Agnatha Nervous System The nervous system of sub-class Agnatha is the most primitive of all the Vertebrates. Though they do have what we would call a brain, it is extremely primitive and lacks a cerebellum, which is in charge of motor-control as well as language, attention and processing mental imagery (Neuroscience, 1997) in other Vertebrates. For the sub-class Agnatha, the cerebrum, olfactory bulb and medulla oblongata are small but present while the optic lobe is particularly weak since they have very basic eyes. For example, the Agnatha class creature call the hagfish is nearly blind (Uzwiak, 2014). The brain of this sub-class is located directly at the anterior of the Notochord. Connected nerves branch out to the rest of the body fro
Taxonomy Introduction The animal kingdom consists of about 800,000 known species (to include those that have been proven to exist). All animals have multiple cells and therefore rely on the cells of other living or dead organisms for their sustenance (growth and development). Animals develop from small groups of unspecialized cells and the animals with simple cells grow their missing body parts through regeneration. There are 36 phyla in the kingdom Animalia, for instance, Porifera, Annelida, Mollusca, Arthropoda, Echinodermata and Chordata among others (Dudley, 2002).
Organism Physiology: The Octopus Bio/101 The cephalopodor octopus is a marine organism that inhabits many diverse regions of the ocean. Its food source consists of crabs, small fish, clams, mussels and other marine animals. The octopus is a predatory animal and has developed many skills to aid in its survival in the
Running Head: HUMAN PHYSIOLOGY Human Physiology Name of Student Name of Institution 1 2 HUMAN PHYSIOLOGY Task 1 A Running when a starting pistol signals the beginning of a race is an activity that encompasses the skeletal system, the muscular system and the nervous system. These systems function interdependently to enable an individual run successfully in a race immediately the pistol shoots
On this image, we see the external dorsal side of a preserved crayfish. As part of the largest animal phylum the Arthropoda, the body of the crayfish is segmented, with jointed appendages and exoskeleton. The paired antennae (1) are long appendages located the front of the mouth and modified for help the animal to sense touch and taste. The antennules (2) are shorter, also paired with the same function but they also help to maintain balance. The chelipeds (3) are located on the front of the thorax, and they are responsible for defence and grasping food. On the at ventral part of the thorax, we found four pairs of walking legs (4), with these legs the crayfish changes locations on the bottom of freshwater lakes, streams and also on land. They
Fig. __ Feed-forward projections from the eyes to the brain and topographic mapping. In each eye the visual field on the left and right of the fovea (the cut goes right through the fovea!) projects to different cortical hemispheres: the ipsilateral retina projects to the ipsilateral visual cortex, and the contralateral retina crosses the contralateral cortex (hemifield crossing in the optic chiasma). The first synapse of the retinal ganglion cells is in the lateral geniculate nucleus (LGN), but information from the left (L) and right (R) eye remains strictly separated. The LGN consists of six layers, layers 1 and 2 are primarily occupied by the magnocellular pathway, and 3–6 by the parvocellular. Information from both eyes comes first together
The planarian is the first organism ever to have a fully productive synaptic nervous system (Mueller 2002). The synaptic nervous system contains nerve cells and it is when a neuron sends a signal, either electric or chemical, to another neuron and that signal contains information to be passed on or acted on (Mueller 2002). With the neural genes that are in planaria, they are able to build another fully function central nervous system, or CNS, without any of the old CNS (Cebria 2002). The CNS of a planarian is consisted of a brain in the head region and two ventral nerve cords that run down the body (Cerbria 2002).
Steele, V.J., and Oshel, P.E 1989. Ultrastructure of the attachment cells of the organ of Bellonci in Gammarus setosus (Crustacea, Amphipoda). Journal of Morphology, 200(1), 93-119.
Kingdom: Animalia Phylum: Chordata Sub-Phylum: Vertebrata Class: Chrondrichthyes Sub-Class: Elasmobranchii Order: Lamniformes Family: Lamnidae Genus: Carcharodon Species: C. carcharias The kingdom Animalia means animal. The phylum Chordata includes animals with vertebrates. The class Chrondrichthyes includes cartilaginous fish, which are fish that has a skeleton made of cartilage rather than bones. The family Lamnidae includes sharks as the white shark and mackerel sharks. These sharks are usually very large and can swim really fast. The genus is the group before the species which includes other sharks that are very similar to the white shark. The species is the last group, which contains the Latin name of the specific organism. Through taxonomy, scientists are easily able to identify and classify species.
Phase 2: Retina is placed in the back side of the eye and it has to „collaborate“ with cornea and lens in order to provide an image for
They are dioecious animals that use external fertilization for reproduction, while Pterobranchia uses mostly asexual reproduction by budding. Their feeding patterns vary from each class, and feeding appendages help them obtain the food they need. They have sense organs such as photoreceptors and a single preoral ciliary organ which is in front of the mouth located at the ventral side of the proboscis of the animal (Dobbs. 1988). The proboscis is important for them because that is where all of the neurosensory cells reside (Barrington. 1965). Therefore, this phylum consists of about 120 species that are mostly known and some not except the main two classes introduced. New species of the phylum hemichordata are yet to
The earthworm brain consists of the celebral ganglion, which is connected throughout the rest of the body using the ventral nerve cord.
Animals classified within this Phylum all share four key features, a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
Synopsis. The chromatophore organs of Loligo are each composed of five types of cells: a central pigment cell; radially arranged, obliquely striated muscle fibers; neuronal pro? cesses; glial cells; and an investment of sheath cells. Sheath cells are absent in Octopus
The cornea, a section of the protective and supportive part of the eye, refracts light to make it focus more on the center of the iris. In the center of the iris is an opening known as the pupil. (Mcdevitt) The iris also regulates light intake by reducing or increasing the size of the pupil. Behind the pupil is the lens of the eye. The lens keeps the light the eye is receiving focused on a specific point on the retina called the fovea. (Starr) The retina is the area in the back of the eye where all of the photoreceptors are located, neuro receptors that are sensitive to light. The fovea is the part of the retina that has the highest preponderance of photoreceptors. (Sung) The lens of the eye also integrates information by determining where the eye is focused. In order to keep the light that bounces off of an object focused on the fovea, the lens must change shape based on distance. The shape of the lens is controlled by a group of ligaments called the ciliated bodies. When the ciliated bodies tenses it causes the lens to be more round allowing the eye to focus on light coming from objects closer to the eye. When the ciliary body relaxes it allows the lens to become more flat allowing the eye to focus on objects further away. (Sung) All of the processes of the eye mentioned up to this point do not directly cause transduction; however they are another illustration of the way that the body performs integration of sensory