Sunday, March 27, 2016

Digestion and Excretion Systems

Digestion and Excretion   Games
Super Size Me    Project Due April 8th Click here for Guidelines     Coach Pease Games
Excretory System Video     Excretory Video        Song       Click Here for a full Excretory diagram   
What happens to the skeletal system when the kidneys fail? Click Here       Sandoval Games
blood pumped by the heart.      red blood cells    More Excretory  Information      
Watch this video about digestion    or this one or Learn more here       Interactive Organs Here!
Watch a cartoon about the Digestive System      Learn more about the Digestive Organs here

Humans need foodwaterand oxygen to surviveFood contains energy that is processed by the bodyThe process by which food is broken down is called digestionAfter digestion,substances that are not used by the body are removed through elimination.
The Digestive System
As shown in Figure 2, the digestive system is made up of several organsFood and water enter the digestive system through the mouth.

Hutchings Photography/Digital Light Source
Figure 2 Food enters the digestive system through the mouthand nutrients are absorbed by the small intestine.
Digestion Before your body can absorb nutrients from foodthe food must be broken down into small molecules by digestion. There are two types of digestionmechanical and chemicalIn mechanical digestionfood is physically broken into smaller pieces. Mechanicaldigestion happens when you chewmashand grind food with your teeth and tongue.Smaller pieces of food are easier to swallow and have more surface areawhich helps with chemical digestionIn chemical digestionchemical reactions through enzymes break down pieces of food into small molecules. Enzymes are proteins that help break down larger molecules into smaller molecules. Enzymes also speed upor catalyzethe rate of chemical reactions.Without enzymessome chemical reactions would be too slow or would not occur at all.

Amylase is an enzyme that helps digest carbohydrates. It is produced mainly in the pancreas and the glands that make saliva. When the pancreas is diseased or inflamed, amylase releases into the blood. 

In the stomach, the enzyme pepsin functions to break proteins into smaller pieces called polypeptides. because pepsin can only break the bonds next to certain amino acids, proteins are only broken into these shorter chains, and not digested all the way to amino acids.
1. Reading CheckWhat are enzymes?
When you swallowfoodwaterand other liquids move into hollow tube called the esophagus (ih SAH fuh gus). The esophagus connects the mouth to the stomach.Digestion continues as food leaves the esophagus and enters the stomachThe stomach i sflexiblebag like organ that contains other enzymes that break down food into smaller parts so that the food can be used by the bodyFigure 3 illustrates how an enzyme helps break down food molecules into smaller piecesNotice in Figure 3 that the food molecule breaks apartbut the enzyme itself does not changeThereforethe enzyme can immediately be used to break down another food molecule.
2. Reading CheckIdentify where food enters the body.
Figure 3 An enzyme helps break down food molecules into smaller pieces.
Absorption Nextfood moves into the small intestineBy the time food gets to the small intestineit is soupy mixtureThe small intestine is tube that has two functionsdigestion and absorptionThe liver makes substance called bileThe pancreas makes enzymesBoth bile and enzymes are used in the small intestine to break down food even moreBecause the small intestine is very longit takes food hours to move through it.During that timeparticles of food and water are absorbed into the blood.
Elimination The large intestineor colon (KOH lun), receives digested food that the small intestine did not absorbThe large intestine also absorbs water from the remaining waste materialMost foods are completely digested into smaller parts that can be easily absorbed by the small intestineHoweversome foods travel through the entire digestive system without being digested or absorbedFor examplesome types of fibercalled insoluble fiberin vegetables and whole grains are not digested and leave the body through the rectum.
As you have readone of the functions of the small intestine is absorptionNutrients are the parts of food used by the body to grow and surviveThere are several types of nutrientsProteinsfatscarbohydratesvitaminsand minerals are all nutrientsNutrition labels on foodas shown in Figure 4, show the amount of each nutrient in that foodBy looking at the labels on packaged foodsyou can make sure you get the nutrients you needDifferent people need different amounts of nutrientsFor examplefootball players,swimmersand other athletes need lot of nutrients for energyPregnant women also need lots of nutrients to provide for their developing babies.
Digestion helps release energy from foodA Calorie is the amount of energy it takes to raise the temperature of kg of water by 1°CThe body uses Calories from proteinsfats,and carbohydrateswhich each contain different amount of energy.
3. Reading CheckName five types of nutrients.

