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Biomedical subjects

P F Harris

Publications and source records attributed to P F Harris.

At least 37 records · Page 2Linked to original sources
PubMed1980

A morphological and histological study of the postnatal development of intervertebral discs in the lumbar spine of the rabbit.

Some basic features in the development of the structure of the annulus fibrosus and nucleus pulposus in the rabbit, as described by previous workers, have been confirmed in the present study. However, the greater thickness of the anterior part of the disc, as compared with the posterior region, and the distinctive arrangement of lamellae in the posterior part of the disc, cannot be attributed, as conventionally claimed from studies of the human spine, to a secondary curvature in the lumbar spine associated with an upright posture: for these features are present in the lumbar spine of the quadrupedal rabbit with its primary curvature. Secondary ossification produces a plate-like epiphysis separating the growth cartilage from the intervertebral disc. A distinct cartilaginous plate, limiting the nucleus pulposus in the rabbit intervertebral disc, only becomes apparent when collagen fibres cease to traverse the area above and below the nucleus pulposus.

Animals↗
PubMed1979

A radiographic study of the human fetal spine. 3. Longitudinal growth.

Regression equations are presented which describe the growth in length of the various regions of the vertebral column in the human fetus. From 8 weeks on the thoracic is always the longest region and the sacral the shortest, while the lumbar region is longer than the cervical. From the regression equations predictions of fetal vertebral length can be made from fetal age: this should be useful in obstetric practice when diagnostic ultrasound techniques are being employed for the diagnosis of growth disorders and skeletal abnormalities. A different developmental pattern emerges when average 'vertebral units' for each region are compared. The lumbar vertebrae are always the largest with the thoracic, cervical and sacral vertebrae being progressively smaller.

Anthropometry↗
PubMed1977

Adaptation of museum specimens for use in anatomical teaching aids.

Colour transparencies are prepared of a re-colourized anatomical specimen after placing labels temporarily in position to indicate specific structures. The specimen is also radiographed to show skeletal and soft tissue structures and radio-opaque materials and letters may used to indicate certain parts. Having mounted the specimen it can then be placed in a teaching carrel together with the radiographs and a back-slide projector for viewing the colour transparencies. The student is guided through an examination of the specimen using a script or soundtape. Frequent cross-reference is made between the actual specimen, the colour transparencies on which certain parts of the specimen have been labelled, and also the radiographs. The examination is followed by self-assessment questions relevant to the specimen and these may include identification of structures on a photograph of the specimen and on duplicate radiographs. In the final section of the aid, the answers of the self-assessment questions are given.

Anatomy↗
PubMed1977

A radiographic study of the human fetal spine. 1. The development of the secondary cervical curvature.

The present study has shown that the secondary curvature in the cervical spine of the human fetus develops at a much earlier age than has been thought. It may, in fact, develop soon after the embryo first acquires a neck and begins to uncurl. The early appearance of this curvature may be related to the early development of function in the muscles responsible for head extension, this movement being a basic component of the primitive "gasp" reflex. It is further suggested that, although the embryo develops in flexion, the traditional assumption that such flexion is a consequence of fetal musculoskeletal development must be questioned, and the expression "normal fetal flexed position" is probably misleading, since it does not take into account the wide range of movements of which the fetus is capable.

Embryo, Mammalian↗
PubMed1976

Ultrasound monitoring of fetal movements. A method for assessing fetal development?

Human fetal movements in utero have been analysed by conventional compound B-scan ultrasound techniques. With practice, movements of specific parts of the fetus can be readily recognised, and even as early as the 6th week after conception gross movements of the whole embryo are visible. Monitoring of fetal movements as an indication of normal or abnormal fetal development appears to have been neglected, and future studies in this important area of antenatal paediatrics are suggested.

Arm↗
PubMed1976

A radiological study of morphology and growth in the human fetal colon.

A radiological study has been made of the colon in 64 human fetuses between 11 and 20 weeks gestation (64-160 mm crown rump (CR) length). A dynamic picture of colon development was obtained from analysis of the radiographs. The findings challenge textbook descriptions, but can be interpreted in terms of the ultimate morphology of the colon. According to the morphology of the proximal (pre-splenic) part of the colon, there are three types of colon. In Type 1 it lies transversely, in Type 2 it is oblique in direction, and Type 3 has a postnatal form with ascending and transverse elements. Although the Type 1 predominates in smaller fetuses and the type 3 is most common in larger fetuses, there is some overlap in their distribution. The ileocaecal junction does not descend, but actually slightly ascends as the fetus grows. The splenic flexure grows in a distinctly cranial direction, and at almost three times the rate of the ileocaecal junction. Thus, as the fetus develops, the ileocaecal junction and splenic flexure grow further apart, and this determines the change from a Type 1 to a Type 2 colon. The divergence of the ileocaecal junction and splenic flexure appears to be related to different rates of growth in the colon, the distal (post-splenic) part growing almost half as fast again as the proximal (pre-splenic) part. The more mature (Type 3) form of colon appears to result from conversion of the Type 2 following early adhesion between the proximal colon and the second part of the duodenum.

Anthropometry↗
PubMed1975

Estimating the age of the human foetus from crown-rump measurements.

When data from various sources were compared, it was found that estimates of foetal age based upon crown-rump measurements varied considerably. These variations are probably related to the positions in which the foetuses were measured. Tables relating foetal age to foetal length should therefore specify the precise posture in which the foetus was placed for measurement. A standard readily reproducible position is proposed for the foetus when recording its length and it is suggested that crown-rump length should be related to "conceptual" age instead of the more conventional "menstrual" age.

Anthropometry↗
PubMed1975

Bone marrow.

Explore the source record for details and available documents.

Bone Marrow↗