Download Diegestion2017 - Lindbergh School District

Digestive
System
1. Teeth
2. Epiglottis
3. Liver
4. Gall bladder
5. Common bile duct
6a. Ascending colon
6b.Transverse colon
6c. Descending colon
6d.Sigmoid colon
6e. Cecum
7. Appendix
8a. Parotid salivary gland
9. Submandibular salivary gland
8c. Sublingual salivary
. Tongue
10. Esophagus
10.5 Cardiac sphincter
11. Stomach (fundus of)
12. Duodenum
13. Pancreas
14a. Jejunum
14b. Ileum
15. Rectum
Anus and anal
sphincter are not
labeled on your
diagram, but you
can add them.
11.5 – Pyloric
sphincter
Phases of Digestion:
1.Cephalic – “Think” about it!
2.Physical – Mastication (chewing)
3.Gastric – Stomach (Hydrochloric
acid and Pepsin)
4.Intestinal – Intestines; inhibits
stomach secretions (negative
feedback.)
Digestive Tract (Alimentary canal)
1.Gastrointestinal canal =
“gastro” stomach and
“intestinal” small and
large intestines only.
2. Digestive Tract extends
from mouth to anus – like
a donut hole, it is an
EXTERIOR part of your
body.
General
Anatomy
Practice
1
Organic Compounds that are digested:
1.Carbohydrates
2. Protein
3. Lipids (Fats)
4. Nucleic Acids (DNA & RNA)
CARBOHYDRATES
 Sugar vs. Fiber
Immediate energy use
(brain’s main energy)
Starch vs. cellulose – is it still there
in the end?
Salivary amylase & pancreatic amylase:
digest starch to monosaccharides.
Protein
 Amino acid subunits (building blocks)
 Used for energy during starvation
 Digested in: - Stomach: HCl & Pepsin
- Small intestine with enzymes from
Pancreas: trypsin, chymotrypsin &
carboxypeptidase.
LIPIDS
 Saturated vs. Unsaturated
 Higher Kcal/gm
Long term energy storage
 Digested via: - Bile emulsification
- Pancreatic lipase
2 Main groups of Digestive Organs
Alimentary Canal (Digestive Tract) :
Mouth, pharynx, esophagus, stomach,
small intestine, large intestine, anus.
Accessory structures: Cheeks, teeth,
tongue, salivary glands, liver, gall bladder and
pancreas.
20 Primary
(baby) teeth
32 Adult teeth
(including the
third molars –
wisdom teeth)
Oral Hygiene Is Important
Don’t use Methamphetamines
Saliva is a good thing!
Antibacterial
Antifungal
Antiviral
Lubrication
3 pairs of Salivary Glands
Parotid glands –
watery saliva, amylase*
 Submandibular glands
– thicker mucus,
amylase*
 Sublingual glands –
mostly mucus, little
amylase*
Amylase begins starch
digestion.

Epiglottis:
Directs
food bolus
down
esophagus
Deglutition (swallowing)
Esophagus




Moves food from
mouth/pharynx to
stomach.
Upper and lower
esophageal*
sphincters
Deglutition –
swallowing
Peristaltic waves
*Cardiac
Pyloric sphincter
Four tunics of the tract
1.Mucosa
2.Submucosa
3.Muscularis
4.Serosa
(peritoneum)
Stomach Anatomy/ Physiology
Cardiac sphincter (6)
Fundus (2)
Pyloric sphincter (9)
Rugae (14)
Pyloric antrum (10)
Body (1)
Greater curvature (4)
Lesser curvature (5)
Hiatal hernias
Hiatal hernia repair –staple
stomach around esophagus.
The
stomach
has many
folds called
Stomach-mechanical & chemical digestion
∞ Mechanical digestion – Peristaltic (mixing) waves from body and
pylorus of stomach.
∞ Chemical digestion -
-Pepsin – enzyme secreted by chief cells as pepsinogen. HCl breaks
pepsinogen to pepsin, which then breaks down proteins.
- Hydrochloric acid (HCl) – secreted by parietal cells; kills microbes,
aids in protein digestion.
-Gastric lipase – begins fat digestion.
Mucus protects stomach from digesting
itself! Stomach is a muscle – meat.
Pepsinogen activated by HCl to
pepsin, which digests protein (muscle.)
the
ust have been
Which came first, HCl,
Pepsin, mucus or
sodium bicarb?
All had to be created
at the same time.
Stomach secretions

INTRINSIC FACTORbinds to Vitamin B12
for small intestine
absorption. Secreted
by Parietal cells.

