externum. 3, Ligamentum annulare radii. 4, Ligamentum cubiti teres.
5, A portion of the ligamentum capsulare cubiti. 6, Distal extremity
of humerus. 7, Ulna. 8, Radius.
_C._ Muscles of the outside surface of the arm. 1, Tensor patagii
longus. 2, Extensor digitorum communis. 3, Tensor patagii brevis. 4,
Anconeus. 5, Flexor carpi ulnaris. 6, Biceps. 7, Triceps. 8.
Deltoid. 9, Brachialis anticus. 10, Flexor metacarpi radialis. 11,
Extensor ossis metacarpi pollicis. 12, Extensor metacarpi radialis
longior. 13, Extensor indicis longus.
]
The _ligamentum ulnare carpi radialis_ is a short ribbon-like ligament
which passes over the above-mentioned ligaments and is attached to the
inner surface of the os carpus radialis.
The _ligamentum ulnare carpi radialis internum_ is a strong ligament
which originates on the inner part of the elbow. It extends to the upper
rim of the base of the main digit.
The _ligamentum radiale carpi radialis externum_ originates on the
outside of the head of the middle digit and inserts to the superior
tuberculum carpi radialis of the radius.
The _ligamentum carpi radialis internum_, a short ligament, extends from
the inside of the head of the main digit to the inner rim of the carpi
radialis.
The _ligamentum carpi interosseum_ is located between the carpal bones.
The _ligamentum ulnare metacarpi internum_ is spread out between the
processus styloideus of the ulna and the tuberositas muscularis on the
upper side of the middle finger base at a point where the second and the
third metacarpi separate.
The _ligamentum ulnare metacarpi externum_ extends from the tubercle of
the distal extremity of the ulna, on the dorsal side, to the tubercle on
the base of the metacarpus.
_Ligamentum radiale metacarpi_ extends from the head of the inner digit
to a point near the tuberculum muscularis of the radius.
The _ligamentum transversum ossis carpi radialis et metacarpi_ is
located between the inferior tuberculum ossis carpi radialis and the
first metacarpal bone.
There is another ligament between the tuberculum superiorus carpi
radialis and the first metacarpal bone.
The _ligamentum ossis carpi radialis internum et metacarpi_ extends from
the inner surface of the carpus radialis to the tuberositas muscularis
of the radius.
The _ligamentum ossis carpi ulnaris externum et metacarpi_ extends from
the ulnar carpal bone to the tuberculum of the metacarpal bone.
The _ligamentum ossis carpi ulnaris internum et metacarpi_ extends from
the processus uncinatus of the ulnar carpal bone to the tuberositas
muscularis of the metacarpal bone.
=Ligaments of the Finger.=—The _ligamentum pollicare_ connects the thumb
with the first metacarpal bone.
The _ligamentum anterius ossis metacarpi et primæ phalangis digiti
secundi_ extends from the tuberculum articulare metacarpi, of the
proximal end of the metacarpus, to the tuberculum articulare of the
first phalanx of the second or large finger. Similarly attached, are
also an internal and a posterior ligament, or _ligamentum internum_ and
_ligamentum posterius_.
The three phalanges are all provided with capsular ligaments, or
ligamenta capsularia, which bind together the several phalanges.
The small or third finger is connected to the metacarpus by a capsular
ligament, the _ligamentum capsulare_, and by an interosseous ligament,
or _ligamentum interosseum digitorum_, to the first phalanx of the
second finger.
=Ligaments of the Pelvis.=—The obturator foramen, formed by the ilium
and the ischium, is covered by a broad membranous ligament (Fig. 4, No.
29).
The oblong foramen, or foramen oblongum, and the foramen ischiadicum,
formed by the ischium and the pubis are covered by broad membranous
ligaments (Fig. 4, Nos. 29 and 60).
_Poupart’s ligament_ or _ligamentum Poupartii_, quite small in fowls,
extends from the anterior lower rim of the ilium to the pelvic cavity,
and is inserted at the bottom of the acetabulum.
