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bone examined under a mieroscope will demonstrate the appearance, as
.shown in Figs. 4 and 5.
The minute structure of bone is examined in five divisions s—viz. («)
the Haversian canals (6) the bony
; Fig
lamellae (c) the Sharpey or perforat-
;
ing fibres (r/) bone lacunae (c) can-
; ;
aliculi ; and (/) bone-cells.
(a) The Haversiax Canals
(Figs. 4 and 5) are named after their
discoverer, Clopton Havers. They
of an inch
are from yglg-Q-th to 2-oir^h
in diameter, occasionally being found
as small as ytfVo^^^ of an inch. The
smallest canals are found near the
surface or outside of the boiie, the
larger ones near the medullary canal.
Their general direction is longitudi-
nal with the axis of a long bone,
althougli they anastomose with .each
other by short or oblique branches
at varying angles,.while others pass
into the periosteum and the medul-
lary cavity, thus forming a reticu-
lated intercommunication by which
capillary blood- and lymph-vessels
pass, not only longitudinally, but from
the outer to the inner portion of the
bone. When the canals are not filled
Section Panllel to the suilice from the "^haft of
by the above vessels the remaining the I emur (niaenitied 100 tirae^) a Ha\ersnn
camlb li HciincL (roni the side r others seen
space is occupied by delicate loose fiom the surface in 1 unellce which me tut hor
izontali\
connective tissue enclosing cellular
elements identical with the bone marrow, hereafter to be described.
(h) The Boxy La:mella is divided into three systems—viz. (1) the
Haversian, (2) interstitial, and general or (3) circumferential systems.
(1) The Haversian or Concenfrie System is a series of concentric ring.^
immediately surrounding each Haversian canal, varying in number from
four to twenty according to the age of the formation. All the laminoe
do not form complete circles, some terminating between two others.
•
Frequently the rings are oval in shape, this form depending to some
extent on the cutting of the section. If cut obliquely to the canal, both
the rings and canal have an oval appearance, though the canal is not
always in the centre of its system.
(2) The Interstitial Si/stcni:—The lamellae of this system are com-
posed of bands of osseous tissue of varying thickness, running in dif-
ferent directi(ms between the Haversian and the circumferential systems.
(3) The Circumferential or Parietal System.—The lamellae here are
principally found upon the surface of bone, although they are also seen
passing through the interstitial system, and even next to the medullary
cavity. They have a general direction parallel to the surface of the
bone.
bone examined under a mieroscope will demonstrate the appearance, as
.shown in Figs. 4 and 5.
The minute structure of bone is examined in five divisions s—viz. («)
the Haversian canals (6) the bony
; Fig
lamellae (c) the Sharpey or perforat-
;
ing fibres (r/) bone lacunae (c) can-
; ;
aliculi ; and (/) bone-cells.
(a) The Haversiax Canals
(Figs. 4 and 5) are named after their
discoverer, Clopton Havers. They
of an inch
are from yglg-Q-th to 2-oir^h
in diameter, occasionally being found
as small as ytfVo^^^ of an inch. The
smallest canals are found near the
surface or outside of the boiie, the
larger ones near the medullary canal.
Their general direction is longitudi-
nal with the axis of a long bone,
althougli they anastomose with .each
other by short or oblique branches
at varying angles,.while others pass
into the periosteum and the medul-
lary cavity, thus forming a reticu-
lated intercommunication by which
capillary blood- and lymph-vessels
pass, not only longitudinally, but from
the outer to the inner portion of the
bone. When the canals are not filled
Section Panllel to the suilice from the "^haft of
by the above vessels the remaining the I emur (niaenitied 100 tirae^) a Ha\ersnn
camlb li HciincL (roni the side r others seen
space is occupied by delicate loose fiom the surface in 1 unellce which me tut hor
izontali\
connective tissue enclosing cellular
elements identical with the bone marrow, hereafter to be described.
(h) The Boxy La:mella is divided into three systems—viz. (1) the
Haversian, (2) interstitial, and general or (3) circumferential systems.
(1) The Haversian or Concenfrie System is a series of concentric ring.^
immediately surrounding each Haversian canal, varying in number from
four to twenty according to the age of the formation. All the laminoe
do not form complete circles, some terminating between two others.
•
Frequently the rings are oval in shape, this form depending to some
extent on the cutting of the section. If cut obliquely to the canal, both
the rings and canal have an oval appearance, though the canal is not
always in the centre of its system.
(2) The Interstitial Si/stcni:—The lamellae of this system are com-
posed of bands of osseous tissue of varying thickness, running in dif-
ferent directi(ms between the Haversian and the circumferential systems.
(3) The Circumferential or Parietal System.—The lamellae here are
principally found upon the surface of bone, although they are also seen
passing through the interstitial system, and even next to the medullary
cavity. They have a general direction parallel to the surface of the
bone.
