The Alimentary System

Flashcards covering terminology, anatomy, physiology, and clinical aspects of the Alimentary System based on the lecture notes.

What does ampulla refer to in anatomical terminology?

A cavity, or the dilated end of a duct.

What does concave mean?

Curves inward.

What does convex mean?

Curves outward.

What does gastro- mean in medical terminology?

Relating to the stomach.

What does hepato- mean in medical terminology?

Relating to the liver.

What is a vestibule in anatomical terms?

A chamber or channel communicating with or opening into another.

Why is knowledge of the Alimentary System important for medical professionals?

To understand abdomen procedures, assessment and diagnosis, communication, and research.

Name the large external glands associated with the alimentary tract.

The three pairs of salivary glands, the liver, gall bladder, and pancreas.

What general tissues line the alimentary tract and what do glands provide?

An epithelium-lined muscular tube; glands provide enzymes and materials needed for digestion and absorption.

Which organs are located outside the tubular tract as major associated glands?

The 3 pairs of salivary glands, liver, gall bladder, and pancreas.

Which is the largest salivary gland and through which duct does it open?

The parotid gland; opens via Stensen’s duct (parotid duct).

Which duct opens Wharton’s duct and is a major submandibular gland?

Wharton’s duct (submandibular duct).

What type of secretion does the sublingual gland primarily produce?

Mucous secretion.

What are the major components of the tongue's surface features on the dorsum?

Sulcus terminalis, foramen caecum, papillae (filiform, fungiform, circumvallate), lingual tonsil, and folds.

What are the three main taste zones on the dorsum of the tongue?

Bitter (posterior), Sour and Salty (middle posterior), Sweet (anterior). [Note: taste zones are described in diagrams as zones for taste modalities.]

Which nerves carry general sensation from the anterior two-thirds of the tongue?

Lingual nerve.

Which nerve supplies taste from the anterior two-thirds of the tongue?

Chorda tympani (branch of facial nerve via lingual nerve).

Which nerve supplies the posterior one-third of the tongue for general sensation?

Glossopharyngeal nerve.

Which nerve supplies the posterior one-third of the tongue for taste?

Glossopharyngeal nerve.

Which nerve supplies the posterior-most part of the tongue for taste and general sensation?

Vagus nerve (via the taste pathway) and general sensation via vagus for specific regions.

Where does the esophagus begin and end?

Begins at the cricoid cartilage and ends as it enters the right side of the stomach.

How long is the human esophagus?

About 25 cm.

What are the three parts of the esophagus in relation to constrictions?

Constrictions occur at the cricopharyngeal sphincter (C6), where it is crossed by the aortic arch/left main bronchus (23 cm from incisors), and the diaphragmatic hiatus (LES) at about 40 cm from incisors.

What are the muscular layers of the esophagus?

Inner circular layer and outer longitudinal layer.

What is the nerve supply of the esophagus in the neck and thorax?

Neck: Recurrent laryngeal nerve; Thorax: Vagal trunks, esophageal plexus, sympathetic trunks.

Which arteries supply the stomach primarily?

Left gastric, right gastric, left gastro-epiploic, right gastro-epiploic, and short gastric arteries.

What are the main surfaces of the stomach called?

Anterior surface and posterior surface.

What are the major parts of the stomach?

Cardia, Fundus, Body, Pylorus.

What is the capacity of the adult stomach approximately?

About 1000 to 1500 ml.

What is the stomach’s function?

Storage of ingested food, enzymatic digestion, absorption of water, glucose, and alcohol; secretion of gastrin; retention time about 3–4 hours.

What are rugae and gastric pits?

Rugae are the folds of the stomach mucosa; gastric pits are indentations that open into glands.

What is the ‘Rule of 2’s’ related to the stomach?

Cardiac and pyloric ends; anterior and posterior surfaces; multiple other paired features (2 ends, 2 surfaces, etc.) used as a teaching mnemonic for stomach anatomy.

Which arteries supply the stomach’s lesser curvature?

Left gastric and right gastric arteries.

Which arteries supply the stomach’s greater curvature?

Left gastro-omental (gastroepiploic) and right gastro-omental arteries.

Which organ stores and concentrates bile?

Gallbladder.

What are the three sections of the small intestine?

Duodenum, Jejunum, Ileum.

From which arteries is the small intestine primarily supplied?

Celiac trunk and Superior mesenteric arteries.

What are the four parts of the duodenum?

Superior, Descending, Horizontal, Ascending parts.

