Week 3.2 Lab Muscle PDF

Muscles Muscles The human body has about 600 muscles some that never stop moving The muscular system helps the human body move sometimes this means moving things inside the body or moving the body from place to place  Muscles Muscles can be found in different shapes and sizes They are complex...

Muscles Muscles The human body has about 600 muscles some that never stop moving The muscular system helps the human body move sometimes this means moving things inside the body or moving the body from place to place  Muscles Muscles can be found in different shapes and sizes They are complex organs that have different types of tissue and they make up about 50% of our body weight Muscles work by contracting or shortening They cause movement by pulling on something such as a bone Can be very long like rec fem Deep Dive MUSCLE TISSUE TERMINOLOGY All muscles share some terminology Prefixes myo and mys refer to “muscle” Prefix sarco refers to “flesh” Contraction and shortening of muscles is due to the movement of microfilaments The individual cells in muscle tissue are called fibres. Muscle Cell = Muscle Fibre size = one tenth of one hair FIGURE 10.3 The Three Connective Tissue Layers Muscle fibers are covered by the endomysium. Bundles of muscle fibers, called fascicles, are covered by the perimysium. The entire Skeletal Muscle is covered in epimysium 253,000 muscle fibres  MYOFIBRILS = inside a muscle(fiber)cell Diagram of part of a muscle fiber showing Sarcolemma the myofibrils. One myofibril extends from the cut end of the fiber. Mitochondrion Myofibril Nucleus © 2016 Pearson Education, Inc. Types of muscles There are three types of muscles cardiac muscle smooth muscle skeletal muscle Examples of skeletal muscle include: The Bicep Brachi that allows us to bend/ flex our elbow The Quadriceps Femoris that allows us to straighten/ extend our knee The Upper Trapezius muscle that allows us to raise our shoulders towards our ears  Smooth muscle are involuntary, meaning they work without thinking examples of smooth muscle include: The muscles of the intestines Smooth muscle The muscles involved in breathing The muscles involved in bladder control  Cardiac muscles are also involuntary they are found in the heart Cardiac muscles contract to pump Cardiac blood through the body throughout muscles its lifetime They have an electrical timer attached to them that allows it to beat without us having to think about it  Functions of skeletal muscle include: Moving the body Functions of the skeletal Stabilizing body posture muscle include Is involved in blood flow Will help us keep us warm when we're cold Muscle movement The only thing in muscle can do is get shorter it can move one bone closer to another the only movement a muscle can do is based on where it starts/origin and where it ends/the insertion the actions of our muscles are able to move our joints Each muscle is able to do only the one thing that allows it to move bones that it is attached to ORIGIN AND INSERTION ORIGIN INSERTION  Each joint can move only a certain number of ways and it has muscles that are able to create those movements These movements are called ranges of motion When we move a joint while carrying a weight this is called an isotonic contraction Joint And isotonic contraction has two parts concentric and movement eccentric The moving the bones closer together is called the concentric part of the contraction The moving them further apart this called the eccentric part of the contraction The same muscle is being used for both movements