Digestion Processes and Types

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Questions and Answers

What is the primary function of digestion?

To break down complex molecules (correct)

To eliminate waste

To increase energy levels

To regulate body temperature

Egestion refers to the absorption of nutrients into the bloodstream.

False

Name the two types of digestion mentioned.

Mechanical digestion and Chemical digestion

The product of digestion that enters the blood stream is referred to as _____ .

nutrients Signup and view all the answers

Which part of the digestive system is primarily responsible for the absorption of nutrients?

Small intestine Signup and view all the answers

Match the digestive processes with their descriptions:

Ingestion = Intake of food Absorption = Nutrients entering the bloodstream Egestion = Removal of waste Mastication = Mechanical breakdown of food Signup and view all the answers

Enzymes involved in chemical digestion can function optimally at any temperature.

False Signup and view all the answers

What is the function of the villi in the small intestine?

To increase the surface area for absorption Signup and view all the answers

What is the primary function of the lacteal found in each villus?

Transport lipids Signup and view all the answers

Excess glucose is converted into urea by the liver.

False Signup and view all the answers

What process is described by the incorporation of absorbed nutrients into the cells of the body?

Assimilation Signup and view all the answers

The _______ is responsible for the metabolism of glucose and deamination of amino acids.

liver Signup and view all the answers

Match the organ with its function regarding blood glucose levels:

Pancreas = Releases insulin to lower blood glucose Liver = Converts excess glucose to glycogen Muscles = Store glucose as glycogen Kidneys = Filter waste products from blood Signup and view all the answers

Which of the following steps is NOT part of the negative feedback mechanism?

Creating an imbalance Signup and view all the answers

The rectum temporarily stores undigested materials until they are excreted.

True Signup and view all the answers

What hormone is released when blood glucose levels are too high?

Insulin Signup and view all the answers

Study Notes

Digestion

Digestion is the physical and chemical breakdown of complex molecules into simple forms, for the body to absorb and sustain life.
It involves five stages: ingestion, digestion, absorption, assimilation, and egestion.
Ingestion: Intake of food.
Digestion: Physical and chemical breakdown of food into simpler forms.
Absorption: The products of digestion diffuse into the bloodstream.
Assimilation: The incorporation of absorbed nutrients into the cells of the body.
Egestion: Removal of undigested waste from the body.

Types of Digestion

Mechanical Digestion: Physical breakdown of large food particles into smaller particles, increasing surface area. Examples include:
- Mastication: Chewing food with teeth.
- Churning: Contractions of the stomach muscles.
- Peristalsis: Rhythmic muscle contractions in the digestive tract, transporting food and water.
Chemical Digestion: Breakdown of large food compounds into smaller compounds using digestive enzymes.
- Enzymes: Biological catalysts that speed up chemical reactions.
- Optimal Conditions: Enzymes work best within specific temperature and pH ranges.
- Emulsification: Breaking down lipids into tiny droplets.

Absorption

Primarily occurs in the small intestine due to its structure which maximizes surface area.
Small Intestine Characteristics:
- Length: Approximately 6 meters long.
- Folds: Transverse folds in the wall.
- Villi: Finger-like projections that increase surface area.
- Microvilli: Tiny projections on the villi, further increasing surface area.
Adaptations of the Villi for Absorption:
- Thin Epithelium: Single-cell layer for quick nutrient passage.
- Goblet Cells: Secrete mucus to keep the surface moist and dissolve nutrients.
- Mitochondria: Provide energy for active nutrient absorption.
- Lacteal (lymph vessel): Absorbs and transports lipids.

Transport of Amino Acids and Glucose

Absorbed into blood capillaries of the villi in the small intestine.
Capillaries merge to form venules, which join the hepatic portal vein to transport to the liver.
Liver functions:
- Glucose: Converts excess glucose to glycogen for storage.
- Amino Acids: Deaminates excess amino acids to form urea, a waste product.

Egestion

Undigested materials pass through the colon, where most water and minerals are reabsorbed.
Temporarily stored in the rectum before excretion through the anus as faeces.

Homeostatic Control of Blood Glucose Levels

Homeostasis: The ability of an organism to maintain internal stability despite external changes.
Negative Feedback Mechanisms: Mechanisms that detect imbalances and restore homeostasis.
Blood Glucose Regulation: Maintained within a narrow range.

Influence of Insulin and Glucagon on Blood Glucose Levels

Insulin: Released by the pancreas when blood glucose levels are high. Stimulates the liver and muscles to convert glucose into glycogen, lowering blood glucose levels.
Glucagon: Released by the pancreas when blood glucose levels are low. Stimulates the liver to break down glycogen into glucose, raising blood glucose levels.

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Description

Explore the intricate processes of digestion and its various stages in this quiz. Learn about mechanical and chemical digestion, including key activities like mastication, churning, and absorption. Test your knowledge to understand how the body sustains life through these essential functions.