Salivary Glands Overview
41 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 effect does high acidity (H+) in the duodenum have on the pyloric sphincter?

  • It causes the pyloric sphincter to relax.
  • It has no effect on the pyloric sphincter.
  • It opens the pyloric sphincter.
  • It closes the pyloric sphincter. (correct)

Which of the following factors slows gastric emptying?

  • Increased liquid volume
  • Particle size less than 1mm
  • High caloric content (correct)
  • Low pH levels (correct)

How do solid foods compare to liquids in terms of gastric emptying?

  • Solid foods empty faster than liquids.
  • Solid foods have a lag phase that slows down emptying. (correct)
  • Both solid and liquid foods empty at the same rate.
  • Liquids always have a lag phase.

What is the consequence of stimulating the duodenum electrically?

<p>Contraction of the pyloric sphincter. (D)</p> Signup and view all the answers

Which combination of factors would result in the slowest gastric emptying?

<p>High caloric content, liquid food, acidic pH (C)</p> Signup and view all the answers

What initiates voluntary control during the swallowing process?

<p>Tongue pressing the bolus against the roof of the mouth (D)</p> Signup and view all the answers

Which phase of swallowing primarily involves the contraction of the pharyngeal constrictors?

<p>Pharyngeal phase (B)</p> Signup and view all the answers

What mechanism helps prevent reflux after a swallow occurs?

<p>Upper esophageal sphincter closure (A)</p> Signup and view all the answers

Which of the following muscles is predominantly involved in the esophageal phase of swallowing?

<p>Smooth muscles of the lower esophagus (A)</p> Signup and view all the answers

What is the primary role of the lower esophageal sphincter (LES)?

<p>Regulating gastric reflux (C)</p> Signup and view all the answers

During which action does the tone of the LES increase due to diaphragm contraction?

<p>Inspiration (B)</p> Signup and view all the answers

What is a common consequence of transient LES relaxation (TLESR)?

<p>Increased risk of gastroesophageal reflux (A)</p> Signup and view all the answers

What triggers the brainstem's swallowing center to activate during the oral phase?

<p>Pressure from the bolus against the roof of the mouth (C)</p> Signup and view all the answers

What is the role of saliva in neutralizing reflux in the esophagus?

<p>Neutralizes acidity with bicarbonate (D)</p> Signup and view all the answers

What condition may lead to extensive ulceration and inflammation in the esophagus?

<p>Gastroesophageal reflux disease (GERD) (D)</p> Signup and view all the answers

What is the primary function of mucins in saliva?

<p>To provide lubrication (A)</p> Signup and view all the answers

Which of the following glands is responsible for producing the majority of stimulated saliva?

<p>Parotid gland (A)</p> Signup and view all the answers

How does the sympathetic nervous system initially affect salivary secretion?

<p>Causes a temporary decrease in blood flow (D)</p> Signup and view all the answers

Which ions are at higher levels in saliva during low food stimuli compared to blood?

<p>K+ (A)</p> Signup and view all the answers

What is the purpose of bicarbonate (HCO3) in saliva during a swallow?

<p>To neutralize stomach acid (A)</p> Signup and view all the answers

What triggers the cephalic phase of salivary secretion?

<p>Thinking or smelling food (D)</p> Signup and view all the answers

What is primarily affected by vagotomy in relation to saliva production?

<p>Significantly decreases saliva production (C)</p> Signup and view all the answers

Which type of cells are responsible for modifying saliva after it is produced by acinar cells?

<p>Duct cells (A)</p> Signup and view all the answers

What role do histatins serve in saliva?

<p>Antibacterial and antifungal (A)</p> Signup and view all the answers

What happens to salivary flow rate when thinking about food?

<p>It significantly increases (D)</p> Signup and view all the answers

Which transport mechanism moves Na+ ions from blood to acinar cells?

<p>Paracellular transport (A)</p> Signup and view all the answers

Which factor negatively influences salivary production?

<p>Acute fear (A)</p> Signup and view all the answers

What is the function of salivary amylase?

<p>Digests starch (D)</p> Signup and view all the answers

Which of the following is NOT a common cause of transient lower esophageal sphincter relaxation (TLESR)?

<p>Frequent burping (D)</p> Signup and view all the answers

What condition is characterized by a lack of peristalsis in the esophagus and a tightly closed lower esophageal sphincter?

