Introduction To Skeletal Muscles Flashcards

What are six functions of the skeletal muscle? 1. Support 2. Protection 3. Movement 4. Maintain body temperature 5. Guard orifices - gives contrl over swallowing, defecation, and urination 6. Allows for breathing (diaphram is a skeletal muscle) Name the muscle sheaths of the skeletal muscle starting at the largest most outer layer and working to a single muscle fiber. Epimysium to the perimyseum, which wraps the fiscicle, then the endomysium, which wraps the miscle fiber. How many muscles does the body have? Close to 700 muscles What does it mean when someone says a skeletal muscle is excitable? That the muscle can generate an electrical current call and Action Potential. What does it mean when someone say a skeletal muscle can show contractability? This means the muscle can generate a force. What is the endomysium? It is the ariolar CT wrapped around each muscle cell What is the fascicle? It is a groups of muscle cells in the muscle organ that are wrapped by the permysium What is the epimysium? It is dense irregular CT that surrounds the muscle organ. Name the four characters of the skeletal muscle. 1. They are excitable (can generate electrical current) 2. Show contractility (can generate force, shortening) 3. Have elasticity (can be twisted and hold shape) 4. Have extensibility (Can be stretched) What is a muscle organ? Muscle organs are all of the different muscles we are learning. The covering is called epimysium Give definition of "endo" within Give definition of "mys" Muscle Give definition of "sarco" Muscle Give definition of "epi" Upon or on Give definition of "peri" On What are the different tissues of muscle organs? 1. Skeletal Muscle 2. Nervous Tissue - Every muscle cell has its own neuron 3. CT Proper - dense irregular connective tissue that makes up the sheath covering muscle organ called epimysium What is a fascicle? A group of muscle cells in the muscle organ. This group of cells is surrounded by the perimysium What wraps around a single muscle cell? Endomysium Describe the muscle organ from the outer sheath to the inner most single muscle cell. 1. Muscle organ is wrapped by dense irregular muslce tissue called epimysium 2. Inside of muscle organ are groups of cells called fasicles. These are wrapped by the perimysium. 3. Inside of the fascible are single muscle cell wrapped in the endomysium. What is an aponeurosis? Sheet like tendon that sometimes attach muscles to bones or to other muscles. (A sheet of pearly-white fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.) What is another name for a muscle cell? Muscle fiber or myofiber. Any of these mean muscle cell Roots sarco-, myo-, or mys are always related to what? Muscles. Nothing else. The "cell membrane' of the muscle is called what? Sarcolemma - made of lipid bilayer The "cytoplasm" of the muscle cell is called what? Sarcoplasm What is a T-Tubule? Or transvers tubules? Where the cell folds in and forms channels across the cell. What is myogloin? It is the hemoglobin of the blood. It binds oxygen in the muscles. This is needed for ATP production. What is glycogin? It is a carbohydrate (a big pollamer of glucose) that provides nutrient The tubelike structures that fill the inside of the sarcoplasm is called what? Myfibrils. What is the job of the sarcoplasmic reticulum? A special smooth sarcoplasmic reticulam (Called SR instead of ER) It has lots of mitochondira to produce energy. What are three things we will see inside of the muscle fibers? 100's - 1000's myfibrils, Glycogin (stores glucose), myglobin (binds oxygen) What surrounds the myofibril and what is in the myofibril. Endomysium sheath surrounds it. Inside is the smooth ER called Sarcoplasmic Reticulum that stores calcium. Also inside is the myofibril are smaller structures called myofiliments. When looking at one miofibril of the muscle cell there are compartments. What are these called? Sarcomere What divides one sarcomere compartment from the next? Z-Disc - a proteing that separtates one compartment from the next. What are the smaller structures inside the sarcomeres? Myofilaments Name the two major types of myofilaments? Thick myofilaments and thin myofilaments. These create the light and dark lines that create striations in skeletal muscles. Where are the thick myofiliments located? In the center of each sarcomere. Where are the thin myofiliments located? Extend from Z-disc and extend towards middle but they don't reach the middle. What crates the "A" band? The entire length of thick filaments in the sarcomere What is the "H' zone? The center of the A-band where is no overlap of thin filaments What is the "I-Band" Where there is only thin filaments (known as light band) What is the "Z-Disk"? A protein disk that runs down the center of the "I-Band" When a muscle contracts, what happens to the I-Band and the H-Zone? They get smaller When a muscle contracts, what happens to the A-Band? It stays the same.