Anatomy, human functional

As we move forward, it will prove helpful to get some basic aspects of the human nervous system in place. An enormous amount of work has gone into making associations between brain anatomy and function. Starting with the three main parts of the brain, we know that the cerebrum is the seat of consciousness. It is divided into two hemispheres, which are linked by the corpus callosum. In a very general sense, the left hemisphere is associated with intellectual and the right hemisphere with emotional responses. Within the cerebrum, one can associate a number of brain areas (the prefrontal, frontal, temporal, parietal, and occipital lobes, for example) with functions including vision and hearing. One can make crude maps in which function is mapped onto brain structure. 

This section reviews basic principles of brain anatomy and function to provide a framework within which to discuss the effect of plants on the CNS. The human nervous system is exceptionally complex, it is the body s major communication system, and is divided into central and peripheral regions. The central nervous system consists of the brain and spinal cord, and the peripheral nervous system consists of all other nerves. Although thought processes and reason are most commonly associated with the CNS, almost every aspect of physiological function is affected by CNS activity. After all, Brain death is widely accepted as the definition of the end of human life 10). The follow description of CNS anatomy and physiology can be foimd in most text books on the and reviews on the subject 11, 17). 

Up until some time ago, the only chance to gain knowledge about the pelvic floor anatomy had been by dissecting human cadavers. Besides artifacts due to the embalming process, this method does not provide any information about the complex functional interaction of the many pelvic floor structures and organs. Therefore, our notion of the pelvic floor anatomy and function may have been distorted and incomplete. 

Woltring H.J., Huiskes R., deLange A., and Veldpaus F.E. 1985. Finite centroid and helical axis estimation from noisy landmark measurements in the study of human joint kinematics. /. Biomech. 18 379. Yoshioka Y., Siu D., and Cooke T.D.V. 1987. The anatomy and functional axes of the femur. J. Bone Joint Surg. 69A 873. 

The multimedia model present in the 2 FUN tool was developed based on an extensive comparison and evaluation of some of the previously discussed multimedia models, such as CalTOX, Simplebox, XtraFOOD, etc. The multimedia model comprises several environmental modules, i.e. air, fresh water, soil/ground water, several crops and animal (cow and milk). It is used to simulate chemical distribution in the environmental modules, taking into account the manifold links between them. The PBPK models were developed to simulate the body burden of toxic chemicals throughout the entire human lifespan, integrating the evolution of the physiology and anatomy from childhood to advanced age. That model is based on a detailed description of the body anatomy and includes a substantial number of tissue compartments to enable detailed analysis of toxicokinetics for diverse chemicals that induce multiple effects in different target tissues. The key input parameters used in both models were given in the form of probability density function (PDF) to allow for the exhaustive probabilistic analysis and sensitivity analysis in terms of simulation outcomes [71]. 

Penfield, W. W. and Jasper, H. Epilepsy and the Functional Anatomy of the Human Brain. Boston, MA Brown, 1954. 

Neurotransmitters and neuropeptides have been implicated in fear and anxiety. Much of our knowledge of the human neural substrates of fear and anxiety is derived from pioneering work using cat and rodent models. As techniques have advanced, our understanding of the anatomy, neurochemistry and physiology of these responses has progressed. In particular, the development of functional imaging techniques has allowed us to confirm that observations made in a number of animal species may also apply to humans. 

We will merely call attention here to the tremendous inter-individual human variability which exists in the anatomy of the endocrine glands. This variability is foreshadowed by the data already given with respect to rabbits and pigeons (pp. 2021). Since a separate chapter is devoted to these glands and their functioning, specific anatomical information with respect to the specific glands will be presented there. It is possible that these anatomical variations are more important from the standpoint of health and well-being than any we have so far discussed. 

We understand many aspects of the anatomy, physiology, and biochemistry of the human nervous system. The central points are the subjects of this chapter. As we come to understand them, much of great interest will be revealed to us. We will get important insights into how the nervous system functions and, in disease, malfunctions. We will also begin to understand why many molecules are effective in treatment of mental health disorders or induce abnormal states of consciousness in people. 

First, you will learn about the human nervous system and how it works when it is healthy. This will include an introduction to the structure (anatomy) of the nervous system and the function (physiology) of the nervous system. Next, we ll describe the things that can go wrong. We ll look at how the system breaks down and malfunctions. Then we ll show you how these breakdowns can result in psychiatric illness. Finally, we ll introduce you to the medications used to treat psychiatric illness. You will learn where these medications work and our best guess of how they work. The presumed mechanism of action of many medications is just that, presumed. In contrast to antibiotics, in which we know quite a lot about the ways that they kill bacteria or stop them from reproducing and how these mechanisms ultimately effect a cure for an infectious disease, less is known about how psychotropic medicines work. Oh, we pretty well understand what psychotropic medicines do when they reach the nerve cell. For example, most of the antidepressants used today block the reuptake of serotonin at the nerve cell, but we re still not sure why blocking serotonin reuptake gradually improves mood in someone with depression. This will lead to a tour, if you will, of what happens to a medication from the time the pill is swallowed, until it exerts its therapeutic effect. 

On the left (A) is a profile of the human brain, and on the right, a magnified view (B) of a slice through the brain as indicated by the dotted line. The anatomy of the brain consists of two hemispheres, each covered with multiple layers of important cells known as the cerebral cortex. White matter, which consists of wiring —projections from one cell to another—lies beneath the cerebral cortex, along with some groups of cells that perform various functions. The ventricles are cavities through which runs a substance called cerebrospinal fluid, which helps protect and cushion the delicate structures of the nervous system. 

In 1997 David Berliner, an anatomy professor turned entrepreneur, reported that when tiny amounts of a synthetic steroid were put on the VNO of men it made them relaxed and their heart rate and breathing rate slowed down. Clearly the VNO is not as inactive as we imagine. And searches for a human genome by a team at The Rockefeller University in New York in 2000 revealed that we still have five potentially functional genes that we share in common with the VNO pheromone receptors of mice. A human sex attractant may yet be developed and maybe sooner than we imagine because a great deal is being discovered about sexual chemistry - see box. 

In humans the olfactory receptor cells lie in the mucous membrane at the top of the air passages on either side of the nasal septum. They occupy a total area of about 2 cm, which is small compared with most other mammals. Evidence from both anatomy and embryology shows that the development of the olfactory tissue is closely linked to that of the pituitary gland which lies at the base of the brain. Among other functions the pituitary plays a key role in the coordination of sexual activity and reproduction. This ancient association between the sense of smell and the reproductive process is one that has important implications for work of the perfumer. 

Platzer, W. Poisel, W. Hafez, E.S.E. Evans, T.N. Functional anatomy of the human vagina. In The Human Vagina, North Holland Publishing Co. New York, 1978 39-53. 

Whereas compartmental models are abstract mathematical representations of an animal or a human body, in the form of a certain number of boxes, PBPK models describe the behavior of xenobiotics on the basis of the actual anatomy, physiology, and biochemistry of human beings and animals. Being realistically modeled on how the body functions, PBPK models take into consideration the complex relationships that exist between critical biological and physicochemical determinants such as blood flow, ventilation rates, metabolic rate constants, tissue solubilities, and binding to proteins (e.g., albumin and glycoproteins) or other macromolecules (e.g., DNA and hemoglobin). 

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