Podcast
Questions and Answers
What happens to the mucosa and submucosa of the stomach when it is empty?
What happens to the mucosa and submucosa of the stomach when it is empty?
Which type of cell in the gastric glands secretes mucous?
Which type of cell in the gastric glands secretes mucous?
What role do parietal cells play in the digestive process?
What role do parietal cells play in the digestive process?
What is the primary function of the submucosa in the digestive tract?
What is the primary function of the submucosa in the digestive tract?
Signup and view all the answers
What is primarily neutralized in the duodenum?
What is primarily neutralized in the duodenum?
Signup and view all the answers
Which structure increases the internal surface area of the small intestine the most?
Which structure increases the internal surface area of the small intestine the most?
Signup and view all the answers
Which reflex type is involved in stimulating peristaltic contractions in response to stretching?
Which reflex type is involved in stimulating peristaltic contractions in response to stretching?
Signup and view all the answers
What is the primary function of the pyloric sphincter?
What is the primary function of the pyloric sphincter?
Signup and view all the answers
What role do mesenteries play in the digestive system?
What role do mesenteries play in the digestive system?
Signup and view all the answers
Which type of cells in the small intestine are responsible for secreting mucus?
Which type of cells in the small intestine are responsible for secreting mucus?
Signup and view all the answers
What is a key function of the buccal cavity?
What is a key function of the buccal cavity?
Signup and view all the answers
What does the inner circular layer of the muscularis externa primarily accomplish?
What does the inner circular layer of the muscularis externa primarily accomplish?
Signup and view all the answers
What type of epithelium lines the lumen of the small intestine?
What type of epithelium lines the lumen of the small intestine?
Signup and view all the answers
What type of chemical messenger is involved in stimulating distant parts of the digestive tract?
What type of chemical messenger is involved in stimulating distant parts of the digestive tract?
Signup and view all the answers
Which type of tissue primarily composes the serosa in the digestive tract?
Which type of tissue primarily composes the serosa in the digestive tract?
Signup and view all the answers
What contributes to the tongue's ability to manipulate food effectively?
What contributes to the tongue's ability to manipulate food effectively?
Signup and view all the answers
What is the primary function of segmentation in the digestive tract?
What is the primary function of segmentation in the digestive tract?
Signup and view all the answers
How often do contractions occur in the duodenum during segmentation?
How often do contractions occur in the duodenum during segmentation?
Signup and view all the answers
What is the composition of feces?
What is the composition of feces?
Signup and view all the answers
What triggers mass movements in the colon?
What triggers mass movements in the colon?
Signup and view all the answers
What is the role of renin secreted by the kidneys?
What is the role of renin secreted by the kidneys?
Signup and view all the answers
Which of the following is NOT a function of the kidneys?
Which of the following is NOT a function of the kidneys?
Signup and view all the answers
What does the migrating motor complex do?
What does the migrating motor complex do?
Signup and view all the answers
Which structure prevents backflow into the ileum from the colon?
Which structure prevents backflow into the ileum from the colon?
Signup and view all the answers
What is the primary role of the glomerulus in the nephron?
What is the primary role of the glomerulus in the nephron?
Signup and view all the answers
What substance is primarily excreted by the distal convoluted tubule?
What substance is primarily excreted by the distal convoluted tubule?
Signup and view all the answers
Which section of the nephron is responsible for reabsorbing the majority of water and solutes?
Which section of the nephron is responsible for reabsorbing the majority of water and solutes?
Signup and view all the answers
What happens to sodium as it passes through the thick segment of the ascending limb?
What happens to sodium as it passes through the thick segment of the ascending limb?
Signup and view all the answers
In which part of the nephron does aldosterone primarily exert its effects?
In which part of the nephron does aldosterone primarily exert its effects?
Signup and view all the answers
What is the osmolarity of the fluid in the distal convoluted tubule?
What is the osmolarity of the fluid in the distal convoluted tubule?
Signup and view all the answers
Which segment of the nephron is highly permeable to water but not to salt?
Which segment of the nephron is highly permeable to water but not to salt?
Signup and view all the answers
What is the osmolarity of the fluid entering the collecting duct?
What is the osmolarity of the fluid entering the collecting duct?
Signup and view all the answers
What is the function of mastication in digestion?
What is the function of mastication in digestion?
