Chapter 10: The Muscular

Chapter 10 The Muscular 10.1 Muscular is divided into axial and appendicular, these are superficial and relatively large. Axial musculature- originates on the axial skeleton - it position the head and vertebral column and helps breathing by moving the rib cage Appendicular musculature- inserts onto and stabilize or moves the appendicular Four groups of Axial muscles 1.Muscles of the head and neck that are not associated with the vertebral column, these includes face, tongue, larynx and eyes. These muscles are responsible for verbal and nonverbal communication, such as laughing, smiling and whistling, also involved with chewing and moving eyes 2.Muscles that move the vertebral column (also referred to as the intrinsic muscle of the back), these group includes flexors and extensor of the axial the skeleton for example: biceps muscle, in the front of the upper arm, is a flexor and the triceps at the back of the upper arm is an extensor 3.Muscle of the rib cage and lateral walls of the abdominal and pelvic cavities. This group, the oblique and rectus muscles, is located between the first thoracic vertebrae, and pelvis. These muscles moves the chest wall during the breathing inspiration and expiation. The abdominal surface are form broad musculla sheets, oblique and rectus muscle in the neck. Although they do not form a muscular wall, they are included in this group because they share a common embryological origin, the diapraghm is within this group because its embyological --origin linked to other muscles of the chest wall ⚫ Muscles that form the floor of the pelvic cavity- these muscle extend between the sacrum and pelvic girdle to support organs of the pelvic cavity, flex joints of the sacrum and coccyx and control movement materials through the urethra and anus Please see fig 10.1 and 10.2 To study the Superficial skeletal Muscles pg.260 Table 10.1 Muscle of Facial Expression The muscle of the scalp and face are thin , sheetlike muscle that have one or more attachments to the connective tissue of the head and the face. All the other muscles of the head and neck attach to bones of the skull and/or neck and move the eye jaw tongue pharynx or larynx. The muscles of facial expression originate on the surface of the skull, at their insertion, the collagen fibers of the epimysium are continuos with the collagen fibers of the drmis of the skin and superfacial fascia. SCALP (EPICRANIUM) Occipitofrontalis (frontal belly)- -origin- epicranial aponeurosis -insertion- skin of eyebrow and bridge of nose -action- raise eyebrows, wrinkles forehead Occipital belly-origin- superior nuchal line and adjacent region of mastoid portion of the temporal bone -insertion- epicranial aponeurosis -action-tenses and retracts scalp Temporoparietalis-tenses the scalp and moves the ear , and occipitofrontalis raises the eyebrows and retract the scalp -has two muscle bellies, the frontal belly and occipital belly separate by a collagenous sheet called APONEUROSIS -origin- fascia around the external ear -insertion-epicranial aponeurosis -action- tenses the scalp and moves auricle of ear MOUTH Orbicularis oris-other muscle moves the lips and the corners of the mouth -origin- maxilla and mandible -insertion- lips(kissing lips) -action- compresses: purse lips Buccinator-has two functions related to feeding -blow-sucking(importance in playing trumpets) -during chewing the buccinator works with the muscles of mastication to move food back across the teeth from the space inside the cheeks -origin- alveolar process of maxilla and mandible opposite the molar teeth -insertion- blends into fibers of orbicularis oris -action- compresses cheeks Mentalis -origin- incisive fossa of mandible -insertion- skin of chin -action- elevates and everts upper lip Risorius -origin- facial surrounding parotid salivary gland -insertion- angle of the mouth -ation- draws the corner of mouth laterally Zygomaticus major-smiling muscles -origin- zygomatic bone near the zygomaticotemporal suture -insertion- elevates corner of mouth and draws it laterally Zygomatic minor-origin- zygomatic bone posterior to zygomaticomaxillary suture -insertion- upper lip -action- elevates upper lip EYE Corrugator supercilli-origin- medial end of superciliary arch -insertion- eyebrow -action- pulls skin inferiorly and medially; wrinkles brow Orbicularis oculi-origin- medial margin of orbit -insertions- skin around eyelids -action- closes eye NOSE