<p>Achalasia (A)</p> Signup and view all the answers

In the stomach, which area is primarily responsible for storing food?

<p>Fundus (A)</p> Signup and view all the answers

What is the primary role of the pyloric sphincter?

<p>Control the entry of chyme into the duodenum (C)</p> Signup and view all the answers

Which phase of the migrating motor complex (MMC) is characterized by strong rhythmic contractions?

<p>Phase 3 (B)</p> Signup and view all the answers

Which factor does NOT influence the duration of gastric emptying?

<p>Temperature of food (B)</p> Signup and view all the answers

What type of muscle contraction does the gastric accommodation involve?

<p>Smooth muscle contraction (A)</p> Signup and view all the answers

Which of the following best describes the muscularis externa of the stomach?

<p>Includes three layers of muscles (B)</p> Signup and view all the answers

During fasted motor activity, what primarily triggers the contractions in phase 3?

<p>Motilin secretion (B)</p> Signup and view all the answers

What role does the vagus nerve play in the gastric accommodation process?

<p>Mediates relaxation of the stomach (C)</p> Signup and view all the answers

Which of the following is a treatment for conditions affecting the lower esophageal sphincter (LES)?

<p>Antacids like Maalox or Pepto-Bismol (D)</p> Signup and view all the answers

What is the primary function of the enteric nervous system in the context of the stomach?

<p>Coordinates muscle contractions in the digestive tract (B)</p> Signup and view all the answers

Which condition leads to autoimmune attacks on smooth muscle, particularly affecting the latter third of the esophagus?

<p>Scleroderma (C)</p> Signup and view all the answers

Flashcards

Lower Esophageal Sphincter (LES)

A ring of smooth muscle at the bottom of the esophagus; controls the passage of food from esophagus to stomach.

LES Tone

The tightness or pressure of the LES. It's crucial for preventing reflux.

Swallowing Phases

Oral, pharyngeal, and esophageal phases sequential steps involved in swallowing

Pharyngeal Phase

Stage in swallowing where the throat muscles move food to the esophagus.

Signup and view all the flashcards

Peristalsis (Esophagus)

Wave-like muscle contractions that move food through the esophagus.

Signup and view all the flashcards

Transient LES Relaxation (TLESR)

Temporary relaxation of the LES, allowing for burping or reflux.

Signup and view all the flashcards

Gastroesophageal Reflux Disease (GERD)

Chronic condition where stomach acid frequently flows back into the esophagus, causing damage.

Signup and view all the flashcards

Swallowing Center

Region in the brainstem controls the process of swallowing.

Signup and view all the flashcards

Reflux

Backward flow of contents of the stomach toward the esophagus.

Signup and view all the flashcards

Esophageal Cancer

Cancer arising from the lining of the esophagus, a disease related to GERD.

Signup and view all the flashcards

Salivary Glands

Glands that produce saliva, crucial for mechanical and chemical digestion, taste, and swallowing.

Signup and view all the flashcards

Saliva composition

99% water, 1% proteins (eg. Mucins). Crucial for lubrication, taste molecule solubilization, speech and overall protection.

Signup and view all the flashcards

Mucins

Proteins in saliva that polymerize to form mucus, providing lubrication and a barrier against bacteria.

Signup and view all the flashcards

Histatins

Antibacterial proteins in saliva, rich in histidine.

Signup and view all the flashcards

Cystatins

Antibacterial proteins in saliva, rich with cysteine.

Signup and view all the flashcards

Salivary Amylase

Enzyme that digests starch.

Signup and view all the flashcards

Salivary Lipase

Enzyme that digests fats.

Signup and view all the flashcards

Submandibular gland

Produces basal saliva, more sticky proteins.

Signup and view all the flashcards

Sublingual gland

Stimulates watery saliva.

Signup and view all the flashcards

Parotid gland

Produces serous cells, mainly watery saliva (50% of total stimulated saliva).

Signup and view all the flashcards

PNS (Parasympathetic)

Increases saliva production and volume, watery.

Signup and view all the flashcards

SNS (Sympathetic)

Initial decrease in saliva production due to vasoconstriction, followed by increase due to vasodilation, important for protein production.

Signup and view all the flashcards

Salivon

Basic structural unit of salivary glands.

Signup and view all the flashcards

Duct cells

Modify saliva by adding or removing ions, adjusting final composition.

Signup and view all the flashcards

UES (Upper Esophageal Sphincter)

Skeletal muscle sphincter that prevents air from entering esophagus and food from entering trachea, high pressure.

