Organism Physiology
The Planarian or "cross-eyed flatworm" is a relatively simple invertebrate organism, belonging to the animal kingdom and the phylum of Platyhelminthes which covers all flatworms. The phylum of Platyhelminthes contains four separate classes: three of these cover parasitic forms of flatworm that live inside other organisms (like the famous tapeworm). The fourth class, Turbellaria, includes all non-parasitic flatworms. One of these is the Planarian, which exists in a number of different genus and species: our diagram is derived from the standard Planarian used for biology students, Girardia Tigrina. A close examination of the structures and functions of the main organs found in this simple organism can explain how the Planarian has evolved physiologically to become suited to its environment.
The first organ to consider in the Planarian is not an internal one. The epidermis, or outer skin layer, of the Planarian (numbered 4 on the diagram above) is a perfect example of adaptation to environmental conditions. First off, we may note that internally the Planarian contains no respiratory or circulatory system: these functions are covered by the epidermis, which absorbs oxygen from the surrounding water, and diffuses carbon dioxide outward in the same way. This Planarian is a completely aquatic animal, therefore the outer skin layer has what Littlewood and Bray (2001) describe as "a complete and dense covering...
Physiology Body Systems Involved in Eating a Snack The first thing I do when eating a snack is to prepare it. In this case, I reach into the cabinet above me and grab a bag of potato chips. I read the label and make sure they are plain chips, because I do not like flavored chips. When I am satisfied they are the type of chip I like, I break open the
Physiology & the Orange As I tune in to "my orange," I find that it is difficult to separate the sensory input that I am experiencing. My mind seems to put integration on automatic pilot. Before I close my eyes, I find my visual sense to be dominant. I know that I tend to be a visually-oriented person anyway, so this is not really a surprise. But in my attempts to
Physiology of Emotions Varying Theories on the Physiology of Emotions In their theory, "How Emotion Shapes Behavior: Feedback, Anticipation, and Reflection, Rather Than Direct Causation," Baumeister, Vohs, DeWall and Zhang show how the secondary function of emotions is much more important to humans than their initial response to an emotion. Emotions in response to stimuli provoke actions that usually begin too late to effectively react to the stimuli. Thus, it makes more
In an acute shock situation, the body shuts down many of its functions in the interest of addressing the patient's most-urgent problem. In addition to reduced kidney function, the patient's brain function slows down; she may appear lethargic, have difficulty talking, and eventually lapse into a coma. This is due to the body's diverting blood supply from the brain, which typically takes 20% of oxygen and nutrition, to other areas
The plaintiff sustained life-changing and debilitating injuries in the form of skin cancer that could have also proven fatal had it not been diagnosed in time to treat. There is still no guarantee that the cancer will not recur and the plaintiff will now have to endure that grave uncertainty for the rest of his life. The employer benefited tremendously from the labor of this employee and it had an
These indications then proceed to the neuromuscular connections of skeletal muscles. From there, acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors of muscles, thereby communicating the stimulus to contract muscle fibers (Ihlen & Vereijken, 2010). Psychological Influences Research on patient's brains scanned by Positron Emmision Tomography have designated that the kind of thoughts people have influence the balance of brain chemicals, so
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