Comparative Comparative AnatomyAnatomyMusclesMuscles

Note Set 8Note Set 8

Chapter 10Chapter 10

MusclesMuscles

Two muscle groups:Two muscle groups: Somatic musclesSomatic muscles

Operate head, trunk, limbsOperate head, trunk, limbs Locomotion and orientationLocomotion and orientation

Visceral musclesVisceral muscles Operate visceral skeletonOperate visceral skeleton Digestion and respiratory movementsDigestion and respiratory movements

Cranial Nerves to Cranial Nerves to MusclesMuscles

Figure 10.1: Facial nerves to muscles

Figure 10.2: Cranial nerves

Two Muscle TypesTwo Muscle Types

Somatic musclesSomatic muscles Skeletal muscleSkeletal muscle Striated and voluntaryStriated and voluntary

Visceral musclesVisceral muscles Smooth muscleSmooth muscle Non-striated and involuntaryNon-striated and involuntary Exception- branchiomerics Exception- branchiomerics

(unsegmented)(unsegmented)

Skeletal MusclesSkeletal Muscles

AxialAxial Trunk and tailTrunk and tail

AppendicularAppendicular Insert on girdles, fins, or limbsInsert on girdles, fins, or limbs

BranchiomericsBranchiomerics Attached to visceral skeletonAttached to visceral skeleton

AxialAxial SharkShark

Epaxial and hypaxial Epaxial and hypaxial musclesmuscles

Body wall musclesBody wall muscles AmphibiansAmphibians

Epaxials above Epaxials above transverse processtransverse process

Hypaxials along Hypaxials along body wall properbody wall proper

MammalsMammals Epaxials subdividedEpaxials subdivided Hypaxials more Hypaxials more

complexcomplex

Figure 10.3: Trunk muscles of vertebrates.

Hypaxial and Epaxial Hypaxial and Epaxial MusclesMuscles

Figure 10.4: Epaxial and hypaxial muclesFigure 10.5: Specific epaxial muscles

Abdominal Muscle Groups in Abdominal Muscle Groups in AmniotesAmniotes

EpaxialsEpaxials Transversospinalis, Transversospinalis,

longissimus, longissimus, iliocostalisiliocostalis

HypaxialsHypaxials Dorsomedials, Dorsomedials,

laterals, ventralslaterals, ventrals Laterals- external Laterals- external

oblique, internal oblique, internal oblique, and oblique, and transverse abdominustransverse abdominus

Ventral- rectus Ventral- rectus abdominusabdominus

Figure 10.6: Epaxial and hypaxial muscles

Head RegionHead Region

Figure 10.8- Axial muscle origin and innervation in vertebrate embryo.

Figures 10.7: Myotomes in the head, neck, and thoracic regions of the embryo.

Head RegionHead Region In branchial region, somites are broken In branchial region, somites are broken

downdown Ventral slips of postbranchial somites Ventral slips of postbranchial somites

become become hypobranchialhypobranchial musculature musculature

Hypobranchial muscles give rise to:Hypobranchial muscles give rise to: SternohyoidSternohyoid SternothyroidSternothyroid OmohyoidOmohyoid Tongue muslcesTongue muslces

GeniohyoidGeniohyoid HyoglossusHyoglossus StyloglossusStyloglossus GenioglossusGenioglossus Lingualis propriaLingualis propria

Appendicular MusclesAppendicular Muscles

ExtrinsicExtrinsic Origin on axial skeleton or fascia of Origin on axial skeleton or fascia of

trunktrunk Insert on girdles and limbsInsert on girdles and limbs

IntrinsicIntrinsic Origin on girdles or proximal skeletal Origin on girdles or proximal skeletal

elements of appendageselements of appendages Insert on more distal skeletal elementsInsert on more distal skeletal elements

Intrinsic MusclesIntrinsic Muscles

Figure 10.9: Intrinsic muscles of pectoral girdle and forelimbs of mammals and their homologues in reptiles.

BranchiomericsBranchiomerics

Arises from lateral plate Arises from lateral plate mesodermmesoderm

Mandibular (1Mandibular (1stst) arch) arch Hyoid archHyoid arch Arches IV to VIArches IV to VI

BranchiomericsBranchiomerics Mandibular (1Mandibular (1stst) arch) arch

Intermandibularis- digasticIntermandibularis- digastic Adductor mandibulae- Adductor mandibulae-

masseter, temporalismasseter, temporalis Hyoid archHyoid arch

Sphincter colliSphincter colli Platysma and mimeticsPlatysma and mimetics

integumentary musclesintegumentary muscles Arches IV to VIArches IV to VI

Trapezius, sternomastoid, Trapezius, sternomastoid,

cleidomastoidcleidomastoid

Figure 10.10: Branchiomeric muscles of gnathostomes.