GASTRIN- hormone
that helps regulate
stomach secretions.
Pancreas
Digests all 4 organic
compounds via:
Trypsin, chymotrypsin - Protein
Carboxypeptidase - Protein
Amylase - Starch
Lipase – Lipids (fats, oils, waxes)
Nucleases – DNA & RNA
Pancreas as an endocrine organ
Blood sugar balanced by
pancreatic hormones:
Insulin: causes sugar
uptake by liver and
muscles
- Glucagon: causes
release of sugar into
blood from glycogen in
liver and muscles.
-
The Liver
Absorbed
nutrients
enter liver
for
processing
Important
for detoxification of
material in
the blood
as well.
Liver from a
human…….
who had liver
cancer.
LIVER FACTS
 Heaviest body organ at ~ 3 lbs.
 Second largest organ of the body.
 Right lobe larger than left lobe
(stomach offset to left)
 Lobes separated by falciform
ligament.
 Gall bladder under right side.
Liver Functions




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

Glycogen (glucose) storage
Protein metabolism
Storage of oil-soluble vitamins, iron and minerals
Removal of toxins, hormones and drugs
Store or secrete compounds into bile
Metabolize thyroid, steroid hormones
Synthesize bile salts using bilirubin
Excretion of bile
Lipid metabolism – synthesizes new cholesterol
and degrades excess cholesterol for bile salts
(fats)
Gall
 Stores bile from
Bladder
liver


Bile emulsifies
(breaks up) fat
globules.
Bile travels down
cystic duct to
common bile duct
SMALL INTESTINE: Major site
of digestion/absorption
Three Divisions:
1. Duodenum (Do-wah-denim or
Do-oh-deenum) 10 inches (25
cm) long; Pancreas &
gallbladder empty enzymes/bile.
2. JEJUNUM: 2.5 meters
nd
(~8 ft) long is 2 part.
Digestions and Nutrient
absorption continues
rd
3
3. ILEUM:
part, ~3.6 meters
(11 ft) long.
Most Bile reabsorption
occurs here.
Attaches to large intestine
at ileocecal sphincter.
Nutrient Absorption in Sm. Intestine
o
o
90% of total nutrient absorption takes place
in the small intestine!
Three design components that increase
surface area:
o
Circular folds
o
Villi
o
Microvilli
Mesentery (connective) tissue
organizes and keeps small intestine
from twisting. Blood vessels and
nervous plexus organized via
mesentary.
Know your gross
anatomy. You will
need to know these
without a word
bank for the test!
.
Small Intestine
 Most
absorption occurs in the
Duodenum & Jejunum
 Fats are absorbed via lymph
tissue called lacteals within the
villi.
Small
intestines
from a
domestic
pig.
Large intestine
(colon)
The ileum dumps
into the cecum
portion of the
colon.
Cecum--------
Large Intestine
(Colon)
Mainly absorbs
excess water from
feces
Vitamins K and
Biotin produced by
bacteria within
colon.
Inside the Colon
Diverticulitis – pockets in
the colon caused by poor
diet (lack of adequate fiber)
that gets infected,
causing fever
and pain!
How much fluid do we excrete
per day in our stool?
NORMAL
(~200 mL)
Cholera

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


Caused by toxin-secreting
strains of Vibrio cholerae
bacteria
Infection occurs by
ingesting contaminated
water or food
Found in sewage and
brackish, standing water
Cholera toxin enters cells in
intestinal epithelium
Massive intestinal salt and
water secretion
How much fluid does someone with
cholera excrete in a day?
NORMAL
(~200 mL)
CHOLERA (~20 L)
What is it called when someone is
excreting that much fluid in their
stool?
Diarrhea
How can diarrhea kill someone?



