Download 19 Digestive flashcards

Digestive (GI) System
What are the two kinds of digestion?
Mechanical
Chemical
Which layer of the digestive tube contains lots
of elastic fibers, blood vessels, and lymphatic
vessels?
Submucosa
The hepatic portal system has two distinct
capillary beds separated by a portal vein. The
functions of these two capillary beds are what?
The first picks up nutrients and the second
delivers these nutrients to liver cells.
What structure flaps over the glottis when we
swallow food?
Epiglottis
Which vitamin requires intrinsic factor in
order to be absorbed?
Vitamin B12
What are the three main characteristics of the
large intestine?
1) It absorbs much of the water and salts
2) It contains the ascending, transverse, and
descending colon.
3) It contains abundant bacteria.
What are the four main characteristics of the
small intestine?
It is the site of nutrient absorption
It breaks down fats, proteins, and carbohydrates
Breakdown products of fats enter its lacteals.
Its walls secrete most of the digestive enzymes
that are active in its lumen.
Where does food first encounter proteinsplitting enzymes?
Stomach
What is the function of the gallbladder?
Storage (not secretion!) of bile
When the acidic contents of the stomach enter
the normally alkaline duodenum, what
hormone is released that causes the pancreas to
secrete bicarbonate?
Secretin
What is the semi-fluid paste called that is a
result of the food in the stomach being
repeatedly squeezed and mixed with gastric
juice?
Chyme
What are four characteristics of the
duodenum?
1) It receives chyme from the stomach.
2) It is within the body cavity with the ileum or
jejunum (not retroperitoneal).
3) It is shorter than either the ileum or jejunum.
4) It is the site of action of liver and pancreas
secretions.
What are the five the primary functions of the
stomach?
1. Store Food, so it can be slowly released into a
small intestine.
2. Churns food into a paste (chime) by
mechanical means
3. Kill bacteria.
4. Starts digestion of proteins.
5. Some absorption of water, alcohol
Does it dehydrate food materials before passing No
them to the small intestine?
Does it store food for later use in the form of
fat?
No
What is the terminal portion of the small
intestine called?
Ileum
Which layer of the digestive tract is responsible
for the peristaltic waves that propel materials
from one portion to another?
muscularis externa
Absorption
Of the basic digestive processes, the one in
which nutrients enter capillaries is called what?
What is the only role of the levator ani muscle
in defecation?
What is the correct sequence of layers in the
wall of the alimentary canal, from internal to
external?
It lifts the anal canal superiorly around the feces.
mucosa, submucosa, muscularis, serosa
What is the digestive organ primarily
responsible for the absorption of water?
Large intestine
Why are bacteria are abundant in the large
intestines, but not in the small intestines or the
stomach?
Secretions of parietal cells kill bacteria in the
stomach, and the Ileocecal valve prevents the
bacteria in the large intestines from migrating up
into the small intestines.
What is the only function of the greater
omentum?
Stores fat
The epithelium that lines the stomach and
intestines is simple columnar. What are the
basic functions of this epithelium?
secretion and absorption
Digestion of what food type would be affected
the most if the bile—secreting liver were
severely damaged?
Lipids
What are three functions of the liver?
1) detoxification of poisons
2) picking up and processing of nutrients from
the portal blood
3) storage of some vitamins
Does it produce digestive enzymes?
No
What cells secrete hydrochloric acid and
digestive enzymes which kill bacteria in the
stomach?
PARIETAL CELLS
What cells secrete an enzyme to digest protein?
CHIEF CELLS
What is the function of all the c cells in the
stomach?
To make mucus to prevent the stomach from
digesting itself
Which cells secrete digestive enzymes in the
pancreas?
Acinar cells
Which region of the pancreas secretes insulin?
Islets of Langerhans
Functions of the digesting system.
1. INGESTION Taking food in by mouth 2.DIGESTION to
break food down into simple molecules (Mechanical:
churning of food in the stomach, manipulation of food with
tongue, tearing and grinding with teeth. (Chemical:
breakdown of food with hydrochloric acid) 3.ABSORPTION
nutrients enter capillaries 4 DEFECATION to eliminate solid
waste products
Uper GI= stomach and areas superior, lower GI = areas
inferior to the stomach
Regional terms of digestive system.
Palate. Hard Palate = bone. Soft Palate = soft tissue.
Roof of the mouth is also known as ?
The flap of skin under the tongue at the midline.
Lingual Frenulum
Good Range of Motion
Fibers in the tongue go in all direction and have no
fascicles, allowing what?
What is the primary function of salivary glands?
How many deciduous teeth (baby teeth) are there?
To prevent bacterial growth
20
How many incisors are there?
8: for cutting like scissors
How many canines are there?
4: for tearing
How many pre-molar bicuspids are there?
(Bicuspids = 2 roots) 8: for chewing, some tearing.
How many molars are there?
12
Gums are also known as what?
Gingiva
What is periodontitis?
The major cause of tooth loss, it is when the gums pull
away from the tooth and the bacteria extends down to
the periodontal ligament.
What is the hardest substance in your body?
The enamel
What is a rhythmic contraction to push something
along by smooth muscle contraction?
Peristalsis
A back-and-forth squeezing of the muscle to grind up
food. Food moves forward then backward a little, then
forward again. Function is to churn up the food inside.
