Transcript AP Digestive System

Digestive System
By Nicole Bacigalupo, Jenna Gurklis, Carlos
Vasquez, Billy Hope, Charline Angelet
Function of the Digestive System
The function of the digestive system
is digestion and absorption.
Digestion is the breakdown of food
into small molecules, which are then
absorbed into the body.
The digestive tract is a continuous
tube with two openings - the mouth
and the anus.
Mouth
● Receives food and begins digestion by
cutting the food into pieces (mechanical
digestion) and and mixing it with saliva
(chemical digestion)
● Saliva consists of 4 enzymes:
○ Salivary amylase: breaks down starch → releases
maltose sugar molecules
○ Lysozyme secretion: breaks down carbohydrates in cell
walls of bacteria that are coming in
○ Lingual lipase: breaks down fat
Salivary Glands
➔Saliva fabricator
◆ Moistens food
◆ Binds the particles
◆ Initiates chemical digestion of carbohydrates
◆ Aids in cleansing mouth and teeth
➔2 cell types in secretion: serous and mucous
◆ Serous produce watery fluid with digestive enzyme
amylase
◆ Mucous produce thick liquid mucus binding food and
Pharynx
● Posterior cavity that connects mouth with esophagus
● Doesn’t digest food, but is used for swallowing
● Structure :
○
Nasopharynx
○
Oropharynx
○
Laryngopharynx
● Swallowing has 3 stages:
Esophagus
★
The esophagus is a muscular tube connecting the throat with the stomach.
★ The upper esophageal sphincter is a bundle of muscles on top of the
esophagus the UES are under conscious control like when breathing, eating,
belching, and vomiting.They keep food and secretions from going down the
windpipe.
★ The lower esophagus sphincter also has bundle of muscles. When the LES is
closed it prevents acid and stomach from traveling backwards to the
stomach.
★ The LES is not under conscious control.
Stomach
The stomach is a muscular organ that’s located on the left side of the upper
abdomen. The stomach’s function is to
Expand to temporarily store food.
Churning the stomach muscles so that it physically breaks down the food.
releases acids and enzymes for the chemical breakdown of food.
The stomach releases food into the small intestine in a controlled and
regulated manner.
Small Intestine
The small intestine is only about as big around as a middle finger. The small
intestine is a muscular tube with three parts. These parts work together to
provide the following functions of the small intestine:
The duodenum breaks down the food.
The jejunum and the ileum absorb nutrients and send them into the bloodstream
The inner lining of the small intestine is folded back and forth to increase
surface area for better nutrient absorption.
These folds create microscopic finger-like projections that are called villi.
Over 95 percent of ingested carbohydrates and proteins are absorbed here
Liver
A healthy liver does the following
Regulates the composition of blood (amounts of sugar, also known as glucose,
protein, and the fat that enters the bloodstream.)
Removes toxins from the blood.
Processes the nutrients absorbed by the intestines during digestion, converts
them into forms that can be used by the body.
Stores nutrients such as vitamin A, iron, and other minerals.
Produces clotting factors, which are the chemicals needed to help blood clot.
Breaks down (metabolizes) alcohol and many drugs.
Creates bile
Gallbladder
➔“Pear-shaped sac on liver’s
inferior surface”
➔Important in digesting fats
correctly
➔Receives bile created by liver
◆ Concentrate the bile and blend with
salts and enzymes
◆ Releases to small intestines
➔Connects to cystic duct
Enzymes of the Pancreas
Pancreas
➔Part of digestive and
endocrine system
➔Associated with small
intestines
➔Secretes “pancreatic juice”
◆ Produced by cells - “pancreatic
acinar”
◆ Cluster and release
◆ Contain enzymes digesting
Pancreatic amylase
Split molecules of starch or glycogen into
double sugars (disaccharides)
Pancreatic lipase
Fat-digesting enzyme; breaks triglyceride
molecules into fatty acids and glycerol
Nucleases
Enzymes that break down nucleic acid
molecules into nucleotides
Trypsin, chymotrypsin,
carboxypeptidase
Protein-splitting enzymes
Large intestine
1. The intestines are an extended, tube running
from the stomach to the anus.
2. The intestines include the small intestine,
large intestine, rectum.
3. The large intestines are the final stages of
digestion.
4. Its task is to absorb nutrients and water
while converting ingested food into feces.
Rectum and Anus
Final sector of the digestive system, performing the act of
defecation, or ridding the body of waste
After being produced by the rest of the digestive system,
stool moves from the descending colon into the rectum
Rectum informs the body that stool needs to be passed
The anus, the opening through which the stool passes,
Body System and Homeostasis
➔ Maintains homeostasis by breaking food down into a chemical form that can
be taken in by the body.
➔ Works closely with circulatory system
◆ Distributes absorbed nutrients throughout body
➔ Works with integumentary system
◆ Intake of vitamin D - absorbing calcium from food particles
➔ Works with lymphatic system
◆
Absorbs fats and fat-soluble vitamins from digestive system
Questions
➔What are the two main functions of
the digestive system?
➔What organ receives food and begins
the digestive process?