Another broad ligament originates from the posterior rim of the ischium
and is attached to the square surface of the first coccygeal vertebra.
The _ilio-pubic ligament_ extends from the pubic spine to the last
rudimentary rib.
=Ligaments of the Hip-joint= (Fig. 25, _F_).—The hip-joint is made up of
the ilium, ischium, pubis and femur and is a deep ball-and-socket joint.
The cavity or acetabulum is called a cotyloid cavity.
The hip-joint is provided with three ligaments.
The _ligamentum capsulare femoris_ is attached around the rim of the
cotyloid cavity and around the rim of the articular head of the femur
(Fig. 25, No. _F_, 4).
The _ligamentum teres_, or _round ligament_, is a very short ligament
which closes the hole at the floor of the cotyloid cavity, at which
point it is attached. It is also attached to the head of the femur.
The _ligamentum ilio-sacrale_ strengthens the hip-joint capsule. It
passes from the lower anterior rim of the os ilii, extending over the
capsule to the neck of the femur to which it is attached.
=The Ligaments of the Knee-joint= (Figs. 16 and 17).—The knee-joint is
made up of the femur, patella, tibia and fibula, and is provided with
the following ligaments:
The _ligamentum extero-laterale genu_ is a strong ligament extending
from the condylus externus femoris, or external femoral condyle to the
outer surface of the head of the fibula, or capitulum fibulæ. From this
head there passes inward, a strong ligament to a point between the femur
and fibula (Fig. 25, No. _D_, 4).
[Illustration:
FIG. 16.—Ligaments and muscles of the hind extremity.
_A._ A transverse section through the tibial or tarsal cartilage,
front view. 1, Gastrocnemius tendon. 2, Flexor perforatus annularis
primus pedis. 3, Flexor perforans digitorum profundus. 4, Flexor
perforatus indicis secundi pedis. 5, Extensor longus hallucis. 6,
The articular surface. 7, Ligamentum capsulare ossis tarsi. 8,
Flexor perforatus medius secundus pedis. 9, Flexor perforatus
indicis secundus pedis. 10, Tendons of the extensor muscles.
_B._ Knee-joint. Inside view of femoro-tibial articulation. 1,
Anterior ligamentum cruciatum. 2, Internal ligamentum laterale genu.
3, Anterior patellar ligament. 4, Patella. 5, Distal end of femur.
6, Proximal end of tibia. 7, Location of meniscus or pad of
fibrocartilage.
_C._ Anterior view of tibio-tarsal articulation. 1, Distal end of
tibia. 2, Its articular surface. 3, Ligamentum anticum. 4, Proximal
end of metacarpus. 6, Pad of fibrocartilage.
_D._ The dorsal surface of the coccyx. 1, The bilobate oil gland. 2,
Its duct. 3, Levator coccygis.
_E._ Inside view of pelvis and thigh. 1, Obturator internus. 2,
Ambiens. 3, Vastus internus. 4, Internal ligamentum laterale genu.
5, Tibialis anticus. 6, Loop through which the tibialis anticus
passes. 7, Adductors of the thigh. 8, Loop for the extensor tendon.
]
The _ligamentum intero-laterale genu_ extends from the outer surface of
the internal condyle of the tibia, or condylus internus tibiæ. It gives
off a thin ligamentous slip which enters the joint and is attached to
the inner half-moon shaped pad of fibrous cartilage, or meniscus, which
it draws backward by the flexion of the knee (Fig. 16, No. _B_, 2).
The _ligamentum popliteum_ arises from the fossa poplitea of the distal
extremity of the femur and extends downward to the posterior rim of the
head of the tibia.
The _anterior ligamentum cruciatum genu_ originates from the fossa
poplitea and extends outward antero-laterally to the rim of the head of
the tibia (Fig. 25, No. 6).
The _posterior ligamentum cruciatum genu_ is a short, strong ligament
which originates from the cavity of the internal condyle of the femur,
or condylus internus femoris, and inserts into the internal glenoid
cavity of the tibia (Fig. 25, No. 1) or cavitas glenoidalis interna.
