Digestive System hard

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Questions and Answers

What components are primarily absorbed in the large intestine?

Proteins and simple sugars

Minerals and amino acids

Fiber and starch

Vitamins and water (correct)

Which of the following statements accurately describes the large intestine?

It is responsible for the majority of nutrient absorption.

It synthesizes certain vitamins like vitamin K. (correct)

It has a higher density of villi than the small intestine.

It is the primary site for protein digestion.

How long does it typically take for food residue to undergo processes in the large intestine?

24 to 30 hours

8 to 10 hours

12 to 16 hours (correct)

2 to 4 hours

What role do gut bacteria play in the large intestine?

They aid in the digestion of complex carbohydrates. Signup and view all the answers

What describes the structural characteristics of the large intestine?

It contains goblet cells that secrete mucus. Signup and view all the answers

What occurs in the rectum regarding waste management?

It stores solid waste until elimination. Signup and view all the answers

Which of the following activities does NOT occur in the digestive system?

Centrifugation Signup and view all the answers

What is the primary function of the salivary glands in digestion?

Produce saliva containing enzymes Signup and view all the answers

Which organ is involved in both digestion and absorption of nutrients?

Small intestine Signup and view all the answers

What is the role of gastric juice in the digestive process?

Breaking down proteins Signup and view all the answers

Which component of the digestive system is primarily responsible for the propulsion of food?

Oesophagus Signup and view all the answers

Which of the following is NOT a part of the alimentary canal?

Gall bladder Signup and view all the answers

What is one of the key outcomes of absorption in the digestive process?

Transport of nutrients into the bloodstream Signup and view all the answers

Which of the following statements about the digestive system is incorrect?

The stomach significantly breaks down carbohydrates. Signup and view all the answers

Which component of the digestive system is primarily involved in chemical digestion?

Small intestine Signup and view all the answers

Which process in the alimentary tract is responsible for the mechanical breakdown of food?

Digestion Signup and view all the answers

What is the main role of hydrochloric acid secreted by the stomach lining?

To create ideal conditions for protein digestion Signup and view all the answers

Which function involves the movement of food and drink into the alimentary tract?

Ingestion Signup and view all the answers

During which process do digestive food substances pass through the walls of the digestive system?

Absorption Signup and view all the answers

What is the primary function of the alimentary tract?

To convert food into nutritional molecules Signup and view all the answers

Which of the following processes is NOT an active process in the alimentary tract?

Circulation Signup and view all the answers

What is one of the roles of microorganisms in the alimentary tract?

Maintaining a balance between immunity and tolerance Signup and view all the answers

Which part of the alimentary tract is primarily involved in propulsion?

Esophagus Signup and view all the answers

Which of the following statements about the alimentary tract is true?

It extends from the mouth to the anus. Signup and view all the answers

What is the process called when waste products are expelled from the alimentary tract?

Defecation Signup and view all the answers

What percentage of saliva is produced by the submandibular gland?

70% Signup and view all the answers

Which gland is located in front of the submandibular gland?

Sublingual Signup and view all the answers

The parotid gland opens into the mouth opposite which structure?

Buccal of the second upper molar Signup and view all the answers

What is the primary purpose of salivary amylase?

To initiate the digestion of carbohydrates Signup and view all the answers

What component makes up 99.5% of saliva?

Water Signup and view all the answers

During the first phase of swallowing, what action does the tongue perform?

Forces food into the pharynx Signup and view all the answers

What action prevents food from entering the lungs during swallowing?

Epiglottis closes off the trachea Signup and view all the answers

The process that pushes food through the pharynx and esophagus is called:

Peristalsis Signup and view all the answers

Which gland contributes only 5% to the total saliva production?

Sublingual Signup and view all the answers

Which of the following is NOT a function of saliva?

Temperature regulation Signup and view all the answers

What is the primary role of pancreatic amylase in digestion?

Conversion of carbohydrates into simple sugars Signup and view all the answers

Which substance is secreted by the pancreas to neutralize stomach acid?

Sodium bicarbonate Signup and view all the answers

What are the functions of the liver related to digestion?

Produces bile and filters blood Signup and view all the answers

What does cholecystokinin stimulate in the digestive system?

Release of bile from the gallbladder Signup and view all the answers

Which enzymes are primarily involved in protein digestion in the pancreas?