78 y\o male presents to the ED with 5 days of
loose, watery stool (diarrhea), fever, and
decreased PO intake. On physical exam he is
hypotensive and tachycardic.
So, how can diarrhea kill someone?
Dehydration!

68 y\o female presents with 5 months of
progressive fatigue. Fecal occult blood
testing shows guaiac positive stool.

Until proven otherwise, what is the most likely
diagnosis?
Colon Cancer


Adenocarcinoma of the colon is the third
most common cancer among men and
women in the US (behind lung,
prostate\breast) – 145,000 in 2004
It is the second leading cause of cancer
deaths in the US – 53,000 in 2004
Risk factors for colon cancer
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Age - 90% older than 50
Family history, inherited conditions
Inflammatory Bowel Disease
Race – Blacks have higher incidence and
mortality from colon cancer, cancer more likely
to be right sided
Lifestyle factors - low fiber, high fat diet, obesity,
tobacco, alcohol
Presentation
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Asymptomatic
Iron deficient anemia
Occult GI blood loss
Hematochezia (bright red blood per rectum)
Obstructive symptoms
Change in bowel frequency, stool caliber
What is the key to prevention?


Screening!
Colon cancer almost always develops from
precancerous polyps.
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Fecal occult blood test – once a year
Sigmoidoscopy – every 5 years
Colonoscopy – every 10 years or if either of above
are positive
Treatment for colon cancer


Surgery – partial colectomy, colostomy
depending on site
Medical – chemotherapy, radiation treatment
for rectal cancer
Colostomy
Accessory Organs

Pancreas

Liver

Gallbladder
The Pancreas

Aids in digestion
and metabolism

Exocrine

Endocrine
Exocrine Functions

Pancreatic Juice

Bicarbonate (HCO3)

Lipase

Amylase

Proteases
Endocrine Functions

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
Insulin
Glucagon
Somatostatin
Diabetes Mellitus

25 million people



Type I and II
Various treatments


8% of adolescents have ‘prediabetes’
Insulin
Complications
The Liver


“Cleans” the blood
Produces bile
Liver Lobules
Liver Disease
The Process of Liver Disease…
Normal, Healthy Liver
Cirrhotic Liver
What causes liver disease?

Drugs

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Viruses

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Alcohol
Tylenol
HBC, HCV
Genetics
Obesity Trends* Among U.S. Adults
BRFSS, 1985
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
Source: BRFSS, Behavioral Risk Factor Surveillance System. Accessed on 2.23.09 from http: //www.cdc.gov/brfss/
Obesity Trends* Among U.S. Adults
BRFSS, 1987
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4”
person)
No Data
<10%
10%–14%
Obesity Trends* Among U.S. Adults
BRFSS, 1989
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
Obesity Trends* Among U.S. Adults
BRFSS, 1991
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
Obesity Trends* Among U.S. Adults
BRFSS, 1993
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
Obesity Trends* Among U.S. Adults
BRFSS, 1995
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
Obesity Trends* Among U.S. Adults
BRFSS, 1997
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
≥20%
Obesity Trends* Among U.S. Adults
BRFSS, 1999
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
≥20%
Obesity Trends* Among U.S. Adults
BRFSS, 2001
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
0%–24%
≥25%
Obesity Trends* Among U.S. Adults
BRFSS, 2003
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
0%–24%
≥25%
Obesity Trends* Among U.S. Adults
BRFSS, 2005
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
20%–24%
25%–29%
≥30%
Obesity Trends* Among U.S. Adults
BRFSS, 2007
Obesity Epidemic
(*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person)
No Data
<10%
10%–14%
15%–19%
20%–24%
25%–29%
≥30%
Source: Behavorial Risk Factor
Surveillance System, CDC. 2014
, or 30 percent of the adult
Obesity Epidemic
About
population,
That’s twice what it was in 1980.
Does obesity
Obesity Epidemic
The more overweight you are, the more likely
you will develop

