Embryonic development is usually distinguished in animals by embryogenesis, which consists of four stages which are the cleavage, patterning, differentiation, and growth. Differentiation stage is a crucial stage in the embryos development because the cells become specialized structures like the neurons, muscles, skin cells, etc..., which are then organized into tissues, tissue organs, and finally organ systems. During this stage, we can identify certain characteristics of the development of specific organ systems such as the nervous system. The nervous system in both invertebrates and vertebrates is crucial because of its specific functions towards the body system. Growth, on the other hand, is relatively important because it allows the certain parts of this nervous system to grow at certain times, ending with the result of a full functioning central nervous system (CNS). The embryonic development of the nervous system on mollusks is very important because of its relative complexity in nervous system to those among the vertebrates, and with enlarged axons, scientist can easily observe and study …show more content…
This central nervous system can be as simple as those found in the Platyhelminthes (flatworms), to those found in Cephalopods (for example squids, octopuses, and the cuttlefish), which are closely related to those in the Vertebrates. This vastly developed nervous system is bilaterally symmetrical and contains ganglia, nerves, connectives and much more, however, this nervous system has a more of a molluscan design rather than one like those in vertebrates. One reason for such complex nervous system is because of their active life-style, flexibility, and their complex behaviors depending on the extremity of circumstances of their environment or surroundings. Moreover, the cephalopods contain a higher cerebral and nervous function than compared to other mollusks (Budelmann,
“Taxonomically speaking, a lobster is a marine crustacean of the family Homaridae, characterized by five pairs of jointed legs, the first pair terminating in large pincerish claws used for subduing prey…. Moreover, a crustacean is an aquatic arthropod of the class Crustacea, which comprises of crabs, shrimp, barnacles, lobsters, and freshwater crayfish” (Wallace, 55). This is an example of Logos since the author uses scientific facts to convey the message he wants to communicate in an objective way. Wallace also uses logos as a persuasive device by presenting facts on the science of the lobster’s neurological system and its ability to feel pain. The Maine Lobster Promotion Council states “The nervous system of a lobster is very simple, and is in fact most similar to the nervous system of a grasshopper. It is decentralized with no brain. There is no cerebral cortex, which in humans is the area of the brain that gives the experience of pain”. Wallace counter-argues this statement by mentioning the fact that since lobsters have a simpler nervous system compared to humans, they are unable to produce their own natural opiates. “One can conclude that lobsters are maybe even more vulnerable to pain, since they lack mammalian nervous systems’ built-in analgesia, or, instead, that the absence of natural opioids implies an absence of the really intense
This system is able to process information quickly due to the short distances between neurons (Williams, 2011). Williams (2011) notes, by invertebrate standards, octopuses show exceptional cognitive mental capabilities that are rivaled only by some of the “higher” vertebrates, such as chimpanzees, dolphins, and humans. The decentralized design of the nervous system allows for decision making at different levels, i.e.: in the brain, or in the arms, which possess their own peripheral nervous system (Mather & Kuba, 2013; Stolzenburg, 1993). The arm’s nervous system has twice as much “neural firepower” as the brain and contains approximately three-fifths of all the body’s neurons (Stolzenburg, 1993; Williams, 2011). This portion of the nervous system is semi-autonomous, performing with minimal input from the brain but, when necessary, can exert centralized control over the arms (Godfrey-Smith, 2013; Williams, 2011). The arms also contain several sensory organs, including statocysts, olfactory organs and a system that is analogous to the lateral line in fishes (Alves et al.,
The purpose of this lab was to study the response of the genus Daphnia to chemical stimuli and to examine human responses to different stimuli. A stimulus is an incentive; it is the cause of a physical response. Stimuli can have a physical or chemical change; an example of a physical change is a change in temperature and sound. An example of chemical change would be changes in hormone levels and pH levels. Muscular activity or glandular secretions are responses that occurs when stimulus information effects the nervous and/or hormone system. Daphnia is a genus; it is a small crustacean that lives in fresh water. The body of the daphnia is visible and its internal organs are clearly seen thus it was chosen for this exercise. The
The neurons or brain cells are shaped like trees. Young brain cells, called soma, resemble an acorn or small seed of a tree. The seed sprouts limbs when stimulated, called dendrites. Further on in development, the cell will grow a trunk like structure called an axon. The axon has an outer shell, like the bark of a tree, called the myelin sheath. Finally, at the base of the cell, there are root-like structures called axon terminal bulbs. Through these bulbs and the dendrite of another cell, cells communicate with each other through electrochemical impulses. These impulses cause the dendrites to
The five environmental influences that I would use to publicize in a campaign to promote healthy prenatal development would be: the effects of the use of alcohol, tobacco, drugs, some medications, and diseases. These environmental influences are the most common problems that women who are pregnant face today. Most lack the knowledge of how and why these influences are harmful to their unborn child, and if needed how they can seek treatment.
