Anatomy Flashcards: Small Intestine Overview

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Questions and Answers

Describe the gross anatomy of the small intestine including its three major regions.

Duodenum, jejunum, ileum.

What are the digestive processes that occur in the small intestine?

Nutrient absorption (correct)

Fat storage

Chemical digestion (correct)

Water absorption

Describe the histology of the small intestine.

Circular folds, villi, and microvilli.

Describe the circular folds of the small intestine.

Plicae circulares. Signup and view all the answers

Describe the villi of the small intestine.

Covered with simple columnar epithelium and contain blood vessels and lacteals internally. Signup and view all the answers

Describe the microvilli of the small intestine.

They are on the apical surface of villar cells and contain brush border enzymes. Signup and view all the answers

Why does the small intestine have circular folds, villi, and microvilli?

To increase surface area for absorption. Signup and view all the answers

Describe the gross anatomy of the large intestine, including all major structures and regions.

Ileocecal valve, cecum, appendix, ascending colon, right colic (hepatic) flexure, transverse colon, left colic (splenic) flexure, descending colon, sigmoid colon, rectum. Signup and view all the answers

Describe the gross anatomy of the anal canal.

Includes rectal valves, internal anal sphincter, external anal sphincter, and anal sinuses. Signup and view all the answers

What are the digestive processes that occur in the large intestine?

Absorbs water and electrolytes, forces feces toward rectum. Signup and view all the answers

What are the accessory digestive organs?

Pancreas, liver, and gallbladder. Signup and view all the answers

Describe the location, anatomy, and functions of the pancreas.

Exocrine functions (digestive enzymes) and endocrine functions (insulin, glucagon). Signup and view all the answers

Describe the anatomy of the liver.

Right lobe, left lobe, caudate lobe, quadrate lobe, hepatic artery, hepatic portal vein, inferior vena cava, gallbladder. Signup and view all the answers

Describe the functions of the liver.

Storage of excess blood nutrients, detoxification of poisons, production of blood proteins, and bile production. Signup and view all the answers

Describe the structure of a hepatic lobule.

A central vein with sinusoids carrying blood surrounding hepatocytes. Signup and view all the answers

Follow the structures bile passes through as it travels from the liver to the duodenum.

Bile duct branches, hepatic ducts, cystic duct, common bile duct, major duodenal papilla. Signup and view all the answers

Describe the location of the peritoneum (visceral and parietal layers).

Parietal peritoneum on the wall, visceral on organs. Signup and view all the answers

Describe the location of the peritoneal cavity.

Below diaphragm and above bladder. Signup and view all the answers

Describe the location of the mesenteries.

Double layer folds of peritoneum around intraperitoneal organs. Signup and view all the answers

Differentiate between intraperitoneal and retroperitoneal organs.

Intraperitoneal organs include the stomach and liver. Signup and view all the answers

Describe hernias.

Inguinal hernia, femoral hernia, hiatal hernia, umbilical hernia. Signup and view all the answers

What is intestinal obstruction?

Any hindrance to movement of chyme or feces through the intestine. Signup and view all the answers

Describe inflammatory bowel disease.

Periodic inflammation of intestinal wall with symptoms including cramping, diarrhea, and weight loss. Signup and view all the answers

What is colorectal cancer?

Second most common cancer diagnosed. Signup and view all the answers

What is liver cirrhosis?

A disorder where liver cells are destroyed and replaced by connective tissue. Signup and view all the answers

What is viral hepatitis?

Inflammation of the liver with flu-like symptoms and jaundice. Signup and view all the answers

What are gallstones?

Crystallization of cholesterol or calcium and bile salts. Signup and view all the answers

What is peritonitis?

Inflammation of the peritoneum. Signup and view all the answers

What type of epithelium is found in the mouth?

Stratified squamous epithelium. Signup and view all the answers

Where do pancreatic juice and enzymes enter the small intestine?

Duodenum. Signup and view all the answers

Study Notes

Small Intestine Anatomy

Comprises three major regions: duodenum, jejunum, ileum.
Key structures include the minor and major duodenal papilla, accessory pancreatic duct, and the main pancreatic duct.
Muscular layers consist of a longitudinal and circular layer; the submucosa supports these layers.
Lined with simple columnar epithelium and suspended by the mesentery proper.

Digestive Processes in the Small Intestine

Primary site for chemical digestion, facilitated by pancreatic enzymes.
Liver bile emulsifies fats for improved digestion.
Responsible for nutrient absorption into the bloodstream.