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Heart disease
Stroke
Diabetes Mellitus Type II
Colon, uterine, prostate cancers
Osteoarthritis
Food Suggestions in 1943
Food Suggestions in 1955
Source:
AMA,Evening
1955 Post, 1943
Source:
Saturday
Basic Nutrition
Old Food Pyramid (1992)
Basic Nutrition
New Food Pyramid (2005)
Basic Nutrition
Harvard’s Food Pyramid (2008)
Basic Nutrition – Carbs
What should I know about

Purpose: major source of energy

Source: bread, rice, pasta, cereal, veggies,
fruits, beans, sweets

Absorption: Small intestine

Different Types:


High Glycemic Index
Low Glycemic Index
Carbs = Energy = Sugar
Basic Nutrition – Carbs
vs
Good = Low Glycemic Index = Whole Foods
Whole grains, whole vegetables, whole fruits
Bad = High Glycemic Index = Processed Foods
Refined sugar, corn syrup, sweets, white flour, soda
Interested in these?
•Blood pressure down
•Cholesterol down
Glycemic Index
Result
•Weight down
Low
Glucose
•Heart disease
risk down
•Diabetes
risk down
Moderate
Glucose
High
Glucose
EAT GOOD CARBS!
Value
0-55
56-69
70 & up
Basic Nutrition – Proteins
What should I know about

Purpose: building blocks of
muscle

Source: meat, beans, dairy,
nuts, seeds

Absorption: Jejunum

Different Types:


Lean Protein
Fatty Protein
Protein=Muscle
Basic Nutrition – Fats
What should I know about

Purpose: Storage of Energy

Source: butter, vegetable oil, fried
foods, nuts, cheese, eggs, avocados

Absorption: Ileum

Different Types



Unsaturated Fats
Saturated Fats
Trans Fats
Fat=Energy Storage
Source: American Heart Association
Basic Nutrition – Nutrition Pathology
The wrong way

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Starvation, skipping meals
Excessive exercise
Vomiting, diuretics
Diet pills, caffeine, fad diets
Anorexia and bulemia require
nutritional replacement and
psychiatric counseling
Basic Nutrition – Nutrition Pathology
The right way

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A lifetime of healthy
eating
Eat whole foods from all 5
food groups
Eat 3 meals a day
Exercise
http://www.hsph.harvard.edu/nutritionsource/he
althy-eating-plate/
http://www.glycemicindex.com/
Body Weight Assessment:

BMI is a quick measure of healthy body weight

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Underweight= <18.5
Normal BMI= 18.5-25
Overweight BMI= 26-29
Obese BMI= 30+
Morbidly Obese= 40+
BMI =
Weight in Pounds
(Height in inches)2
x 703
Anorexia Nervosa and Bulemia


Media Images
influence our opinion
of a perfect body
Many young women
take drastic measures
to lose weight or
prevent weight gain
Anorexia Nervosa

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Refusal to maintain normal, healthy body weight
Intense fear of gaining weight or becoming fat
Complications are serious!

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Cardiac: arrhythmias, sudden death
Renal: decreased function and filtration rate
Heme: low Hb, White blood cells, platelets
Endo: amenorrhea, osteoporosis, short stature
Neuro: weakness, seizures
Bulimia Nervosa

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Recurrent episodes of binge eating
Inappropriate compensatory behaviors to
prevent weight gain, such as vomiting,
inducing diarrhea, and diuretic use
These methods of purging can cause
dehydration, electrolyte imbalances, damage
to the esophagus and teeth and even sudden
death
Gastric Bypass Surgery

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Generally performed on
the morbidly obese (BMI
> 40)
OR if weight is causing a
life-threatening or
disabling condition
Over the course of 5
years patients lost an
average of 82% of their
excess weight
Weight can be regainedlifestyle change indicated!