Signup and view all the answers
Which portion of the tooth is located above the gum line?
Which portion of the tooth is located above the gum line?
Signup and view all the answers
What is the role of the periodontal ligament?
What is the role of the periodontal ligament?
Signup and view all the answers
What anatomical feature is located at the basal end of each root canal?
What anatomical feature is located at the basal end of each root canal?
Signup and view all the answers
Which structure acts as a muscular funnel connecting the oral cavity to the esophagus?
Which structure acts as a muscular funnel connecting the oral cavity to the esophagus?
Signup and view all the answers
What is the primary function of the lower esophageal sphincter?
What is the primary function of the lower esophageal sphincter?
Signup and view all the answers
What happens during the buccal phase of swallowing?
What happens during the buccal phase of swallowing?
Signup and view all the answers
Which type of tissue primarily makes up the tooth?
Which type of tissue primarily makes up the tooth?
Signup and view all the answers
What is the primary function of intrinsic factor in the digestive system?
What is the primary function of intrinsic factor in the digestive system?
Signup and view all the answers
Which hormone is primarily responsible for stimulating gastric acid production?
Which hormone is primarily responsible for stimulating gastric acid production?
Signup and view all the answers
What is one way the stomach protects its lining from acidic damage?
What is one way the stomach protects its lining from acidic damage?
Signup and view all the answers
What percentage of dietary fats is digested in the stomach?
What percentage of dietary fats is digested in the stomach?
Signup and view all the answers
Which treatment is effective against gastritis caused by Helicobacter pylori?
Which treatment is effective against gastritis caused by Helicobacter pylori?
Signup and view all the answers
What substance does the mucous coat in the stomach primarily consist of?
What substance does the mucous coat in the stomach primarily consist of?
Signup and view all the answers
Which hormone is released to reduce gastric motility when chyme enters the duodenum?
Which hormone is released to reduce gastric motility when chyme enters the duodenum?
Signup and view all the answers
What cellular structure in the stomach prevents gastric juices from seeping between epithelial cells?
What cellular structure in the stomach prevents gastric juices from seeping between epithelial cells?
Signup and view all the answers
Study Notes
Exam 4 Review Sheet
- Gastroenterology is the study of the digestive tract and its disorders
- The digestive system processes food, extracts nutrients, and eliminates waste
- Five stages of digestion:
- Ingestion: selective intake of food
- Digestion: mechanical and chemical breakdown of food
- Absorption: uptake of nutrients into the bloodstream and lymph
- Compaction: absorbing water and consolidating waste into feces
- Defecation: elimination of feces
- Mechanical digestion: physical breakdown of food (e.g., chewing, churning)
- Chemical digestion: breakdown of dietary macromolecules into monomers (e.g., proteins to amino acids) by enzymes
- Digestive enzymes include salivary amylase (starch digestion), lingual lipase, pepsin, pancreatic amylase, pancreatic lipase, and others
- The digestive tract has four major tissue layers, from deep to superficial: mucosa, submucosa, muscularis externa, and serosa
Digestive Tract Subdivisions
- Alimentary canal includes mouth, pharynx, esophagus, stomach, small and large intestine
- Accessory organs include teeth, tongue, salivary glands, liver, gallbladder, and pancreas
Basic Structural Plan: Digestive Tract
- Mucosa: epithelium specialized for absorption/secretion, lamina propria, muscularis mucosae. Thickened in places to form sphincters that regulate passage of material
- Submucosa: loose connective tissues, blood vessels, lymphatic vessels, nerves to regulate digestive activity
- Muscularis externa: contains two layers of smooth muscle- inner circular layer and outer longitudinal layer. Responsible for motility to move food through the tract
- Serosa: areolar tissue and mesothelium. Prevents friction
Regulation of Digestive Tract
- Neural regulation includes short (myenteric) reflexes (related to stretch or chemical stimulation), and long (vagovagal) reflexes (parasympathetic stimulation)
- Hormonal regulation involves chemical messengers (e.g., gastrin, secretin, and others), secreted into bloodstream
- Paracrine secretions: chemical messengers that diffuse through tissue fluids to nearby target cells
Stomach and Intestines
