Enzymes in Digestion
40 Questions
0 Views

Enzymes in Digestion

Created by
@IrresistibleTroll

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

In which condition does saliva excrete glucose?

  • Hyperparathyroidism
  • Hyperthermia
  • Nephritis
  • Diabetes mellitus (correct)

    • What helps in loss of heat and regulation of body temperature in dogs and cattle?

  • Sweat glands
  • Tears
  • Saliva (correct)
  • Urine

    • What happens to salivary secretion when the body water content decreases?

  • It increases
  • It decreases (correct)
  • It remains the same
  • It fluctuates

    • What type of nervous mechanism regulates salivary secretion?

    <p>Nervous mechanism</p> Signup and view all the answers

    Which division of the autonomic nervous system supplies salivary glands?

    <p>Parasympathetic and sympathetic divisions</p> Signup and view all the answers

    Where are the parasympathetic preganglionic fibers to submandibular and sublingual glands situated?

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

    What is the final destination of the preganglionic fibers to submandibular and sublingual glands?

    <p>Submaxillary ganglion</p> Signup and view all the answers

    What happens to thirst when water is taken?

    <p>It decreases</p> Signup and view all the answers

    Which of the following is NOT a function of salivary amylase?

    <p>Breaks down proteins into amino acids</p> Signup and view all the answers

    What is the primary role of lingual lipase in digestion?

    <p>Digestion of fats in milk</p> Signup and view all the answers

    What is the role of lysozyme in saliva?

    <p>Protection against bacteria</p> Signup and view all the answers

    What substance in saliva helps protect teeth by stimulating enamel formation?

    <p>Proline-rich proteins</p> Signup and view all the answers

    Which of the following enzymes is NOT involved in the breakdown of carbohydrates?

    <p>Lingual lipase</p> Signup and view all the answers

    Which of the following substances is NOT excreted in saliva?

    <p>Vitamin C</p> Signup and view all the answers

    Which of the following is a function of saliva that directly affects speech?

    <p>Lubrication of the mouth</p> Signup and view all the answers

    Which of the following is NOT a characteristic of saliva?

    <p>It is a highly acidic fluid</p> Signup and view all the answers

    Which of the following conditions can cause temporary hyposalivation?

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

    Which of the following is NOT a parasympathomimetic drug that increases salivary secretion?

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

    What is the term for the excessive secretion of saliva in pathological conditions?

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

    Which of the following is an example of an unconditioned reflex involving salivary secretion?

    <p>Salivation in response to chewing food</p> Signup and view all the answers

    Which of the following conditions is NOT a cause of permanent hyposalivation?

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

    Which of the following substances is known to decrease salivary secretion?

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

    Which of the following is a physiological condition associated with hypersalivation?

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

    Which of the following statements about conditioned reflexes is TRUE?

    <p>Conditioned reflexes can be elicited by the sight, smell, or thought of food.</p> Signup and view all the answers

    Which of the following conditions can cause Xerostomia?

    <p>All of the above</p> Signup and view all the answers

    What is the primary reason for drooling in children during teeth eruption?

    <p>Increased saliva production due to irritation</p> Signup and view all the answers

    Which of the following conditions is NOT directly associated with drooling?

    <p>Chorda Tympani Syndrome</p> Signup and view all the answers

    What is the primary symptom of Chorda Tympani Syndrome?

    <p>Excessive sweating during meals</p> Signup and view all the answers

    Which of the following is a potential cause of Xerostomia?

    <p>All of the above</p> Signup and view all the answers

    Why is drooling often associated with difficulty swallowing?

    <p>Difficulty swallowing causes saliva to pool in the mouth</p> Signup and view all the answers

    Which of the following conditions can be a direct consequence of Xerostomia?

    <p>All of the above</p> Signup and view all the answers

    What is the primary physiological reason for drooling in children with upper respiratory tract infections?

    <p>Difficulty breathing through the nose</p> Signup and view all the answers

    What type of saliva is produced when the parasympathetic fibers are stimulated?

    <p>Watery saliva with less organic constituents</p> Signup and view all the answers

    From where do the parasympathetic preganglionic fibers of the parotid gland arise?

    <p>Medulla oblongata</p> Signup and view all the answers

    What neurotransmitter is primarily involved in the parasympathetic stimulation of salivary glands?

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

    Which type of reflex regulates salivary secretion?

    <p>Unconditioned and conditioned reflexes</p> Signup and view all the answers

    What effect do sympathetic fibers have on saliva secretion?

    <p>Stimulate thick saliva rich in mucus</p> Signup and view all the answers

    Where do the postganglionic fibers from the otic ganglion reach the parotid gland?

    <p>Through the auriculotemporal branch of the mandibular nerve</p> Signup and view all the answers

    Which structure does the sympathetic preganglionic fibers primarily originate from?

    <p>Lateral horns of the first and second thoracic segments</p> Signup and view all the answers

    What is the primary effect of sympatho-adrenal stimulation on salivary glands?

