Body Systems of Humans, Crayfish, Pigs, and Earthworms

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Body Systems of Various Organisms
All organisms in the world have a range of systems and organs in their body. Some organisms may share similar body systems while others have absolutely nothing in common. Several of those organisms include humans, pigs, crayfish, and earthworms. From their mushy, gushy organs to their soft, gentle skin, you may think, “How are humans and pigs possibly alike? Or a crayfish and an earthworm?” In many ways they may not be, but in other ways, they are very much alike. The body systems that will be compared and contrasted of these organisms are the nervous, circulatory, reproductive, muscular, integumentary, digestive, excretory, and skeletal systems.

The anatomy of a human is very complex with many body systems and organs. Those systems and organs help our body function and carry out everyday activities. Our brain, spinal cord, peripheral nerves, and basic nerves help collect, transfer, and process information with the help of the nervous system. It helps command our body’s motor functions, the way that we move, and response to stimuli. Compared to a human, pigs have the same type of nervous system with the same parts and the same functions. As for a crayfish’s nervous system, it is composed of a ventral nerve cord fused with segmental ganglia, sup esophageal, and sub esophageal ganglia.  The sup esophageal and sub esophageal ganglia control the head appendages in response to the sensory input received from receptors. An earthworm also has the same type nervous system as a human, just like a pig.

As for the circulatory system, a human’s pumps blood to and from the body and lungs with the help of the heart, blood vessels, and arteries. A pig, however, has a heart, blood, blood vessels, lungs, and a circulatory mechanism. The heart, blood, blood vessels, and lungs have the same functions and structures as humans but the circulatory mechanism’s function is quite unique. Its circulatory mechanism circulates blood between the heart and the rest of the body except for the lungs. The crustaceous crayfish’s and squirming earthworm’s circulatory systems are the same as a human’s.

Reproduction of a human involves the joining of a male sperm cell and a female egg cell. The reproductive system of a male involves the testes, vas deferens, seminal vesicles, prostate gland, and the penis. As for the female, the ovaries, ovum, fallopian tube, uterus, vagina, and mammary glands are involved. A male uses his penis and deposits a sperm cell into a woman’s vagina and then the sperm travels up to fertilize her egg cell. The reproductive system of a pig is also the same as a human’s reproductive system. A crayfish has some similar bodily structures for reproduction as a human. A male has vas deferens, seminal vesicles, prostate gland, and a penis while a female has a fallopian tube, ovum, uterus, vagina, and mammary glands. The only difference from humans is that the fertilization of the egg occurs outside of the fish body. The female releases the egg and the male fertilizes it soon after it comes out. An earthworm’s reproduction is the most unique. It involves clitella’s in both males and females. They reproduce by two worms coming together in opposite directions with their clitella’s in contact of their mating partners.

A humanoid muscular system involves three types of muscles: skeletal, smooth, and cardiac. All of these muscles work together to help our body move. Skeletal muscles are attached to bones, smooth muscles surround blood vessels and organs in our digestive system, and cardiac muscle is the muscle found only in the heart. As for a pig’s muscular system, it includes smooth muscle found in the digestive system and genital areas as well as on the walls of the blood vessels. The cardiac and skeletal muscles are the same and have the same functions as humans. All the muscles help give an extra layer of defense and protection within the said parts of the body. The crayfish’s muscular system covers...
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