Human Anatomy: Digestive System Quiz
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Questions and Answers

What is the primary function of the venous sinus in the spleen?

  • Produce red blood cells
  • Transport oxygen to tissues
  • Remove old and damaged erythrocytes (correct)
  • Promote the growth of erythrocytes

    • Which arteries branch from the celiac trunk?

  • Renal artery
  • Right gastric artery (correct)
  • Inferior mesenteric artery
  • Superior mesenteric artery

    • Which part of the gastrointestinal tract is considered a derivative of the foregut?

  • Large intestine
  • Rectum
  • Cecum
  • Distal duodenum (correct)

    • What characterizes the composition of the splenic venous sinuses?

    <p>Leaky endothelial walls</p> Signup and view all the answers

    At which spinal level does the celiac trunk branch off from the abdominal aorta?

    <p>T12</p> Signup and view all the answers

    What is the primary role of mastication in food preparation?

    <p>Forming food into a bolus</p> Signup and view all the answers

    Which part of the tongue is responsible for articulation of words?

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

    What structure connects the tongue to the floor of the mouth?

    <p>Frenulum of tongue</p> Signup and view all the answers

    Which muscle of the tongue is specifically responsible for protruding and retracting the tongue?

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

    Which of the following cranial nerves is NOT involved in the oral cavity?

    <p>CN 8</p> Signup and view all the answers

    The mucosa of the anterior part of the tongue is primarily characterized by which feature?

    <p>Rough surface due to papillae</p> Signup and view all the answers

    What type of glands are salivary glands classified as?

    <p>Exocrine glands</p> Signup and view all the answers

    Which pair of salivary glands is located anteriorly and under the tongue?

    <p>Sublingual glands</p> Signup and view all the answers

    What are the primary processes carried out by the digestive system?

    <p>Mixing food, moving food through the digestive tract, and using chemicals to break down food</p> Signup and view all the answers

    Which organ is not part of the gastrointestinal tract?

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

    Which anatomical structure separates the oral cavity from the nasal cavity?

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

    Which part of the digestive system is responsible for the initial taste of food?

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

    What is the approximate length of the gastrointestinal tract?

    <p>5-7 meters</p> Signup and view all the answers

    Which of the following is considered an accessory digestive organ?

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

    In which section of the digestive system would you find the duodenum?

    <p>Upper GI tract</p> Signup and view all the answers

    What is one of the major roles of the peritoneum in the gastrointestinal system?

    <p>To support and protect abdominal organs</p> Signup and view all the answers

    What type of glands does the pancreas contain?

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

    Which part of the pancreas is located at the tail?

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

    Which anatomical structure empties the digestive enzymes produced by acinar cells into the duodenum?

    <p>Main pancreatic duct</p> Signup and view all the answers

    What type of muscle comprises the upper third of the oesophagus?

    <p>Skeletal muscle</p> Signup and view all the answers

    Which layer of the gastrointestinal tract is composed of epithelium, lamina propria, and muscularis mucosa?

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

    What is the primary function of the islets of Langerhans in the pancreas?

    <p>Produce insulin and glucagon</p> Signup and view all the answers

    What is the location of the majority of the liver in relation to the ribs?

    <p>Deep to ribs 7-11</p> Signup and view all the answers

    What histological type is found in the epithelium of the oesophagus?

    <p>Stratified squamous epithelium (non-keratinised)</p> Signup and view all the answers

    What is the primary function of the muscular layers in the oesophagus?

    <p>Peristaltic movement to push bolus food</p> Signup and view all the answers

    What does the portal triad in the liver consist of?

    <p>Hepatic artery, hepatic portal vein, and bile duct</p> Signup and view all the answers

    Which part of the abdominal cavity is primarily used by clinicians to explain pain locations?

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

    Which ligament of the liver has a free edge containing the remnant of the umbilical vein?

    <p>Falciform ligament</p> Signup and view all the answers

    In which abdominal region is the stomach primarily located?

    <p>Epigastric and Umbilical</p> Signup and view all the answers

    What is the role of the hepatoduodenal ligament within the liver anatomy?

    <p>Surrounds the portal triad</p> Signup and view all the answers

    What type of innervation is responsible for controlling the lower oesophageal sphincter?

    <p>Enteric nervous system</p> Signup and view all the answers

    Which of the following organs or tissues would you NOT find in the left hypochondrium region?

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

    Which layer of the muscularis externa is unique to the stomach and allows for vigorous contraction?

    <p>Inner oblique layer</p> Signup and view all the answers

    What is the clinical significance of the pylorus being located at the L1 vertebrae level?

