The Digestive System
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the name given to the process of breaking down food in the digestive system?

  • Digestion (correct)
  • Propulsion
  • Ingestion
  • Elimination

    • What is the function of the papillae on the superior surface of the tongue?

  • Receiving nerve endings responsible for taste (correct)
  • Grinding and tearing food
  • Regulating body temperature
  • Aiding speech and facial expression

    • What is the role of the accessory organs in the digestive system?

  • Absorbing nutrients into the bloodstream
  • Breaking down food into smaller molecules
  • Contributing to the function of the digestive system (correct)
  • Eliminating waste products from the body

    • What is the name given to the process of moving food along the length of the digestive system?

    <p>Propulsion</p> Signup and view all the answers

    What is the function of the lips and cheeks in the mouth?

    <p>Moving food and mixing with saliva</p> Signup and view all the answers

    What is the name given to the process of taking food into the digestive system?

    <p>Ingestion</p> Signup and view all the answers

    What is the function of the tongue in the mouth?

    <p>Moving food around the oral cavity</p> Signup and view all the answers

    What is the length of the digestive system approximately?

    <p>10 m</p> Signup and view all the answers

    What is the primary function of the parasympathetic fibres from the vagus nerve in the stomach?

    <p>To stimulate gastric motility and secretion of gastric juice</p> Signup and view all the answers

    How many layers of smooth muscle are present in the muscularis of the stomach?

    <p>Three</p> Signup and view all the answers

    What is the approximate volume of an empty stomach?

    <p>50 mL</p> Signup and view all the answers

    Which type of cell produces intrinsic factor?

    <p>Parietal cells</p> Signup and view all the answers

    What is the primary function of pepsin in the stomach?

    <p>To break down protein into smaller peptide chains</p> Signup and view all the answers

    Which phase of gastric juice secretion is stimulated by the sight, taste, or smell of food?

    <p>Cephalic phase</p> Signup and view all the answers

    What is the primary function of secretin and cholecystokinin (CKK) in the intestinal phase?

    <p>To reduce gastric motility and juice secretion</p> Signup and view all the answers

    Which type of cell produces gastrin in the stomach?

    <p>Enteroendocrine cells (G cells)</p> Signup and view all the answers

    What is the primary function of bile in the small intestine?

    <p>To emulsify fats and fatty acids, making it easier for lipase to break them down</p> Signup and view all the answers

    What is the end product of protein digestion in the small intestine?

    <p>Tripeptidases and amino acids</p> Signup and view all the answers

    What is the primary function of bicarbonate ions secreted by the cells of the pancreatic ducts?

    <p>To neutralize acidic chyme from the stomach</p> Signup and view all the answers

    What is the main function of the small intestine in the digestive process?

    <p>Absorption of nutrients, electrolytes, and water</p> Signup and view all the answers

    At what pH range are the actions of amylase and lipase most effective?

    <p>pH 6-8</p> Signup and view all the answers

    What type of tissue does the pancreas consist of?

    <p>Both exocrine and endocrine tissue</p> Signup and view all the answers

    What is the function of pancreatic amylase in the small intestine?

    <p>To break down carbohydrates that have not been broken down by salivary amylase</p> Signup and view all the answers

    What is the function of trypsinogen, chymotrypsinogen, and procarboxypeptidase in pancreatic juice?

    <p>To protect the digestive system structures from protein-digesting enzymes</p> Signup and view all the answers

    What is the approximate volume of pancreatic juice produced by the pancreas daily?

    <p>1.2-1.5 L</p> Signup and view all the answers

    What stimulates the production of secretin?

    <p>The presence of hydrochloric acid in the duodenum</p> Signup and view all the answers

    Where does pancreatic juice enter the small intestine?

    <p>At the hepatopancreatic ampulla</p> Signup and view all the answers

    What is the function of bile produced by the liver?

    <p>To emulsify fats</p> Signup and view all the answers

    What is the function of the islet cells of the islets of Langerhans?

    <p>To produce the hormones insulin and glucagon</p> Signup and view all the answers

    What is the composition of bile?

    <p>Bile salts, bilirubin, cholesterol, fat-soluble vitamins, fat, mineral salts, and mucus</p> Signup and view all the answers

    What is the daily production of bile by the liver?

    <p>1 L per day</p> Signup and view all the answers

    Which nerve stimulation promotes the release of pancreatic juice?

    <p>Parasympathetic vagus nerve stimulation</p> Signup and view all the answers

    What is the primary function of the liver in relation to erythrocytes?

    <p>Recycling of erythrocytes</p> Signup and view all the answers

    What is the stimulus for gallbladder contraction?

    <p>The hormone CKK</p> Signup and view all the answers

    What is the primary function of the large intestine?

    <p>Absorption of water and electrolytes</p> Signup and view all the answers

    What is the function of goblet cells in the large intestine mucosa?

    <p>Secretion of mucus</p> Signup and view all the answers

    What is the function of the liver in relation to hormones?

    <p>Deactivation of hormones</p> Signup and view all the answers

    What is the function of the gallbladder?

