Structures & Functions of the LOWER Digestive Tract Flashcards
A muscular tube which extends
from the lower end of your
stomach to your anus, the
lower opening of the digestive
tract. also called the bowel
intestines
three features of small intestine
mucosal folds, villi, micro villi
the longest part of the digestive system and extends from the stomach to the large intestine and consists of three parts: duodenum, jejunum and ileum.
small intestine
It has features which allow it to have such a huge absorptive surface area packed into a relatively small space
small intestine
This is not only increases the surface area but helps regulate the flow of digested food through the intestine.
mucosal folds
Helps absorb nutrients from the food that passes through.
villi
This helps increase the surface of each individual cell so that each cell can absorb nutrients.
micro villi
PARTS OF THE SMALL INTESTINE
First part of the small intestine that extends from the pyloric sphincter
of the stomach, wraps around the
head of the pancreas in a C-shape
and ends at duodenojejunal flexure.
Duodenum
PARTS OF THE SMALL INTESTINE
This part begins the digestive process of
breaking down and absorbing nutrients
needed by the body and is also considered the “mixing pot” of the small intestine because of the churning process that takes place there.
Duodenum
PARTS OF THE SMALL INTESTINE
Hormone that is released when the pH of the duodenum needs adjusting
Secretin
PARTS OF THE SMALL INTESTINE
Hormone which is released to aid
in the digestion and absorption of
nutrients such as fats and proteins
Cholecystokinin
PARTS OF THE SMALL INTESTINE
This structure is important for immune support that acts as a barrier to prevent harmful microbes from entering the body.
Duodenum
PARTS OF THE SMALL INTESTINE
This 2nd part of the small intestine begins at the duodenojejunal flexure and is
found in the upper left quadrant of the
abdomen.
Jejunum
PARTS OF THE SMALL INTESTINE
The main function of this part is the absorption of important nutrients such as sugars, fatty acids,
and amino acids.
Jejunum
PARTS OF THE SMALL INTESTINE
The involuntary contraction of smooth muscles that moves nutrients through the digestive system, keeps the food moving gradually forward and is vigorous and quick in the jejunum.
Peristalsis
PARTS OF THE SMALL INTESTINE
The last and longest part of the small intestine.
Found in the lower right quadrant of the abdomen.
Ileum
PARTS OF THE SMALL INTESTINE
Ileum
At the junction between the ileum and the cecum lies the __________, a functional sphincter formed by the circular muscle layers of both the ileum and cecum.
ileocecal valve
This valve that is located in between the ileum and cecum prevents a reflux of the bacteria-rich content from the large intestine into the small intestine.
ileocecal valve
Food spends the most time in the _____, where the most water and nutrients are absorbed, and its peristaltic contractions are slower.
Ileum
This part of small intestine is responsible for :
- Enzymatic cleavage of nutrients
- Absorption of vitamin B12 (with intrinsic factor from the stomach), fats (especially fatty acids and glycerol) and bile salts
- Immunological function (access and transfer of antigens)
Ileum
It is the last part of the gastrointestinal (GI) tract. Also called the large bowel, is where food waste is formed into poop, stored, and finally excreted.
large intestine
An intestine that includes the colon, rectum and anus.
large intestine
Its function is to dehydrate what’s left of the food and form it into stool by slowly absorbing water and electrolytes as its muscle system
moves the waste along.
large intestine
PARTS OF THE LARGE INTESTINE
This pouch, the first 6 inches of the colon, is also the widest portion of the large intestine
Cecum
PARTS OF THE LARGE INTESTINE
It absorb fluids and salts that remain after completion of intestinal digestion and absorption and to mix its contents with a lubricating substance, ______.
Cecum
mucus
PARTS OF THE LARGE INTESTINE
The internal wall of the _______ is composed of a thick mucous membrane, through which water and salts are absorbed
Cecum
PARTS OF THE LARGE INTESTINE
the second part of the large intestine,
continuing from the cecum that is about 20–25 cm (7.8–9.8 in) long
Ascending colon
PARTS OF THE LARGE INTESTINE
It absorbs the remaining water and nutrients from indigestible matter, and solidifies it to form stool.
Ascending colon
PARTS OF THE LARGE INTESTINE
the longest and most mobile part of the colon that runs from the right to the left of the abdomen and connects the end of the ascending colon to the start of the descending colon.
Transverse colon
PARTS OF THE LARGE INTESTINE
It absorbs water and salts from indigestible
food matter, making it easier for waste products to move through the body.
Transverse colon
PARTS OF THE LARGE INTESTINE
It begins at the end of the transverse colon and
moves material down the left side of the
abdomen about 10–15 cm (3.9–5.9 in) long.
Descending colon
PARTS OF THE LARGE INTESTINE
It stores stool before this moves to the next
compartment — the sigmoid colon.
Descending colon
PARTS OF THE LARGE INTESTINE
The last part of the colon that looks like an S-shaped tube that hangs off of the descending colon and leads to the rectum.
Sigmoid colon
PARTS OF THE LARGE INTESTINE
It transports fecal matter from the descending
colon to the rectum and anus and absorb water, vitamins, and other nutrients from the feces, before they are moved to the rectum.
Sigmoid colon
This structure is at the end of the large intestine that makes up the last 6 inches or so, just before it turns into the anal canal.
Rectum
This is the last stop on the food’s journey through the gastrointestinal (GI) tract before it exits. As food waste passes from the colon into your _____, it collects there until nerves trigger the urge to poop.
rectum
The primary function of this structure is to collect and hold the fecal matter until it’s time to release it. It relaxes and stretches to accommodate the waste as it gradually comes in from the colon.
rectum
This is the end of the large intestine, where food waste completes its journey
through the digestive tract and makes its exit.
anus
Muscles, nerves, and mucous membranes in this structure work together to make healthy bowel movements that can be controlled. They also work to keep the it closed to infections coming in from the outside.
anus
This facilitates the bowel movements. Nerves and muscles surrounding the it coordinate to tell you when you need to poop, while allowing you to hold it in until you’re able to reach a toilet.
anus
