small Intestine: Intestinal juices, bile, and pancreatic juices act to complete digestion, turning chyme into chyle (containing water, nutrients, and remaining products).

Absorption in the Small Intestine

High surface area for nutrient absorption (approximately 200 square meters).
- Length: The small intestine is 7-8 meters long.
- Intestinal Mucus (Internal Walls): Tiny structures (folds, villi, microvilli) increase surface area significantly, up to approximately 600 times.
  - Folds in the intestinal wall.
  - Tiny finger-like projections (villi) covering the folds.
  - Even smaller projections (microvilli) on the surface of the villi.
  - Extensive network of blood vessels and capillaries within the villi.

Absorption in the Large Intestine

Absorbs water and minerals.
- Difference from small intestine: Larger diameter (approximately 1 meter) but no villi.
- Gut flora (bacteria): Breakdown undigested material into feces for egestion (defecation) through the anus.
- Dietary fibre: Not digested by human enzymes, therefore cannot be absorbed.

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Description

Explore the processes of mechanical and chemical digestion, covering key concepts like mastication and the role of gastric juices. This quiz also dives into the absorption of nutrients in the small intestine, emphasizing its structure and efficiency. Test your understanding of how food transforms into energy!