Digestive System - nwtech.k12.wa.us · Digestive System • The digestive system consists of the...
Transcript of Digestive System - nwtech.k12.wa.us · Digestive System • The digestive system consists of the...
Digestive System
Digestive System
• The digestive system consists of the organs that make up the alimentary canal.
• The digestive system performs these functions:
▫ Physically breaks down food into smaller pieces
▫ Chemically breaks down food into fat, carbohydrates, and protein
▫ Absorbs nutrients into the blood for use in the body
▫ Helps maintain the proper amount of water, electrolytes, and other nutrients in the body
▫ Eliminates waste products
Connections to other systems….
• What kind of MUSCLE makes up the organs of the
digestive system?
• Which division of the NERVOUS system controls the
major organs of the digestive system?
• Voluntary movements like chewing?
• Involuntary movements like a churning stomach?
Mouth
• Food enters the alimentary canal,
and the digestive system
• Mastication
• Bolus
Pharynx
• Pharynx
• The pharynx can carry both air
and food.
• Epiglottis
Esophagus
• Esophagus
• Peristalsis
• Food exits the esophagus into the
stomach by way of the Cardiac
Sphincter. The cardiac sphincter is a
one-way valve that allows food to
enter the stomach, but keeps stomach
acid from entering the esophagus (if
everything is working right…)
Peristalsis explained
• http://www.youtube.com/
watch?v=rJS-Kh5wCQU
Normal Esophagus vs Barrett’s Esophagus
The stomach (as illustrated by Tokeru
Kobayashi, World Champion Hotdog eater)
Empty, the stomach is about the same size as your fist.
However, the stomach can expand to over 20 times its original size!
Stomach
• Saclike, muscular organ that
receives the bolus from the
esophagus
• Cardiac sphincter
• Chyme
• Pyloric sphincter
Small Intestine
• Most of the digestive products
pass into the bloodstream in the
small intestine.
• Digestion is completed in the
small intestine
• Next the chyme passes into the
large intestine.
Large Intestine and Anus
• Most of the water from ingested
food is absorbed back into the
bloodstream in the large
intestine.
• Escherichia coli (E-coli).
• Rectum
• Anus
• Defecation.
Accessory Organs of the Digestive System
• Three accessory organs carry
digestive juices to the
digestive tract:
▫ pancreas
▫ liver
▫ gallbladder
Constipation
• Risk factors may include:
• Being an older adult
• Being a woman
• Being dehydrated
• Eating a diet that's low in fiber
• Getting little or no physical activity
• Taking certain medications, including
sedatives, narcotics, some antidepressants
or medications to lower blood pressure
• Having a mental health condition such as
depression or an eating disorder
• Blockage or fissure
• Diabetes
• Hypothyroidism
• Chronic constipation is infrequent bowel
movements or difficult passage of stools
that persists for several weeks or longer.
• Constipation is generally described as
having fewer than three bowel movements
a week.
• Though occasional constipation is very
common, some people experience chronic
constipation that can interfere with their
ability to go about their daily tasks. Chronic
constipation may also cause excessive
straining to have a bowel movement and
other signs and symptoms.
• Treatment for chronic constipation depends
in part on the underlying cause. However, in
some cases, a cause is never found.
Ulcer
• An ulcer is an open sore on the lining of the digestive tract.
• The main cause is stress or bacteria known as Helicobacter pylori (H. pylori), either of which increases the amount of stomach acid being produced. As a result, damage to the lining of the digestive tract occurs.
• Symptoms include burning pain and indigestion.
• Treatment involves antacids, reducing stress, and avoiding caffeine, alcohol, and tobacco. If the ulcer is caused by bacteria, antibiotics may also be used.