BIO 160: Introduction to Human Anatomy and PhysiologyBiology 160Pima Community College, Downtown CampusLAB SIGN OFF PAGE – Lesson 5: CHAPTER 6Name ___________________________Please staple all of your lab pages for this Chapter together with this page as the top. You will use this page to get your Labs for the Chapter signed off by the Biology Learning Center staff. You need to have all of the following steps initialed by a staff member before you can be allowed to take the Chapter Exam.After you have obtained all of your sign offs for this Chapter, be sure that a BLC staff member indicates on your Lab Card that you are OK to take the Chapter Exam. Also, keep this sign off page, along with your completed lab worksheets, as proof of your lab completion. If your Lab Card indicates that you have not completed the required Labs for this Chapter, and you feel that you have, it is up to you to provide proof that you have indeeddone the Labs. Keep this page!___________ Muscles and movements___________ Electromyography10/2/141BIO 160: Introduction to Human Anatomy and PhysiologyLesson 6: The Muscular System Overview of Muscle TissuesWhat are the 3 types of muscle tissue? 1. ____________________________ 2. _________________________3. _____________________________________Which type of muscle tissue is not striated? _______________________________Which type of muscle tissue is comprised of long fibers with numerous nuclei? ___________________________In which type of muscle do branched cells connect to each other by intercalated discs? ___________________ Which type of muscle tissue is voluntary?___________________________Where is the one place cardiac muscle is located? ______________________________Name two places where you find smooth muscle. ________________________ and ______________________Skeletal muscle tissue is wrapped in connective tissue to give it greater strength. A single muscle fiber is wrapped in the endomysium. A group of muscle fibers are called a fascicle and they are wrapped in the _______________________ The whole muscle is wrapped in the _____________________________ and around that is fascia. Muscles connect to bones primarily by means of ____________________________________Name 4 functions of muscle.1. _____________________________________________2. _____________________________________________3. _____________________________________________4. _____________________________________________Microscopic Anatomy of Skeletal MuscleThe plasma membrane of a muscle fiber is called the _____________________________.The cytoplasm of a muscle fiber is filled with myofibrils. Perfectly aligned myofibrils give skeletal muscle fibers their striated appearance. The dark bands are called __________ bands.The light bands are called ___________ bands. Each myofibril is comprised of two types of protein called myofilaments. The thick myofilaments are called ________________________ .The thin myofilaments are called _________________________.10/2/142BIO 160: Introduction to Human Anatomy and PhysiologyThe sarcomere is the contractile unit of muscle and is composed of overlapping myofilaments. Each sarcomere extends from Z disc to Z disc. Thousands of sarcomeres line up in a row the length of a myofibril. In one sarcomere, myosin extends the length of the A band. The Z disc is in the middle of the I band and is the anchoring place for actin. The H zone of the sarcomere is also called the bare zone when the muscle is at rest. When the muscle contracts the actin slides on the myosin and the bare zone decreases and can disappear. Muscle fibers have a specialized endoplasmic reticulum called the ___________________________ and their function is to store calcium ions and to release it on demand when the muscle fiber is stimulated to contract.Skeletal Muscle ActivitySkeletal muscle must be stimulated by nerve impulses to contract. A motor unit is one __________________________ and all of the muscle fibers innervated by it. A motor neuron reaches the muscle fibers by way of a long axon that branches into a number of axon terminals.Each axon terminal forms a junction with a muscle fiber at a _______________________________ junction. The ______________________________ is the space between the axon terminal of the neuron and the musclecell. The two membranes do not touch and there is interstitial fluid in the synaptic cleft. When a nerve impulse reaches the axon terminal the neurotransmitter ____________________________ is released. The acetylcholine travels across the synaptic cleft and connects with acetylcholine _____________________. Following the binding of acetylcholine to the acetylcholine receptors the sarcolemma becomes permeable to sodium ions (Na+).Na+ rushes into the cell followed by ____________________ rushing out of the cell. The movement of ions causes a depolarization followed by a repolarization of the sarcolemma called an action potential. The action potential travels the length of the ___________________________. The action potential travels to the interior of muscle fiber by T tubules. The action potential in the T tubules triggers the release of calcium ions from the sarcoplasmic reticulumCalcium ions bind to the actin molecules. Crossbridges form between actin and myosin molecules. This is done repetitively causing the muscle fiber toshorten. Individual muscle fibers contract in an “all or none” manner. Each action potential stimulates a muscle fiber tocontract maximally. There are no partial contractions of muscle fibers.10/2/143BIO 160: Introduction to Human Anatomy and PhysiologyWhole muscles contract in a __________________________________ manner. There are different degrees of contraction for a whole muscle.A twitch is a single muscle contraction followed by its relaxation. Tetanus occurs when the muscle contracts again before completely relaxing. There is a __________________________ of contractions as they get progressively stronger with stimulation. Complete tetanus is a sustained muscle contraction when there is no relaxation between contractions. Muscle force depends on the number of _____________________________ contracting. Initially, muscles use ATP as an energy source. There is only 4-6 second’s worth of stored ATP to contract a muscle. When ATP runs out, a muscle fiber first turns to ____________________________ ___ to generate more ATP.Creatine phosphate supplies are diminished in ________________________ seconds. Aerobic