Digestive System

The ____, ____, and ____ are the three major GI tract organs. The ____, ____, ____, and ____ are the four major accessory organs.

- Stomach, Small intestine, and Large intestine - Liver, Gallbladder, Salivary glands, and Pancreas

The outer layer has two different names depending on where it is located. Within the esophagus and the rectum it is called ____; within the stomach, small and large intestines it is called _____.

1. Adventitia 2. Serosa

The colon is divided into four regions, the ____ on the right side of the abdomen, the ____ which crosses the abdomen from right to left, the ____ on the left side of the abdomen, and the ____ which is the final region before the rectum.

1. Ascending colon 2. Transverse colon 3. Descending colon 4. Sigmoid colon

____ is the digestive juice that is produced by the liver. This digestive juice's function is to ____.

1. Bile 2. Emulsify fat globules

The main function of the jejunum is to ____and ____nutrients. It does this more efficiently due to the ____ , ____, and ____that increase surface area.

1. Chemically digest and absorb 2. Circular folds, villi, and microvilli / brush border

List the 3 modifications of the small intestine's inner wall that function to increase surface area:

1. Circular folds 2. Intestinal villi 3. Microvilli (brush border)

The digestive juices of the pancreas are secreted into the ____ region of the ____ (an organ).

1. Duodenum 2. Small intestine

The small intestine is divided into three sections. What are the names of the three sections and in the correct order?

1. Duodenum 2. Jejunum 3. Ileum

The smallest folds in the small intestine are folds of the plasma membranes of the____ cells of the small intestine mucosa. These projections are called ____ and are so small that they can only be seen using a microscope set at high magnification.

1. Epithelium (columnar) 2. Microvilli / brush border

The four primary roles of the digestive system are..?

1. Food intake 2. Digesting macro molecules taken in as food into usable monomers 3. Absorbing nutrients and water into the body 4. Eliminating the undigested wastes from the body

As chyme reaches the bottom of the esophagus, the ____sphincter opens. It controls the entrance of chyme into the ____ (an organ).

1. Lower esophagus / cardiac 2. Stomach

What are the three phases of vomiting?

1. Nausea - the unpleasant sensation of wanting to vomit 2. Retching - strong involuntary effort to vomit 3. Vomiting - forceful expulsion of gastric contents

List the three sheets of muscle in the stomach's muscularis externa (lumen -> out):

1. Oblique Muscle Layer 2. Circular Muscle Layer 3. Longitudinal Muscle Layer

The first section of the GI tract is the ____. After the food in the oral cavity is swallowed, the next section of the GI tract that it moves through is the ____.

1. Oral Cavity 2. Pharynx

After several hours of digestion in the stomach, the ____ sphincter will open to allow passage of chyme out of the stomach and into the ____ (an organ).

1. Pyloric 2. Small intestines

Most blood vessels and nerve fibers of the GI tract are found in the ____ tissue layer of the GI tract. This layer is made of ____ tissue.

1. Submucosa 2. Dense irregular connective

15. The digestive system organs fall into two major groups: the ____ and the ____.

Alimentary Canal / Digestive Organs

The ____ is a tiny pouch-like organ, roughly the size of one's index finger, that is part of the cecum.

Appendix

What does the gallbladder store?

Bile

The mucosa of the small intestine is very folded to increase its surface area. There are three types and sizes of folds: The largest folds are visible to the naked eye. They are called ____.

Circular folds

_____ means breaking things down into smaller pieces, such as when macromolecules in foods are broken down into monomers.

Digestion

The chyme (does/doesn't) pass through the accessory organs?

Doesn't

What section of the small intestine begins with the pyloric sphincter?

Duodenum

What section of the small intestine do the digestive juices from the accessory glands enter?

Duodenum

One major function of the pancreas is to make several different ____ (a type of protein), which become mixed with the chyme.

Enzymes

The ____is the next section of the GI tract after the pharynx.

Esophagus

Which alimentary canal organ carries chyme downward through the thoracic cavity, into the abdominal cavity?

Esophagus

What sphincter is located in the anal canal (voluntary skeletal muscle)?

External Anal Sphincter

What is the function of the large intestine, the digestive juices it uses, and the food particles that are broken down?

Function: Absorption of water and bacterial breakdown of complex saccharides Digestive Juices: None Food Particles: None

What is the function of the small intestine, the digestive juices it uses, and the food particles that are broken down?

Function: Chemical Digestion Digestive Juices: Maltase, Sucrase, Lactase, Intestinal Peptidase Food Particles: Carbs & Proteins

What is the function of the stomach, the digestive juices it uses, and the food particles that are broken down?

Function: Mechanical & Chemical Digestion Digestive Juices: HCl, Pepsin, & Gastric Lipase Food Particles: Proteins & Lipids

What is the function of the mouth, the digestive juices it uses, and the food particles that are broken down?

Function: Mechanical and Chemical Digestion Digestive Juices: Salivary Amylase & Lingual Lipase Food Particles: Carbs & Lipids

What is the function of the liver, the digestive juices it uses, and the food particles that are broken down?

Function: Secretes bile & maintains nutrient blood levels Digestive Juices: Bile Food Particles: Lipids

What is the function of the pancreas, the digestive juices it uses, and the food particles that are broken down?