    <p>Indicates the position of the stomach in the abdominal cavity</p> Signup and view all the answers

    What is the main function of the rugosities (rugae) in the stomach's mucosa?

    <p>Expansion and contraction of the stomach</p> Signup and view all the answers

    Which components make up the gastric pits in the stomach?

    <p>Mucous-producing cells</p> Signup and view all the answers

    Which of the following organs is NOT directly related to the stomach?

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

    What characterizes the superior part of the duodenum?

    <p>It has no circular folds</p> Signup and view all the answers

    What is the primary function of the circular folds (plicae circulares) in the duodenum?

    <p>Slowdown digestion process</p> Signup and view all the answers

    Where does the major duodenal papilla open?

    <p>Into the descending part of the duodenum</p> Signup and view all the answers

    Study Notes

    Gastrointestinal Tract: Gross Anatomy & Microanatomy

    • The digestive system has three main processes: mixing food, moving food through the digestive tract (peristalsis), and breaking down food into smaller molecules.
    • Two main parts: gastrointestinal tract (GI tract) and accessory digestive organs.
    • GI Tract is a continuous tube from mouth to anus.
    • Accessory digestive organs include teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

    Learning Outcomes

    • M1.I.GAS.ANA1: Describe the functional anatomy of the digestive tract (oral cavity, esophagus, stomach, duodenum, jejunum, ileum, cecum, and colon), accessory digestive organs (salivary glands, liver, gallbladder, pancreas), and the spleen.
    • M1.I.GAS.ANA2: Outline the major structures of the neurovascular supply to the gastrointestinal system.
    • M1.I.GAS.ANA3: Describe the organisation and clinical significance of the parietal and visceral peritoneum, the greater and lesser sacs, mesenteries, and peritoneal ligaments.
    • M1.I.GAS.ANA4: Understand specific common clinical examples associated with the gastrointestinal system.

    Introduction

    • The digestive system carries out three processes: mixing food, moving food through the digestive tract (peristalsis), and using chemicals to break down food into smaller molecules.
    • Two organs involved:
      • GI tract (alimentary canal): a continuous tube from mouth to anus, passing through thoracic and abdominopelvic cavities. Organs include the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.
      • Accessory digestive organs: teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

    Part 1: Upper GI Tract

    • Oral Cavity (Mouth): Ingestion point of food. Includes lips, cheeks, teeth, gums, tongue, palate, and uvula.
    • Pharynx: Passageway for food and air between oral cavity and esophagus.
    • Esophagus: Muscular tube connecting pharynx to stomach.
    • Stomach: J-shaped organ for food storage and initial digestion. Has 4 parts (cardia, fundus, body, pylorus).
    • Liver: Largest gland, has multiple functions, including bile secretion.
    • Pancreas: Accessory organ, produces enzymes for digestion, located behind stomach and connected to duodenum through ducts.
    • Gallbladder: Stores bile from liver; connects to duodenum via the common bile duct.

    LECTURE OVERVIEW

    • Thoracic region:
      • Oral region
      • Pharynx
      • Esophagus
    • Abdominal region:
      • Surface anatomy of abdominal regions
      • Stomach
      • Small intestine (duodenum)
      • Pancreas
      • Liver
      • Biliary tree & gallbladder
      • Spleen
      • Blood supply to the GI tract

    What we will cover

    • Functional anatomy of areas of the oral region, oesophagus, stomach, duodenum.
    • Peritoneal cavity and its subdivisions.
    • Functional anatomy of the pancreas, liver, gall bladder.
    • Upper GI, hepatic and pancreatic histology.
    • Their vascular supply and nerve supply.

    Oral Region (Mouth)

    • Point of food entry into the digestive system.
    • Structures: lips (labia), cheeks, oral (buccal) cavity, teeth, gingivae (gums), tongue, palate, region of palatine tonsils.

    Oral (Buccal) Cavity

    • First part of the digestive system.
    • Food and drinks are tasted.
    • Mastication (chewing) occurs to prepare food into a bolus.
    • The oral cavity has two parts: oral vestibule and oral cavity proper.

    Boundaries of Oral Cavity

    • Anterior and lateral boundaries: lips, cheeks, body of the tongue.
    • Superior boundary: hard palate, soft palate
    • Inferior boundary: floor of the mouth – supported by muscles such as geniohyoid and mylohyoid.
    • Posterior boundary: oropharynx

    Tongue

    • Main function: articulation of words and manipulating food.
    • Tongue has 3 parts: root, body, and apex.
    • Dorsum has 2 surfaces: oral (anterior two-thirds) and pharyngeal (posterior one-third).
    • Divised by V-shaped groove: terminal sulcus (meeting point as foramen cecum).
    • Has Taste buds (receptors) and lingual tonsils (lymphoid nodules).
    • Extrinsic muscles change the position of the tongue, and intrinsic muscles change the shape of the tongue.
    • Inferior surface (underside) of tongue: frenulum, sublingual folds, sublingual caruncles.

