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THE MUSCULAR SYSTEM
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The Muscular Cladogram depicts a nested hierarchy of anatomical features of animal muscular systems. All vertebrates posses the traits given at the node for the vertebrate ancestor (node 11). All tetrapods possess the traits given at the node for the tetrapod ancestor (node 15). All placental mammals possess the traits given at the node for the placental mammal ancestor (node 19). Apes consistently appear as a real, biological group—not a group of completely unrelated organisms which happen to share traits for no apparent reason. Placental mammals are a real group. Amniotes are a real group. Deuterostomes are a real group, etc. Biological groups are real—or at least there is an overwhelming amount of evidence that suggests that they are. MUSCULAR CLADOGRAM
1.
LUCA—Last common ancestor of all modern life on earth
2.
Ancestor of Protists, Plants,
Fungi, and Animals --actin and myosin (Amos, 2004; Egleman,
2003).
3.
Ancestor of Animals
4.
Ancestor of Animals with Tissues --musculo-epithelial cells in circular, longitudinal, and sometime
oblique layers (Fretter 56-8) --some
musculo-epithelial cells are striated and some
insert into mesoglea (Hickman, p. 137) --ctenophores
possess true muscle cells (Hickman, p. 181) --Twist expression first occurs in the entocodon,
the mesoderm-like layer from which muscle tissue differentiates in cnidarians
(Castanon, 2002). The
development of striated and smooth muscle from this third cell layer have
led some to consider cnidarians as tribloblastic
(Muller, 2003). --In
bilateran animals, some of the genes which are
essential for the embryonic formation of muscle are members of the basic
helix-loop-helix gene family (bHLH). Jellyfish are known to possess at least four
bHLH transcription factors.
The sequence, dimerization, and expression
of the JellyD1 protein in striated
muscle indicate that it is a homolog of
MyoD in bilaterans. Vertebrate MyoD genes,
which can form both homodimers and heterodimers, can form dimers with
JellyD. This
indicates that the striated muscle of jellyfish is homologous to that
of bilaterans (Muller, 2003).
5.
Ancestor Bilateran Animals --subepidermal and mesenchymal muscle
which is more similar to the muscle of higher animals (Hickman). --in addition to moving the body, muscle serves
both the mouth and reproductive structures. Beklemishev,
vol. 2) --peristalsis (Beklemishev, vol.
2)
6.
A nemertine-like ancestor
of complex bilateran animals --all
vertebrates and invertebrates ranging from nematodes to arthropods use
troponin and tropomyosin. a homolog
of titin is known in nematodes (Hoar, 1983,
p. 325).
7.
Coelomate Ancestor --Titin is known in arthropods (
8.
Deuterostome Ancestor
9.
Chordate Ancestor --Tunicates
do possess homologs of vertebrate genes involved
in heart formation, but typically fewer members than contained in vertebrate
gene families (Dehal, 2002 --myotomes since cephalochordates (Cameron, 2000)
10.
Craniate Ancestor --hypobranchial musculature (Romer,
p. 288) --both
fast and slow twitch muscles (Hardisty, p. 357). --myotomes from head region of jawless and cartilaginous fish
embryos suggest that the ancestral condition included pro-otic
somites whose muscles produced the muscles which
move the eye. The first pro-otic somite forms the superior rectus, inferior rectus, internal
rectus, and inferior oblique and is innervated
by III. The second pro-otic
somite forms the superior oblique, IV. The third becomes external rectus, abducens VI. (Weichert, 1970).
11.
Vertebrate Ancestor
12.
Gnathostome Ancestor --horizontal
septum divides epaxial and hypaxial
(dorsal and ventral) musculature (Romer, p.
282) --eye
muscles standardized (Romer, p. 291) --dorsal
and ventral fin musculature (Romer, p. 292) --branchiomeric musculature well developed (Romer, p. 306) --cucullaris (trapezius of tetrapods; the only branchial bar
levator which tetrapods
retain) (Romer, p. 307) --hyoid
arch and its musculature modified (becomes operculum) (Romer,
p. 309) --adductor
mandibulae (will divide in tetrapods
to form the temporalis, masseter,
and pterygoid muscles) (Kardong,
p. 393; Romer, p. 312) --epihyoideus (contributes to mammalian facial musculature including
platysma) (Kardong,
p. 393)
13.
Bony Fish Ancestor
14.
Sarcopterygian Fish Ancestor
15.
Tetrapod Ancestor --external
oblique produces serratus anterior, levator scapulae, and rhomboid muscles (Romer,
p. 287) --hypobranchial musculature produces glossus
and hyoid groups of muscles (Kardong, p. 378;
Romer, p. 288-9) --pectoralis, coracobrachialis, biceps
brachii, brachialis
(Romer, p. 295) --puboischiofemoralis internus (becomes
psoas, iliacus, and
pectineus muscles in mammals) (Kardong 387; Romer, p. 297) --ambiens or iliotibialis (sartorius in mammals) (Kardong,
p. 387; Romer, p. 297) --triceps
femoris of ampibians
(iliotibialis and femortibialis in
reptiles; quadriceps in mammals) (Romer, p.
