Podcast
Questions and Answers
What active process occurs in the ducts as primary saliva is modified?
What active process occurs in the ducts as primary saliva is modified?
How does the composition of saliva change as it modifies in the ducts?
How does the composition of saliva change as it modifies in the ducts?
What drives the passive movement of electrolytes during saliva modification?
What drives the passive movement of electrolytes during saliva modification?
Which of the following ions is actively secreted to balance the charge in saliva?
Which of the following ions is actively secreted to balance the charge in saliva?
Signup and view all the answers
What is the primary source of saliva before modification occurs in the ducts?
What is the primary source of saliva before modification occurs in the ducts?
Signup and view all the answers
What electrical negativity is created in the salivary ducts due to excess Na+ reabsorption over K+ secretion?
What electrical negativity is created in the salivary ducts due to excess Na+ reabsorption over K+ secretion?
Signup and view all the answers
Which type of reflex is triggered by the presence of food in the mouth?
Which type of reflex is triggered by the presence of food in the mouth?
Signup and view all the answers
What function does the glossopharyngeal nerve (cranial nerve IX) serve?
What function does the glossopharyngeal nerve (cranial nerve IX) serve?
Signup and view all the answers
What is the role of salivary amylase in saliva?
What is the role of salivary amylase in saliva?
Signup and view all the answers
Which type of salivary reflex occurs without oral stimulation?
Which type of salivary reflex occurs without oral stimulation?
Signup and view all the answers
Which cranial nerve is responsible for taste sensation from the posterior one-third of the tongue?
Which cranial nerve is responsible for taste sensation from the posterior one-third of the tongue?
Signup and view all the answers
What happens to chloride ions in the salivary ducts due to electrical negativity?
What happens to chloride ions in the salivary ducts due to electrical negativity?
Signup and view all the answers
Which glands are stimulated by the facial nerve?
Which glands are stimulated by the facial nerve?
Signup and view all the answers
What is the primary role of the parasympathetic nervous system in salivary gland activity?
What is the primary role of the parasympathetic nervous system in salivary gland activity?
Signup and view all the answers
Which condition is associated with increased saliva production?
Which condition is associated with increased saliva production?
Signup and view all the answers
Which of the following glands secretes Hydrochloric acid?
Which of the following glands secretes Hydrochloric acid?
Signup and view all the answers
What is the dominant role of the parasympathetic nervous system in the context of salivary secretion?
What is the dominant role of the parasympathetic nervous system in the context of salivary secretion?
Signup and view all the answers
Pepsinogen released by gastric glands is important for which digestive process?
Pepsinogen released by gastric glands is important for which digestive process?
Signup and view all the answers
What does the sympathetic nervous system primarily produce in terms of salivary secretion?
What does the sympathetic nervous system primarily produce in terms of salivary secretion?
Signup and view all the answers
Where is the gastric mucus located primarily?
Where is the gastric mucus located primarily?
Signup and view all the answers
Which component is essential for the absorption of Vitamin B12?
Which component is essential for the absorption of Vitamin B12?
Signup and view all the answers
The primary function of mucus in gastric secretion is to:
The primary function of mucus in gastric secretion is to:
Signup and view all the answers
Chopping a pencil, which is a rough object, has what effect on saliva production?
Chopping a pencil, which is a rough object, has what effect on saliva production?
Signup and view all the answers
What do parietal cells primarily secrete?
What do parietal cells primarily secrete?
Signup and view all the answers
Which cells are primarily responsible for secreting pepsinogen?
Which cells are primarily responsible for secreting pepsinogen?
Signup and view all the answers
What is the main purpose of mucus secreted by mucous neck cells?
What is the main purpose of mucus secreted by mucous neck cells?
Signup and view all the answers
What two components are required for the formation of hydrochloric acid (HCl) in the canaliculi?
What two components are required for the formation of hydrochloric acid (HCl) in the canaliculi?
Signup and view all the answers
Which mechanism is used to transport hydrogen ions (H⁺) into the canaliculi?
Which mechanism is used to transport hydrogen ions (H⁺) into the canaliculi?
Signup and view all the answers
What happens when carbon dioxide (CO₂) combines with water (H₂O) in the presence of carbonic anhydrase?
What happens when carbon dioxide (CO₂) combines with water (H₂O) in the presence of carbonic anhydrase?
Signup and view all the answers
What is the function of the microvilli lining the canaliculi?
What is the function of the microvilli lining the canaliculi?
Signup and view all the answers
What is the role of bicarbonate in the gastric system?
What is the role of bicarbonate in the gastric system?
Signup and view all the answers
What is the role of pepsin in the stomach?
What is the role of pepsin in the stomach?
Signup and view all the answers
Which cells are responsible for secreting intrinsic factor?
Which cells are responsible for secreting intrinsic factor?
Signup and view all the answers
What condition results from a deficiency of vitamin B12?
What condition results from a deficiency of vitamin B12?
Signup and view all the answers
How does the destruction of parietal cells affect digestion?
How does the destruction of parietal cells affect digestion?
Signup and view all the answers
What effect does chronic gastritis have on the body’s ability to absorb vitamin B12?
What effect does chronic gastritis have on the body’s ability to absorb vitamin B12?
Signup and view all the answers
G cells in the pyloric glands are responsible for secreting which hormone?
G cells in the pyloric glands are responsible for secreting which hormone?
Signup and view all the answers
What is the main function of the thick mucus secreted by surface mucous cells?
What is the main function of the thick mucus secreted by surface mucous cells?
Signup and view all the answers
What is a consequence of achlorhydria?
What is a consequence of achlorhydria?
Signup and view all the answers
What happens to folic acid levels when vitamin B12 is deficient?
