Anatomical Overview

A slightly more detailed airway organization suggested by the ICRP Task Group on Lung Dynamics divides the airway into five regions nasal 

FIGURE 5.14 (a) Anatomical overview of che human respiratory tract. The larynx generally 

Ambient air entering tbe oral cavity during oral breathing confronts a variety of surface structures. Inspired air initially passes between highly vascular lips and across the teeth, w hich can be viewed as a series of heat transfer fins. The tongue and buccal surfaces (both rough, highly vascular 

FIGURE 5.15 Cross-section of human nasal turbinates at various positions along the airway. Distances indicated are from the nares. The medial surface in each cross-section represents the nasal septum. (Modified from Guilmette et al. ) 

The estimated number of tubes in each airway generation depends on the bifurcation model used in describing the tracheobronchial tree. Though bronchial bifurcations are asymmetric, symmetric models, exemplified by Weibel, or asymmetric models, such as one suggested by Horsfield, can 

---

Adenosine A-l receptor density was examined in rat brain by means of quantitative autoradiography to obtain a detailed anatomical overview of the changes during ageing (Murillo-Rodriguez et al. 2004). A-l receptor binding was assessed in young, old, and senescent animals of 3, 24, and 30 months old, respectively. 

In-depth discussions of the anatomy of the eye and adnexa have been adequately covered elsewhere in the pharmaceutical literature [13-17] and in recent texts on ocular anatomy. Here a brief overview is presented of the critical anatomical features that influence the nature and administration of ophthalmic preparations. In this discussion, consideration will be given primarily to drugs applied topically, that is, onto the cornea or conjunctiva or into the palpebral fornices. Increasingly, drugs are being developed for administration by parenteral-type dosage forms subconjunctivally, into the anterior and posterior chambers, the vitreous chamber, Tenon s capsule, or by retrobulbar injection. 

J. G. Hall, The lymphatic system in drug targeting An overview, in Targeting of Drugs. Anatomical and Physiological Considerations (G. Gregoriadis and G. Poste, eds.), Plenum Press, New York, 1985, p. 15. 

The therapeutic outcome of topically applied agents used to control oral infections will depend on the characteristics of drugs that take advantage of the unique physiological and anatomical circumstances in the oral cavity. This section is a broad overview of important oral pharmacokinetic principles. 

The CNS can be grossly divided into the brain and spinal cord (Fig. 5-1). The brain is subdivided according to anatomic or functional criteria. The following is a brief overview of the general organization of the brain and spinal cord, with some indication of where particular CNS drugs tend to exert their effects. This chapter is not intended to be an extensive review of neuroanatomy—a more elaborate discussion of CNS structure and function can be found in several excellent sources.25 28,40,41... 

This chapter provides an overview of factors affecting dermal absorption. Factors influencing absorption are among others related to the skin (e.g. anatomical site, difference between species, metabolism, etc.) and the exposure conditions (e.g. area dose, vehicle, occlusion and exposure duration). In order to provide relevant information for the risk assessment of pesticides, dermal absorption studies should take these aspects into account. With respect to the methods being used nowadays for the assessment of dermal absorption, it is important to realize that neither in vitro nor in vivo animal studies have been formally validated. Available data from various in vitro studies, however, indicate that the use of the total absorbed dose (i.e. the amount of test substance in the receptor medium plus amount in the skin) could be used in a quantitative manner in risk assessment. Tape stripping of the skin can be adequate to give a good indication of test chemical distribution, and hence its immediate bioavailability. 

Mansour A, Watson SJ (1993) Anatomical disdibudon of opioid receptors in mammalians an overview, hr Opioids I (Herz A, ed), pp 79—105. Berlin Springer-Verlag. 

Hall JG. The lymphatic system in drug targeting an overview. In Gregoriadis G, Poste G, eds. Targeting of Drugs—Anatomical and Physiological Considerations. New York Plenum Press, 1985 15. 

The second part will deal with anatomical aspects of transmitter Glu and provide an overview of the neuronal populations that use Glu as a neurotransmitter. As Glu immunogold data have not been reviewed in this Handbook Series (except in chapters on specific regions, e.g. Jones, 1998) we will devote much of Section 3 to these. Reference to earlier work with other techniques will largely be made through citation of review articles (e.g. Ottersen and Storm-Mathisen, 1984a Fonnum, 1984, 1991 Storm-Mathisen and Ottersen, 1988 Ottersen, 1991 Fonnum and Hassel, 1995 Storm-Mathisen et al., 1995). The reader is referred to these publications for a complete bibliography. 

---