297) --gluteal muscles (iliofemoralis in
reptiles) (Romer, p. 297) --puboischiofemoralis externus (develops
into obturator externus
and quadratus femoris
in mammals) (Kardong, p. 387; Romer,
p. 297) --ischiotrochantericus (develops into obturator
internus and gemellus
in mammals) (Kardong, p. 387; Romer,
p. 297) --gracilis muscles (puboischiotibialis
in reptiles) (Romer, p. 298) --gastrocnemius (Romer, p. 300) --operculum
lost and hyoid arch musculature expands into neck (Romer,
p. 309) --iliofemoralis (tensor fascia latae,
pyriformis, and gluteus muscles of mammals)
(Kardong, p. 387) --depressor
mandibulae (retained only as stapedius
in mammals) (Kardong, p. 393) --levatores arcuum (sternomastoid and cleidomastoid
in mammals (Kardong, p. 386) --latissimus dorsi, triceps, pectoralis (Kardong, p. 386) --hip
and leg muscles: tibialis anterior, peroneus longus, extensor digitorum longus, peroneus brevis, extensor digitorum brevis, caudofemoralis (Kardong, p. 386) --dorsalis scapulae and procoracohumeralis
longus (acromiodeltoid
and scapulodeltoid in mammals) (Kardong,
p. 386) --arm
muscles: extensor digitorum communis,
extensor carpi radialis,
extensor carpi ulnaris,
extensores digitorum breves, supinator, dorsal interossei, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, pronator profundus (quadratus), flexor palmaris (digitorum) profundus (Romer, p. 302-3) --interspinalis muscles (Webster, 1974)
16.
Amniote Ancestor --dorsalis trunci divides into medial,
intermediate, and lateral groups (Romer, p.
283; Kardong 382) --(and
fossil amphibians) external and internal intercostal
muscles develop from the external and internal obliques
(Romer, p. 284) --subvertebral muscles become more developed (Romer, p. 284) --levator palpebrae superioris for eyelid (and nictitating membrane in some) (Romer, p. 291) --latissimus dorsi and deltoid prominent
(Romer, p. 293) --subcoracoscapularis (subscapularis
in mammals) (Romer, p. 294) --scapulohumeralis (teres minor in
mammals) (Romer, p. 294) --musculature
of the dorsal forearm fairly standardized (Romer,
p. 294) --adductor
femoris (Romer, p.
298) --flexor
tibialis externus
and internus (hamstrings in mammals) (Romer,
p. 298) --pubotibialis (adductor longus in
mammals) (Romer, p. 298) --caudofemoralis (Romer, p. 298) --sternomastoid and cleidomastoid
develop from trapezius (Romer,
p. 309) --interhyoideus (forms digastric in
mammals) (Kardong, p. 393; Romer,
p. 310) --extensions of the oblique muscles form the
intercostal and scalene muscles of amniotes. (Webster,
1974; Weichert, 1970, p.512). --a longissimus coli
and levatores costarum
(Webster, 1974; Weichert,
1970, p.512). --sphincter
colli deep to the integument of the head (Weichert, 1970)
17.
Mammal Ancestor --epaxial musculature less segmented in nature; includes sacrospinalis (Romer, p. 284) --rectus abdominis produces the diaphragm
(Romer, p. 290) --caudal
muscles reduced (Romer, p. 290) --scapular
origin of deltoid on the spine (Romer, p. 293) --teres major produced from the latissimus
dorsi (Romer, p. 293) --dermal
panniculus carnosus
from pectoralis (Romer, p. 295) --the
reptilian supracoracoideus divides to become
the supraspinatus and infraspiantus
(Romer, p. 296) --homologue
of reptilian iliofibularis often lost (Romer, p. 297) --hyoid
arch musculature expands to form facial muscles (Romer,
p. 310) --pectoralis muscle splits to form the pectoralis
major, pectoralis minor, pectoantebrachialis,
and xiphohumeralis (Kardong,
p. 387 ) --biceps
with two heads (from the fusion of two ancestral muscles) (Kardong,
p. 387) --reptilian
gastrocnemius internus
forms gastrocnemius medialis
and flexor hallucis longus
in mammals (Kardong, p. 388) --reptilian
gastrocnemius externus
forms gastrocnemius lateralis,
soleus, and plantaris
in mammals (Kardong, p. 388) --intercostals are move developed (Webster, 1974; Weichert,
1970, p.512) --the
multifidus is a mammalian remnant of transversospinalis muscles in reptiles (Weichert,
1970, p. 513). --the
ancestral single sheet of the latissimus dorsi divides to form the latissimus
dorsi, the teres major
and cutaneous maximus in mammals (Webster,
1974, p.139; Hartman, 1933). --the
pectoralis splits and also forms part of the
cutaneous maximus. (Webster, 1974,
p.139; Hartman, 1933). --
remnants of the cranial portions of this ancestral rectus
abdominis in head region include the sternohyoid, sternothyroid, geniohyoid, omohyoid, and thyrohyoid. (Weichert, 1970).