Histology of the Small Intestine

Characterized by circular folds, villi, and microvilli to enhance surface area.
Circular folds (plicae circulares) create bumps for increased absorption.
Villi covered with simple columnar epithelium, containing blood vessels and lacteals.
Microvilli form the brush border on villar cells, housing brush border enzymes.

Large Intestine Anatomy

Consists of ileocecal valve, cecum, appendix, ascending colon, right colic flexure, transverse colon, left colic flexure, descending colon, sigmoid colon, and rectum.
Lined by simple columnar epithelium.
Unique features include teniae coli (muscle ribbons), haustra (pouches), and epiploic appendages.

Anal Canal Anatomy

Contains rectal valves (transverse folds) to separate feces from gas.
Internal anal sphincter (smooth muscle, involuntary) vs. external anal sphincter (skeletal muscle, voluntary).
Anal sinuses produce mucus for lubrication.

Digestive Processes in the Large Intestine

Absorbs water and electrolytes.
Propels feces towards the rectum.

Accessory Digestive Organs

Includes pancreas, liver, and gallbladder, which secrete substances to aid digestion.
Not part of the gastrointestinal tract but vital for digestion.

Pancreas Anatomy and Functions

Exocrine: Acinar cells produce digestive enzymes, secreted via pancreatic ducts.
Endocrine: Pancreatic islets produce insulin and glucagon.

Liver Anatomy

Comprised of right, left, caudate, and quadrate lobes.
Blood vessels: hepatic artery, hepatic portal vein, and inferior vena cava.
Surrounded by falciform ligament which supports the structure.

Liver Functions

Stores excess nutrients, detoxifies substances, clears debris, and produces blood proteins (albumin, globulins).
Synthesizes bile for digestion.

Hepatic Lobule Structure

Contains hepatocytes surrounded by sinusoids carrying blood.
Blood flows toward the central vein; bile flows through canaliculi to bile ducts.

Bile Transport

Bile made in the liver travels through hepatic ducts, merges with the cystic duct from the gallbladder, and enters the common bile duct to duodenum.
Gallbladder functions: storage and concentration of bile.

Peritoneum Location

Parietal peritoneum lines abdominal wall; visceral peritoneum covers organs.
Mesentery connects the two layers and contains blood vessels.

Peritoneal Cavity Location

Found below the diaphragm and above the bladder; associated with structures like greater omentum and mesocolon.

Mesenteries

Double-layered folds of peritoneum that support intraperitoneal organs.
Includes greater omentum, lesser omentum, mesentery proper, and mesocolon.

Organ Classification

Intraperitoneal: stomach, jejunum, ileum, transverse/sigmoid colon, appendix, liver, spleen.
Retroperitoneal: most duodenum, ascending/descending colon, rectum, pancreas, kidneys.

Hernias

Inguinal hernia: intestines push through inguinal canal, common in males.
Femoral hernia: intestines push through femoral triangle, common in females.
Hiatal hernia: stomach protrudes through esophageal hiatus.
Umbilical hernia: intestines push through rectus abdominis.

Intestinal Obstruction

Refers to any blockage hindering chyme or feces movement in the intestine.

Inflammatory Bowel Disease

Causes periodic intestinal inflammation with symptoms like cramping, diarrhea, weight loss, and bleeding.

Colorectal Cancer

Second most common cancer; early detection through colonoscopy is essential.

Liver Cirrhosis

Liver cells are damaged and replaced with connective tissue, often due to alcohol consumption.
Symptoms include jaundice and toxin buildup; treatment typically involves liver transplant.

Viral Hepatitis

Involves liver inflammation accompanied by flu-like symptoms and jaundice.

Gallstones

Formed by crystallization of cholesterol or calcium salts in bile.

Peritonitis

Inflammation affecting the peritoneum, often due to infection or irritation.

Epithelial Types in the Digestive Tract

Mouth, oropharynx, laryngopharynx, esophagus: stratified squamous epithelium.
Stomach: simple columnar epithelium (not ciliated).
Small intestine (duodenum, jejunum, ileum): ciliated simple columnar with villi/microvilli.
Colon: simple columnar epithelium.

Pancreatic Juice Entry

Pancreatic juices and enzymes enter the small intestine through the duodenum.

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Description

This quiz focuses on the gross anatomy of the small intestine, detailing its three major regions: the duodenum, jejunum, and ileum. You'll also learn about the various structures involved in digestive processes and the anatomical features that contribute to its function.