Download Period 3 - Digestive System

Period 3 – Digestive System
Oral Cavity , Pharynx, salivary gland, tongue, and teeth
1. What is the oral cavity and what does it contain?
a. The oral cavity is the first part of the digestive tract. It contains the mouth, teeth, gums, the hard
and soft palate, the floor of the mouth, and checks.
2. What is the function of the salivary glands?
.
The function of the salivary gland is produce saliva to keep the mouth and and other parts of the
digestive system moist. It's also help break down carbohydrates.
3. What is the function of the tongue?
.
The function of the tongue is chewing and swallowing food, as well as for speech.
4. What is a bolus?
.
A bolus is a small rounded mass of substance especially of chewed food at the moment of swallowing.
5. What are the soft and hard palate located and what are their functions?
.
The palate is the roof of the mouth. The hard palate is in the front of the top of the mouth and the soft
palate is in the back of the top of the mouth. The soft palettes function is to close off nasal passages during the
act of swallowing, and also closing off the airway. During sneezing, it protects the nasal passage by diverting a
portion of the excreted substance to the mouth. The hard palate is important for feeding and speech.
6. What mechanical and chemical digestion occurs in the oral cavity?
.
Mechanical digestion begins in the mouth as the food is chewed. Chemical digestion involves breaking
down the food into simpler nutrients that can be used by the cells. Chemical digestion begins in the mouth
when food mixes with saliva. Saliva contains an enzyme (amylase) that begins the breakdown of
carbohydrates.
7. What mechanisms are in place to make sure food does not “go down the wrong tube” and into
windpipe?
.
The esophagus and stomach.
8. How many teeth does an adult normally have?
.
The normal adult human being has 32 teeth. 8 incisors, 4 canines,8 premolars, 12 molars.
Esophagus and Stomach
1. What is peristaltic movement and how does it function in the esophagus?
Peristaltic is muscle contraction that happen in the digestive tract and also happens in organs like where the
kidneys connect to the bladder.
2.
Does any digestion of food occur in the esophagus?
No digestion occurs in the esophagus but the salivary glands are the first to act upon food. They produce
enzymes called ptyalin that helps digestive starch from food into small molecules so it can be easier for the
stomach to also digest the food more.
3.
What are the primary functions of the of the stomach?
The stomach has three different layers. The layers produce acid. The stomach muscles mix acid, food, and
enzymes o break down the food you have you eaten so that you get the nutrients and vitamins from the food
you have eaten.
4.
What is chyme and how does the stomach mix this material?
It is a thick fluid that is partially digested food. Chyme is the result of mechanically and chemically digested
food. Chyme is very acidic.
5.
What role does the stomach play in decontaminating the incoming food matter?
The stomach secretes gastric juice which is a of mucus, hydrochloric acid, and digestive enzymes. The
digestive enzymes break down proteins and kill bacteria.
6.
Why doesn't gastric juice digest the inside of the stomach?
The stomach is lined with epithelial cells that secrete a protective layer of mucus and bicarbonate that can’t be
digested by the gastric juice.
7.
What are sphincters and how are they related to the stomach?
A sphincter in a ring of muscle surrounding and serving to guard or close an opening or tube. The stomach has
two sphincters. The esophageal, which takes food in and the pyloric sphincter, which takes food out.
Sphincters in the stomach are used for letting food in or out then closing so anything that shouldn’t leave the
stomach won’t.
8.
What mechanical and chemical digestion occurs in the stomach?
The stomach uses mechanical digestion when it does the mixing action where the walls of the stomach
produce contractions known as mixing waves. This will mix the food with the gastric juice and makes a liquid
called chyme. The stomach’s chemical digestion is with the gastric juice and it digests large molecules into
their smaller subunits. The gastric juice and food make chyme which continues throughout the intestines. The
chemical digestion continues in the intestines, but that’s all the stomach does. If there is any food that needs
more time to digest then it will stay in the stomach for longer.
More on the stomach and esophagus:
1. Peristaltic movement is when your esophagus pushes the food that you eat down in a wave-like
motion. Peristaltic movement in the esophagus happens when food is eaten. Ethan
2. No digestion occurs in the esophagus. The esophagus pushes the food to the stomach so it can
digest. Scott
3. The main function of the stomach is to break down and digest food in order to extract necessary
nutrients from what you have eaten. Ethan
4. Chyme is a thick fluid that is made partially of digested food. Muscle contractions mix the
different components of chyme to make chyme. Scott
5. The stomach releases enzymes that kill bacteria in food and balance pH. It also breaks down
and digest the food. Ethan
6. The stomach has an inner wall made up of epithelial tissue that helps protect from the acid from
eating the stomach which is made mainly of protein Scott
7. Sphincters are circumferential muscles that can relax or constrict to regulate the passage of
material through a particular area. Allows foods to enter from the esophagus after swallowing to
let the food enter into the stomach and right before the food is going to enter into the small
intestine. Ethan
8. Mechanical digestion occurs when food is being chewed and when muscle contractions help
push it to the stomach. Chemical digestion occurs when the saliva is mixed with the chewed
food and chemical digestion involves breaking down the food into nutrients that can be used by
cells. Scott
The Small Intestine:
The small intestine is located within the digestive. System and is positioned between the
stomach and the large intestine. Another name for the small intestine is the Small Bowel. The small
intestine is so called because it's lumen diameter is smaller than that of the large intestine, although it
is larger in length than the large intestine.