Omikron/Photo Researchers
Figure 4 The information on nutrition label can help you decide whether food is healthful to eat.
Visual CheckHow many servings are in this food container?
The Excretory System
The excretory system removes solidliquidand gas waste materials from the bodyThe lungsskinliverkidneysbladderand rectum all are parts of the excretory system.
The lungs remove carbon dioxide (CO2and excess water as water vapor when you breathe outor exhaleThe skin removes water and salt when you sweat.
The liver removes wastes from the bloodAs you have readthliver also is part of the digestive systemThe digestive and excretory systems work together to break down,absorband remove food.
When the liver breaks down proteinsurea formsUrea is toxic if it stays in the bodyThe kidneysshown in Figure 5, remove urea from the body by making urineUrine contains waterureaand other waste chemicalsUrine leaves each kidney through tubecalled the ureter (YOO ruh tur), and is stored in flexible saccalled the bladderUrine is removed from the body through tube called the urethra (yoo REE thruh).
Like the liverthe rectum is part of the excretory system and the digestive systemFood substances that are not absorbed by the small intestine are mixed with other wastes and form fecesThe rectum stores feces until it moves out of the body.

Excretory System (a. k. a. Urinary System) 
Have you ever wondered why your body has to urinate? Where does that fluid come from? Why is it yellow? You'll learn the answers to these and more questions as you read our information about the excretory system. Video        Song
Parts of the Excretory System 
 the kidneys: they contain filters that take the waste out of the blood 
 the nephrons: remove the waste materials from blood and make urine 
 the ureters: tubes that carry the urine to the bladder 
 the bladder: a 'bag' that collects the urine 
 the urethra: a tube that carries the urine out of the body 

What does the excretory/urinary system do? 

The kidneys, the bladder, and their tubes all work together to form the urinary system. Waste that's left over from breaking down food and your body's other activities naturally builds up in your blood. Your blood passes through your kidneys and when this happens, your kidneys act like a filter to clean the waste from your blood. Then they mix the waste with a little water to create urine. The urine goes to your bladder, which you empty when you urinate (pee). Kidneys and Nephrons 

One of the main jobs of the kidneys is to filter the waste out of the blood. First, blood is carried to the kidneys by the renal artery. As the blood passes through the kidneys, it deposits used and unwanted water, minerals, and a nitrogen-rich molecule called urea. More than 1 million tiny filters inside the kidneys remove this waste. These filters, called nephrons, are so small you can see them only with a high-powered microscope. 

Kidneys normally come in pairs. If you've ever seen a kidney bean, then you have a pretty good idea what the kidneys look like. Each kidney is about 5 inches long and about 3 inches wide. 

 Ureter, Bladder and Urethra The waste that is collected combines with water (which is also filtered out of the kidneys) to make urine. As each kidney makes urine, the urine slides down a long tube called the ureter and collects in the bladder, a storage 'bag' that holds the urine. When the bladder is about halfway full, your body tells you to go to the bathroom. When you urinate, the urine goes from the bladder down another tube called the urethra and out of your body. 

If the urinary system is healthy, the bladder can hold up to 16 ounces (2 cups) of urine comfortably for 2 to 5 hours.

What happens to the skeletal system when the kidneys fail? Click Here

More about the kidneys...
Although the kidneys are small organs by weight, they receive a huge amount -- 20 percent -- of the blood pumped by the heart. The large blood supply to your kidneys enables them to do the following tasks:
  • Regulate the composition of your blood: Keep the concentrations of various ions and other important substances constant; Keep the volume of water in your body constant; Remove wastes from your body (urea, ammonia, drugs, toxic substances); Keep the acid/base concentration of your blood constant
  • Help regulate your blood pressure
  • Stimulate the making of red blood cells
  • Maintain your body's calcium levels
More Information

Fun Facts  
Interesting Stuff....

1.. For every 2 weeks, the human stomach produces a new layer of mucous    
lining, otherwise the stomach will digest itself.

2. The human liver performs 500 different functions.

3. Liver is the largest and heaviest internal organ of the body and weighs about 1.6 kilos.

4. The Liver is the only organ of the body, which has the capacity to regenerate itself completely even after being removed almost completely.

