ZOOL 3214 1st Edition Lecture 16Muscular System • 639 Named MusclesIII. Muscle DescriptionsA. Naming Muscles (read text)• Shape• Length• Bones• Region• # of Heads (ex. Triceps)• MovementB. Functional Groups• Lever Systems: mech. Engineering, Physics, PT- 1st Class: TMJ (move head front & back)- 2nd Class: ankle movement- 3rd Class: elbow movement- Things considered here include: pivot point, load/resistance, and effort- Lots of variables can change*Size of load*Pivot Location*Lengths of arms* Also put functional systems (levers) togetherThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.*Arm: shoulder to elbow* Forearm: elbow to hand- Action: flexion @ elbow (bring forearm to arm)• Muscles and their Roles1. Brachialis muscle: prime mover (most effort/force)2. Biceps brachiim: synergist (adds force)3. Triceps brachii muscle: antagonist (relaxes during movement, still control)4. Rhomboid muscles: fixators (stabilizing muscle)C. Attachments: w/CT1. Direct w/collagen fibers- Ex. Brachialis muscle to distal half of humerus2. Indirect via tendons- Direct bands of CT (ex. Biceps brachii muscle inserts on radius)- Sheets of CT: Aponeuroses (ex. Galea aponeuroses between frontalis and occipitalis muscles (helmet upon the brain))D. Origins, Insertions, and Actions, Innervations- Origins: usually the less mobile attachment- Insertions: usually the more mobile attachment(can vary with the movement in question ex. The hyoid)- Action: what happens when muscle contracts- Innervations: describe specific branches of cranial & spinal nerves that stimulate the muscle to contract(each muscle is innervated)E. Sternocleidomastoid muscle: head & neck- Origin: manubrium, medial 1/3rd clavicle- Insertion: mastoid process, lateral ½ of superior nuchal line of occipital bone- Action: primary neck flexor*Bilateral contraction: pulls head to chest (prayer muscle)*Unilateral contraction: looking over the shoulder left or