What are the (3) sections of the small intestine and what role does each section play in
digestion or absorption?
a. Duodenum
The Duodenum is the first and shortest section of the small intestine. The partially digested
food from the stomach (other wise known as chyme) travels here and is prepared to be
absorbed into the other parts of the small intestine.
b. Jejunum
The Jejunum is the middle section of the small intestine found between the duodenum and the
ileum. Most of the nutrients which are digested within the jejunum are then passed onto the
ileum to become further absorbed.
c. Ileum
The ileum is the last part of the small intestine and is there to absorb the last of the vitamin
B12 and bile salts along with the last of any useful proteins left over from the jejunum. The
inside of the ileum is an interesting structure, with many folds containing finger like
appendages called villi.

What is the pH within the small intestine and how is the pH maintained?
pH is the highly acids within the stomach and is rapidly changing throughout the body. pH
gradually increases within the small intestine. Within the duodenum it is pH 6, and is between 7 to 9
in the Jejunum, to about 7.4 in the Ileum. Sodium bicarbonate released by the pancreas maintains pH
levels.

Where do bile and pancreatic enzymes enter the small intestine?
Bile and pancreatic enzymes within the body enter the small intestine through the Duodenum.

How does food move through the intestines?
The intestines have muscles which allow the walls of the intestines to move. The movements
of these walls can propel food and water and also mix with the contents of other organs.
What enzymes act inside the small intestine and what are the functions of these
enzymes?
Chemical breakdowns of food begin in the stomach and move along through the large
intestine. Proteolytic enzymes, including trypsin and chymotrypsin, are secreted from the pancreas
and cleave proteins into smaller peptides to move throughout the body. Another enzyme,
Carboxypeptidase, is a pancreas brush border enzyme which splits one amino acid at a time.
The Large Intestine
The function of the large intestine is to absorb water from remaining food matter, move feces to the next bowel
system and make the stools solid.-HS
The three sections of the large intestine are the cecum, colon and rectum. The cecum holds the appendix, which
can become inflamed. Next is the colon which has three parts, ascending, transverse and descending. In the first
two, salts and fluids are absorbed from ingested food and produce a mucus that helps feces move more easily
into the rectum. There the feces wait to be excreted into the next bowel system. -HS
The large intestine helps maintain water balance in the body by absorbing the water out of food.
Pancreas
The general function of the Pancreas is to produce enzymes.
1. The size of the pancreas is about 6 inches long and sits across the back of the abdomen, behind the
stomach.The head of the pancreas is on the right side of the abdomen and is connected to the
duodenum through a small tube called the pancreatic duct. AW
2.
The pancreas produces important enzymes and hormones that help break down foods.The pancreas
releases, these juices or enzymes produced by the pancreas which are secreted into the small intestine to
further break down food after it has left the stomach. The gland also produces the hormone insulin and
secretes it into the bloodstream in order to regulate the body's glucose or sugar level. AW
3. The pancreas connects to the rest of the digestive system by creating insulin. Insulin works to help the
broken down carbohydrates get into cells. Then the cells can use the insulin to create energy. CSH
4. The enzymes produced by the Pancreas include Trypsin, Chymotrypsin, Amylase and Lipase. Trypsin and
Chymotrypsin work together to digest proteins. Amylase helps digests sugars or carbohydrates. Lipase helps
digest lipids or fats.CSH
5. Insulin takes the glucose, which are carbohydrates that are broken down by the digestive system, and helps
them get through the cell membrane into the cells to provide them with energy. CSH
Liver and Gallbladder:
ZGH Intro: The gallbladder’s primary function is to store and concentrate bile, a yellow-brown digestive enzyme
produced by the liver. It also drains waste products from the liver into the duodenum.
ZGH 4. The gallbladder is a pear shaped organ that is 1 inch wide and 3 inches long when not filled with
bile.After meals, the gallbladder releases bile into the duodenum to aid with digestion. The cystic duct carries
bile from the gallbladder to the bile duct, which empties into the duodenum. Entry of bile into the duodenum is
regulated by layers of muscle called the sphincter of Oddi.
ZGH 5. Bile contains bile acids, which are critical for digestion and absorption of fats and fat-soluble vitamins in
the small intestine. Many waste products, including bilirubin, are eliminated from the body by secretion into bile
and elimination of feces.
1. GH: The size of the liver is 7 cm for women and is 10.5 cm for men, and Is in the upper right portion of
the abdomen and is above the stomach.
2. GH: The liver processes the nutrients that have been absorbed by the small intestine also produces bile
that plays a important role in digestion of fat.
3. GH: The liver regulates most chemical level, the blood from the stomach and intestines go through the
liver which the liver breaks down, balances, and makes nutrients for the body and also filters the blood
and gets rid of the harmful substances like drugs and alcohol.
Liver and Gallbladder
The liver filters blood from the digestive tract and the gallbladder stores and concentrates bile from the liver.
1. The liver is the largest in the human body. 7 cm long for women, 10.5cm for men. Located in superior,
right abdomen, superior to stomach, inferior to diaphragm.
2. The liver processes the nutrients absorbed from the small intestine. Bile is also secreted from the liver
into the small intestine to help the chemical digestion of fat.
3. The liver produces proteins that are important in blood clotting, it also breaks down old or damaged
blood cells. It plays a role in the metabolic process in the body, breaking down nutrients from food to
produce energy. It detoxifies chemicals and metabolizes drugs. The liver also helps fight infection by
removing bacteria from the blood. And lastly it produces bile to digest fats and absorb vitamins.
4. The liver produces bile and the gallbladder stores it and concentrates it until it is needed. When we eat
the bile is released to digest foods and absorb vitamins.
5. Bile increases absorption of fats, it also absorbs fat-soluble substances like vitamin A,D,E, and K. It
enters the digestive tract through the bile duct from the gallbladder. The bile duct is a small tube
structure where it then empties into the upper part of the small intestine.