- Mesenteries: sheets of connective tissue, suspend stomach and intestines from the abdominal wall
- Help avoid twisting or excessive movement of the organs
Buccal Cavity (Mouth)
- Contains teeth, tongue, and salivary glands
- Vallate papillae are V-shaped rows marking the boundary of the body and root of the tongue, located on the posterior tongue
- Lingual frenulum: median fold that attaches body to floor of the mouth
- Lingual papillae: bumps on the tongue that contain taste buds
- Fungiform papillae: contain taste buds and found on the sides and tip of the tongue
- Filiform papillae: provide friction to the tongue for chewing; most numerous
- Foliate papillae: contain taste buds, located near the back of the tongue and line the sides
Teeth
- Deciduous (baby) teeth: 20
- Adult teeth: 32
- Different types of teeth including incisors, canines, premolars, and molars
- Teeth develop beneath gums and erupt in predictable order
Muscles of Mastication
- Masseter
- Temporalis
- Medial and lateral pterygoids
Teeth Anatomy
- Regions: crown (above gum), root (below gum), neck (where crown, root, and gum meet)
- Tissues: enamel (crown), dentin (most of tooth), cementum (root), and pulp (contains nerves and blood vessels)
Periodontal Structures and Saliva
- Alveolus: tooth socket in bone
- Periodontal ligament: anchors tooth firmly in alveolus; allows slight movement under pressure of chewing
- Gingiva: gums, covers alveolar bone
- Saliva functions for moistening mouth, aiding in digestion, cleansing teeth, inhibiting bacterial growth, dissolving molecules for taste buds, and lubricating food bolus for swallowing
Salivary Glands
- Three pairs of extrinsic salivary glands- parotid, submandibular, and sublingual.
- Secrete 1-1.5L of saliva per day
- Intrinsic salivary glands are dispersed among other oral tissues
Pharynx
- Muscular funnel connecting oral cavity to esophagus and allows air from nasal cavity to larynx
- Intersect of digestive and respiratory tracts
- Three regions: Nasopharynx, Oropharynx, Laryngopharynx
- Epiglottis: flap of tissue that guards superior opening of larynx. Guides food to esophagus
Esophagus
- Muscular tube extending from pharynx to stomach
- Lower esophageal sphincter prevents backflow of stomach contents
- Food passes through esophageal hiatus in diaphragm
- Swallowing includes buccal phase (voluntary), pharyngeal phase (involuntary), and esophageal phase (involuntary)
Stomach
- Muscular sac
- Stores food, begins protein digestion, and turns food into chyme
- Four regions: cardiac, fundus, body, and pylorus
- Produces gastric juice containing hydrochloric acid and pepsinogen
- Enzymes include pepsin, hydrochloric acid, and gastric lipase
- Intrinsic factor is needed for vitamin B12 absorption
- Hormones produced by stomach include gastrin and other hormones
Duodenum and Small Intestine
- Duodenum - first part of small intestine
- Receives chyme, pancreatic juice, and bile
- Responsible for chemical digestion, absorption of nutrients, and more
- Other parts of small intestine include jejunum and ileum
- Absorption of most nutrients occurs in the small intestine via villi
Large Intestine
- Absorbs water, salts, and electrolytes from undigested food
- Mixes waste
- Stores waste until it can be eliminated
- Regions include ascending, transverse, descending, and sigmoid colon, and rectum
- Processes fecal matter and eliminates waste via rectum and anus
- Different types of cells: goblet cells (mucus production)
- Rectum stores feces and anal canal (end of the large intestine) opens to outside for release
Liver and Gallbladder
- Liver- produces bile
- Stores glycogen for glucose regulating, excretes bilirubin
- Bile acids are required for lipid digestion and absorption
- Gallbladder - stores and concentrates bile for release into duodenum
- Removes toxins, hormones, and other waste products from the blood
- Regulates blood glucose and produces proteins essential for blood clotting
- Hepatocytes are the functional cells of the liver
Pancreas
- Has endocrine and exocrine functions.
- Endocrine functions include regulation of blood glucose (e.g., islets of Langerhans)
- Exocrine function includes secretion of pancreatic juice containing digestive enzymes
- Produces insulin and glucagon
- Bicarbonate secretions neutralize acidic chyme entering the small intestine
- Digestive enzymes break down proteins, carbohydrates, and fats
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the anatomy and functions of the digestive system with this quiz. Explore questions about the stomach's mucosa, gastric gland cells, and the roles of various digestive structures. Gain a deeper understanding of how digestion processes work.