Segmentation
The esophagus goes through the thoracic cavity and
empties to the stomach through this. IT is a thickening
of the muscularis externa
Cardiac Sphincter.
What are the regions of the stomach?
1. Cardiac region. 2. fundus 3. body 4. pyloric region.
5. pyloric sphincter.
What are the folds that allow the stomach to expand?
Rugae
The parietal cells in the stomach secrete a substance
called?
Intrinsic factor.
What vitamin requires intrinsic factor in order to be
absorbed
B12
Third layer of the muscularis externum that churns
food.
Oblique Layer
.
This describes the phenomena where acid from the
stomach leaks into the esophagus, and causes erosion of
the lining. This is a cause heartburn.
Acid reflux
How is Helicobacter pylori infections spread?
Vitamin B12 requires intrinsic factor in order to be
absorbed.
Why do people vomit?
Because the cardiac sphincter is not a true sphincter, it
doesn’t close well, which allows us to throw up.
Part of the stomach, protrudes through esophageal
hiatus, that causes pain and difficulty swallowing.
HIATAL HERNIA
This is where most digesting and absorption takes
place.
Small Intestine.
Folds in the small intestine.
Plicae Circularis
What is a Brush Border?
Epithelial cells in each villi known as microvilli.
Duodenum, jejunum, ileum
Regions of the small intestine.
It is the site of action of liver and pancreas secretions.
DUODENUM
an endocrine gland, and also participates in digestion.
Most of the digestive enzymes are made here. It also
produces bicarbonate (from a hormone called secretin)
to increase the pH (decrease the acidity) of the chyme
coming from the stomach. If there is too much acid
there, get a duoduneal ulcer
What happens when bile salts crystallize?
Pancreas
Gall Stones Form.
What are treatments for gall stones?
Gall bladder is usually taken out.
This is the part of the small intestine where most
digestion and absorption occurs
JEJUNUM
Much of the absorption takes place here.
Ileum
Crypt of Lieberkuhn
This is where the new epithelial cells come from, and
they are pushed upwards into the villi to replace the
digested cells.
Its function is to absorb breakdown products of fat
Lacteals
Its an autoimmune disease of the GI tract, and
commonly affects the small intestine. It is usually
caused by genetics, and commonly occurs to males in
their 20’s
Genetic autoimmune disorder of the small intestine,
causing chronic diarrhea. When the person is allergic to
gluten. Causes destruction of microvilli and villi. It is
characterized by having pale, loose and greasy stools
(steatorrhoea) which are voluminous and malodorous.
It often presents with abdominal pain and cramping,
abdominal distension, and sometimes mouth ulcers.
Without adjusting the diet, coeliac disease leads to an
increased risk of adenocarcinoma (small intestine
cancer).
Crohns Disease.
Celiac disease
How do you get intestinal gas?
When there are certain carbohydrates that are not
digested, and are instead eaten by bacteria in the
intestine.
a disease which attacks the large intestine, preventing
water absorption, and can be fatal in 24-48 hours.
Cholera
Regions of the Large Intestine
Cecum, Ascending colon, Transverse colon,
descending colon, sigmoid colon, rectum, anus
This is below the cecum and is a lymph node, and
contains E Coli
Appendix
This muscle allows gas to pass when relaxed, and when
contracted allows fecal matter to release.
Levator Ani muscle
This muscle also controls defecation.
Internal and External anal sphincter.
How long does it take food to be processed through the
entire digestive tract?
is a group of inflammatory condition of the colon and
small intestine.
An intermittent disease, with periods of exacerbated
symptoms, and periods that are relatively symptomfree. The main symptom is constant diarrhea mixed
with blood, of gradual onset. Colectomy (partial or
total removal of the large bowel through surgery) is
occasionally necessary, and is considered to be a cure
for the disease.
Symptoms of this are chronic abdominal pain, bloating,
and alteration of bowel habits in the absence of any
detectable organic cause. May manifest as diarrhea or
constipation or may alternate between the two
24 hrs
Inflammatory Bowel Disease (IBD)
Ulcerative Colitis
IRRITABLE BOWEL SYNDROME (IBS)
Sigmoidoscopy
What is an accurate test for colon cancer?
varicose veins in the rectum.
Hemorrhoids
This is the largest internal organ of the body, located on
the right side, below the diaphragm, and extends below
the costal margin (can palpate). It has many functions
and is the most complex organ except the brain, and as
over 500 known functions.
The Liver
What are the two main sources of blood for the liver?
The hepatic artery, and the Hepatic portal system.
What is the functional unit of the liver?
Liver Lobules
Function of Hepatocytes
Detox of poisons, picking up and processing of
nutrients from the portal blood, and storage of some
vitamins.
What are Kupffer Cells?
They are macrophages. As blood flows through the
sinusoids, they phagocytize old erythrocytes. The
released Hgb is given to the hepatocytes, which convert it
to bilirubin, one of the main components of BILE.
What is Hepatitis?
Infection of the liver.
What are the blood tests for liver function?
Why is it that liver transplant patients and donors end
up successful?
Congenital condition in which the major visceral
organs in the thorax and abdomen are reversed or
mirrored from their normal positions.
Gamma-glutamyl transferase, Lactate dehydrogenase,
Prothrombin time.
Because the liver is able to regenerate
Situs Inversus