18 different members of a multigene family encoding seven transmembrane domain proteins have been identified to be involved in olfactory expression. Studies suggest detection of chemically distinct odorant result from the association of odorous ligands with specific receptors on olfactory neurons. However, the receptors themselves have yet to be identified. Olfactory sensory neurons are bipolar. Its Dendritic processes extend to the mucosal surface and give rise to a number of specialized cilia. Its axons project to the olfactory bulb of the brain towards subcortical and cortical regions for discrimination of odors. Recent experiments have yielded results and data that indicate a family of genes transducing signald via GTP-binding proteins encoding thousands of different receptors likely to only recognize a small number of odorants.
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The human eye works by reacting to light and pressure and provide a three-dimensional moving image. Rod and cone cells are responsible for conscious light perception, color differentiation, and perception of depth. The approximate field of view varies by facial anatomy. As soon as the eye finds a target, it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil. Dark adaptation takes place in approximately four seconds of profound uninterrupted darkness. Full adaptation is dependent on blood flow and therefore can be affected by many external and internal factors.
The integrative function of the central nervous system accounts for our ability of understanding reason, being conscious, and having complex behavioral patterns and emotions. These are functions not directly related to sensory or motor inputs. Certain parts of the brain have been identified: the limbic system and the neocortex. The neocortex is a part of the mammalian brain involved in higher-order functions such as perception and spatial reasoning and is the largest part of the cerebral cortex. It is also the most developed in its organization and number of layers of all cerebral tissues. It contains both excitatory and inhibitory neurons. The limbic system is on both sides of the thalamus and supports functions like emotion, motivativation, and long-term memory.
Marsupials have less specialized forelimbs than eutherians and tend to specialize their hindlimbs rather than their forelimbs. Recent studies have suggested the presence of a marsupial forelimb complex. This complex forms a constraint as a result of functional requirements of a metatherian newborn crawl to the teat. Because metatherian gestation is a lot shorter than eutherian gestation, immature neonate crawl to the teat limits the forelimb and limits the developmental morphology of the forelimb. This theory proposes the existence of an evolutionary constraint under the assumption that because the mammalian hindlimb is more important for propulsion than the forelimb, the forelimb should therefore exhibit a higher level of evolutionary flexibility and thus be more capable of specialization for diverse functions.
S.A node firing of the heart results from a spontaneous depolarization. Acetycholine is released by parasympathetic nervous system and binds to muscarinic receptor which activates G protein coupled receptors and blocks the CAMP pathway normally activated by noradrenaline in the sympathetic system. The release of noradrenaline in the sympathetic system allows an influx of cations in order to reach the threshold and cause action potential firing of the S.A node. Together, these two mechanisms account for heart rate at rest. Electrical activity is then propagated through cardiac tissue to produce timed contractions of various chambers by slowing down at the S.A and A.V nodes to allow for right atrium contraction and repolarization prior to ventricular contraction.
Carbon monoxide is so deadly because hemoglobin has a higer binding affinity for it than it does for oxygen. In the presence of both, hemoglobin binds to the carbon monoxide. This affects rates of alveolar ventilation and perfusion. Thr higher the concentration of carbon in the body, the lower the PH, the less O2 taken up by hemoglobin. As a result, oxygen cannot be transported to body tissues efficiently.
The three basic principles of circulatory function are the following: blood flow to each tissue is controlled in relation to tissue need, cardiac output is controlled by the sum of all tissue flows, and arterial pressure regulation is independent of local blood flow control or cardiac output. In aortic valve stenosis, the diameter of the aortic valve opening is reduced significantly, and the aortic pressure pulse is decreased because of diminished blood flow outward through the stenoic valve. This is directly related to a problem with delayed compliance. In normal vessels an increase in volume first shows an increase in pressure, then delayed stretching due to the vessel's distensibility causes the pressure to return back to normal pressures. If this delayed stretching is disturbed, pressure control will diminish and blood flow will be greatly affected.
In this lab we investigated the properties of magnetism and magnetic induction. We are using the knowledge that there is a magnetic field that mediates the force between magnetic objects. We were able to show how magnetic fields can generate an electric current and how electric currents generate magnetic fields. First, we used a compass and magnet to show how magnets interact at opposite poles. Then, we utilized a magnet and coil combination to show how magnetic fields can generate current. Lastly, we used a two-coil system to prove there was a voltage across the terminals of the second coil.
Magnetic flux is basically the number of magnetic field lines that passes through a closed surface. Magnetic flux depends on and is also equal to the product of surface area and magnetic field. It depends on it changing with time. When a magnetic is near a compass and the south pole of the compass needle is pointing at the magnetic, the needle’s point must be at the north pole of the magnet (a compass needle is simply a small magnet balanced on a pin). We then can infer that when the compass needle is exposed to a magnetic field it will pivot (because it wants to align with the field lines of the magnet). This is because the north pole will repel the north pole of the magnet and vise versa with south. On the other hand, the north pole will attract the south-pole (opposites attract).
We decided to investigate tree species richness and diversity of a small hill in Thatcher way and on University Drive behind the school parking lot in Southwest. These two places are at least 1.5 miles away from each other meaning the areas are different enough to have different populations. The trees of interest on Thatcher way are on a hill in an isolated area in the Northeast residential area on campus, whereas the trees on University Drive are surrounded by parking lots and involve a larger surface area. The trees on University Drive appear to be more spread out, therefore receive sunlight and rain more directly than the trees on Thatcher way. Temperature is most likely the same in both areas. The trees in Thatcher way are in a steeper area compared to the trees in Southwest. We predicted there would be more species richness and diversity in the Southwest area. Our predictions were based on observations of Southwest receiving more direct water and sunlight. This would make it easier for them to create their own food and energy through photosynthesis. An increased space promotes growth and resistance to stress whereas a tighter space makes the trees more vulnerable to disease, fire, and droughts. If our predictions are correct, the Southwest area will have a higher Shannon Index, meaning a greater variety of species and a somewhat equal distribution. If we are wrong, this means we overlooked other factors that could contribute to a reduced diversity in the Southwest area.
The anti-apoptotic Bcl-2 family members interact to maintain mitochondrial integrity and regulate cellular commitment to apoptosis. Apoptosis, cell death, is crucial for development and homeostasis. These signals are normally tightly regulated in cells. An unbalance is needed for tumorigenesis to occur and becomes even greater when the tumor becomes resistant to the treatments. By specifically regulating these proteins and the pathways involved, it can be possible to have more control in the way cancer cells act.