Digestive System PT.2 Objectives

Lecture Exam 5

Large Intestine Function (Four Answers)

Reabsorbs water to consolidate chyme into feces

Stores feces until defecation

Houses normal flora

Propulsion

Mucosa is made of

Simple Columnar

Describe Mucosa

Absorptive cells and Lubricates the solidifying mass of material

Describe Muscularis (Four Answers)

Circular layer present throughout

Longitudinal layer concentrated into the 3 teniae coli

Muscle tone causes the large intestine to gather

Produce haustra

What is Teniae Coli?

Three ribbon-like bands of longitudinal muscle

What is Haustra?

Pouch-like sacs formed by the teniae coli, pulling on the colon wall

Why are there so many goblet cells in the Large Intestine?

They Produce mucus

Do Water Absorption

Protection

List the different parts & regions of the large intestine where materials are traveling (Seven Answers)

Cecum

Ascending colon

Transverse colon

Descending colon

Sigmoid colon

Rectum

Anal canal

Cecum Function

Entry point to the large intestine; Material enters from the ileum

Ascending Colon Function

Moves material up the right side of the abdomen

Transverse Colon Function

Carries material across the abdomen (right to left)

Descending Colon Function

Moves material down the left side of abdomen

Sigmoid Colon Function

Curves inward toward the midline, leading to the rectum

Rectum Function

Stores feces before elimination

Anal Canal Function

Final passage; materials exit the body through the anus

Explain why the colon and the large intestine are not exactly the same thing

Because the colon is a part of the large intestine

Ileocecal Valve Function

Controls the flow of material from the small intestine into the large intestine and Prevents backflow

Normal Flora Function (Six Answers)

Produce vitamin K and some B vitamins

Influence regularity

Immune function

Fat deposition

Evidence of influence on CNS and neurological function

Produce flatus—farts

Rectum Function

Stores feces until they are ready to be eliminated

Rectal Valves Function

Separate liquid, gas, and solid waste

Allowing gas to pass without releasing feces

What is the Anal Canal?

Passageway out of the rectum

What are Hemorrhoids?

Swollen blood vessels in the rectum or anus that can cause pain, itching, and bleeding during bowel movements

What is the relationship between the Anal Canal?

The anal canal is the final part of the digestive tract where feces pass through before elimination

What is the relationship between the Internal Anal Sphincter?

It is involuntary and relaxes to allow feces to enter the anal canal.

What is the relationship between the External Anal Sphincter

It is voluntary and controls when feces are released, allowing you to hold or release until it's appropriate to defecate

What is the Visceral Peritoneum

Covers the surface of many abdominal organs

What is the Parietal Peritoneum

Lines the body wall

What is the Mesentery

Visceral peritoneum folded back on itself with no abdominal organ in between

Greater Omentum Function

Greater curvature to transverse colon

Mesentery Function

Houses blood vessels

Holds organs in place

Is the site of adipose tissue deposition

What does it mean if an organ is described as being retroperitoneal?

Means the organ is behind the peritoneum and is not fully surrounded by it

List the organs classified as Retroperitoneal (Seven Answers)

Duodenum

Pancreas

Ascending Colon

Descending Colon

Rectum

Kidneys/Adrenal gland

Urinary bladder

What is the Right Lobe

The largest lobe of the liver

Where is the Right Lobe located?

On the right side of the abdomen

Where is the Left Lobe located?

On the left side of the abdomen

What is the left lobe

The smaller lobe

What is the quadrate lobe

A small lobe located on the posterior side of the liver

What is the caudate lobe

A small lobe located on the anterior side, near the gallbladder

Liver Function (Eight Answers)

Stores and releases glucose, Synthesizes and stores lipids, Regulates circulating lipids, Produces plasma proteins, Amino Acid interconversion and breakdown, Detoxifies absorbed toxins, Removes old RBCs & cellular debris, Produces Bile

What are the right and left lobes of the liver separated by?

Falciform Ligament

Falciform Ligament Function

Anchors the liver to the anterior abdominal wall and diaphragm, helping to hold it in place

What are Hepatocytes?

Main cells of the liver

Hepatocytes Function (Four Answers)

Make bile and blood proteins

Process nutrients

Store vitamins and glycogen

Detoxify drugs, alcohol, and harmful substances

What is a Liver Lobule?

The liver’s basic unit

Portal Triad is made of

Made of a branch of the hepatic artery, Portal vein, and Bile duct

What is a Sinusoid?

Blood-filled spaces between liver cells, where blood from the triads flows toward the central vein

What is a Bile Canaliculi?