➔What organ is used for swallowing?
➔Which organ creates bile?
➔What three systems work closely with
the digestive system?
Diseases
Colon (Large intestine) diseases & conditions
There are many diseases and conditions
that are associated with the colon. Like
colorectal cancer that occurs in the
colon.
It is one of the most common causes of
cancer cancer associated death. The
american cancer society estimates there
will be 93,090 new cases of colon cancer.
And one out of 20 will get colon cancer
in their lifetime
But what happens is that these things
called polyse are an abnormal growth
tissue. There noncancerous tumors but
sometimes can turn into cancer
You have a greater chance of getting polyps if you are
● Age over 50
● Have a family member with polyse
● Have had polyse before
Esophagus
The most common problem with
the esophagus is
gastroesophageal fluid
disease (GERD) it happens
when a band of muscle at the
end of your esophagus does
not close properly. Over time
this can lead to problems
like heartburn and cancer.
Celiac Disease
Celiac disease is a digestive and autoimmune disorder that results in damage
to the lining of the small intestine when foods with gluten are eaten. Gluten
is a form of protein found in some grains. The damage to the intestine makes
it hard for the body to absorb nutrients, especially fat, calcium, iron, and
folate.
When people with celiac disease eat foods containing gluten, their immune
system forms antibodies to gluten which then attack the intestinal lining.
This causes inflammation in the intestines and damages the villi, the hairlike structures on the lining of the small intestine. Nutrients from food are
normally absorbed by the villi. If the villi are damaged, the person cannot
absorb nutrients properly and ends up malnourished, no matter how much he or
she eats.
Symptoms: Digestive problems, severe skin rashes, iron deficiency,
musculoskeletal problems, growth problems (in children) and seizures
Gallstones
hard particles that develop in the gallbladder
Cause :
Bile contains too much cholesterol/bilirubin
Gallbladder doesn’t empty enough/completely
2 types
Cholesterol stones, made of cholesterol
Pigment stones, made of bilirubin
Risk groups
Gallstones
Symptoms (don’t always occur, asymptomatic gallstones)
Abdominal pain (+5 hours)
Nausea and vomiting
Fever
Jaundice (skin/eye is yellow)
Tea-colored urine, light colored stools
Treatment
If no symptoms occur → no treatment needed
Dysentery (Billy)
Dysentery is an inflammation in the intestines resulting in extreme diarrhea containing
blood and/or mucus. Dysentery is dangerous in that it quickly removes bodily fluids
necessary for functions to continue. It can be detected before severity from:
Painful stomach cramps
A high temperature (generally around 100F)
Loss of appetite
Weight loss
Dehydration
In industrialized countries, dysentery is often much less serious and easily treatable.
However, it is extremely harmful in third world countries due to:
Dysentery (cont.)
There are two main types of dysentery.
Bacillary dysentery,
which is caused by a bacteria called shigella. This type is most
common in industrialized areas such as the United States and various European countries.
Bacillary is the most common type of dysentery.
Causes: poor hygiene, sex involving anal contact
Amoebic dysentery, which is caused by an amoeba called Entamoeba histolytica. This type is
most common in the tropics. Amoebic dysentery is much more infective than Bacillary due to
cysts that come out inside or attached to the stool.
Causes: poor hygiene, sex involving anal contact, contaminated food/water, Amoebic
cysts
Dysentery is an extremely infectious disease, which constitutes its main danger. It tends
to be less common and drastic in industrialized countries because of a higher average of
cleanliness and sanitation. In third world countries, if not combatted, it can cause
serious damage to local communities.
➔
Cirrhosis of the Liver
➔
Cirrhosis = slow disease in which liver’s healthy
tissue is replaced with scar tissue resulting in
dysfunction of the liver
➔ Scar tissue prohibits blood flow through liver ➔
◆
Slowed processing of nutrients, hormones, and
toxins
◆
Slowed production of proteins fabricated by liver
Symptoms of cirrhosis (not limited to)
◆
Fatigue
◆
Yellowing skin / itchy skin
◆
Fever
◆
Light stool / blood in stool
◆
Bruises
◆
Fluid retention (swelling)
Diagnosis procedures
◆
Physical exam
◆
Blood test
◆
CT scan (computerized tomography scan)
◆
Biopsy
◆
Surgery
●
Laparoscopy exam
Prevention
◆
Avoid alcohol
◆
Maintain healthy eating habits
◆
Avoid uncooked foods (especially
shellfish)
◆
Protected sex
➔
➔ Causes of cirrhosis (not limited to)
◆
Cystic fibrosis
◆
Glycogen storage disease
◆
Alpha 1 antitrypsin deficiency
Facts
◆
Form of “liver
disease”
◆
Mostly results
from alcohol
abuse
◆
12th leading
cause of death
◆
1 in 10 diagnosed
Introduction to the Digestive System
Kahoot
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Diagram Labeling
Use your word bank to
label the diagram of the
digestive system
Anus
Gallbladder
Pharynx
Pancreas
stomach
salivary glands
Esophagus
Rectum
mouth
Liver
Small intestines
Large Intestines