The meniscus of the femoro-tibial articulation is divided into four
parts, as follows: first, the _internal adhesio cornu antici
cartilaginis lunatæ_; second, the _posterior adhesio cornu antici
cartilaginis lunatæ_; third, the _external cornu cartilaginis lunatæ_;
fourth, the _anterior cornu antici cartilaginis lunatæ_. The latter
originates between the condyles and passes around the ligamentum
cruciatum genu posticum (Fig. 16, No. _B_, 7).
The inner semi-lunar fibrous cartilage is well developed and is joined
by two ligaments between the femoral and the tibial surfaces (Fig. 25,
No. 1).
The external semi-lunar cartilage lies in a cavity between the external
femoral condyle and the head of the fibula (Fig. 25, No. 2).
The fibrous cartilages are bound posteriorly by a ligament, and by a
second ligament to the head of the fibula, or capitulum fibulæ. Both
pads of fibrous cartilage are connected by a transverse ligament called
the _ligamentum transversale commune_ (Fig. 25, No. 5).
The patella is provided with several ligaments, as follows:
The _anterior patellar ligament_, broad, strong, and irregular in
thickness, extends from the inferior margin of the patella to the rim of
the second tibial crest (Fig. 16, No. _B_, 3).
The _ligamentum capsulare capituli fibulæ_ is spread out between the
head of the fibula, or capitulum fibulæ, and the superficies glenoidalis
peronea tibiæ.
[Illustration:
FIG. 17.—Muscles and tendons of the head and posterior extremity.
_A._ Section of neck with superficial muscles removed. 1,
Obliquo-transversales. 2, Interspinales. 3, Intertransversales. 4,
Interarticulares.
_B._ Head showing muscles. 1, Beak. 2, Nostril. 3, Tongue. 4,
Sublingual salivary gland. 5, Pterygoideus. 6, Stylo-hyoideus. 7,
Temporal. 8, Flexor capitis inferior. 9, Rectus capitis lateralis.
10, Rectus capitis posticus major. 11, Trachelo-mastoideus. 12, Eye.
13, Mylo-hyoideus. 14, Genio-hyoideus. 15, Biventer maxilla. 16,
Digastricus. 17, Rectus capitis anterior minor.
_C._ Foot of hen showing tendons. 1, Flexor perforans digitorum
profundus. 2, Flexor perforatus medius primus pedis. 3, Sheath at
joint through which tendon passes. 4, Flexor perforatus indicis
primus pedis. 5, Flexor perforatus medius secundus pedis. 6, Flexor
perforatus annularis primus pedis. 7, Flexor longus hallucis.
_D._ Outside view of leg of hen. 1, Biceps flexor cruris. 2,
Semitendinosus. 3, Loop through which biceps flexor cruris passes.
4, Tibialis anticus. 5, Flexor perforatus indicis secundus pedis. 6,
Flexor perforatus medius primus pedis. 7, Gastrocnemius. 8, Flexor
perforatus annularis primus pedis. 9, Flexor perforatus medius
secundus pedis. 10, Extensor longus hallucis.
]
The _ligamentum tibio-fibulare_ extends from the head of the fibula, or
capitulum fibulæ, to the inner surface of the external crest, or crista
externa tibiæ, of the tibia (Fig. 25, No. 3).
The _ligamentum interosseum_ is a delicate ligament located between the
tibia and fibula (Fig. 25, No. 4) which very early becomes ossified.
=Ligaments of the Tibio-metatarsal Joint= (Fig. 16).—The tibio-tarsal
joint is made up of the tibia and metatarsus.
The _ligamentum capsulare ossis tibio-metatarsi_ connects the tibia and
the metatarsus and surrounds the joint (Fig. 16, Nos. _A_, 7 and _C_,
7).
The _ligamentum externum_, a long strong ligament, originates on the
upper and outer surface of the external condyle, or condylus externus of
the tibia and is attached to the upper rim of the os metatarsi (Fig. 23,
No. 15).