    <p>Storage of bile</p> Signup and view all the answers

    What is the role of CKK in relation to the gallbladder?

    <p>Stimulates the contraction of the gallbladder</p> Signup and view all the answers

    What is the fate of food residue after entering the caecum?

    <p>It passes up the ascending colon</p> Signup and view all the answers

    Study Notes

    The Digestive System

    • The digestive system, also known as the gastrointestinal system or alimentary canal, is approximately 10 m long and travels through the body from the mouth to the anus.
    • It consists of main digestive system structures (mouth, pharynx, oesophagus, stomach, small intestine, and large intestine) and accessory organs (salivary glands, liver, gallbladder, and pancreas).

    The Activity of the Digestive System

    • The digestive system involves five processes: ingestion, propulsion, digestion, absorption, and elimination.
    • Ingestion involves taking food into the digestive system, while propulsion moves food along the length of the digestive system.
    • Digestion breaks down food mechanically (chewing) or chemically (enzymes), and absorption involves the products of digestion entering the blood or lymph capillaries for distribution.
    • Elimination involves the excretion of waste products from the body as faeces.

    The Mouth (Oral Cavity)

    • The teeth grind and tear food, while the lips and cheeks move food and mix it with saliva.
    • The tongue is a large, voluntary muscular structure with papillae (taste buds) containing nerve endings responsible for the sense of taste.
    • The tongue is involved in swallowing, moving food around the oral cavity, and speech.

    The Stomach

    • The vagus nerve innervates the stomach with parasympathetic fibres that stimulate gastric motility and secretion of gastric juice.
    • Sympathetic fibres from the celiac plexus reduce gastric activity.
    • The stomach contains many gastric glands that secrete substances like mucus, hydrochloric acid, pepsinogen, and hormones like gastrin.
    • Regulation of gastric juice secretion occurs in three phases: cephalic, gastric, and intestinal phases.

    Chemical Digestion

    • Carbohydrates are broken down by salivary amylase and pancreatic amylase.
    • Bile emulsifies fat, making it easier for lipase to break down fats into fatty acids and glycerol.
    • Proteins are denatured by hydrochloric acid in the stomach and further acted upon by enzymes like trypsin, chymotrypsin, and carboxypeptidase.

    The Small Intestine

    • The small intestine produces mucus to protect itself from acidic chyme and secretes intestinal juice and pancreatic juice to increase the pH of chyme.
    • Bile enters the small intestine to emulsify fat, and enzymes like trypsin, chymotrypsin, and carboxypeptidase break down carbohydrates, proteins, and fats.
    • Mechanical digestion occurs through peristalsis and segmentation, and the small intestine is structurally designed for maximum absorption of nutrients, electrolytes, and water.

    The Pancreas

    • The pancreas consists of exocrine and endocrine tissue and is responsible for producing endocrine hormones like insulin and glucagon, and exocrine products like pancreatic juice.
    • Pancreatic juice contains water, mineral salts, pancreatic amylase, lipase, and trypsinogen, chymotrypsinogen, and procarboxypeptidase.
    • Two hormones, secretin and CKK, regulate the secretion of pancreatic juice, and parasympathetic vagus nerve stimulation also promotes the release of pancreatic juice.

    The Liver and Production of Bile

    • The liver is the body's largest gland, weighing between 1 and 2 kg, and produces up to 1 L of yellow/green alkaline bile per day.
    • Bile consists of bile salts, cholesterol, fat-soluble vitamins, fat, mineral salts, and mucus.
    • The liver has additional functions like detoxification of drugs, recycling of erythrocytes, deactivation of hormones, production of clotting proteins, storage of vitamins and minerals, and synthesis of vitamin A.

    The Gallbladder

    • The gallbladder is a small, muscular sac that lies posterior to the liver and functions as a reservoir for bile, concentrating bile by absorbing water.
    • The stimulus for gallbladder contraction is the hormone CKK, which stimulates the secretion of pancreatic juice and relaxation of the hepatopancreatic sphincter.

    The Large Intestine

    • The large intestine measures 1.5 m in length and 7 cm in diameter and is continuous with the small intestine from the ileocaecal valve to the anus.
    • The large intestine mucosa contains goblet cells that secrete mucus to ease the passage of faeces and protect the walls of the large intestine.
    • The large intestine absorbs water and turns food residue into semi-solid faeces, and also absorbs some vitamins, minerals, electrolytes, and drugs.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    The Digestive System PDF

    Description

    Learn about the gastrointestinal system, its length, and the main structures involved in digestion, from the mouth to the anus.

    More Like This

    Human Digestive System Overview
    6 questions

    Human Digestive System Overview

    InvincibleAlder avatar
    InvincibleAlder
    Human Digestive System
    10 questions

    Human Digestive System

    BullishRhenium avatar
    BullishRhenium
    Human Digestive System
    16 questions

    Human Digestive System

    ChivalrousNash avatar
    ChivalrousNash
    Anatomy of Digestive System
    8 questions

    Anatomy of Digestive System

    CheerfulFir avatar
    CheerfulFir
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser