The folllowing sample essay on Crayfish Skeletal System discusses it in detail, offering basic facts and pros and cons associated with it. To read the essay’s introduction, body and conclusion, scroll down.
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.
Worm Muscular System
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 emale 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 parts of its legs, tail, and abdominal area. It is mainly just skeletal muscle and tissue that covers and protects the outer bone lining. Basically speaking, an earthworm has two muscles, circular and longitudinal, that allow for locomotion with the muscular system. They run throughout their entire bodies and also help with contraction. Integumentary systems of humans include the skin, nails, and hair. They act as the barrier between the body’s internal and external environments. A pig’s integumentary system is also the same as a humans’. The crayfish’s ntegumentary system consists of its outer shell and its gills. The shell keeps things out of its body and the gills allow them to breathe. An earthworm’s integumentary system controls many of the worm’s life processes. Its body absorbs oxygen from its surroundings and allows it to diffuse into the blood through the layered skin. The skin also activates sensitivity to light, touch, and other chemicals in its environment. Our mouth, esophagus, stomach, pancreas, liver, gallbladder, large intestine, small intestine, rectum, and anus come together to form the digestive system which breaks down our food into simpler molecules.
The food enters through the mouth, travels down the esophagus, breaks down in the stomach, pancreas, liver, and gallbladder and then moves through the intestines down to the rectum and anus. A pig’s digestive system is no different than a human’s. A foregut, midgut, hindgut, and a digestive gland form the digestive system of a crayfish. The foregut contains the stomach (partially breaks the food down), the midgut is an extension of the foregut, the hindgut consists of the anus (releases the digested enzymes), and the digestive gland secretes enzymes that aid in the absorption of the digested products.
As for an earthworm’s digestive system, it is partitioned into many regions, each with a certain function. It consists of the pharynx, the esophagus, the crop, the intestines, anus, and the gizzard. Food enters through the mouth, it’s swallowed by the pharynx, passes through the esophagus, moves to the gizzards where the food is completely broken down, and then travels through its intestines and down to the anus. Humans, like many other organisms, have excretory systems that remove wastes from our bodies. They include the skin, lungs, kidneys, ureters, bladder, and urethra.
Our excretory system also helps us maintain homeostasis. The kidneys, aorta, kidney pylorus, ureters, bladder, and urethra make up the excretory system of pigs. Its waste removal process helps it maintain its fluid balance as well as processing protein absorption. A crayfish’s excretory organs are called the antennal glands because they are located at the base of the second antenna. They excrete the waste products of blood filtration and remove them from the body. An earthworm has niphridia, which are similar to kidneys, and nephridia, which are ventral pores that excrete waste in the excretory system.
Unprocessed waste comes down to the niphridia and is then processed completely and removed through the nephridia. The human skeletal system includes our bones and tissues that aid in the support, protection, and movement of our body. A normal human skeleton consists of 206 bones; however, extra bones can form due excess amounts of tissue. Pig’s have the same type of skeletal system but have 216 bones rather than 206. A crayfish has a hard exoskeleton that protects and supports the body. It has 8 jointed walking legs, a segmented body, 2 pairs of sensory antennae, and a pair of compound eyes.
These make up the skeletal system that supports, protects, and helps move the body. Earthworms don’t have a skeletal system for they are invertebrates and have no bones in their bodies at all. In conclusion, humans, pigs, crayfish, and earthworms all have body systems that are both unique and also different. Humans and pigs have the same nervous, reproductive, integumentary, digestive, and skeletal systems. Humans and crayfish both have an identical circulatory system while humans and earthworms have alike nervous and circulatory systems.
Pigs and crayfish don’t have exactly alike systems but their circulatory systems both pump blood to their hearts and bodies in similar ways. As for pigs and earthworms, they have similar nervous systems that control motor functions as well as response to stimuli. Crayfish and earthworms have identical circulatory systems for blood filtration throughout the body. All of the body systems within a number of organisms are unique in their own way. Some organisms have similar body systems and body functions but all of them are different in one way or another. It could be size, color, configuration, location, name, etc. Overall, body systems are crucial in all organisms to carry out normal daily activity whether it’s a small ant, gigantic whale, or a normal five-foot human.
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