Signup and view all the flashcards

Swallowing reflex

Movement of food from the oral cavity through the UES, oropharynx and hypopharynx into esophagus.

Signup and view all the flashcards

Pyloric Sphincter Contraction

The pyloric sphincter contracts in response to high H+ (acidity) or osmolarity in the duodenum; it also contracts when the duodenum is electrically stimulated.

Signup and view all the flashcards

Gastric Emptying Rate (Solids)

Emptying rate of solids depends on their toughness and particle size after the lag phase where food breaks down to 1 mm in diameter

Signup and view all the flashcards

Gastric Emptying Rate (Liquids)

Empty faster than solids with factors like calorie count, large volume emptying faster than small, fats & osmolarity slowing it down, and pH levels influencing speed or slow-down

Signup and view all the flashcards

Extrinsic Neural Control Pyloric sphincter

Sensory neurons in the duodenum send signals regarding high H+ and osmolarity to the brain stem and spinal cord, leading to varying autonomic responses (SNS contraction; low/high frequency PNS opening/closing)

Signup and view all the flashcards

Food Toughness Impact on Emptying

The toughness of solid food plays a significant role in determining the amount of time required to break down the foodstuff particles to 1mm before moving into the duodenum

Signup and view all the flashcards

TLESR

TLESR is the transient lower esophageal sphincter relaxation, a problem related to high frequency of TLESR.

Signup and view all the flashcards

Dysmotility

Dysmotility is the uncoordinated movement of smooth muscle, especially in the GI tract.

Signup and view all the flashcards

Scleroderma

Scleroderma is a rare autoimmune disorder attacking smooth muscle, impacting esophageal peristalsis.

Signup and view all the flashcards

Achalasia

Achalasia is a disorder where the esophagus lacks peristalsis, resulting in a relaxed, dilated esophagus with a tightly closed LES.

Signup and view all the flashcards

Gastric Emptying

The process of chyme moving from the stomach to the small intestine.

Signup and view all the flashcards

Peristalsis

Wave-like muscle contractions that move food through the digestive tract.

Signup and view all the flashcards

Pyeloric Sphincter

Muscular valve at the end of the stomach that controls the flow of chyme into the small intestine.

Signup and view all the flashcards

Migrating Motor Complex (MMC)

A series of contractions in the empty stomach to clear out undigested material.

Signup and view all the flashcards

Receptive Relaxation

Relaxation of the upper stomach when food is swallowed, increasing stomach volume.

Signup and view all the flashcards

Gastric Accommodation

Increased stomach volume by wall relaxation to accommodate food.

Signup and view all the flashcards

Lesser Curvature

Inside curve in the stomach.

Signup and view all the flashcards

Greater Curvature

Outside curve in the stomach.

Signup and view all the flashcards

Cardia

The top part of the stomach where food enters.

Signup and view all the flashcards

Fundus

The upper right (on paper) part of the stomach, higher than the body.

Signup and view all the flashcards

Corpus

The body part of the stomach.

Signup and view all the flashcards

Anemia

A condition where the body lacks enough red blood cells.

Signup and view all the flashcards

Study Notes

SALIVARY GLANDS

  • Oral cavity's job includes mechanical digestion (chewing), enzymatic/chemical digestion (salivary enzymes), and chemosensation (taste). Swallowing is also a function.
  • Saliva is an exocrine secretion, producing 500-600 mL per day. It contains lots of proteins, but 99% is water and 1% protein.
  • Saliva's functions include lubrication, solubilizing taste molecules, aiding speech, and protection.
  • Proteins in saliva, such as mucins, create mucus for lubrication.
  • Histatins and cystatins are antibacterial and antifungal proteins.
  • Salivary amylase digests starch, while salivary lipase/lingual lipase digests triglycerides.
  • Salivary immune bodies and lysozyme target bacterial walls.

GLANDS

  • Submandibular glands produce basal saliva, which is sticky.
  • Sublingual glands produce saliva in response to stimulation.
  • Parotid glands, with serous cells, produce 50% of stimulated saliva, which is watery and rich in ions.

AUTONOMIC N.S INPUT

  • PNS input produces watery saliva in large volumes.
  • SNS input initially results in low volume due to vasoconstriction, but increases volume later from vasodilation.