Piatigorsky, Z., Kozmik. 2004.Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems. Int J Dev Biol 48: 719–729
A better way to understand if they communicate using their chromatophores, it might be best to know exactly what the chromatophores are and what they can do. Camouflage is the most important defense action in cephalopods. The cephalopod chromatophore system has captivated people since squid and octopus and cuttlefish were discovered. Chromatophores are specific cells which can contain or produce pigment, or reflect light in a precise way to create a certain desired color. The system is the only known example of skin reflectance under direct neural control, as opposed to the...
1.1 Describe, in-depth, stages of development from conception to birth in groups of 4 weeks i.e. 0-4, 4-8, 8-12...36-40 weeks.
The marine creatures commonly known as jellyfish are members of the phylum Cnidaria. Of the four classes of cnidarians, jellyfish come from both the Hydrozoa and Scyphozoa classes. Most jellyfish are schphozoids, while the Portuguese Man-of-War (Physalia physalis) is a hydroid. As cnidarians, jellyfish possess two tissue types: endoderm and ectoderm, in addition to a single cell layer of jelly-like mesoglea between the endoderm and the ectoderm (Russell 21). Jellyfish exhibit radial symmetry and have tentacles with stinging cells known as cnidocytes. They range in size from a few millimeters up to a bell size of two meters across, with tentacles up to thirty-six meters long. Typically less than five percent of a jellyfish’s body is "solid organic material" (Halstead, Poisonous 96-97).
carry signals toward the cell body. They are usually more, shorter and more branched than axons.
The neuron plays an important role in the occupation of the brain (Rollin Koscis). A neuron is...
Baby’s take an average of 38-40 weeks to fully develop and prepare for birth. This time period of approximately nine months is broken down into 3 periods in which the baby spends growing from a tiny mass of cells into a functional, healthy, bouncing baby. If all goes smoothly the birth of a baby, including labor time could take between 4-8 hours, sometimes more, sometimes less. There are many factors that can affect the baby’s growth and development, called teratogens, but overall baby will slowly grow and develop until he or she is prepared to enter into the world.
Phylum chordates are a taxonomic rank below kingdom that includes organisms such as mammals, fish, birds, reptiles, amphibians, all vertebrates, tunicates, and cephalochordates. To be in the phylum of chordates you must at some point in your development of life have a dorsal nerve, or hollow nerve cord which is in the central nervous system that acts as a support to the locomotion system. I will discuss the different kind of organisms along with some characteristics of the organisms found in the chordates phylum, I will then break down some specific species within the phylum group and will discuss their individual characteristic such as what they eat, where they are found, how and when they reproduce, and if they are social or solitary.
Stem cells are a type of cell unlike any other inside a human. They have unique properties as to what they are or can become. The U.S. Department of Human and Health Services states, “Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth” (stem cells). Because of this capability, they are the base of every single muscle and tissue in the human body. ”When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell,” or any other type of cell (stem cells). This special kind of cell has opened a new door of possibilities to all of
Stem cells research can help the human with cancer, birth defects and help to build normal cells it is only normal that we should research stem cells. Stem cells are special cells that are undifferentiated and have the capability to become many other types of cells. All stem cells have the ability to renew, replicate, and divide; thus, producing new cells. These cells are separated into categories according to their potential to become other types of cells. Two main stem cell types are embryonic stem cells and adult stem cells. Embryonic stem cells come from four to five day old embryos. They can be found on the inside of the placenta. These stem cells are considered pluripotent, meaning that they can become almost all possible types of