Transcript The Digestive System 2.04 Understand the Digestive System

DIGESTION
The process of changing complex solid foods into
simpler soluble forms which can be absorbed by
body cells.
BOLUS – soft, pliable ball – created from
chewing and addition of saliva – it slides down
esophagus
PERISTALSIS – wavelike motions, moves food
along esophagus, stomach and intestines
Structures of the digestive system
Digestive system

Also known as:




Alimentary Canal
Digestive Tract
Gastrointestinal
Tract
 Upper GI
 Lower GI
Over 30’ in length
from mouth to anus
3
Structures of the digestive system
Primary structures





Mouth
Esophagus
Stomach
Small intestines
Large intestines
Accessory structures






Tongue
Teeth
Salivary glands
Pancreas
Liver
Gall bladder
2.07 Remember the structures of the
digestive system
4
Structures of the digestive system
Mouth
 (buccal cavity)






Tongue
Teeth
Salivary Glands
Palate
Uvula
The physical
breakdown of food
begins here
first…digestion
begins in the
mouth
5
Structures of the digestive system
Tongue



Attached to floor of
mouth
Made of skeletal
muscle attached to
four bones
Taste buds on the
surface
 Sweet
 Sour
 Bitter
 Salty
6
Structures of the digestive system
Teeth

Primary (deciduous)


20 “baby teeth”
Secondary
(permanent)

32 “adult teeth”
7
Structures of the digestive system

Salivary glands

Parotid gland




Largest salivary gland
Ptyalin in saliva converts
starches to simple
sugars causes the initial
chemical breakdown.
Submandibular gland
Sublingual gland
2.07 Remember the structures of the
digestive system
8
Structures of the digestive system
Palate – separates
the mouth from the
nasal cavity


Hard
Soft
Uvula

Flap of skin
hanging in the
back of the throat
2.07 Remember the structures of the
digestive system
9
Structures of the digestive system

Pharynx (throat)



Nasopharynx
Oropharynx
Hypopharynx
2.07 Remember the structures of the
digestive system
10
Structures of the digestive system

Esophagus


Muscular tube, 10”
long
Connects the pharynx
and stomach
11
Structures of the digestive system

Stomach




Upper left
quadrant of the of
the abdominal
cavity
Fundus
Body
Pylorus
2.07 Remember the structures of the
digestive system
12
Cardiac sphincter - controls passage of food into
stomach and keeps it from going back into the
throat.
PYLORIC SPHINCTER – valve, regulates the
entrance of food into duodenum
RUGAE – mucous coat lining of stomach in folds
when the stomach is empty
Stomach has muscular coat that allows it to
contract (peristalsis) and push food into the small
intestine
Structures of the digestive system

Small intestines
– main function is
absorption of NUTRIENTS

Duodenum



Jejunum



First segment
12’ long
Second segment
8’ long
Ileum


Third segment
10-12’ long
15
Structures of the digestive system

Large intestines



Approximately 2” in
diameter
5’ long
Responsible for
elimination of waste
and absorption of
water
16
Functions of the digestive system
Teeth


Define mastication.
How is the tooth’s shape
related to its function?

Incisors

Cuspids

Bicuspids

Molars
2.08 Understand the functions and disorders of
the digestive system
17
Accessory Organs of Digestion
PANCREAS




Located behind stomach
Exocrine function – secretes digestive
enzymes to break down food.
Also has endocrine function.
Feather shaped organ
Functions of the digestive system
Liver

Produce and store glucose in the form of
GLYCOGEN

Detoxify alcohol, drugs and other harmful
substances

Manufacture blood proteins
Manufactures bile
Store Vitamins A, D and B complex



Connects to gall bladder and small intestine
by ducts
19
Functions of the digestive system
Gallbladder



Small muscular green
sac that secretes and
stores bile
Located in the right upper
quadrant of abdominal
cavity.
When fatty foods
digested, bile released by
gallbladder
20
Functions of the digestive system