Which part of the duodenum is smooth-walled and named the duodenal cap?

The first part, the duodenal bulb (duodenal cap).

What is Meckel’s diverticulum?

A vestigial remnant of the omphalomesenteric (vitelline) duct present in some newborns.

What are the three parts of the large intestine?

Cecum and appendix, Colon (ascending, transverse, descending, sigmoid), Rectum and anal canal.

What is the main function of the large intestine?

Absorption of water and storage of feces; bacterial synthesis of vitamins.

Where is the caecum located and what is its relation to the ileocecal junction?

Located in the right iliac fossa; ileocecal junction is the connection with the ileum; appendix arises below this junction.

What is the vermiform appendix, where does it arise from, and what is its blood supply?

A small tubiform diverticulum arising from the postero-medial wall of the caecum about 2 cm below the ileocecal junction; supplied by the appendicular artery (branch of the ileocolic artery).

What is McBurney’s point?

A surface landmark for the base of the appendix, at the junction of the middle and outer third of a line from the umbilicus to the anterior superior iliac spine.

What are the two major flexures of the colon and where are they located?

Hepatic (right) flexure near the liver; Splenic (left) flexure near the spleen.

Which arteries form the marginal artery of Drummond in the colon?

Anastomosis between the ileocolic and right/left colic arteries (branches of SMA and IMA).

What is the transverse mesocolon?

A broad peritoneal fold suspending the transverse colon from the posterior abdominal wall.

Which part of the colon is retroperitoneal?

Ascending and descending colon (anterior surfaces are peritoneum-covered; posterior surfaces are non-peritoneal in part).

Which structures define the rectum’s peritoneal relations in males and females?

In males, rectovesical pouch and associated coils; in females, rectouterine pouch (Douglas) with uterus and vagina relations.

What are Houston’s valves?

Permanent transverse folds (valves) in the rectum that help support feces and prevent instrument passage.

What are the three sphincters of the anal canal?

Internal sphincter (involuntary), external sphincter (voluntary), and the pubo-rectal sling contributing to sphincter control.

Where does the portal-systemic venous drainage communicate via the rectum?

Superior rectal vein drains into the inferior mesenteric vein (portal system); middle and inferior rectal veins drain into systemic veins (internal iliac and pudendal).

What is the single largest gland in the body and where is it located?

The liver; located on the right side under the diaphragm.

What are the four lobes of the liver?

Left lobe, Right lobe, Caudate lobe, Quadrate lobe.

What is the porta hepatis (hilus)?

The entry/exit point of vessels and ducts on the visceral surface of the liver.

What is the function of bile and where is it produced?

Bile emulsifies fats; produced by the liver.

Which duct carries bile from the liver to the gallbladder and onward?

Common hepatic duct to cystic duct (gallbladder) and then to the bile duct toward the duodenum.

What is the role of the gallbladder?

Stores and concentrates bile; releases bile into the duodenum in response to fatty meals.

What is the major duct system that leads bile and pancreatic juice to the duodenum?

Common bile duct and major pancreatic duct reaching the second part of the duodenum via the sphincter of Oddi.

What is the pancreas’ basic functional classification?

Both endocrine and exocrine gland.

Where do the pancreas’ ducts release their secretions into the duodenum?

Through the main pancreatic duct and the major shared duct leading to the ampulla of Vater via the sphincter of Oddi.

What is the structure and location of the stomach’s lesser and greater curvatures?

Lesser curvature is the shorter right border; greater curvature is the longer left border.

Which layer primarily supplies the stomach’s arterial blood to the lesser curvature?

Left and right gastric arteries along the lesser curvature.

Which layer supplies the stomach to the greater curvature?

Left and right gastro-omental (gastroepiploic) arteries along the greater curvature.

Which nerves provide parasympathetic supply to the stomach?

Vagal trunks (anterior and posterior) with branches to hepatic and gastric regions.

What are the gastric glands, where are they located, and what do they secrete?

Cardiac glands (mucus) in the cardia; Fundic & body glands (zymogenic/chief cells secrete pepsin; oxyntic cells secrete HCl); Pyloric glands (mucus; gastrin).

Which part of the small intestine begins immediately after the pylorus?

Duodenum (first part immediately after pylorus).

What are plicae circulares and where are they most numerous?

Circular folds of the mucosa; most numerous in the jejunum.

What is the duodenal cap?

The smooth-walled first part of the duodenum (duodenal bulb).

Which arteries supply the duodenum?