The _ligamentum anticum_ is spread out between the fossa
intercondyloidea of the tibia and the tuberculum ossis metatarsi of the
proximal end of the metatarsus (Fig. 16, No. _C_, 3). Just posterior to
this ligament, there is an interosseous ligament, the _ligamentum
interosseum_.
A semi-lunar pad of fibrous cartilage, the _cartilago semi-lunaris_ is
located between the outer distal extremity of the tibia and upper
articular surface of the metatarsus (Fig. 16, No. _C_, 6). Its concave
portion is directed anteriorly and receives an insertion from the
ligamentum externum, or external ligament.
The tendon Achillis (Fig. 16, No. _A_, 1) may become ossified.
=Ligaments of the Toes= (Fig. 16).—In addition to the capsular
ligaments, which all true joints have, we find the following in
connection with the toes:
The _ligamentum superius_ and the _ligamentum inferius_ connect the
second toe with the great toe, or hallux.
The _ligamentum laterale externum_ and the _ligamentum laterale
internum_ unite the bases of the second, third and fourth toes to the
lateral faces of the trochleas of the inferior extremity of the
metatarsus.
The bases of the toes are held together by the _ligamenta transversa_.
All the rest of the toes are held together by the _ligamenta capsularia
digitorum pedis_ and by two lateral ligaments, namely: the _ligamentum
laterale externum_ and the _ligamentum laterale internum_.
MYOLOGY
=Kinds and Structure of Muscles.=—Muscles are highly specialized
structures which have the property of contractility when stimulated, and
thus produce motion. Muscular tissue is sometimes called flesh. Two
kinds of muscles are recognized; muscles of locomotion and visceral
muscles.
The muscles of locomotion may be in masses of different shape attached
to the skin, the _dermal_, or to the skin and skeletal structure, the
_dermo-osseous_, or from one bone to another, the _skeletal_. The
visceral muscles form sheets and make up a portion of the wall of many
of the hollow organs, such as the intestines, the stomach, the gizzard,
the esophagus, and the blood-vessels. A special type of muscle forms the
heart.
When classified with reference to structure, muscular tissue is divided
into three types, as follows: voluntary-striated, involuntary, and
involuntary-striated. The microscopic examination of each of these types
of muscle shows it to be made up of fibers, these fibers to be made up
of muscle cells, the muscle cell to be inclosed in a delicate tubular
sheath, or membrane, called the _sarcolemma_. This membrane, tough and
elastic, isolates each fiber. The bundles of fibers, called _fasciculi_,
are surrounded by a fibrous sheath, which is called the _perimysium
internum_; and the entire muscle has likewise an investing sheath of
connective tissue, called the _perimysium externum_. The muscular cells
show a longitudinal striation marking the fibrillæ, and they also show a
cross striation. Nuclei are found just beneath the covering, or
sarcolemma, in the striated muscle cell (Fig. 77, No. 2). In the
involuntary and in the involuntary-striated muscle cell, the nuclei are
centrally located.
The _voluntary-striated muscles_ consist of cylindrical fibers and with
a few exceptions, are under the control of the will. A muscle of this
type, the regular skeletal form, usually has at each extremity a fibrous
structure, called a tendon, by means of which it is attached to the
bones. The intermediate fleshy portion of the muscle, in case of
considerable bulk, is called the belly of the muscle.
The _involuntary_, _non-striated_, or _smooth muscle_, cells are
spindle-shaped, long, and pale in color (Fig. 77, No. 1). The cells lie
end to end forming fibers. These fibers do not terminate in tendons, but
are arranged in sheets and aid in forming the walls of the digestive
tract, to which they give the power of contraction and expansion.
_Involuntary-striated_, or _heart muscle_ (Fig. 77, No. 4), occupies an
intermediate position between the two muscles just described. It is
composed of cells which branch, are somewhat rectangular. They possess
both longitudinal and transverse striation. Among the fibers is found a
small amount of connective tissue, as in the former types of muscle,
which gives support to the blood-vessels and nerves.