Large intestine
CHYME – semi-liquid food and
gastric juices
Approx 2” in diameter
Also called the colon
CECUM – lower right portion of large
intestine
APPENDIX-blind sac attached to
cecum, having no known function
RECTUM – last portion of large
intestine
ANUS – external opening of the Lg.
intestine
21
Disorders of the digestive system

Anorexia

Anorexia nervosa

Decreased or poor
appetite


Symptom

Eating disorder
characterized by
refusal to eat
Psychiatric disorder
Bulimia nervosa
(binge eating and
purging) is a
psychiatric disorder
as well
22
Obesity is one of the common eating disorders in the United
States.
A person is considered obese if their BMI (body mass index
is above 30.
How to calculate BMI:
(weight in pounds * 703 )
BMI =
( lbs/inches² )
————————————
height in inches²
BMI
Weight Status
Below 18.5
Underweight
18.5 -24.9
Normal
25 - 29.9
Overweight
30 & Above
Obese
Disorders of the digestive system
Caries

Cavities
How often should you
brush and floss?
2.08 Understand the functions and disorders of
the digestive system
24
Disorders of the digestive system
Cholecystitis

Inflammation of the gall bladder

Sx = pain that radiates to right
shoulder…frequently after
eating fatty foods

How is it treated? cholecystectomy

Cholelithiasis – gall stones
25
Disorders of the digestive system
Cleft palate

Hard and/or soft
palate doesn’t close
completely during
fetal development

Problems swallowing
Surgery needed to
repair

2.08 Understand the functions and disorders of
the digestive system
26
Disorders of the digestive system
Cirrhosis
Chronic, progressive
disease of liver
Normal tissue replaced by
fibrous connective tissue.
75% caused by excessive
alcohol consumption (also
caused by Tylenol use)
27
Disorders of the digestive system
Constipation
 When defecation delayed,
feces become dry and
hard
 Rx – diet with cereals,
fruits, vegetables,
(roughage), drinking
plenty of fluids, exercise,
and avoiding tension
2.08 Understand the functions and disorders of
the digestive system
28
Disorders of the digestive disorders
Diarrhea

Loose, watery,
frequent bowel
movements when
feces pass along
colon too rapidly

Caused by infection,
poor diet,
nervousness, toxic
substances or
irritants in food
29
Disorders of the digestive disorders
Gastroenteritis





Inflammation of mucous
membrane lining of
stomach and intestine
Common cause = virus
Sxs – nausea, vomiting,
diarrhea for 24-36 hours
Complication = dehydration
Prevention…good
handwashing
30
Disorders of the digestive system
Gastroesophageal
reflux disease
(GERD)


Reflux of gastric acid
into the espohagus
Sx – burning
sensation that often
worsens with laying
flat…gets better
with sitting up or
raising head of bed
31
Disorders of the digestive system
Hepatitis



Acute
Chronic
Hepatitis A
(contaminated food or
water borne), B
(blood borne), C
(blood borne), D, E
2.08 Understand the functions and disorders of
the digestive system
32
Disorders of the digestive system
Irritable bowel
syndrome
 Cause unknown
Sx – abdmonial pain, bloating,
diarrhea and constipation
(alternating)
Trt – lifestyle and diet changes,
medication
2.08 Understand the functions and disorders of
the digestive system
33
Disorders of the digestive system
Chron’s Disease
and Ulcerative
Colitis
• Autoimmune disorders
• Type of inflammatory
bowel disease
• Sxs – abdominal pain,
severe diarrhea,
malnutrition
Disorders of the digestive system

Peptic ulcer - Sore or
lesion that forms in the
mucosal lining of the
stomach



Gastric ulcers in the stomach
and duodenal ulcers in the
duodenum
Cause – H. pylori (bacteria) is
primary cause
Lifestyle factors that
contribute: cigarette smoking,
alcohol, stress, certain drugs
35
Relevance of nutrition to the
digestive system

Vitamins

Fat soluble


Vitamins A, D, E, K
Water soluble

Vitamins C, B

Electrolytes






Proteins aid in wound

Calcium
Chloride
Magnesium
Phosphorus
Potassium
Sodium
healing

Carbohydrates such as
bread and pasta offer
quick energy
36