Procerus-origin- lateral nasal cartillages and the aponeuroses covering the inferior portion of the nasal bones -insertion- aponeurosis at bridge of nose and skin of forehead -action- moves nose, changes position, shape of nostrils: draws medial angle of eyebrows inferiorly Nasalis-origin- maxilla and alar cartilage of nose -insertion- bridge of nose -action- compresses bridge of nose; depress tip; elevates corners of nostrils NECK Platysma(flat)-origin- fascia covering the superior parts of the pectoralis major and deltoid -insertion- mandible and skin of cheek -action- tenses skin of neck, depresses mandible EXTRA-OCULAR MUSCLES table 10.2 6 extra-ocular muscles called oculomotor or extrinsic eye muscles, originate on the orbit insert onto the sclera (white of the eye) just posterior to the cornea and change the position of each eye. Inferior rectus -Origin- sphenoid around optical canal -Insertion- inferior, medial surface of eyeball -action- eye looks down Medial rectus-origin- sphenoid around optic canal -insertion- medial surface eyeball -action- eye looks medially Superior rectus-origin-sphenoid around optical -insertion- superior surface of eyeball -action- eye looks up Lateral rectus-origin- sphenoid around optical canal -insertion- laterals surface of eyeball -action- eye looks laterally Inferior oblique-origin- maxilla at anterior portion of orbit -insertion- inferior, lateral surface of eyeball -action- eye rolls, looks up and laterally Superior oblique-origin-spenoid around optic canal -insertion- superior, lateral surface of eyeball -action- eye rolls, looks down and laterally Table 10.3 Muscle of Mastication Masseter-origin- aponeurosis and bones of the zygomatic arch -insertion- lateral surface and angle of mandibular ramus -Action-elevates mandible and closes jaws, assists in protracting and retracting mandible and moving side to side Temporalis-Origin- along temporal lines of skull -insertion- coronoid process of mandible and the anterior border of the mandibular ramus -action- elevates mandible and closes jaws, assists in retracting and moving mandble from side to side Pterygoid Medial Ptreygoid-origin- medial surface of the lateral pterygoid plate and adjacent portions of palantine bone and maxilla -insertion- medial surface of mandibular -action- elevates the mandible and closes the jaws , or moves mandible side to side Lateral pterygoid- origin-lateral surface of the lateral pterygoid plate and greater wing of sphenoid -insertion- anterior part of the neck and mandibular condyle -action-open jaws, protrudes mandible, or moves mandible side to side Tongue- glossus Table 10.5 Muscle and pharynx The name of the muscle of pharynx tell you their origins and insertion : palato-palate; salingo-tube ; stylo-styloid process; veli- membranous structure Pharayngeal constrictors- constrict pharynx to propel bolus into esophagus Superior constrictor -origin- pterygoid process of sphenoid medial surfaces of mandible, and the side of tongue -insertion- median raphe attached to occipital bone Anterior Muscle of Neck Please see Fig. 10.9 for pictures and identifying the parts 10.3 Muscles of the Vertebral Column The superficial layer of the instrinsic back muscles is the splenius group. These posterior neck muscle extend, rotate, and laterally flex the cervical vertebrae Diaphragm is a major muscle for breathing, contracting the diaphragm increases the volume of the thoracic cavity, aiding inhilation. Belly of the muscles- the widest part of a muscle is called belly, the origin and insertion deal with tendon attachments . First of all, the bone needs to be anchored : the attachment to the unmoving bone is called origin Aponeurosis- is a thin sheets of connective tissue that helps connect your muscles to your bones. Aponeurosis are similar tendons , they support your muscle and give your body strength and stability. Aponeurosis absorb energy when muscles move, you have aponeurosis all over your body. I will give you a picture of several muscle images which are labeled with the name of the muscles. Be sure you can identify these muscles. The muscles will obviously be attached the body part. You should know the muscles we cover on Monday before the exam. ( You will be tested only on the muscles we get through in class that day. The remaining muscles will be on the mid-term-DR. Olin Please see all the figure, for the body parts Good luck to Us. If im missing stuff or question please update it thak thanks