=Fascia.=—The term fascia is applied to membranous expansions, differing
materially in strength, texture, and relations. Fascia is composed of
loosely arranged white fibrous connective tissue. At least two layers
may usually be distinguished, the superficial fascia and the deep
fascia.
Below the skin is the _superficial fascia_, which forms a continuous
covering over the whole body and serves to attach the skin to the
underlying structure.
The _deep fascia_ more densely constructed, may be attached to the
skeleton, ligaments, and tendons.
When the fascia spreads out, becomes denser, and acts as a continuation
of a muscle, it is called an aponeurosis.
=The Muscular Nomenclature.=—In the fowl there are 162 muscles, single
or in pairs. These muscles are named from their location, as the
lingualis; others from their attachments, as the dermo-temporalis; some
from their form, as the rhomboideus; others from their use, as the
flexor or extensor; and still others from their direction, as the
transversus.
THE DERMAL MUSCLES
Birds are provided with a system of delicate muscles divided into
numerous fasciculi, which harmoniously act upon the feather quills and
collectively agitate the plumage. These are the dermal muscles. This
group is divided into two subgroups: the true dermal muscles, that is,
those that have their origin and insertion to the under surface of the
skin; and the dermo-osseous, those that originate on the surface of some
bone and insert to the inner surface of the skin.
TRUE DERMAL MUSCLES
Dermo-frontalis
Dermo-dorsalis
Dermo-tensor patagii
Dermo-humeralis
Dermo-pectoralis
=Dermo-frontalis.=[3] _Location._—This muscle is somewhat rudimentary
and may be entirely absent. It is located in the frontal region and is
about 2 or 3 centimeters long and not so wide.
Footnote 3:
The classification of Shufeldt is used.
_Origin and Insertion._—Closely attached to the skin.
_Shape._—Flat and rather rectangular.
_Relations._—Superiorly with the skin and inferiorly with the frontal
bones.
_Action._—By contraction the feathers on the top of the head lie flat.
Those above the eyes are elevated.
=Dermo-dorsalis.= _Location._—In the median line of the neck and back.
_Origin and Insertion._—Adhering closely to the skin, it generally
becomes lost at the occiput; it is most highly developed in the
mid-cervical region, and it gradually disappears over the caudal region.
_Shape._—Delicate and ribbon-shaped.
_Relations._—Superiorly it is attached to the skin. Fat sometimes
surrounds the muscle.
_Action._—By contraction it raises the feathers along the superior part
of the neck and dorsal region.
=Dermo-tensor Patagii.= _Location._—Between the root of the neck and top
of the shoulder.
_Origin and Insertion._—Attached to the skin in the region of the
anterior part of the root of the neck, some fibers passing obliquely
upward and blend with fibers of the dermo-temporalis. It blends, by a
slender tendon, with that of the tensor patagii longus.
_Shape._—A bundle of muscular fibers later becomes thin, delicate, and
triangular in shape.
_Relations._—Externally to the skin.
_Action._—Auxiliary to the tensor patagii longus. A tensor of this
region.
The patagii are associated with the wing fold of skin which fills the
angle between the arm and forearm. This fold contains elastic tissue and
muscle.
=Dermo-humeralis.= _Location._—Lateral thoracic region.
_Origin and Insertion._—Fan-like delicate fibers from the skin in the
abdominal integument, contracting into a long narrow fasciculus of
fibers, again spreading out in fan-shape to be inserted to the tendon of
the pectoralis major, just below its insertion.
_Shape._—Triangular, fan-shape.
_Relations._—Superiorly with the skin.
_Action._—Controls the skin in this region. The anterior end being
fixed, the muscles are raised; and the posterior end acting as the fixed
point, the feathers are caused to lie close to the body.
=Dermo-pectoralis.= _Location._—On each side of the chest, lying in a
longitudinal manner.
_Origin and Insertion._—Attached to the skin on either side of the
thorax corresponding to the dermo-dorsalis. Anteriorly it disappears
over the region of the origin of the cleido-trachealis, and posteriorly
just behind the tips of the post-pubic parts of the pelvis.
