Author Archives: hanapisova

Development of cranial foramina

foraminaThere are plenty of reports about anatomical and morphological variation of cranial foramina; however, their developmental mechanisms fundamental for interpretation of such a variation and understanding of vital medical conditions related to their aberrant formation are poorly known. Cranial foramina transmitting the vessels and nerves emerge within the cranial bones which themselves show complex origin and development. Recent embryological study in chicks by Akbareian et al. (2015) presents development of cranial foramina in mesoderm derived occipital bone arising through endochondral ossification. Unexpectedly, the formation mechanism did not show any extensive apoptotic cell activity and target proliferation. Instead as a “clearing” mechanism forming the cavity of foramina was proposed localized restriction of ossification caused by the presence of vessel and nerve elements with minimal mesenchymal cell death. Further importance for morphological studies of foramina can bear a discovery that the shape of vessel dictates the overall shape of the foramen.

Hana Pisova



Age related changes of adult cranial morphology

lebka_urbanAge-related cranial morphological changes in adult humans are generally considered as minor or negligible. However, with age the adult human cranium undergoes non-pathological processes of thickening. In the case of hyperostosis frontalis interna, for example, thickening preferentially involves the inner part of frontal bones, influencing the cranial morphology. Recently, a geometric morphometric study of recent human crania also revealed age related cranial shape changes. The shape differences in males and females ranging between 20-99 years can be mainly detected in the cranial vault and at the anterior and middle cranial fossa. In contrast, no changes were found in the posterior cranial fossa. In the vault, there are corresponding morphological changes on the outer and inner surfaces. The authors suggest that some shape modifications can reflect the increase of grey matter volume in early age groups (up to 30 years), and its loss in older age groups. Hence, such age-dependent changes are supposed to be secondary consequences of the relationship between cranial morphology and brain volume. Males generally showed more marked differences. Nevertheless, the small sample size for each age group makes this study preliminary.

Hana Pisova

Australopithecus deyiremeda

Picture of the upper jaw of a recently discovered hominin species

New human ancestor species discovered in Ethiopia

Head cooling device

TUntitled-1he brain thermoregulation is an important issue from anthropology to medicine. The brain thermodynamic mechanisms in humans are still not well known and additional heat regulations in certain physiological and pathological conditions are crucial to prevent irreversible damages. Namely hyperthermia is a life-threatening condition causing severe functional alterations. The brain temperature can increase as a consequence of drug abuse, head injuries, strokes, etc. Releasing of the heat stress can be treated by plenty of invasive and non-invasive methods, systemic or selectively aimed. However, establishing new effective thermodynamic techniques to treat pathological conditions is still relevant issue. In craniotomies, the cooling method can consist of simple system of drainage tubes directly attached to the dural layers or brain passing a cooling liquid directly to the affected tissue. Such selectively aimed device can help the post-operative recovery and prevent possible complications. The principles of the device remotely reminds of radiator theory, possible thermoregulatory adaptation in human lineage ancestors proposed in paleoanthropology few decades ago.

Hana Pisova

Nonmetric trait database

SkullTo bring out scientific data from lifelong research and to offer them freely for the further investigation is a unique act in the field of anthropology and archaeology. The first comprehensive database with original data published already years ago by W. W. Howells consists of craniometric measurements. Recently, N. S. Ossenberg presented database composed of cranial nonmetric features including also complete methodological manual and documentation available for various types of analytical comparisons. Scores of tens of cranial morphological traits of more than 8000 individuals from various parts of the world are now open to comparative studies; most importantly, from several populations which are not accessible anymore due to American repatriation laws. So, let’s go ahead!

Hana Pisova

Old features with new characters

Modified according to Matsushima et al. 2014Studies in cranial morphology which consider at the same time soft and hard tissues are an indispensable source of information in medicine and evolutionary biology. Generally, medical studies use to provide rather descriptive analyses with direct relevance for, e.g. surgical treatment. However, combining different complementary approaches like computed tomography in living humans, microsurgery of cadavers, macroscopic inspection of dry skulls etc.,  we can supply quantitative data to understand normal and rare skeletal features, and assess the importance of specific traits in biological anthropology. A patent example is represented by the anatomical studies of blood vessels, analysing directly the vascular tissues but also their traces left on the cranial bones.

For instance, several types of intracranial orifice connections of posterior condylar emissary vein in the cranial base were recently identified. Following different course of condylar canal through which the vein is transferred through the bone it could be assessed with which venous structure the vein was interconnected. Additionally, the shifted location of the intracranial orifice can in specific cases indicate the presence of other venous structures as marginal sinus or occipital sinus which rarely leaves any visible routes in occipital bone although the actual prevalence in humans is high. Condylar canal belongs to skeletal nonmetric foraminal variants used as markers of phenotypic distances in various bioarchaeological targets. Traditionally, the major distinguishing value ascribed to nonmetric traits is their presence or absence; nevertheless, foramina express lower hereditary values in comparison with nonmetric traits of hyperostotic background. This could be explained by composite character of foraminal traits manifesting high variation in several aspects (e.g. number, branching patterns, ramification, bone position, size and length of orifices). Accordingly, it can be difficult to understand if and which specific morphological character can be used to evaluate biodistance discriminatory values. Medical and anatomical studies are essential in evidencing new unconsidered phenotypic variations which may become important in further bioarchaeological research, representing a promising way to improve our understanding of past populations.

                                                                                                     Hana Pisova