Superior pancreatico-duodenal artery (branch of gastroduodenal) and inferior pancreatico-duodenal artery (branch of superior mesenteric artery).

What are the two types of lymphatic drainage patterns in the stomach?

Drainage to gastric and gastro-omental lymph nodes, eventually to the celiac nodes.

What are the primary pathways of venous drainage from the stomach?

Right and left gastric veins to the portal vein; short gastric and left gastro-epiploic veins to the splenic vein; right gastro-epiploic to the superior mesenteric vein.

Which part of the gut is referred to as the abdominal tonsil and why?

Appendix; it is devoid of taeniae coli and is rich in lymphoid tissue.

What is Meckel’s diverticulum and why is it clinically important?

A vestigial remnant of the omphalomesenteric (vitelline) duct; may present with diverticulum symptoms in infants/children.

Where is the vermiform appendix typically located and how is it supplied?

Arises from the postero-medial wall of the caecum about 2 cm below the ileocaecal junction; supplied by the appendicular artery.

What landmark indicates the base of the appendix on the caecum’s surface?

Convergence of the taeniae coli at the base of the appendix.

What are the major features of the rectum’s musculature?

Thickened circular muscle forming the internal anal sphincter; longitudinal muscle blends with taeniae coli and forms the external sphincter and pubo-rectalis sling.

What is Hilton’s line?

The anal inter-sphincteric groove indicating the lower end of the internal anal sphincter.

What is the pectinate (dentate) line?

The muco-cutaneous junction in the anal canal delineating upper and lower areas. Above it: endodermal origin; below it: ectodermal origin.

Which structures lie anterior to the rectum in males and females?

Males: base of the bladder, vas deferens, prostate, seminal vesicles; Females: posterior vaginal wall and vagina.

What are Houston’s valves and where are they found?

Transverse rectal folds in the rectum that support feces and reduce instrument passage.

What is the distinguishing feature of the anal canal’s interior zones?

Upper area with anal columns and valves; intermediate area (pectinate zone) with internal venous plexus; lower area (anal verge) with true skin.

What is the role of the internal and external anal sphincters?

Internal sphincter: involuntary (sympathetic and parasympathetic control). External sphincter: voluntary; supplied by inferior rectal branch of pudendal nerve.

What is the liver’s porta hepatis?

The hilus on the visceral surface where vessels and ducts enter or leave the liver.

What are the hepatic lobes visible on the visceral surface?

Right lobe, Left lobe, Caudate lobe, Quadrate lobe.

What is the function of the hepatic portal system?

Deliver nutrient-rich blood from the gut to the liver for processing.

Where is the bile duct system connected to the liver and gallbladder?

Common hepatic duct from the liver fuses with the cystic duct (gallbladder) and joins the main pancreatic duct via the ampulla of Vater.

What are the main components of bile?

Bile salts, bile pigment (bilirubin), cholesterol, phospholipids, electrolytes.

What makes up the gallbladder’s primary function?

Storing and concentrating bile for release into the duodenum.

What is the general function of the pancreas beyond digestion?

Endocrine and exocrine roles; secretes digestive enzymes and hormones (e.g., insulin) into the bloodstream.

Explain the difference between the foregut and midgut derivatives in the context of the small intestine.

Duodenum is foregut-derived; jejunum and ileum are midgut-derived in development.

Where is the transverse colon suspended from and what is its key vascular feature?

Suspended by the transverse mesocolon; supplied by middle colic artery branches forming the marginal artery of Drummond.

What is the significance of the caecum’s taeniae coli?

Taeniae coli converge at the base of the appendix, marking its relationships and aiding surgical orientation.

What marks the ileocaecal valve’s location and function?

Located at the caecum opening to the ileum; regulates flow from ileum to caecum and prevents backflow.

What describes the appendix’ peritoneal covering and taeniae?

Covered by a meso-appendix; lacks taeniae coli, sacculations, and appendices epiploicae.

Which vessels supply the sigmoid colon and what veins drain it?

Sigmoid arteries from the inferior mesenteric artery; veins drain into the inferior mesenteric vein.

What landmark delineates the boundary between the anal canal and the skin?

Pectinate line (dentate line) marks muco-cutaneous junction.

What are the major arterial supplies to the stomach’s lesser and greater curvature?

Lesser curvature: left and right gastric arteries; Greater curvature: left and right gastro-omental (gastroepiploic) arteries.

Describe the posterior relations of the stomach.

Posterior surface lies near the pancreas, spleen, left kidney, and the transverse mesocolon; in the lesser sac, it is related to the pancreas.