DIGESTIVE SYSTEM

The digestive system's function is to break down food into molecules the body can use. The organs within the digestive tract carry out the digestive process. There are two ways that break down food into nutrients. There is mechanical which is chewing and chemical which are enzymes. The intestine is responsible for the absorption of nutrients in the blood to be delivered throughout the body. 

Advantages of the digestive system for some animals are their ability to absorb nutrients by diffusion. For example, earthworms have a straight intestine so it's beneficial to them because they absorb nutrients by diffusion. Breaking down carbohydrates, protein and lipids are important because they help provide or store energy and build muscle and tissue. The stomach walls provide gastric juices that help kill off germs that enter the body. The liver is beneficial because it separates the good stuff and the waste. To maintain a good digestive system, you obviously need to have a healthy diet and exercise. 

There aren't that many disadvantages for the digestive system. I think a disadvantage of a straight intestine is that it's harder to break things down. There are some problems that have to do with the intestines like irritable bowel syndrome, inflammatory bowel syndrome and cancer of the bowel. 

Sources:

http://answers.yahoo.com/question/index?qid=20120602233022AAhePnf

http://visual.merriam-webster.com/human-being/anatomy/digestive-system.php

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?id=2727&np=152&p=335

Holt, Rinehart and Winston Modern Biology

Austin: Holt, Rinehart and Winston, 2002

 

CIRCULATORY SYSTEM

 

The circulatory system has different functions. It transports gases like oxygen from lungs to cells and carbon dioxide from cells to lungs. It transports nutrients like glucose. It also transports wastes from cells to organs that eliminates them. The circulatory system has cells that fight infections and foreign bodies. It maintains pH and fluid levels. Lastly, it helps maintain body temperature especially in endothermic animals. There are two types of circulatory systems, one is an open system and the other is a closed system. In an open system, blood isn't contained in the blood vessels. In a closed system, blood is actually contained in the blood vessels. Structures like the heart, blood and blood vessels are a part of this system. 

Advantages of animals with an open system are able to control over their body temperature. For example, it prevents them from dying out. They're not exposed to pressure as much which lets some organisms live very deep in the ocean. Animals with a closed system have a good control over the oxygen's delivery to the tissues. The lymphatic system helps decrease the pressure of tissues. Blood is very important because it helps fight off infections. For example, white blood cells act as antibodies and prevent diseases. 

Disadvantages of animals with open systems are low metabolism. They have low metabolism because of their diffusion limitations. Transportation in an open system is slow, therefore there's a limit on the oxygen the take and the blood flow. Animals with a closed system have high blood pressure. The heart maintains the circulation of the blood around our whole body with high pressure. 

Sources:

http://daman92.hubpages.com/hub/Circulatory-System

http://www.arthursclipart.org/frogs/frogs/page_01.htm

http://library.thinkquest.org/26153/marine/arthro.htm

http://sciencenotes.wordpress.com/2012/01/21/traces-of-evolution/earthworm-circulatory-system-3d/

http://www.cartage.org.lb/en/themes/sciences/zoology/AnimalPhysiology/CirculatorySystem/CirculatorySystem.htm

Holt, Rinehart and Winston Modern Biology

Austin: Holt, Rinehart and Winston, 2002

RESPIRATORY SYSTEM

The respiratory system's function is to exchange gases of oxygen and carbon dioxide by the process of diffusion. Oxygen is needed for cellular respiration; Carbon dioxide is the waste product. This system includes skin, gills and lungs. There's external and internal respiration. External respiration has to do with the exchange of gases between the atmosphere and blood. For internal respiration, it's between blood and the cells of the body. Pulmonary respiration is respiration through lungs. Cutaneous respiration is respiration through skin. 

Inside the system, there's a trachea which includes cilia. Cilia is helpful because it traps dust from entering the lungs. An advantage of the respiratory system basically makes you capable of absorbing nutrients in the air and breathing out waste. 

A disadvantage of this system is inhaling chemicals, fumes, anything that can damage the lungs. The air that we breathe is of course not 100% clean, therefore any of us can catch sickness, infections or diseases. Chemicals can cause diseases. If you inhale smoke, it ends up burning your tiny bronchioles.  

Sources:

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookrespsys.html

http://yr11-biology-revision.wikispaces.com/Gaseous+exchange

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?id=2406&np=152&p=335

Holt, Rinehart and Winston Modern Biology

Austin: Holt, Rinehart and Winston, 2002

SKELETAL SYSTEM

The skeletal system provides a strong framework to hold a body up, maintain its shape, protect soft organs and provide sites for muscles to attach for movement. There are three skeleton types which are hydrostatic, exoskeleton and endoskeleton.

I think the main advantage of the skeletal system is that it provides protection for our internal organs. It's what helps us move! It supports parts of our bodies. It's our framework.  Advantages of organisms that have a hydrostatic skeleton is that they're very flexible and can squeeze themselves to fit in between spaces and pathways. For animals with exoskeletons, they have shells that provide them protection and support. Their shells are really hard which is beneficial so they won't get crushed easily. 

For hydrostatic skeletons, a disadvantage would be is not being able to lift things. They also don't have protection since they're just made of water and muscles. For exoskeletons, they can't grow much so a limitation on size would be a disadvantage. For endoskeletons, our protection externally would be our skin and our skin isn't hard nor tough like exoskeletons. I think another disadvantage is to fracture a bone. 

Sources: 

http://biology.clc.uc.edu/courses/bio105/bone.htm 

http://www.infovisual.info/02/028_en.html 

http://www.sas.upenn.edu/~rlenet/Earthworms.html

http://www.davidlnelson.md/Cazadero/Crawdad.htm       

http://www.ehow.com/facts_5521715_advantages-disadvantages-hydrostatic-skeleton.html

Holt, Rinehart and Winston Modern Biology

Austin: Holt, Rinehart and Winston, 2002

                                    

INTEGUMENTARY SYSTEM

The integumentary system contains skin, shell, feathers, nails, claws and hair. The system's function is to protect against disease, get rid of waste, keep the body temperature constant and to prevent dehydration. Skin is made of two layers. The outer layer is called the epidermis and the inner layer is called dermis. The epidermis is mostly dead cells and the dermis consists of living cells and special structures like nerves, muscles, hair, glands and blood. Nails and are made of keratin. They protect ends of fingers and toes. Nails grow about 1mm per week and throughout our lives. They're good indicators of health. Hair protects and insulate the body. Hair's produced by hair follicles. Skin glands release sweat and oil. They release excess water, salts, and urea. This helps regulate body temperature. Oil glands on the face and hair conceal sebum. Sebum prevents water loss, lubricates and softens the skin and hair. Acne results from oil glands clogging up due to a lot of sebum. 

An advantage of the integumentary system is protection. Animals that have shell have a good protection since shells are hard. Hair's beneficial because it helps maintain body temperature and also homeostasis. Since skin is the outer layer, it usually prevents germs and dirt. I think mitosis is a big factor since it helps with growth and repair. We can sense the feeling of things with skin. I used to think sweat wasn't really beneficial until I found out that we sweat because it helps us cool down.  

A disadvantage for this system is tiny insects attach to hair which can cause a disease. People shouldn't be out in the sun too much without protection like sun block. Our skin's prone to drying and burning. Skin isn't hard so it's easily to scrape or cut ourselves. Acne's the result of clogged oil glands. People usually get blackheads because their pores are clogged. 

Sources:    

http://bio1152.nicerweb.com/Locked/media/ch43/integumentary.html  

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1766