    <p>Vasoconstriction and reduced saliva secretion</p> Signup and view all the answers

    Study Notes

    Lingual Lipase

    • Lingual lipase is a lipid-digesting (lipolytic) enzyme that digests milk fats (pre-emulsified fats).
    • It hydrolyzes triglycerides into fatty acids and diacylglycerol.

    Salivary Enzymes

    • Salivary amylase:
      • Secreted by all salivary glands
      • Activated by acid medium
      • Converts cooked starch into maltose
    • Maltase:
      • Secreted by major salivary glands
      • Activated by acid medium
      • Converts maltose into glucose
    • Lingual lipase:
      • Secreted by lingual glands
      • Activated by acid medium
      • Converts triglycerides of milk fat into fatty acids and diacylglycerol

    Functions of Saliva

    • Cleansing and protective functions:
      • Rinses the mouth and teeth to remove food debris, shed epithelial cells, and foreign particles
      • Prevents bacterial growth by removing materials that may serve as culture media
      • Contains lysozyme, which kills certain bacteria
      • Contains proline-rich proteins and lactoferrin, which possess antimicrobial properties and protect teeth by stimulating enamel formation
      • Contains secretory immunoglobulin IgA, which has antibacterial and antiviral actions
      • Contains mucin, which protects the mouth by lubricating the mucous membrane
    • Role in speech:
      • Moistens and lubricates soft parts of the mouth and lips to facilitate speech
    • Excretory function:
      • Excretes substances like mercury, potassium iodide, lead, and thiocyanate
      • Excretes some viruses, such as those causing rabies and mumps
      • May excrete certain substances in pathological conditions, such as glucose in diabetes mellitus
    • Regulation of body temperature:
      • In dogs and cattle, excessive dripping of saliva during panting helps in loss of heat and regulation of body temperature
    • Regulation of water balance:
      • Decreased salivary secretion causes dryness of the mouth, inducing thirst
      • When water is taken, it reduces thirst and restores body water content

    Regulation of Salivary Secretion

    • Salivary secretion is regulated only by nervous mechanism through autonomic nervous system
    • Parasympathetic fibers:
      • Stimulate salivary secretion, causing a large quantity of watery saliva with less organic constituents
      • Activate acinar cells and dilate blood vessels of salivary glands
      • Neurotransmitter is acetylcholine
    • Sympathetic fibers:
      • Stimulate salivary secretion, causing less secretion of thick, rich-in-mucus saliva
      • Activate acinar cells and cause vasoconstriction by secreting noradrenaline

    Reflex Regulation of Salivary Secretion

    • Salivary reflexes:
      • Unconditioned reflex: present since birth, induces salivary secretion when any substance is placed in the mouth
      • Conditioned reflex: acquired by experience, needs previous experience, and is elicited by sight, smell, hearing, or thought of food

    Effect of Drugs and Chemicals on Salivary Secretion

    • Substances that increase salivary secretion:
      • Sympathomimetic drugs like adrenaline and ephedrine
      • Parasympathomimetic drugs like acetylcholine, pilocarpine, muscarine, and physostigmine
      • Histamine
    • Substances that decrease salivary secretion:
      • Sympathetic depressants like ergotamine and dibenamine
      • Parasympathetic depressants like atropine and scopolamine

    Applied Physiology

    • Hyposalivation:
      • Reduction in salivary secretion
      • Temporary hyposalivation occurs in emotional conditions, fever, and dehydration
      • Permanent hyposalivation occurs in obstruction of salivary duct, congenital absence or hypoplasia of salivary glands, and paralysis of facial nerve
    • Hypersalivation:
      • Excess secretion of saliva
      • Physiological condition: pregnancy
      • Pathological conditions: decay of tooth or neoplasm in mouth or tongue, diseases of esophagus, stomach, and intestine, neurological disorders, and some psychological and psychiatric conditions
    • Other disorders:
      • Xerostomia (dry mouth): due to hyposalivation or absence of salivary secretion
      • Drooling: uncontrolled flow of saliva outside the mouth, often seen in children during teeth eruption, upper respiratory tract infection, or nasal allergies
      • Chorda tympani syndrome: sweating while eating due to trauma or surgical procedure affecting parasympathetic nerve fibers to salivary glands

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Saliva - General Physiology PDF

    Description

    This quiz covers the functions and characteristics of lingual lipase, salivary amylase, and maltase in breaking down fats and carbohydrates in the digestive system.

    More Like This

    Pancreatic Lipase Mechanism of Action Quiz
    18 questions

    Pancreatic Lipase Mechanism of Action Quiz

    PlentifulPyrite avatar
    PlentifulPyrite
    Lipid Digestion Enzymes Overview
    20 questions

    Lipid Digestion Enzymes Overview

    StableWombat avatar
    StableWombat
    Digestive Enzymes Flashcards
    5 questions

    Digestive Enzymes Flashcards

    ReputableTangent4657 avatar
    ReputableTangent4657
    Digestive Enzymes Flashcards
    8 questions

    Digestive Enzymes Flashcards

    InvulnerableGold2463 avatar
    InvulnerableGold2463
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser