Presentation 11: Muscles Flashcards
Tendons
Connective tissue that connects muscle to bone (ex. collagen fibers) and include aponeuroses and fascia
Aponeuroses
Thin, flat sheets of connective tissue that connects muscle to bone or organs
Fascia
Layers of loose connective tissue that connect muscles to muscles
Origin
Where muscles attach to structures w/ fixed attachment
Insertion
Where muscles attach to structures and are free to move
Flexor
Bend limbs together (reduces the angle between two structures)
Extensor
Increases angle between 2 structures (straighten limbs out)
Adductor
move limbs towards midline of body (decrease angle)
Abductor
move limbs away from midline of body (increase angle)
Levator
Special kind of adductor to close jaw
Depressor
Special kind of abductor, opens jaw
Protractor
Contraction leads to projection of a part away from its base (eg. sticking tongue out)
Retractor
Brings projected part (from protractor) back towards its base
Constrictor
Surrounds tubes/openings and constricts (generally to close)
Sphincter
Type of constrictor e.g. controls digestive system
Dilators
acts opposite to constrictor to open orifice closed by constrictors/sphincters
Somatic muscles
one category of grouped muscles based on embryonic origin derive from myotomes and include body wall, tail muscles, hypobranchial muscles, tongue muscles, appendicular (limb) muscles, and the extrinsic muscles of the eye. generally voluntary
Visceral Muscles
one category of grouped muscles based on embryonic origin, derive from endoderm/migrated neural crest cells, include muscles surrounding organs, surrounding blood vessels, intrinsic muscles of the eye, branchiomeric muscles (gills in embryos), cardiac muscle, erectors
Skeletal Muscles
Striated, voluntary, associated w/ skeleton
Cardiac Muscles
Striated, involuntary, only in the heart
Smooth Muscles
Non-striated, involuntary, associated with visceral organs
Axial Muscles
Ancestrally segmented, metameric (have myomers and myosepta)
Associated with vertebral column
Horizontal septum divides into epaxial (dorsal) and hypaxial (ventral) muscles
At the gill area, dorsal = epibranchial and ventral = hypobranchial
Branchiomeric muscles
Associated w/ the gills
Gill arch #4 = constrictors, levators, interarcuals, and adductors (mandibular and hyoid arches lack adductors and interarcuals)
Appendicular muscles
Associated w/ limbs/appendicular skeleton
Extrinsic (start on axial skeleton -> appendicular)
Intrinsic (start on appendicular and go distally)
or primary/limb bud: new muscles, evolve with the limb
or secondary appendicular muscles: hypaxial or branchiomeric muscles
Branchiomeric constrictors
Associated w/ dorsal/ventral skeletal elements
ex. Dorsal constrictors: Adductor Mandibulae, Dorsal Hyoid Constrictor, etc.
ex. Ventral Constrictors: Intermandibularis and Interhyoideus
Branchiomeric Levators
Associated between dorsal gill elements and axial skeleton
ex. Levator palatoquadrati, Levator Hyomandibulae, Cucullaris
Branchiomeric Interarcuals
connect epibranchials to pharyngobranchials
Branchiomeric Adductors
epibranchial to ceratobranchial connection
Agnathan diversity
- Axial musculature not divided dorsa-ventrally
- Lack branchiomeric muscles
Gnathostomes
- Horizontal septum divides muscles into epaxial and hypaxial
- Hypob
- Hypobranchials help with opening and closing the jaws and gills
