Page 237 - My FlipBook
P. 237
—
BLOOD-VESSEL SYSTEM OF THE HEAD, ETC. 247
brandies pass through the intervertebral foramina in close relation with
the cervical nerves, and supply the bodies of the vertebrae, the spinal
cord and its membranes, and anastomose at the upper portion of the
cord with the ascending pharyngeal artery.
The luferioi' Laryngeal Artery is not uniform in size, and arises from
the inferior thyroid in close proxijnity to the thyroid body. It passes
upward, accompanied by the recurrent or interior laryngeal nerve,
behind the inferior angle of the thyroid cartilage, and is distributed
to the muscles and mucous membrane of the larynx.
The Tracheal Artery is very constant in its existence. It arises from
the inferior thyroid opposite the transverse process of the seventh cervi-
cal vertebra, and passes downward behind the trachea to a point in close
relation to the bifurcation of the trachea. Here the artery divides into
branches which supply the trachea, bronchial tubes, lymphatic glands,
and lower portion of the longus colli muscle, and anastomoses with
the intercostal and bronchial arteries.
The Suprascapular Artery (transverse scapular or transverse humeral)
is about 3^ mm. (^ inch) in calibre. It arises from the thyroid axis,
and passes outward and downward to the scapula. Its branches are the
thoracic, acromial, supraspinous, and infraspinous.
The Transversalis Colli, or Transverse Cervical Artery, arise from the
thyroid axis, and passes outward in a tortuous course to the superior
angle of the scapula, where it divides into the superficial cervical and
posterior scapular arteries.
The Internal Mammary and Superior Intercostal Arteries are import-
ant to the head and neck, as they by their relation with other arteries
complete the system of collateral circulation. The supetior gives olf
the deep cervical, which communicates with the arteria princeps cervicis
of the occipital artery.
THE VEINS.
The veins are those vessels of the body through which the blood is
returned to the heart. They originate at the termination of the capil-
laries (minute vessels between the arteries and veins) throughout the
body, .and unite and anastomose to form larger vessels as they approach
the heart. They inosculate more freely than do the arteries, and, unlike
these, contain throughout their course numerous valves which open
toward the heart and j)revent regurgitation of the l)lood. The veins
are divided into two groups—systemic and pulmonary.
The Systemic Veins are those which collect the blood from all portions
of the body excepting the lungs. They are divided into two sets
those that collect the blood from the head, upper and lower extrem-
ities, and the greater ])ortion of the body ; and those that collect the
blood from the alimentary canal and its glandular ai)paratus below the
diaphragm, and terminate in the portal system. The systemic veins are
again divided into superficial and deep.
The Pulmonary Veins, four in number, tM'o for each lung, collect the
blood, which is arterial, from the capillaries of the lungs and convey it
to the left auricle of the heart.
BLOOD-VESSEL SYSTEM OF THE HEAD, ETC. 247
brandies pass through the intervertebral foramina in close relation with
the cervical nerves, and supply the bodies of the vertebrae, the spinal
cord and its membranes, and anastomose at the upper portion of the
cord with the ascending pharyngeal artery.
The luferioi' Laryngeal Artery is not uniform in size, and arises from
the inferior thyroid in close proxijnity to the thyroid body. It passes
upward, accompanied by the recurrent or interior laryngeal nerve,
behind the inferior angle of the thyroid cartilage, and is distributed
to the muscles and mucous membrane of the larynx.
The Tracheal Artery is very constant in its existence. It arises from
the inferior thyroid opposite the transverse process of the seventh cervi-
cal vertebra, and passes downward behind the trachea to a point in close
relation to the bifurcation of the trachea. Here the artery divides into
branches which supply the trachea, bronchial tubes, lymphatic glands,
and lower portion of the longus colli muscle, and anastomoses with
the intercostal and bronchial arteries.
The Suprascapular Artery (transverse scapular or transverse humeral)
is about 3^ mm. (^ inch) in calibre. It arises from the thyroid axis,
and passes outward and downward to the scapula. Its branches are the
thoracic, acromial, supraspinous, and infraspinous.
The Transversalis Colli, or Transverse Cervical Artery, arise from the
thyroid axis, and passes outward in a tortuous course to the superior
angle of the scapula, where it divides into the superficial cervical and
posterior scapular arteries.
The Internal Mammary and Superior Intercostal Arteries are import-
ant to the head and neck, as they by their relation with other arteries
complete the system of collateral circulation. The supetior gives olf
the deep cervical, which communicates with the arteria princeps cervicis
of the occipital artery.
THE VEINS.
The veins are those vessels of the body through which the blood is
returned to the heart. They originate at the termination of the capil-
laries (minute vessels between the arteries and veins) throughout the
body, .and unite and anastomose to form larger vessels as they approach
the heart. They inosculate more freely than do the arteries, and, unlike
these, contain throughout their course numerous valves which open
toward the heart and j)revent regurgitation of the l)lood. The veins
are divided into two groups—systemic and pulmonary.
The Systemic Veins are those which collect the blood from all portions
of the body excepting the lungs. They are divided into two sets
those that collect the blood from the head, upper and lower extrem-
ities, and the greater ])ortion of the body ; and those that collect the
blood from the alimentary canal and its glandular ai)paratus below the
diaphragm, and terminate in the portal system. The systemic veins are
again divided into superficial and deep.
The Pulmonary Veins, four in number, tM'o for each lung, collect the
blood, which is arterial, from the capillaries of the lungs and convey it
to the left auricle of the heart.