SALIVA FORMATION

  • Acinar cells produce unmodified saliva.
  • Duct cells modify saliva by adding or removing ions from the blood.
  • Ions in blood are regulated in the order of Na+ > Cl- > HCO3- > K+.

ACINAR CELLS PRODUCE INITIAL SALIVA

  • Na+ moves from blood to acinar cells via paracellular transport.
  • Cl- moves into the cells via a cotransporter and exits via a channel.
  • K+ moves into the cells via ATPase and out via a channel.
  • Water also crosses via a paracellular pathway.

DUCT CELLS

  • Remove Na+ and Cl- from saliva
  • Add K+
  • Na+ is removed into the capillary.
  • K+ is secreted into the lumen.
  • Cl- is reabsorbed via an anion exchanger.

FLOW RATE

  • High flow rate occurs during stimulated states (thinking, smelling, seeing food) and chewing.
  • Low flow rate allows saliva to be modified by duct cells.

HCO3

  • Saliva is isotonic (290-300 mosmol).
  • Bicarbonate neutralizes stomach acid reflux.

REGULATION OF SALIVARY SECRETIONS

  • PNS input stimulates a large volume, watery secretion with HCO3.
  • SNS input is biphasic, initially reducing blood flow and increasing protein production, then increasing blood flow and secretion.

PHARYNX ANATOMY

  • The pharynx is the throat, which food and air pass through.
  • It's made up of skeletal muscle structures, including constrictors.
  • Three parts of the pharynx are nasopharynx, oropharynx, and hypopharynx.
  • The pharynx moves food from the mouth to the esophagus and air to the trachea.

DURING A SWALLOW

  • Food is prevented from going into the trachea.
  • The upper esophageal sphincter (UES) is opened, allowing food to pass to the esophagus.
  • The UES is made of skeletal muscle and has high pressure.

ESOPHAGUS ANATOMY

  • The esophagus is a transit tube for food.
  • Its upper third is skeletal muscle, followed by mixed and then smooth muscle.

SWALLOWING PROBLEMS

  • Dysmotility is a lack of coordination with peristalsis.
  • Scleroderma and other conditions might impact smooth muscle function.
  • Achalasia is a condition where there is no peristalsis in the esophagus.

STOMACH

  • The stomach stores ingested food and uses contractions to mix food with acids.
  • Layers of muscle in the stomach wall contribute to digestion.

ANATOMY AND MOTOR ACTIVITY

  • The stomach initially accommodates food for up to an hour.
  • Muscle contractions occur in layers, and prior to a meal, the muscles are contractured.
  • When a meal is taken, swallowing prompts receptive relaxation.

FED MOTOR ACTIVITY

  • Peristalsis starts at the stomach top and goes toward the pyloric sphincter.
  • Food is propelled through the stomach due to contraction, while undigested food is pushed back.

FASTED MOTOR ACTIVITY MMC

  • There are three phases of contractions in the stomach when there is no food present (fasting).
  • Phases include quiescence, peristalsis, and rhythmic contractions.

PYLORIC SPHINCTER

  • The pyloric sphincter regulates food/chyme entry into the small intestine.
  • It has all circular muscle and significant nerve supply. It's tightly closed during most of the fed state.
  • Increased peristalsis pushes stuff through to the small intestine during feeding.

GASTRIC EMPTYING

  • Stomach empties contents during fed activity.
  • Liquid food empties faster in the absence of a lag phase.
  • Food density, volume, and other factors influence the speed of emptying.

Studying That Suits You

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

Quiz Team

Related Documents

Salivary Glands - NPB114 MT2 PDF

Description

This quiz explores the function and structure of salivary glands, including the types of saliva produced and its components. Learn about the roles of different salivary proteins and the autonomic nervous system's influence on saliva secretion. Perfect for students studying human anatomy and physiology.

More Like This

Digestive System: Salivary Glands
20 questions

Digestive System: Salivary Glands

CalmFairy avatar
CalmFairy
Human Anatomy: Salivary Glands
5 questions

Human Anatomy: Salivary Glands

GentlestRomanArt avatar
GentlestRomanArt
Physiology of Mastication & Swallowing
69 questions

Physiology of Mastication & Swallowing

SociableEinsteinium avatar
SociableEinsteinium
Human Anatomy and Physiology Quiz
60 questions

Human Anatomy and Physiology Quiz

CuteEllipse6228 avatar
CuteEllipse6228
Use Quizgecko on...
Browser
Open
Browser
Browser