Muscles (day 2)

Muscle #1: intercostals What is the fxn of muscles found between the ribs? REMOVE the ARM of your Maniken Make/get some spaghetti strands Place a strand between each rib, starting at the back where it attaches to the vertebral column, all the way around to the rib’s attachment at the sternum Use your thumb or a tool to flatten these strands- intercostals do not stick out of the chest!

Muscle #2: Serratus anterior Attach the ‘stand off’ to the torso, but do not yet tighten the screws completely Origin of serratus anterior: lateral surface of ribs 1-8 (bone only, not cartilage) Insertion: medial border of the scapula We will build OVER the stand off. This muscle would normally attach to scapula, but building over will make it look like that when arm is reattached. Take spaghetti and attach strands from medial side of rib 1-8 (where dashes are shown) to the stand-off on the arm. (note that this muscle’s action is for big scapular mvmnts such as swimming, pitching, or bench press Reattach the arm of your Maniken

Muscle #3- pectoralis minor Origin: anterior surface of ribs 3-5 (just past origins of serratus anterior Insertion: coracoid process of scapula (piece of scapula visible on the front) Use spaghetti strands. Place one small strand at the origin of each rib and run these three strands together as they attach to scapula. Built in a similar manner to the serratus. This is a shoulder forward rotation muscle. Try it out!

Muscle #4- pectoralis major (part one- abdominal head) There are actually 3 different ‘heads’ or pieces to this muscle. Where might this muscle attach? Origin: ribs 5-7 (attaches to fascia of abs) Insertion: lateral edge of the most proximal part of humerus Make a long carrot. Flatten slightly to make a tongue shape. Gently lay across the chest from origin to insertion. Muscle should have teardrop shape. You can mark the places you will need to trim to make the size and shape you want. Take muscle off Maniken and do your trimming. Attach muscle to Maniken. Make sure to add striations in the direction the muscle moves!

Muscle #4- pectoralis major (part Two- Sternal/sternocostalis head) Where might this muscle attach? Origin: ribs 1-5 on the lateral edge of sternum (no clay on sternum) Insertion: lateral edge of humerus, inferior to insertion of abdominal head Make a short, fat carrot. Flatten slightly to make a thick triangle. Gently lay across chest of Maniken from origin to insertion. The long end of carrot should point toward humerus. The origin will overlap with the abdominal head. Outline the shape you will need as before, remove from Maniken, and make changes with tools. No clay should extend over the sternum. Attach the muscle and striate appropriately. Which motion does this muscle perform?

Muscle #4- pectoralis major (part three: clavicular head) Where does this muscle attach? Origin: medial half of inferior edge of clavicle Insertion: lateral edge of the proximal humerus, inferior to insertion of sternal head Make a small carrot. Flatten slightly to make a shape like an isosceles triangle. Lay across Maniken from origin to insertion. Long end of carrot should point towards the humerus. Insertion will cross over the insertion of the other two pectoral muscles. Mark the size and shape you will need. Remove and cut to fit. Attach muscle. Add striations. What is the motion of this muscle?