Chapter 9 and Some of 11 Study Guide Answers 1 List 3 types of muscle tissue Skeletal Cardiac Smooth 2 Describe skeletal muscle tissue Classify skeletal muscle tissue as involuntary or voluntary striated or nonstriated and contract rapidly and powerfully Skeletal muscle is voluntary and striated It consists of long fibers that are multinucleated 3 Describe cardiac muscle tissue Identify where cardiac muscle tissue is located Classify cardiac muscle tissue as involuntary or voluntary striated or nonstriated Define intercalated disc Name two types of cell junctions that are located in intercalated discs Cardiac muscle tissue is found only in the heart It is involuntary and striated Intercalated discs are specialized connections between cardiac cells containing desmosomes and gap junctions 4 Describe smooth muscle tissue Identify where smooth muscle tissue is located Classify smooth muscle tissue as involuntary or voluntary striated or nonstriated Smooth muscle is located in the walls of hollow organs such as the stomach and blood vessels It is involuntary and non striated 5 List and define four special characteristics of muscle tissue Excitability ability to respond to stimuli Contractility ability to shorten when stimulated Extensibility ability to be stretched Elasticity ability to recoil to original length after stretching 6 List two additional terms that both mean excitable Irritable Produce movement responsible for locomotion and manipulation Responsive 7 List and describe functions of muscles Maintain posture and body position Stabilize joints Generate heat as they contract 8 List 3 features of a skeletal muscle organ Attachments Nerve and blood supply Connective tissue sheaths muscle and remove metabolic wastes 9 Describe general functions of nerves and blood vessels that are part of a skeletal Nerves stimulate muscle fibers to contract Blood vessels supply oxygen and nutrients 10 Describe the general function of a skeletal muscle s 3 connective tissue wrappings These wrappings support muscle cells reinforce the muscle and provide elasticity 11 Be able to list in order from most superficial to deep the 3 connective tissue wrappings of a skeletal muscle Define fascicle Epimysium surrounds entire muscle Perimysium surrounds fascicles bundles of muscle fibers Endomysium surrounds each individual muscle fiber Fascicle a bundle of muscle fibers wrapped in perimysium 12 Differentiate between a skeletal muscle s origin and insertion Origin attachment to immovable or less movable bone Insertion attachment to movable bone 13 Define sarcolemma sarcoplasm myoglobin myofibrils myofilaments thick and thin Sarcolemma plasma membrane of a muscle fiber Sarcoplasm cytoplasm of a muscle fiber Myoglobin protein storing oxygen in muscle Myofibrils rod like structures within muscle fibers Myofilaments actin thin myosin thick filaments involved in contraction 14 Explain the importance of a skeletal muscle fiber having many mitochondria Mitochondria produce ATP which is required for muscle contraction 15 A myofibril is composed of a long chain of Sarcomeres 16 Define sarcomere Be able to describe the structure of a sarcomere Z discs thick myofilaments thin myofilaments H zone I band A band Name the protein that makes up the thick myofilaments name the most plentiful protein in the thin myofilaments Sarcomere the functional contractile unit of muscle Thin filaments actin most abundant plus tropomyosin and troponin Z discs boundaries of sarcomere Thick filaments myosin H zone only thick filaments I band only thin filaments A band overlap of thick and thin filaments 17 Describe the physical change that occurs to cause a sarcomere to shorten contract Thick filaments pull thin filaments toward the sarcomere s center shortening the entire 18 Of the structures listed in 16 above which is found in the dark striations of a skeletal muscle fiber Which is found in the light striations of a skeletal muscle fiber Dark A band thick and overlapping thin filaments Light I band only thin filaments and heads of this protein 19 Name the protein that makes up the thick myofilaments Differentiate between the tail Myosin makes up the thick filaments The tail is the central shaft region while the heads project outward and contain binding sites for actin and ATP 20 Give the general functions of the actin binding site ATP binding site myosin ATPase Are these three structures found in the head or tail or a myosin molecule Actin binding site attaches to actin to form cross bridges ATP binding site binds ATP for energy Myosin ATPase enzyme that breaks down ATP for energy All are located in the myosin head 21 Before myosin heads can bind to the thin myofilament they must first be Activated ATP 22 Myosin heads are activated by energy released from the breakdown of 23 List three proteins that are found in the thin myofilaments Which contains the myosin binding site What is the general function of the myosin binding site Actin tropomyosin troponin unit Actin contains the myosin binding site The myosin binding site allows myosin heads to attach and form cross bridges 24 Define cross bridge filament A cross bridge is the physical connection formed when a myosin head binds to the actin 25 Describe the roles troponin and tropomyosin play in the formation of a cross bridge Tropomyosin blocks the myosin binding site on actin in relaxed muscle Troponin binds calcium ions and moves tropomyosin away from the binding site allowing cross bridge formation 26 Name the ion that s stored in the sarcoplasmic reticulum Name the type of voltage gated ion channels that are located in the wall of the sarcoplasmic reticulum Calcium ions Ca2 Voltage gated calcium ion channels 27 Describe simple diffusion of calcium ions after the voltage gated calcium ion channels on the sarcoplasmic reticulum open Name the thin myofilament protein that calcium ions bind to Calcium diffuses into the sarcoplasm and binds to troponin 28 Describe the location and function of the T tubules T tubules are extensions of the sarcolemma that penetrate into the muscle fiber they transmit action potentials deep into the cell 29 Define resting membrane potential The membrane potential of a cell is measured in Resting membrane potential is the electrical charge difference across the plasma membrane of a resting cell Measured in millivolts mV 30 List and describe four factors that cause a cell s resting membrane potential to be negative Negatively charged proteins inside the