Arrangement of Fascicles Remember: a fascicle is several sheathed muscle fibers wrapped by a coarse fibrous membrane

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Arrangement of Fascicles Remember: a fascicle is several sheathed muscle fibers wrapped by a coarse fibrous membrane Slide 2 Arrangement of Fascicles Common fascicle patterns: Circular When fascicles are arranged in concentric rings (sphincters) Convergent When the fascicles converge to a single insertion Triangular or fan-shaped Parallel The length of the muscle runs parallel to the long axis of the muscle Strap like Slide 3 Arrangement of Fascicles Common fascicle patterns: Fusiform Modified parallel form Has a spindle-shaped muscle Has an expanded belly or gastor Pennate Short fascicles Attach obliquely to a central tendon Unipennate insert into one side of the tendon Bipennate inserts into opposite sides of the tendon Multipennate inserts into multiple places of the tendon Slide 4 Head and Neck Muscles Facial Muscles Frontalis covers the frontal bone from the cranial aponeurosis to the skin of the eyebrow Raises the eyebrows Occipitalis covers the posterior aspect of the skull Pulls the scalp Orbicularis Oculi fibers run in circles around the eyes Allows eye closing, squinting, blinking and winking Slide 5 Frontalis Slide 6 Slide 7 Occipitalis Slide 8 Orbicularis Oculi Slide 9 Slide 10 Head and Neck Muscles Facial Muscles Orbicularis Oris the circular muscle of the lips Opens the mouth and protrudes the lips (kissing muscle) Buccinator fleshy, runs horizontally across the cheek Inserts into the orbicularis oris Flattens the cheek Doubles as a chewing muscle Slide 11 Orbicularis Oris Slide 12 Buccinator Slide 13 Head and Neck Muscles Facial Muscles Zygomaticus extends from the corner of the mouth to the cheek smiling muscle Raises the corners of the mouth Slide 14 Slide 15 Slide 16 Head and Neck Muscles Chewing Muscles Buccinator already mentioned Masseter covers the angle of the lower jaw Runs from the zygomatic process of the temporal bone to the mandible Closes the jaw Temporalis fan-shaped, overlying the temporal bone Inserts into the mandible and is a synergist to the masseter Slide 17 Masseter Slide 18 Temporalis Slide 19 Head and Neck Muscles Neck muscles Platysma single sheet-like muscle Covers the anterolateral neck Originates from the connective tissue of the chest muscle and inserts in the area around the mouth Pulls the corners of the mouth inferiorly Sternocleidomastoid paired muscle Two headed muscles, one on each side of the neck One head arises from the sternum, the other from the clavicle Head fuses before insertion into the mastoid process of the temporal bone Flex the neck Slide 20 Platysma Slide 21 Sternocleidomastoid Slide 22 Slide 23 Trunk Muscles Divided into Anterior and Posterior muscles Anterior Pectoralis Major large fan-shaped muscle covering the upper part of the chest Origin is in the sternum, should girdle, and first 6 ribs Insertion is on the proximal end of the humerus Flexes the arm Slide 24 Slide 25 Slide 26 Trunk Muscle Anterior Muscles Intercostal Muscles deep muscles of the ribs External intercostal muscles are used in breathing Raise the rib cage (air in) Internal intercostal muscles deeper than the external Used in breathing Lower the rib cage (air out) Muscles of the Abdominal Girdle reinforce the body trunk Consists of : rectus abdominis, external and internal obliques, and transverse abdominis. Look like plywood Muscles run in different directions Slide 27 Intercostal Muscles Slide 28 Slide 29 Trunk Muscle Anterior Rectus oblique strap-like muscles Most superficial muscles of the abdomen Run from the pubis to the rib cage Flex the vertebral column Depress the abdomen during defecation and child birth External oblique paired superficial muscles Make up the lateral walls of the abdomen Fibers run downward and medially from the ribs to the illium Flex the vertebral column, and rotate the trunk Slide 30 Slide 31 Trunk Muscles Anterior Internal oblique paired muscles Deep to the external obliques Fibers run at right angles to those of the external obliques Rise out of the iliac crest and insert into the last 3 ribs Transversus abdominis deepest muscle of the abdomen Fibers run horizontally across the abdomen Arises from the lower ribs and iliac crest Inserts into the pubis Slide 32 Internal Oblique Slide 33 Slide 34 Trunk Muscles Posterior Muscles Trapezius Most superficial muscles of the posterior neck and upper trunk Together form a diamond shape Have a broad origin From the occipital bone of the skull to the end of the vertebral column Flare to insert into the scapular spine and clavicle Slide 35 Slide 36 Trunk Muscles Posterior Muscles Latissimus Dorsi Large flat muscle pair which covers the lower back Origin is in the lower spine and ilium Inserts into the proximal end of the humerus Extends and abducts the humerus Slide 37 Slide 38 Trunk Muscle Posterior Muscle Erector Spinae Back extension prime mover Deep muscles of the back Have 3 muscle columns Longissimus Iliocostalis Spinalis They span the entire length of the vertebral column They are back extensors and help bending at the waist Slide 39 Slide 40 Trunk Muscles Posterior Muscles Deltoid Fleshy triangular shaped Form the shoulder Origin is in the spine of the scapula to the clavicle Insertion is at the proximal end of the humerus Prime mover of arm abduction Slide 41 Slide 42