Function: Secretes enzymes & buffers for chemical digestion Digestive Juices: Pancreatic amylase, lipase, and protease Food Particles: Carbs, Lipids, and Proteins

What is the function of the esophagus, the digestive juices it uses, and the food particles that are broken down?

Function: Transport bolus to stomach Digestive Juices: None Food Particles: None

Trace the path of bile from the gallbladder to the duodenum.

Gall bladder -> Cystic duct -> Common bile duct -> Duodenum

Trace the path of blood from the gut through the liver to the heart.

Gut (stomach/small intestine -> Hepatic portal vein (in lesser omentum) -> through Sinusoids (in liver lobules) -> Central vein -> Hepatic vein -> Inferior vena cava -> Heart (right atrium)

What valve is located between the small intestine & large intestine?

Ileocecal Valve

The passage of chyme from the small intestine into the large intestine is controlled by the ____ sphincter.

Ileocecal valve

What section of the small intestine absorbs vit. B12, bile salts, and leftover nutrients?

Ileum

What section of the small intestine makes contact with the ileocecal valve?

Ileum

What sphincter is located between in the anal canal (involuntary smooth muscle)?

Internal Anal Sphincter

What section of the small intestine does the most digestion and absorption take place?

Jejunum

Bacteria are mostly found in the ____ organ of the digestive system.

Large intestine

This alimentary canal organ has the appendix located at its beginning and contains a lot of bacteria. What is it?

Large intestine

What sphincter is located between the esophagus & stomach?

Lower Esophageal Sphincter

The central hollow area inside the gastrointestinal tract, where the chyme passes through, is called the _____.

Lumen

In addition to digestion and absorption, the ileum also contains large clusters of ____ that play a role in immunity.

Lymph nodes

Vomiting is stimulated by the ____.

Medulla Oblongata

What structure is a double sheet of serosa that suspends abdominal cavity, contains blood vessels, nerves, and lymphatics?

Mesenteries

The wall of the GI tract has four major tissue layers. From the lumen outward, the first three are the ____, ____, and ____.

Mucosa, Submucosa, and Muscularis Externa

What is the common passageway for food & air?

Oral Cavity

Smooth muscles in the gastrointestinal tract are responsible for propelling chyme from mouth to anus. This processes is called _____.

Peristalsis / Peristaltic Movement

What sphincter is located between the stomach & small intestine?

Pyloric Sphincter

The liver is located mostly on what side of the abdominal cavity?

Right

This alimentary canal organ separates the pyloric sphincter from another organ, most digestion and absorption take place here, is the largest organ in this canal, and has folds called villi. What is it?

Small intestine

Where does the most digestion and absorption in the GI tract takes place???

Small intestine

The pancreas is a long, roughly triangular organ located just inferior to the ____ (a GI tract organ).

Stomach

This alimentary canal organ separates the pyloric sphincter from another organ and contains gastric juices. What is it?

Stomach

Why does the epithelium layer of the mucosa vary alone the digestive tract?

The epithelium changes along the alimentary canal because of functional changes (stratified squamous = friction/abrasion protection; columnar = secretion & absorption)

Unlike the muscularis externa in other regions of the GI tract, the muscularis externa of the stomach has how many layers?

Three

What sphincter is located between the pharynx & esophagus?

Upper Esophageal Sphincter

List two main divisions of the digestive system

alimentary canal and accessory organs

Label the path of bile from gallbladder to duodenum

gallbladder -> cystic duct -> common bile duct -> duodenum

What are liver cells called?

hepatocytes

In addition to the circular folds in the small intestine, there are smaller finger-like projections called ____. These are easily seen using a microscope set at low magnification.

intestinal villi

12. There are two types of digestion: ____ digestion and ____ digestion.

mechanical and chemical

The ____, a feather-shaped organ located behind the stomach, secretes buffers and digestive enzymes

pancreas

The function of the gallbladder is to _____ _____ produced by the liver

store bile

What is chyme?

the acidic fluid that passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.

The major function of the large intestine is absorption of ____ and ____.

water and vitamins

Imagine eating a soda cracker, which is basically carbohydrates, fats, and proteins. How would each of these components be digested? Where within the digestive system would they be digested? Are any accessory organs involved?

• Digestion begins in the oral cavity. Food triggers saliva from the salivary glands and tongue. Carbs begin digestion with the addition of salivary amylase from the submandibular and parotid glands. Lipids begin digestion with the addition of lingual lipase from the tongue • The tongue and teeth cooperate to mix all together and form a bolus. Swallowing reflexes send it to the stomach. Proteins begin digestion with HCl which denatures the proteins allowing pepsin to break them down. Lipids continue digestion with gastric lipase. • It then travels to the small intestine, in the duodenum many digestive juices come together from the gall bladder, liver, and pancreas. Carbs are further digested with pancreatic amylase (from pancreas). Lipids finish digestion with pancreatic protease (from pancreas) and pancreatic lipase (from pancrease) • In the jejunum final digestion of carbs and proteins take place. Carbs finish with the addition of Maltase, Sucrase, Lactase. Proteins finish with the addition of peptidase. • Accessory Organs: Saliva - salivary glands Bile - Liver/Gallbladder Pancreatic Juices - pancreas