    Nerves of Oral Cavity

    • Five Cranial nerves involved in oral cavity: CN5, CN7, CN9, CN10, and CN12.

    Salivary Glands

    • Three pairs of salivary glands: parotid, submandibular, and sublingual glands.
    • Secrete saliva, a clear, tasteless, and odourless fluid, crucial for digestion, moistening food and protection of oral cavity.
    • Glands are exocrine, not endocrine, and their function is to secrete digestive enzymes.

    Histology of Salivary Glands

    • Made up of secretory acini and ducts.
    • Two types of secretions: serous (watery fluid) and mucous (mucin lubricant).
    • Parotid glands are mostly serous.
    • Sublingual glands are predominantly mucous.
    • Submandibular glands have a mix of both types.

    Pharynx

    • A musculofascial (voluntary skeletal ms.) tube.
    • Connects the oral and nasal cavities to the larynx and esophagus.
    • Parts of the pharynx include the nasopharynx, oropharynx, and laryngopharynx.
    • Important for swallowing and speech.

    Oesophagus

    • Muscular tube that transports food from pharynx to stomach.
    • Passes through the thoracic cavity and enters the abdomen through the esophageal hiatus in the diaphragm.
    • Sphincters at top (anatomical, cricopharyngeus m.) and bottom (physiological) to prevent backflow of food or stomach acid.

    Lower Oesophageal Sphincter

    • Maintained by:
      • Acute angle between esophagus and stomach (cardial notch).
      • Diaphragmatic musculature (right crus).
      • Intra-abdominal section's compression with positive intra-abdominal pressure.
    • Dysfunction can lead to gastroesophageal reflux disease (GORDs).

    Oesophagus Histology

    • Muscular tube made up of skeletal and smooth muscle layers.
    • Upper third is skeletal, middle third is mixed skeletal & smooth, and lower third is smooth muscle.
    • Outer layer - Longitudinal muscle
    • Inner layer - Circular muscle

    Histology of GI Tract

    • General histology showing 4 basic layers in the GI Tract: mucosa, submucosa, muscularis externa, and serosa/adventitia. These layers demonstrate regional variations.

    Histology of Oesophagus

    • Epithelium type: Stratified squamous epithelium (non-keratinised).
    • 2 muscle layers: outer longitudinal and inner circular.
    • Innervation: Enteric nervous system (part of ANS) Myenteric plexus

    Surface Anatomy of Abdomen Regions

    • Abdominal cavity can be described by regions or quadrants.
    • Clinicians often use these when explaining pain location in the abdomen.

    Stomach

    • J-shaped, intraperitoneal organ.
    • Capacity of up to 3 liters.
    • Location: epigastric and umbilical regions.
    • May vary in location depending on the individual and body type, and changes during respiration and after meals.
    • Four parts: cardia, fundus, body, and pylorus.

    Stomach Relations (surrounding viscera)

    • Greater omentum
    • Lesser omentum
    • Liver
    • Spleen
    • Pancreas
    • Left kidney and suprarenal gland
    • Transverse colon
    • Diaphragm

    Stomach Histology

    • Muscularis externa – is three layered unique to stomach allowing for vigorous contraction eg churning.
    • Inner oblique layer, middle circular, and outer longitudinal layers of muscle.
    • Mucosa – lining (0.3–1.5 mm thick) forms folds called rugae which flatten when stomach expands.

    Histology Stomach - Epithelium Type

    • Simple columnar, forms pits with gastric glands.
    • Mucous cells protect the stomach lining.
    • Parietal cells produce hydrochloric acid (HCl).
    • Chief cells produce pepsinogen, an enzyme for protein digestion.
    • Enteroendocrine cells produce local hormones.

    Duodenum

    • C-shaped, retroperitoneal organ.
    • Lies in the umbilical region.
    • Four parts: Superior, Descending, Inferior, and Ascending.
    • Curved around the head of the pancreas.
    • Has circular folds (plicae circulares) that slow food passage.