_Shape._—Thin, delicate.
_Relations._—Superiorly with the skin.
_Action._—The anterior part acting as the fixed point, the feathers of
the chest are raised; and the posterior end acting as the fixed point,
the feathers are made to lie flat.
THE DERMO-OSSEOUS MUSCLES
Dermo-temporalis
Platysma myoides
Dermo-cleido dorsalis
Cleido-trachealis
Dermo-spinalis
Dermo-iliacus
Dermo-ulnaris
=Dermo-temporalis= (Fig. 18, No. 1). _Location._—From the temporal
region down the side of the neck to the anterior part of the thoracic
region.
_Origin._—By a broad tendinous attachment from a small depression above
and anterior to the temporal fossa. From here the fibers pass upward and
backward and then downward.
_Insertion._—A few fibers blend with those of the cleido-trachealis. The
fibers are then lost upon the skin in front and opposite the
shoulder-joint. Some of the fibers blend with those of the dermo-tensor
patagii.
_Shape._—Long, flat, and ribbon-shaped. The lower portion consists of
delicate fibers.
_Relations._—Superior to the temporal muscle and sphenotic process.
Superior to the cleido-trachealis and inferiorly to the shoulder-joint.
The superior portion touches the skin throughout its entire length.
_Action._—A tensor of the lateral cervical integument. It is an
auxiliary to the tensor patagii.
=Platysma Myoides.= _Location._—The inferior portion of the throat.
_Origin._—From the lower margin of the rami of the jaw. Just inferior to
the attachment of the masseter.
[Illustration:
FIG. 18.—Muscles of the upper neck region, 1, Dermo-temporalis. 2,
Cornu of the os hyoideum. 3, Carotid artery. 4, Jugular vein. 5,
Pneumogastric nerve. 6, Esophagus. 7, Trachea.
]
_Insertion._—From the point of origin it spreads out into a thin
fan-like layer and meets its fellow in the median raphe. It is attached
to the skin in this region.
_Shape._—A very thin fan-shaped muscle.
_Relations._—Closely adherent to the skin.
_Action._—Assists in supporting the lingual apparatus and superior
larynx. Compresses and elevates the part.
=Dermo-cleido Dorsalis.= _Location._—Anterior shoulder region.
_Origin._—From the upper mesial part of the clavicular bone.
_Insertion._—Three fasciculi forming a fan-like arrangement attached to
the skin in the shoulder-joint and scapular region. The extremities of
the fasciculi may meet in the median line of the dorsal region and merge
with the dermo-dorsalis.
_Shape._—Three fasciculi forming a fan-shaped radiation.
_Relations._—Superiorly with the skin. Inferiorly with the
shoulder-joint.
_Action._—Contracting with the origin as the fixed point, they brace the
skin over the forepart of the back. With the integumental attachment as
the fixed point, they aid in the act of respiration.
=Cleido-trachealis.= _Location._—Extending from the shoulder to the
superior laryngeal region.
_Origin._—From a small area on the antero-inner part of the middle of
the arm of the furcula.
_Insertion._—The fibers pass upward and become flattened and attached to
the skin and dermo-temporalis muscle. They touch each other on the
anterior border of the superior larynx, the trachea, and the skin over
these parts.
_Shape._—A slender bundle of muscles.
_Relations._—Superiorly the skin, and internally the larynx and the
trachea.
_Action._—Controls the skin region of this part of the neck.
=Dermo-spinalis.= _Location._—In the region of the shoulder.
_Origin._—In an attenuated fascia from the crest of the neural spines of
the first, the second, and the third dorsal vertebræ.
_Insertion._—To the skin in a broad pale stratum, over the scapular
region.
_Shape._—Thin, pale, and very delicate.
_Relations._—Superiorly with the skin, and inferiorly with the shoulder.
_Action._—Controls the skin of the region.
=Dermo-iliacus.= _Location._—Along the back on either side of the spine.