Branchiomeric MusclesBranchiomeric Muscles

Figure 10.11: Branchiomeric muscles and their innervations.

Extrinsic Eye MusclesExtrinsic Eye Muscles

Six eyeball musclesSix eyeball muscles 2 obliques2 obliques

Superior and Superior and inferior on anterior inferior on anterior portionportion

4 rectus4 rectus Arise in posterior Arise in posterior

portion of orbitportion of orbit Innervated by Innervated by

oculomotor, oculomotor, trochlear, and trochlear, and abducensabducens

Figure 10.12: Innervation of eye muscle in embryo.

Extrinsic Eye MusclesExtrinsic Eye Muscles

Figure 10.13: Dorsal view of extrinsic muscles of the left eyeball.

Figure 10.14: Lateral view of extrinsic muscles of eyeball in humans.

DiaphragmDiaphragm

Mammalian muscle structureMammalian muscle structure Covers lungs and heart in abdominal Covers lungs and heart in abdominal

cavitycavity

Figure 10.15: Human diaphragm.

Dermal or Integumentary Dermal or Integumentary MusclesMuscles

Fish & tailed Fish & tailed amphibians- skin is amphibians- skin is firmly attached to firmly attached to musculaturemusculature

Sphincter colli- first Sphincter colli- first muscle to move skinmuscle to move skin Subdivides down Subdivides down

neck- platysmaneck- platysma Extrinsic and Extrinsic and

intrinsic muscle intrinsic muscle groupsgroups

Figure 10.16: Evolution of mammalian facial muscles. Shows sphincter colli (SC) spreading into platysma (P).

ExtrinsicExtrinsic Integumentary Muscles Integumentary Muscles Costocutaneous muscles- allows rectilinear Costocutaneous muscles- allows rectilinear

motion (reptiles--snakes)motion (reptiles--snakes) Panniculus carnosus-sheet surrounds bodyPanniculus carnosus-sheet surrounds body Cutaneous maximus- to shake skin (higher Cutaneous maximus- to shake skin (higher

mammals)mammals) Patagial muscles- bat wingsPatagial muscles- bat wings Auricularis- moves human earAuricularis- moves human ear Caninus muscle- arises with aggressionCaninus muscle- arises with aggression

IntrinsicIntrinsic Integumentary Muscles Integumentary Muscles Arrectores plumarum (birds) & arrectores Arrectores plumarum (birds) & arrectores

pilorum (mammals)- errects hair and featherspilorum (mammals)- errects hair and feathers

Specialized MusclesSpecialized Muscles

Electric organsElectric organs In fishIn fish Modified hypaxial musclesModified hypaxial muscles

Figure 10.17: Electric eel.

Literature CitedLiterature CitedFigure Figure 10.1- http://www.city.ac.uk/optometry/Biolabs/cranial.1- http://www.city.ac.uk/optometry/Biolabs/cranial

%20nerves/cranial_nerves_lab.htm%20nerves/cranial_nerves_lab.htm

Figure Figure 10.2- .2- http://mywebpages.comcast.net/epollak/PSY255_pix/PSY255_pix.hthttp://mywebpages.comcast.net/epollak/PSY255_pix/PSY255_pix.htmm

Figure Figure 10.3, .3, 10.8, .8, 10.9, .9, 10.11, .11, 10.12, 10.13, 10.16- Kent, George C. .12, 10.13, 10.16- Kent, George C. and Robert K. Carr. Comparative Anatomy of the Vertebrates. 9and Robert K. Carr. Comparative Anatomy of the Vertebrates. 9thth ed. McGraw-Hill, 2001.ed. McGraw-Hill, 2001.

Figure Figure 10.4 & .4 & 10.5- .5- http://www.mut.ac.th/~vet/Anat-html/muscle/muscle.htmlhttp://www.mut.ac.th/~vet/Anat-html/muscle/muscle.html

Figure Figure 10.6, .6, 10.10- http://people.eku.edu/ritchisong/342notes6.htm.10- http://people.eku.edu/ritchisong/342notes6.htm

Figure Figure 10.7- .7- http://connection.lww.com/products/sadler/imagebank.asp

Figure Figure 10.14- .14- http://www.bmb.leeds.ac.uk/illingworth/motors/myosin.htmhttp://www.bmb.leeds.ac.uk/illingworth/motors/myosin.htm

Figure Figure 10.15- http://whyfiles.org/204endurance_training/2.html.15- http://whyfiles.org/204endurance_training/2.html

Figure Figure 10.17- http://www.aqua.org/animals_electriceel.html.17- http://www.aqua.org/animals_electriceel.html