Trypsin and chymotrypsin Signup and view all the answers

What is the result of the action of pancreatic lipase?

Breakdown of lipids into fatty acids and glycerol Signup and view all the answers

What type of acids do nucleases hydrolyze?

Nucleic acids Signup and view all the answers

Which vitamin is NOT stored in the liver?

Vitamin C Signup and view all the answers

What is the main effect of the bicarbonate solution secreted by the pancreas?

Create an alkaline environment Signup and view all the answers

What is the primary component of bile that assists in fat digestion?

Bile salts Signup and view all the answers

Study Notes

Digestive System: Anatomy and Function

The digestive system is responsible for breaking down food into smaller molecules to be absorbed and utilized by the body.
It consists of the alimentary tract (also known as the alimentary canal, gastrointestinal tract, or digestive tract): a continuous tube extending from the mouth to the rectum.
Key processes:
- Ingestion: Taking in food and drink
- Propulsion: Mixing and moving contents along the tract
- Digestion: Mechanical breakdown of food and chemical digestion by enzymes
- Absorption: Digestive food substances pass through the tract walls into the blood and are used by body cells
- Elimination (defecation): Excretion of waste products

Alimentary Tract Components

Mouth:
- The first stage of digestion.
- Contains salivary glands that produce saliva.
Salivary Glands:
- Produce saliva which is composed mainly of water and contains digestive enzymes like salivary amylase, which breaks down carbohydrates.
- There are three pairs of salivary glands:
  - Submandibular
  - Sublingual
  - Parotid
Oesophagus:
- A muscular tube connecting the mouth to the stomach.
- Transports food to the stomach via peristalsis (wave-like muscular contractions).
Stomach:
- A muscular sac that churns food and mixes it with gastric juices, containing digestive enzymes and hydrochloric acid.
- The stomach lining secretes hydrochloric acid which creates an ideal environment for protein digestion enzymes to work and kills bacteria, protecting the body.
Small Intestine:
- The longest part of the digestive tract.
- Responsible for most nutrient absorption.
Large Intestine:
- The final part of the GI tract.
- Absorbs remaining water and electrolytes from indigestible food.
- Contains bacteria that synthesize certain vitamins (e.g., Vitamin K and some B vitamins).
Rectum:
- The last 13 cm of the large intestine.
- Stores solid waste until it is eliminated through the anus.

Accessory Organs

Liver:
- The heaviest organ in the body.
- Plays a major role in digestion by producing bile.
- Stores vitamins (A, D, E, K, B12).
- Regulates blood glucose levels with the pancreas.
Gallbladder:
- Stores and concentrates bile from the liver.
- Releases bile into the small intestine when needed for fat digestion.
Pancreas:
- Produces pancreatic fluid containing digestive enzymes that aid in the breakdown of carbohydrates, proteins, and lipids.
- Secretes sodium bicarbonate to neutralize the acidity of stomach contents entering the small intestine.

Important Hormones

Cholecystokinin (CCK): A hormone that stimulates the pancreas to release digestive enzymes and the gallbladder to release bile.

Bile

Consists of salts and phospholipids.
Bile salts help emulsify fats, breaking them down into smaller droplets for easier digestion.
Phospholipids aid in the absorption of fats in the small intestine.

Large Intestine & Waste Elimination

Indigestible food residues from the small intestine are passed into the large intestine.
Water and electrolytes are absorbed in the large intestine.
Bacteria in the large intestine ferment some undigested material, resulting in gas production.
Waste products are stored and eliminated as faeces.

Key Functions of the Large Intestine

Absorbs remaining water and electrolytes.
Synthesizes vitamins (vitamin K and certain B vitamins).
Stores and eliminates waste.

Differences Between Small & Large Intestines

Small Intestine:
- Muscle layers are thicker.
- Contains villi (finger-like projections) that increase surface area for nutrient absorption.
- Primary site of nutrient absorption.
Large Intestine:
- Muscle layers are thinner.
- Contains more goblet cells, which secrete mucus for lubrication.
- No villi.
- Main function is to absorb remaining water and electrolytes and to store and eliminate waste.

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Description

Explore the anatomy and function of the digestive system in this quiz. Learn about the key processes involved in digestion, from ingestion to elimination. Delve into the components of the alimentary tract and discover how the body processes food.