    Duodenum: Internal Features

    • Superior part lacks circular folds (L1 level)
    • Other parts have circular folds(Plicae circulares).
    • Also called Valves (Kerkring) large valvular flaps that project into lumen.
    • Circular folds slow the passage of food.
    • Descending part (L2-L3): Major duodenal papilla – bile and main pancreatic duct opening.
    • Ascending part (4th part) – ends as duodenojejunal flexure- continues as jejunum at L2 vertebrae level.

    Pancreas

    • Elongated, accessory gland.
    • Location: Epigastric, Left Hypochondrium.
    • Four parts: head (with uncinate process), neck, body, and tail.
    • Retroperitoneal except for the tail.

    Pancreas Histology

    • Exocrine part: Acinar cells produce digestive enzymes
    • Empties to the duodenum via two ducts—main and accessory pancreatic duct.
    • Endocrine part: Islets of Langerhans produce hormones—glucagon, insulin, and somatostatin.

    Liver

    • Largest gland in the body.
    • Intraperitoneal organ.
    • Protected by ribs 7-11 in the right hypochondrium, upper epigastric, and left hypochondrium regions.
    • Two main surfaces:
      • Diaphragmatic surface, mainly at the anterosuperior part, and direct contact with diaphragm.
      • Visceral surface (postero-inferior) has impressions from other organs.

    Liver Anatomical and Functional Lobes

    • Anatomical lobes: Right and left with accessory lobes of quadrate and caudate.
    • Functional lobes: The right and left lobes are independent with the quadrate and caudate being part of the left lobe.
    • Each lobe receives supply from its own hepatic artery and portal vein and drains via its own hepatic duct.

    Liver Ligaments

    • Falciform ligament – free edge that has the remnant of the umbilical vein.
    • Coronary ligament (anterior and posterior folds).
    • Triangular ligaments (right and left).
    • Lesser omentum: Hepatogastric and hepatoduodenal ligaments surround the portal triad

    Liver Blood Supply

    • Dual blood supply (afferent vessels).
    • Hepatic artery.
    • Hepatic portal vein (HPV): main blood supply, carrying absorbed nutrients from the small and large bowl (75%).

    Liver Histology

    • Polygonal hepatic lobules—basic functional unit.
    • The periphery of the hexagon has structures known as the portal triad.
    • Bile flow is opposite to the flow of blood.
    • Bile canaliculi are the smallest branches of the biliary tract.
    • Stellate macrophages (Kupffer cells) phagocytose aged erythrocytes and foreign bacteria.
    • Hepatic sinusoids—leaky endothelial walls—facilitate greater contact with hepatocytes.

    Biliary Ducts & Gallbladder

    • Gallbladder: intraperitoneal pear-shaped sac.
    • Location: between the right and quadrate lobe of the liver. Stores bile secreted by hepatocytes.
    • Capacity: 30–50 ml.
    • Three parts: fundus, body, and neck.

    Biliary Ducts & Gallbladder– Intra/Extrahepatic Parts

    • Extrahepatic bile passages and pancreatic ducts:
      • Sphincter of bile duct
      • Sphincter of pancreatic duct
      • Hepatopancreatic sphincter (Sphincter of Oddi)

    Spleen

    • Ovoid-shaped, largest lymphoid organ.
    • Located in the left hypochondrium, protected by the inferior thoracic cage and the rib cage.
    • Surfaces: diaphragmatic surface and visceral surface.
    • Relations: to stomach, tail of the pancreas, diaphragm, left colic flexure, and left kidney.
    • Internal Features:
      • Red pulp: contains red blood cells, venous sinuses rich in macrophages (removes old and damaged erythrocytes, recycles iron).
      • White pulp: contains white blood cells (T and B lymphocytes).
      • Splenic venous sinuses - leaky endothelial walls to allow transportation of cells.

    Blood Supply (Abdominal Viscera)

    • Unpaired visceral arteries—branching from the abdominal aorta in the midline
    • Celiac trunk (T12)
    • Superior mesenteric artery (L1)
    • Inferior mesenteric artery (L3)

    Blood Supply: Celiac Trunk and its Branches

    • Common hepatic artery
    • Hepatic artery proper
    • Right gastric artery
    • Gastroduodenal artery
    • Right gastro-omental artery
    • Left gastric artery
    • Splenic artery
    • Left gastro-omental artery
    • Short gastric arteries
    • Dorsal pancreatic artery
    • Inferior pancreatic artery

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    UM1011-GI Part 1- Upper GI (1) PDF

    Description

    Test your knowledge on the functions and structures of the digestive system, including the spleen, oral cavity, and gastrointestinal tract. This quiz covers key topics such as the celiac trunk, salivary glands, and the role of mastication. Perfect for students of human anatomy and physiology.

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