--mammals
the reptilian sphincter colli differentiates
into facial muscles although they are poorly developed in most mammals. The outer layer of the sphincter colli (the platysma layer) forms
the auricularis frontalis,
orbicularis oculi, mentalis, quadratus labii inferiors, and zygomatic. The deep layer of the sphincter colli gives rise to muscles of the nose, the orbicularis oris, and buccinator muscles. (Weichert, 1970,
529).
18.
Therian Mammal Ancestor (Marsupials and Placentals)
19.
Placental Mammal Ancestor
20.
Primate Ancestor
21.
Anthropoid Primate Ancestor (monkeys, apes, and humans)
22.
Catarrhine Primate Ancestor (Old World Monkeys, apes and humans)
23.
Ape Ancestor --caudal
muscles converted into pelvic diaphragm -- flexor digitorum
brevis is intermediate between humans and lower primates (Hartman,
1933,p 172). -- usually lack the epitrochleo-anconeus
of lower primates, which was originally derived from the flexor carpi ulnaris (Hartman, 1933, p.
137) --a
deep head of the pronator teres (Hartman, 1933, p. 138). --a
radial origin of flexor digitorum sublimis
(Hartman, 1933, p. 138) --vestiges
of the muscles which are used in tailed primates to flex the tail usually
exist (such as the sacrococcygeus anterior in
humans). --the ancestral pubo-iliocaudalis
is attached to the visceral organs and becomes the levator
ani -- the pectoralis
minor inserts onto the coracoid process instead
of the arm (Hartman, 1933) 23A. Higher Apes —extensor
indicis usually doesn’t insert on digit IV (Gibbs,
2002) —rectus femoris with 2 heads (variable
in all but humans) (Gibbs, 2002) —articularis genus (Gibbs, 2002) --extensor pollicis brevis (Hartman, 1933, p. 141) --the latissimus dorsi developed an additional origin on the iliac crest.
(Hartman, 1933).
24.
African Ape Ancestor —origin
of flexor pollicis brevis
limited to flexor retinaculum and trapezium
(Gibbs, 2002) —flexor
digitorum superficialis
originates from intermuscular septum (Gibbs,
2002) —pronator teres obliquely oriented
(Gibbs, 2002) —flexor
pollicis longus from
anterior radius and interosseous membrane (Gibbs,
2002) —extensor
digitorum IV sends slips to digits III and V
(Gibbs, 2002) —origin
of coroacobrachialis from intermuscular
septum (Gibbs, 2002) —anterior
extension of coracobrachialis ussually
present (Gibbs, 2002) —origin
of extensor pollicis brevis
from ulna and interosseous membrane (Gibbs,
2002) --
extensor indicis usually doesn’t insert on digit
III (Gibbs, 2002) —teres minor inserts below greater tubercle (Gibbs, 2002) —origin
of subclavius on first rib only (Gibbs, 2002) —origin
of psoas major reaches S1 (Gibbs, 2002) —piriformis usually fused with gluteus medius
(Gibbs, 2002) —adductor
magnus and quadratus
femoris insertions meet (Gibbs, 2002) —peroneus brevis may insert onto
digit V proximal and middle phalanges (Gibbs, 2002) —origin
of soleus frequently on tibia (Gibbs, 2002) --although
the peroneus tertius
has frequently been described as a muscle which only exists in humans
as an adaptation to bipedal locomotion, it occasionally occurs in gorillas
and rarely in chimps (Hartman, 1933, p. 166). --the deep extensor layer is reduced (Hartman, 1933) --the psoas minor may be absent in African apes but seems constant
in other mammals (Hartman, 1933, p. 149). 24B. Humans and Chimps —origin
of extensor digitorum on antebrachial
fascia (Gibbs, 2002) —origin
of lateral head of triceps from lateral intermuscular
septum (Gibbs, 2002) —extensor
carpi ulnaris sometimes
extends to proximal phalanx V(Gibbs, 2002) —Teres major and minor share an origin from intermuscular septum (Gibbs, 2002) —reduction
of clavicular origin of pectoralis
major (Gibbs, 2002) —proximal
portion of tensor fascia lata fused to gluteus
maximus (Gibbs, 2002) —origin
of extensor digitorum on crural
fascia (Gibbs, 2002) —insertion
of abductor hallucis may include medial cuneiform
(Gibbs, 2002) —origin
of flexor digitorum brevis
on plantar aponeurosis (Gibbs, 2002) --frequently a coronoid origin
of the flexor digitorum sublimis;
(Hartman, 1933, p. 138). |
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