What happens to folic acid levels when vitamin B12 is deficient?
Signup and view all the answers
The primary alkalinity of the mucus produced in the pyloric glands serves to:
The primary alkalinity of the mucus produced in the pyloric glands serves to:
Signup and view all the answers
Which gland produces the majority of saliva in the human mouth?
Which gland produces the majority of saliva in the human mouth?
Signup and view all the answers
What is the primary function of salivary alpha amylase?
What is the primary function of salivary alpha amylase?
Signup and view all the answers
Which component of saliva plays a role in lubricating food in the mouth?
Which component of saliva plays a role in lubricating food in the mouth?
Signup and view all the answers
What is the pH range of saliva?
What is the pH range of saliva?
Signup and view all the answers
Which of the following is NOT a major component of saliva?
Which of the following is NOT a major component of saliva?
Signup and view all the answers
Which electrolytes are found in saliva in higher concentrations compared to plasma?
Which electrolytes are found in saliva in higher concentrations compared to plasma?
Signup and view all the answers
What role do proline-rich proteins play in saliva?
What role do proline-rich proteins play in saliva?
Signup and view all the answers
The buccal glands primarily secrete which type of saliva?
The buccal glands primarily secrete which type of saliva?
Signup and view all the answers
Which GIT hormone is primarily responsible for stimulating the secretion of gastric juice?
Which GIT hormone is primarily responsible for stimulating the secretion of gastric juice?
Signup and view all the answers
Which factor contributes to the hypotonic nature of saliva?
Which factor contributes to the hypotonic nature of saliva?
Signup and view all the answers
Which gland is mainly responsible for producing the enzyme amylase in saliva?
Which gland is mainly responsible for producing the enzyme amylase in saliva?
Signup and view all the answers
Which type of secretion do submandibular and sublingual glands mainly produce?
Which type of secretion do submandibular and sublingual glands mainly produce?
Signup and view all the answers
What is the primary reason for the antibacterial properties of saliva?
What is the primary reason for the antibacterial properties of saliva?
Signup and view all the answers
What is the daily secretion range of saliva in milliliters?
What is the daily secretion range of saliva in milliliters?
Signup and view all the answers
Study Notes
Saliva and Gastric Secretions
- Saliva is a mixture of secretions produced by three glands: sublingual, submandibular, and parotid.
- Daily saliva secretion ranges from 800 to 1500 ml.
- Saliva pH is between 6-7.
- Saliva is alkaline in nature.
- Parotid glands are the largest
- Buccal glands secrete mucus only.
- Salivary glands are controlled primarily by the parasympathetic nervous system.
- Salivary secretion is a two-stage process. The first stage (acini) produces a primary secretion similar in composition to plasma which contains ptyalin, mucus, and extracellular fluid. Second stage (ducts) modifies saliva, through processes of sodium absorption and potassium secretion, thus becoming less similar to plasma and slightly alkaline.
- Saliva components include water (90%), electrolytes, salivary alpha amylase (ptyalin), lingual lipase, mucin, IgA antibody, antibacterial substances, lysosome, and prolinrich proteins.
- Saliva functions include taste, oral hygiene, protection, digestion, mastication, swallowing, buffering, singing, and speech.
- Two types of salivary reflexes include simple (unconditioned) and acquired (conditioned).
- Unconditioned reflex is triggered by oral stimulation by the presence of food.
- Conditioned reflex occurs without oral stimulation (thinking, seeing, smelling, or hearing of pleasant food).
- Salivation factors include sour taste (acids), smooth objects, rough objects, taste/smell of food, and presence of food.
- Salivation is inhibited by some factors and excited by others.
Gastric Secretions
- Stomach mucosa has two types of tubular glands: oxyntic (gastric) glands and pyloric glands.
- Oxyntic (gastric) glands are located on the inside surfaces of the body and fundus (80%).
- Oxyntic glands secrete hydrochloric acid, pepsinogen, intrinsic factor, and mucus.
- Pyloric glands are located in the antral portion (20%).
- Pyloric glands secrete mucus for protection and gastrin.
- Oxyntic gland is composed of parietal cells, peptic cells (chief cells), and mucous neck cells.
- Parietal cells secrete hydrochloric acid and intrinsic factor.
- Peptic cells (chief cells) secrete pepsinogen.
- Mucous neck cells secrete mucus.
- Mucus is rich in bicarbonate to prevent acid damage.
- HCl formation involves combining hydrogen and chloride ions. Hydrogen ions are transported into the canaliculi via the H+/K+ ATP pump (exchanging H+ for K+). Hydroxyl ions combine with CO2 to form bicarbonate (HCO3-), which is released into the interstitial space via chloride-bicarbonate exchange.
- Gastric secretion has three phases: cephalic, gastric, and intestinal.
- Cephalic phase occurs before food enters, stimulated by sight, smell, thought, or taste of food.
- Gastric phase is triggered by food entering the stomach, stimulated by distension, local reflexes, the vagus nerves, and gastrin.
- Intestinal phase inhibits gastric secretion by reverse enterogastric reflex and hormones like secretin, gastric inhibitory peptide, and cholecystokinin. These hormones act in response to pH<2 (or presence of lipids) in small intestine.
- Gastrin is a peptide hormone secreted by G cells in the pyloric glands. Gastrin stimulates ECL cells to release histamine which further increases HCl production and secretion.
- Enterochromaffin-like (ECL) cells are stimulated by gastrin to secrete histamine which is required for HCL production.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of the processes involved in saliva modification within the salivary ducts. This quiz covers key concepts such as ion transport mechanisms, neural control, and the functions of salivary components. Challenge yourself to recall the details of salivary reflexes and the role of various cranial nerves.
