The calcium and phosphorus content of giraffe (Giraffa camelopardalis) and buffalo (Syncerus caffer) skeletons
Osteophagia, variable serum calcium (Ca) and phosphorus (P) concentration, high serum alkaline phosphatase activity, a high growth rate, and a large skeletal mass, all suggest that Ca and P requirements and availability are finely balanced in giraffes. The mineral content of some marker bones in skeletons obtained from adult male giraffes (browsers) and adult male […]
A Comparative Assessment of the Size of the Frontal Air Sinus in the Giraffe (Giraffa camelopardalis)
The current study examines the frontal air sinus of the giraffe (Giraffa camelopardalis) cranium with the aim of evaluating previously offered hypotheses as to why they have such an atypically voluminous frontal sinus relative to other artiodactyls. To date, no quantification of the frontal sinus in the adult or developing giraffe has been undertaken or […]
Structural evidence for insertion of collagen fibers to smooth muscle cells in the carotid arterial system of the giraffe (Giraffa camelopardalis)
Previous anatomical studies have failed to resolve the question relating to whether or not collagen fibers, like elastic fibers, are attached to smooth muscle cells in the arterial wall. The current ultrastructural study demonstrates the insertion of collagen fibers to the sacrolemmal dark areas in the smooth muscle cells of the carotid arterial system of […]
Origin of mean arterial and jugular venous blood pressures in giraffes
Using a mechanical model of the giraffe neck and head circulation consisting of rigid, ascending, ‘carotid’ limb, a ‘cranial’ circulation that could be rigid or collapsible, and a descending, ‘jugular’ limb that also could be rigid or collapsible, we have analyzed the origin of the high arterial and venous pressures in giraffe, and whether blood […]
The maximum attainable body size of herbivorous mammals: morphophysiological constraints on foregut, and adaptations of hindgut fermenters
An oft-cited nutritional advantage of large body size is that larger animals have lower relative energy requirements and that, due to their increased gastrointestinal tract (GIT) capacity, they achieve longer ingesta passage rates, which allows them to use forage of lower quality. However, the fermentation of plant material cannot be optimized endlessly; there is a […]
Giraffes, Rats, and Man — What is the importance of the ‘structural factor’ in normo- and hypertensive states?
The normal structural adaptation of heart and vessels to regional changes in load or/and tissue demands is surveyed with respect to its importance for cardiovascular function in normotension as well as in physiological (giraffes) and pathophysiological (e.g. human and rat primary hypertension) variants of high pressure states. At the local level it implies an entirely […]
Subfamily Giraffinae – Giraffe
Subfamily Giraffinae is a monotypic subfamily, represented by a single surviving species, the Giraffe Giraffa camelopardalis. The Giraffe , Giraffa camelopardalis, is the only extant representative of the genus Giraffa. Together with the only other living giraffid, the Okapi Okapia johnstoni, they represent the extant members of a previously more diverse group. This chapter covers […]
Jugular venous pooling during lowering of the head affects blood pressure of anesthetized giraffe
How blood flow and pressure to the giraffe’s brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the […]
On the origin, evolution and phylogeny of giraffes Giraffa camelopardalis
The origin, phylogeny, and evolution of modern giraffes (Giraffa camelopardalis) is obscure. We review here the literature and conclude that the proximate ancestors of modern giraffes probably evolved in southern central Europe about 8 million years ago (Mya). These ancestors appear to have arisen from the gelocid ancestral assemblage of 20–25 Mya via the family […]
The digestive morphophysiology of wild, free-living, giraffes
We have measured rumen-complex (rumen, reticulum, omasum, abomasum) and intestine (small and large combined) mass in 32 wild giraffes of both sexes with body masses ranging from 289 to 1441 kg, and parotid gland mass, tongue length and mass, masseter and mandible mass in 9 other giraffes ranging in body mass from 181 to 1396 […]