Muscles Read pages 31 -35 in your shark book https://www.youtube.com/watch?v=BXOTb4ZxKDI&feature=related#t=9.101

Muscles Types of muscles Skeletal Locomotion - movement Posture Generation of Heat Support Joints Tendons Ligaments Cardiac muscles of the heart involuntary pumps blood throughout the body

Cardiac/Smooth Muscle involuntary controls the contractions of the blood vessels forces blood through arteries/veins lines the outside of certain organs stomach – aids in digestion of food

Skeletal Muscles Muscle Movement Attach at no less than 2 points Origin Where the muscle is attached to the least movable bone (skeleton) Insertion Attached to bone that moves toward the origin Action Result of movement Voluntary Actions

Skeletal Muscles Muscles can only contract Abductors move away from midline Adductors move toward midline Flexors reduce angle Extensors increase angle Protractors move limb forward Refractors move limb backward

Action of Muscles Flexion bend at a joint Extension straighten, increasing the angle Adduction move appendage toward sagittal midline Abduction move appendage away the sagittal midline Supination turn palm of hand upward walk on outside of foot Pronation turn palm of hand downward walk on inside of foot Rotation move structure about a point

Action of Muscles Circumduction when distal end describes a circle while the proximal end remains fixed

Muscles = Myotomes (Myomeres) Epaxial above the horizontal septum Hypaxial below the horizontal septum Branchial area of the gills Opening and closing of gill pouches during exchange of gases during respiration Hypobranchial area of the pharynx Opening mouth for swallowing

Branchiometric Muscles Muscles of the gill (branchial) and head Specialized muscles to open and close the gill pouches as well as the opening and closing of the jaw 3 main groups Constrictors help with gill muscles, gill pouches Levators raise jaw and 5 gill arches Interarcuals act on the gill arch cartilages

Branchiometric Muscles Adductor Mandibulae large muscle below spiracle closes the jaw Intermandibularius ventral surface posterior to the jaw elevates the floor of the mouth to force water out of gill slits

Axial Muscles Skeletal muscles of trunk and tail Horizontal septum anchored to the dorsal and ventral ribs myosepta Linea alba connective tissue ventral hypaxial muscles that meet at the midline

Appendicular Muscles Operate the pelvic and pectoral fins Dorsal extensors Elevator Pectoral abductor Ventral flexors Depressor Pectoral adductor