Transcript Digestion 2nd half File

Digestive System
(2nd half)
Enzyme
Salivary
amylase
Pepsin
Place
(of action)
Mouth
Substrate
(molecule)
Products
Starch,
glycogen
Maltose
Peptides
Lipase
Pancreatic
amylase
Maltose
Pancreatic
lipase
Trypsin
Maltase
Simpler
peptides
Origin
(of enzyme)
salivary glands
Enzyme
Place
(of action)
Substrate
(molecule)
Starch,
glycogen
Products
Origin
(of enzyme)
Salivary
glands
Stomach
glands
Salivary
amylase
Mouth
Pepsin
Stomach
Protein
Peptides
Lipase
Sm. Int.
Fats
Glycerol,
fatty acids
Stomach
glands
Pancreatic
amylase
Sm. Int
Starch
Maltose
Pancreas
Pancreatic
lipase
Sm. Int
Fats
Glycerol,
fatty acids
Pancreas
Simpler
peptides
Product of
enzymes from
pancreas and
duodenum
Trypsin
Maltase
Sm. Int
Sm. Int
Peptides
Maltose
Maltose
Two
Glands in wall
glucose
of small int.
molecules
Table 11-2
p. 365
http://www.ed.gov.nl.c
a/edu/k12/curriculum/
guides/science/bio220
1/appendix_A.pdf
Fitness and Nutrition (pg 370-371)
A healthy lifestyle includes good nutrition and exercise
Good nutrition provides
• energy for our body’s needs & essential building materials
Exercise…
• Helps maintain a healthy weight
• Is important for muscle function, including those in the digestive system
• is recommended to treat some digestive disorders (IBS - irritable bowel
syndrome) and prevent others
•
•
a healthy digestive system breaks down food
also need a healthy circulatory system to distribute those nutrients
To maintain a healthy weight (fig 11.13 pg
370) Canada’s Food Guide says:
• eat a variety of foods from all four food groups
–
–
–
–
meats/meat alternatives
milk/dairy
fruits / vegetables
breads/cereals
• Only 30% of the calories to take in should come
from fat
• exercise 2 to 3 times a week
• drink lots of water (approx. 8 glasses daily)
Fitness
• the ability to deal with daily
routine without fatigue
–still have energy left over for
recreation
–implies a healthy
cardiovascular system.
• Regular exercise/physical activity
and good nutrition habits are
necessary to develop a strong
and vigorous body.
Some health benefits of regular exercise
include:
•
•
•
•
•
•
•
•
•
increased lung capacity
increased strength, stamina and endurance
increased coordination, flexibility, balance and agility
improved posture
improved blood circulation
improved mental and physical performance
decreased stress and tension
helps control weight & decreases appetite
decreased total cholesterol and increased HDL (the ‘good’ cholesterol that
clears arteries of plaque).
• Being fit and at a healthy weight contributes to total good health
Weight Loss
• If overweight, many people try to lose weight
• healthy vs unhealthy ways
• A healthy weight loss diet includes:
–eat small amounts from all four food
groups
–cut down fat intake (forces
body to use excess fat)
• exercise more
• drink lots of water
Many ways of
unhealthy weight loss
Fad diets
• most focus on one food/nutrient and exclude others
• eg. Grapefruit diet, protein diet, carbohydrate diet
• dangerous and unhealthy
• important nutrients that the body needs are ignored
• better to change eating behaviours gradually.
– losing 2 lbs. a week is healthy
– more than 2lbs is not healthy, may lead to regain of
weight, and places too much stress on body
Common Eating Disorders (p. 372-373)
• linked to lifestyle and
lifestyle choices.
• our society places great
value on being thin
• results in many quick and
unhealthy weight loss
options.
• more common in women
than in men.(why?)
Anorexia nervosa
• fear of gaining weight.
• very restrictive diet.
• people suffering from this usually weigh only 85% of their normal
mass.
• always see themselves as fat.
• Force-feeding is often necessary, and death can occur
Symptoms include:
• Low blood pressure
• Irregular heartbeat
• Menstruation stops
• Internal organ trouble
• Dry skin
Bulimia nervosa
• binge eating (eat a lot)followed by purging (elimination),
usually accomplished by vomiting or taking laxatives.
• may be associated with anorexia and obesity.
• individuals are concerned with body shape and mass.
Effects include:
• Damage to heart and kidneys
• Vomiting leads to damage of pharynx, esophagus, and teeth
• Antidepressants may help patients.
Digestive Disorders (pg 369)
• our digestive system helps to keep us healthy
and maintains balance of our systems
• it provides nutrients as we need them and
stores some for later use.
• When the digestive system is impaired the
results vary depending on the
disease/disorder:
Ulcer (fig. 11.12, pg 369)
• stomach lining secretes mucus
(protection from the stomach acids)
• ulcers occur when acid gets past the
mucous and begins to erode the stomach
wall.
• an ulcer is a slow healing sore
• ulcers can have several causes including:
– acid resistant bacteria can attach to the
stomach wall and stop the production of
mucus
– lifestyle choices including smoking, caffeine,
alcohol, and stress
• treatments include: medication (reduce acid production,
increase mucous, antibiotics etc), lifestyle changes, and surgery
Gallstones: (pg 369)
• small hard masses that form in the
gallbladder.
• cholesterol in bile can precipitate
(solidify) out and crystallize.
• crystals grow and form gallstones
• Causes: obesity, excessive alcohol
use and heredity
• Treatments: medication or lithotripsy
(ultrasound shock waves break up
gallstones)
Ileitis (pg369-370)
• inflammation of the ileum (part of the small intestine)
• part of Crohn’s disease and a form of inflammatory bowel
disease (IBD)
• inflammation extends deep into the lining of the infected
organ causing pain resulting in diarrhea.
• Difficult to diagnose because symptoms are similar to
ulcerative colitis - inflammation and ulcers occur in the top
layer of the lining of the colon (large intestine)
• seems to run in some families
• no cure but drugs are used to relieve pain
• surgery can be performed to remove the diseased segment
• the disease often reoccurs several years later.
Colitis (pg 370)
• inflammation and ulceration
of the colon lining
• symptoms: loose bloody
stool, abdominal cramps, skin
lesions, joint pain and failure
to grow normally in children
• treatments: medications,
surgery (entire bowel and
rectum are removed &
external opening, an
ileostomy, is created for
waste
Alternative Solutions to a Healthy Diet
(pg370-371)
• many people get all nutrients from food, including
vitamins and minerals
• some people need another source (multivitamins)
• obviously if not obtained from diet they are still
needed in the body
• p.370
Herbal Supplements
• other supplements commonly taken are herbal supplements
• typically made from wild plants; used for centuries as medicines
• few scientific supporters but many people DO believe in
preventative and healing effects
Common herbal remedies:
• St. John’s wort - to alleviate depression
• Echinacea - prevent/treat infections and colds; and improve
immune system
• ginkgo biloba - promote/maintain circulation; increase energy