THE PHILIPPINE WATER BUFFALO

average of 9.32 cm (3.66 in.) in length. Its minimum diameter
is 1.49 cm; the maximum 2.36 cm; and the average, 1.67
cm. The sigmoid flexure has a minimum length of 15.24
cm (6 in.), a maximum of 21.59 cm (8.5 in.), and an
average of 17.73 cm (6.98 in.). The diameter ranges from
2.54 to 3.63 cm, with an average of 2.79 cm. The root of
the organ has a minimum diameter of 3.33 cm and a
maximum of 4.9 cm, with an average of 4.19 cm. The
penis at the region of the body presents on its dorso-lateral
aspect a deep arteria profunda penis. The glans presents
on its dorsal and ventral surfaces finger-like projections
radiating from the thin tunica albuginea, the dorsal projection
being much longer than either of the two ventral ones. The
corpus cavernosum penis at the glans has finer trabeculae
and much more cavernous spaces embedded with more
minute blood vessels than the rest of the organ.
Keywords: histo-anatomical study, penis, Philippine
carabao
* The Philippine Journal of Veterinary Medicine, 3(2): 219-
232, 1964.
A-85
SOME OBSERVATIONS ON THE EXTRAMURAL AND
INTRAMURAL VASCULAR SUPPLY PATTERNS OF
THE UTERI AND OVARIES OF PHILIPPINE
CARABAO (Bubalus bubalis)*
E. L. Enriquez-Yap, Instructor, College of Veterinary Medicine, University
of the Philippines Diliman
The extramural and intramural vascular supply patterns of
the uteri and ovaries of the Philippine carabao heifers have
been successfully demonstrated by special injection
techniques employing various injection masses and
procedures. It is observed in the present study that the
vascular supply patterns described for cattle and sheep by
foreign workers are similar to that of the Philippine carabao
heifers. However, the latter ruminant has revealed some
vascular features distinct from those reported for the cow
and ewe. A correlation of the present findings on the vascular
supply patterns of the chief organs of the female reproductive
system with the present concept on the existence of the
so-called “uterine luteolytic system”, believed to be
responsible for the early regression phenomenon of the
cycling corpus luteum of the mammalian ovary, is also
herein discussed. It is highly possible that a similar uterine
luteolytic system, as reported in the cow and ewe, is
likewise present in the carabao heifer. The same type of
pathway and mechanism may also be operated along
similar manner, as clearly demonstrated by the carabao
heifer’s vascular anatomical organization. Further studies
34
ABSTRACT OF RESEARCHES ON
THE PHILIPPINE WATER BUFFALO
should be undertaken to definitely isolate and identify this
so-called “uterine luteolytic factor” in the Philippine carabao
heifers.
Keywords: vascular supply, uterus, ovaries, Philippine
carabao, Bubalus bubalis
*The Philippine Journal of Veterinary Medicine, 14(2): 1-
22, 1975.
A-86
CYTOARCHITECTURAL PATTERN OF THE
THYMUS GLAND OF THE PHILIPPINE CARABAO
(Bubalus bubalis) FETUS IN EARLY ANTE NATAL
DEVELOPMENT *
E. L. Enriquez-Yap, Instructor, College of Veterinary Medicine, University
of the Philippines Diliman
The cytoarchitectural pattern of the thymus gland of the
Philippine carabao (Bubalus bubalis) fetus at its very early
developmental stage was studied. The prenatal thymus is
a unilobed whitish structure, irregular in contour, and
measures from 0.25 – 0.5 in long. It is located on the
antero-ventral portion of the mediastinal space closely
related to the base of the heart and the roots of the great
blood vessels. The entire thymus is enclosed by a thin
fibrous capsule, which in turn gives origin to the septa and
series of trabeculae that subdivide the thymic parenchyma
into lobules. Each lobule consists of an outer, dark, critical
substance and an inner, pale, medullary substance.
Frequently, many of the lobules are devoid of the medullary
substance; thus, the lobule consists entirely of the cortical
substance with the small lymphocytes (thymocytes) as
the predominating cellular elements. The medulla consists
mainly of large and medium thymocytes (immature forms):
some plasma and epithelial reticular cells are also present.
Plasma cells and many lymphocytes exhibiting mitotic
figures are more common in the cortex than in the medulla.
The thymic bodies or Hassal’s corpuscles, in different
stages of development, a common feature of the medulla,
are specifically diagnostic for the carabao prenatal thymus.
However, not all the medulla exhibit thymic bodies. The
presence of mitotic figures, as exhibited by the lymphocytes,
strongly suggests that the prenatal thymus is the primary
organ involved in lymphopoiesis. The presence of plasma
cells, small lymphocytes (thymocytes) and epithelial
reticular cells is evidence that the prenatal thymus is already
a major contributor of immunologically competent cells
which are the constituents of the specific immune system
of the carabao body, specifically, humoral (antibody) and
cell-mediated immune systems. Generally, the
cytoarchitectural pattern of the prenatal carabao thymus