Mammal Anatomy

Mammals are warmblooded vertebrates that have hair and breathe air. All females of this group have milk-producing mammary glands with which to feed their young. Mammals also have a diaphragm that pulls air into the lungs and a four-chambered heart for efficient circulation of blood. The teeth of mammals are specialized by size and shape for particular uses. 

Marine mammals are subdivided into four categories cetaceans, animals that spend their entire lives in the ocean sirenians, herbivorous ocean mammals pinnipeds, web-footed mammals and marine otters. Animals in all four categories have the same characteristics as terrestrial mammals, as well as some special adaptations that enable them to survive in their watery environment. 

The cetaceans, which include whales, dolphins, and porpoises, have streamlined bodies, horizontal tail flukes, and paddle-like flippers that enable them to move quickly through the water. Layers of blubber (subcutaneous fat) insulate their bodies and act as storage places for large quantities of energy. Their noses (blowholes) are located on the tops of their heads so air can be inhaled as soon as the organism surfaces above the water. 

Manatees and dugongs are the only sirenians. These docile, slow-moving herbivores lack a dorsal fin or hind limbs but are equipped with front limbs that move at the elbow, as well as with a flattened tail. Their powerful tails propel them through the water, while the front limbs act as paddles for steering. 

The sea otters spend their entire lives at sea and only come ashore during storms. They are much smaller than the other marine mammals. Even though otters are very agile swimmers and divers, they are clumsy on shore. Their back feet, which are flipperlike and fully webbed, are larger than their front feet. Internally, their bodies are adapted to deal with the salt in seawater with enlarged kidneys that can eliminate the excess salt. 

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Andres K. (1970). Anatomy and ultrastructure of the olfactory bulb in fish, amphibia, reptiles, birds and mammals. In Taste and Smell in Vertebrates (Wolstenholme G. and Knight J., eds.). J A Churchill, London, pp. 177-193. 

Kratzing J.E. (1982). The anatomy of the rostral nasal cavity and vomeronasal organ in Tarsipes rostratus (Marsupialia Tarsipedidae). Aust Mammal 5, 211-219. 

There are many similarities and differences in the anatomy and physiology of mammals, birds, and humans. It is outside the scope of this chapter to elaborate on the individual differences. For a brief review, refer to the third edition of Modern Pharmaceutics [9] and the second edition of Development and Formulation of Veterinary Dosage Forms [10]. 

The relevance of odours to mammals is also reflected in their anatomy. The olfactory bulbs are large relative to the rest of the forebrain and projections from... 

The anatomy of the northern fulmar s olfactory bulbs is better suited for powerful odor detection than for keen odor discrimination. The periglomerular and external tufted cells are relatively sparse. These cells are important for superior odor discrimination in macrosmatic mammals. The interior granule cells are also loosely organized (Meisami and Wenzel, 1987). 

The probable biological function of spermaceti oil has been deduced from research on the anatomy and feeding behavior of the sperm whale. These mammals feed almost exclusively on squid in very deep water. In their feeding dives they descend 1,000 m or more the deepest recorded dive is 3,000 m (almost 2 miles). At these depths, there are no competitors for the very plentiful squid the sperm whale rests quietly, waiting for schools of squid to pass. 

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. 

The same conclusions were also recorded for vertebrate herbivores. For example rabbits (Cuniculus europaeus) and hares (Lepus europaeus) clearly prefer the sweet plants and leave the bitter plants almost untouched, at least as long as there is an alternative food source. In conclusion, although taste perception in mammals and insects differs in many aspects, there also some similarities both in anatomy and in the function of the bitter taste perception. A comparison of the effects of alkaloids, as well as of other bitter compounds, will be assisted by further advances in the knowledge of the structure of taste genes and receptors. 

Nowak, Ronald M., et al. Walker s Marine Mammals of the World. Baltimore, Md. Johns Hopkins University Press, 2003. An overview on the anatomy, taxonomy, and natural history of the marine mammals. 

The antidiuretic mechanism in mammals involves two anatomical components a CNS component for the synthesis, transport, storage, and release of vasopressin, and a renal collecting-duct system composed of epithelial cells that respond to vasopressin by increasing their permeability to water. The CNS component of this mechanism, called the hypothalamiconeurohypophyseal system, consists of neurosecretory neurons with perikarya located predominantly in two specific hypothalamic nuclei, the supraoptic nucleus (SON) and the paraventricular nucleus (PVN). The long axons of magnocellular neurons in the SON and PVN terminate in the neural lobe of the posterior pituitary (neurohypophysis), where they release vasopressin and oxytocin. The relevant anatomy of the renal collecting-duct system is described in Chapter 28. 

NADPH diaphorase histochemistry is now the most widely used method for revealing the distribution of NOS in the nervous system. Using this approach, the anatomy of putative NO-producing neurons has been described in the nervous systems of several mammalian species, a variety of other vertebrate species, and invertebrates (7—11). A major advantage of the NADPH diaphorase method over such alternatives as NOS immunocytochemistry and in situ hybridization is that the only specific reagents required are NBT and NADPH, both of which can be easily purchased Moreover, to date anti-NOS antibodies have been raised only to forms of the enzyme obtained from mammals and... 

Nadol J.B. Jr. (1988). Comparative anatomy of the cochlea and auditory nerve in mammals. Hear. Res. 

Da Vinci studied human and animal anatomy. This inquiry led him to the understanding that there are many similarities between human and animal organs. It also led him to realize that all living systems could be viewed within a larger framework. From da Vinci s vantage point, differences between mammals are insignificant and, in fact, a unified picture of nature can and does emerge. This concept was rediscovered several centuries later in the scientific community by systems scientists. In fact, only recently, in the second half of the twentieth century, has the science of the holistic... 

These are problem relative - there is a model for the blood system of a mammal and another for the nervous system, both abstracted from the body of the animal in question. To create an analytical model the anatomist must be able to observe the body of the animal in question as a concrete source of the abstract lay out of the various anatomical systems that can be represented in diagrams. Newton s model of the solar system as a system of perfect material spheres obeying Kepler s laws of motion and the inverse square law of gravitational attraction was derived by abstraction and ideahzation of observable fears of the actual solar system (Frigg 2010 251-268). Analytical models can be wholly pictorial as in anatomy or they can be abstract and partially mathematical as in the Newtonian cosmology. 

Mammalian Olfaction, Reproductive Processes and Behavior" (1976) which was edited by one of the wave of younger researchers, R. L. Doty, deals specifically with mammals, as the title shows. It contains up-to-date information on the role of smell in the reproductive behaviour and endocrinology of mammals, and in addition, accommodates chapters on the anatomy, physiology and development of the nasal chemosensory pathways and an important critique of the pheromone concept in mammalian chemical communication by J. R. Beauchamp, R. L. Doty, D. G. Moulton and R. A. Mugford. A review of reproductive endocrine influences on human nasal chemoreception emphasizes the pressing need for more intensive critical investigation of the behavioural role of olfaction in humans, a line of research which, in fact, Doty subsequently followed up. 

The microscopic anatomy of glomus cells in vertebrates has been described in the aortic and carotid bodies of mammals (59,88) and birds (48,68,71) and the carotid labyrinth of amphibians (40,49). Although there is reflex and neurophysiological evidence for 02-sensitive chemoreceptors in the gills of larval amphibia (44,45,83), they have not been examined microscopically. Reptiles do not appear to have distinct carotid bodies or labyrinths. However, clusters of glomus cells have been identified microscopically in the central cardiovascular region, in connective tissue around the pulmonary, carotid, and aortic arches in turtles and lizards (4,42,75). 

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