Ch. 10 The Muscular System

I. Introduction A. Types of Muscles by function 1. Agonist or Prime mover - main responsibility for movement Synergists: fixators stabilize origin 2. Antagonist:

B. Naming Skeletal Muscles 1. Direction of fibers Rectus = straight 2. Relative size Maximus = largest

3. By location Temporalis 4. By number of origins Triceps , Biceps

Naming Skeletal Muscles 5. By origin/insertion location Sternocleidomastoid 6. By shape Deltoid = triangular 7. By action Flexor and extensor

C. Arrangement of muscle fibers into Fascicles: can be circular or straight, long or short Figure 6.14

What To Know for lab– MUSCLES **Identify muscle Muscles Groups (Quadriceps …) *Actions from lab book Prime Mover, Synergistic, Antagonistic *Origin & Insertion: from Lab Book and general location on bone– distal, middle proximal

II. Muscles that cause facial expressions and that move the head Epicranius Galea aponeurotica Corrugator supercilii *Frontal belly (Frontalis) *Orbicularis oculi Occipital belly Levator labii superioris *Zygomaticus minor and major *Temporalis *Buccinator *Masseter Risorius *Sternocleidomastoid *Orbicularis oris *Trapezius Mentalis Splenius capitis Depressor labii inferioris Depressor anguli oris Platysma Figure 10.6

Head and Neck Muscles- Muscle to do in Lab Figure 6.15

A. MUSCLES OF MASTICATION AND TONGUE MOVEMENT Temporalis Four pairs: 1. Prime movers of jaw closure a) Temporalis and masseter Cranial Nerve VII, Facial Do in lab 2. Grinding movements b) Medial and lateral pterygoids Cranial nerve V (trigeminal nerve) See LAB BOOK for INSERTIONS, ORIGINS, and ACTIONS Masseter Medial & Lateral pterygoid muscles

Temporalis Orbicularis oris Masseter Buccinator (a) Figure 10.7a

Lateral pterygoid Medial pterygoid Masseter pulled away (b) Figure 10.7b

B. Facial Expression Muscles-- SEE LAB BOOK a) Epicarnius-Frontal Belly = Frontalis Elevates eyebrows & wrinkles forehead b) Orbicularis muscles = muscle forms a ring around a part of the face i) Orbicularis Oculi: encircles eye Closes eye ii) Orbicularis Oris: encircles lips/mouth Brings lips together, kissing c) Zygomaticus (two parts) Elevates sides of mouth, smiling d) Buccinator– mostly deep to iand below the most- inferior zygomaticus - Compresses checks inward-- wistling

C. Muscles of the Neck that move Head FLEXION a) Sternocleidomastoid— If both sides contract together causes head flexion If one side contracts only, causes lateral rotation b) Scalenes— - deep to Sternocleidomastoid - Cause lateral head rotation EXTENSION Trapezius: upper back muscle that extends to back of head - Extends head and other movements will do later © 2013 Pearson Education, Inc.

Base of occipital bone 1st cervical vertebra Mastoid process Middle scalene Sternocleido- mastoid Anterior scalene Posterior scalene (a) Anterior Figure 10.9a

END Platysma (cut) Mylohyoid Omohyoid (superior belly) Sternohyoid Figure 10.9b Muscles of the anterior neck and throat used in swallowing. Platysma (cut) Mylohyoid Omohyoid (superior belly) Sternohyoid Sternocleido- mastoid END © 2013 Pearson Education, Inc.

© 2013 Pearson Education, Inc. Figure 10.10b Muscles of the neck and vertebral column that move the head and trunk. Mastoid process Splenius capitis Spinous processes of the vertebrae Splenius cervicis Posterior © 2013 Pearson Education, Inc.

© 2013 Pearson Education, Inc. Figure 10.10d Muscles of the neck and vertebral column that move the head and trunk. Ligamentum nuchae Mastoid process of temporal bone Semispinalis capitis Longissimus capitis Semispinalis cervicis Iliocostalis cervicis Longissimus cervicis Semispinalis thoracis Iliocostalis thoracis Longissimus thoracis Spinalis thoracis Iliocostalis Erector spinae Longissimus Spinalis Multifidus Iliocostalis lumborum Quadratus lumborum External oblique © 2013 Pearson Education, Inc.