5. Liver cells take several years to replace themselves.

6. A healthy liver processes 720 liters of blood per day.

7. The human stomach contains about 35 million small digestive glands.

8. The human stomach produces about 2.5 liters of gastric juice everyday.

9. In an average person, it takes 8 seconds for food to travel down the food pipe, 3-5 hours in small intestine and 3-4 days in the large intestine.

     1. Our blood passes through our kidney's 300 times a day.
2. our nephrons can clean our blood within 45 minutes.
3. Everyday our nephrons send 6 cups of urine to our bladder
          4. The average person pees about 3000 times a year.       
          5. The 
average person poops about 305 pounds a year
The liver is rubbery to touch. 

Why is urine yellow? 
Some European alchemists in the middle ages apparently thought one possible reason was that there was gold in urine. This led to fruitless, and possibly quite disgusting, efforts to extract that gold.

The yellow color in urine is due to chemicals called urobilins. These are the breakdown products of the bile pigment bilirubin. Bilirubin is itself a breakdown product of the heme part of hemoglobin from worn-out red blood cells. In the bloodstream the Bilirubin is extracted by the kidneys where, converted to urobilins, it gives urine that familiar yellow tint.

Why does urine change colors?
 You might notice that sometimes your urine is darker in color than other times. Remember, urine is made up of water plus the waste that is filtered out of the blood. If you don't take in a lot of fluids or if you're exercising and sweating a lot, your urine has less water in it and it appears darker. If you're drinking lots of fluids, the extra fluid comes out in your urine, and it will be lighter. 

Beets turn your urine pink.
4. Key Concept CheckHow does food enter and leave the body?
Figure 5 The kidneys remove waste material from the body.
 Lesson Review
Visual Summary
The kidneys remove liquid wastes from the body.
The circulatory system transports nutrientsgaseswastesand other substances through the body.
Immune cells detect and destroy virusesbacteriaand other foreign substances.

Omikron/Photo Researchers
What do you think NOW?
You first read the statements below at the beginning of the lesson.
1. human body has organ systems that carry out specific functions.
2. The body protects itself from disease.
Did you change your mind about whether you agree or disagree with the statements?Rewrite any false statements to make them true.

Lesson Assessment
Use Vocabulary
1. Use the term organ system in sentence.
2. Define homeostasis in your own words.
3. A(n__________ is type of white blood cell.
Understand Key Concepts
4. Organs are groups of __________ that work together.
5. Compare and contrast mechanical and chemical digestion.
6. Differentiate the role of the liver in the digestive system from its role in theexcretory system.
7. Examine how the circulatory system and the respiratory system work together andmove oxygen 
the body.
8. Contrast infectious diseases and noninfectious diseases.
9. Which body system removes carbon dioxide and waste?
10. Which body system makes immune cells?
11. Which are bundles of cells in the lungs that take in oxygen?
12. Which are proteins that recognize specific proteins on bacteria?
13. Which is NOT type of blood vessel?
Interpret Graphics
14. Analyze the nutrition label belowHow many Caloriescarbohydratesfatsand proteins are in 
of this food?

Photograph of a nutrition label
Mark Steinmetz


Summarize Copy and fill in the graphic organizer below to show how food travels through the 

Example of a graphic organizer with boxes arranged vertically and connected by arrows

16. Describe the roles of the structure shown below in digestion.
Illustration of part of the digestive system; the small intestine is identified
17. Compare the functions of lymphatic vessels and blood vessels.
18. Predict how your daily life would change if your skin contained no melanin.
19. Evaluate how the skinability to continually produce new skin cells helps protectyour body.
20. Relate the organs of the lymphatic system to immunity.
21. Identify the main functions of the digestiveexcretoryrespiratorycirculatoryand 
Writing in Science
22. Write five-sentence paragraph that distinguishes the two main types ofdiseasesBe sure to 
topic sentence and concluding sentence in your paragraph.
Math Skills
Use Proportions
23. If 30.of milk contains 18 Chow many Calories will you consume by drinking glass of milk
244 g)?
24. Which type of chicken in the table below has the fewest Calories per gram?

Data table showing the number of calories in different pieces of chicken
25. small 140g apple and 100banana each provide 70 of energyHow many Calories would there be in 200g- serving of fruit salad that contained equal amounts of apple and banana?
HintAdd the values for the apple and the banana first.]
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