Tiny channels between hepatocytes that collect bile and carry it away from the lobule toward the bile ducts

Describe Blood through a lobule

Blood flows from the portal triads into the sinusoids, where it's cleaned by hepatocytes, then drains into the central vein

Describe Bile Flow through a Lobule

Bile flows in the opposite direction, made by hepatocytes, and it enters the bile canaliculi and moves toward the bile duct in the triads

What is the Hepatic Portal System?

A special network of veins that carries nutrient-rich blood from the digestive organs to the liver before it goes to the rest of the body

What are the major veins that contribute to the hepatic portal system?

Inferior Mesenteric Vein

Splenic Vein

Superior Mesenteric Vein

Hepatic Portal System Function

The liver processes nutrients

Removes toxins

Filters blood before it enters the general circulation

What are the two vessels that supply the liver with blood?

Hepatic Artery and Hepatic Portal Vein

Hepatic Artery Function

Brings O2-rich blood into the liver

Hepatic Artery Oxygen

High

Hepatic Artery Nutrients

Low

Hepatic Portal Vein Function

Brings nutrient-rich blood from the digestive organs to the liver for processing

Hepatic Portal Vein Oxygen

Low

Hepatic Portal Vein Nutrients

High

What is the difference between the Hepatic Veins and the Hepatic Portal Veins?

The hepatic portal vein brings nutrient-rich blood to the liver, while the hepatic veins carry filtered blood away from the liver. 

Gallbladder Location

Anterior to the right lobe of the liver

Gallbladder Function

Stores and concentrates bile produced by the liver

What is Bile?

A yellow-green fluid produced by the liver and stored in the gallbladder

Bile Function

Emulsifies fat and Excrete cholesterol and bilirubin

Bile Components (Five Answers)

Bile salts, Bilirubin, Cholesterol, Water, Electrolytes

Pancreas Location

Located posterior to the stomach

Exocrine Function of the Pancreas

The secretion of pancreatic juice into the duodenum via the pancreatic duct

Endocrine Function of the Pancreas

Secretes hormones Insulin and Glucagon, which are involved in the regulation of blood sugar

What are the components of Pancreatic Juice (Four Answers)

Amylase, Lipase, Proteases, Nucleases

Amylase breaks down

Carbohydrates

Lipase breaks down

Fats

Proteases break down

Proteins

Nucleases break down

Nucleic Acids

What are the Hormones Produced By The Pancreas?

Insulin and Glucagon

Insulin Function

Reduces blood sugar and encourages cells to store away nutrients

Glucagon Function

Increases blood sugar and encourages cells to release stored energy

What are Acini Cells?

Small clusters of cells in the pancreas that make up its exocrine part

What are Acinar Cells?

Individual cells in each acinus, Produce and secrete digestive enzymes into the pancreatic ducts

What part of the ANS stimulates the digestive system in a way that increases its activity?

The Parasympathetic Nervous System stimulates the digestive system and increases its activity

Folds of the parietal peritoneum, which extend from the body wall to the organs in the peritoneal cavity, are called

Mesentery

Organs that are not surrounded by a peritoneum are said to be

Retroperitoneal

The mesentery, which separates the right and left lobes of the liver and attaches the liver to the anterior body wall and diaphragm, is called

Falciform Ligament

Nutrient-rich, venous blood from the stomach and intestines is carried to the liver by

Hepatic Portal Vein

Oxygen-rich blood is carried to the liver by

Hepatic Artery

Which vessels take blood from the liver and drain into the inferior vena cava?

Hepatic Veins

Bile is produced by the liver and stored in the

Gallbladder

What is the role of the bile salts in the digestive process

Breaks large droplets into smaller droplets that remain mixed with water

The main bile pigment is bilirubin, which is formed from

Hemoglobin during the breakdown of erythrocytes.

Bile is secreted from the liver via

Right and left hepatic ducts

Which duct is from the gallbladder?

Cystic Duct

The cystic duct from the gallbladder merges with the common hepatic duct to form the

Common Bile Duct

The buildup of bile pigments in the blood due to liver disease or blockage of bile ducts results in the skin taking on a yellow color.  This is called

Jaundice

The specialized endocrine cells in the pancreas are called

Islets of Langerhans

Longitudinal bands of smooth muscle along the length of the colon are called

Teniae Coli

The internal anal sphincter is Voluntary or Involuntary?

Involuntary

The internal anal sphincter is composed of

Smooth Muscle

The external anal sphincter is Voluntary or Involuntary?

Voluntary

The external anal sphincter is composed of

Skeletal Muscle

Bile is produced by

Liver