Lecture Exam 3 - Muscular System Study Guide Flashcards
Define term: Energy
Capacity to do work
Define Term: Potential Energy
Energy stored by matter due to its position
Define Term: Kinetic Energy
energy associated with matter in motion
Define Term: Chemical Energy
a form of potential energy stored in the bonds of compounds and molecules
Define Term: Exergonic Reaction
chemical reactions that release more energy than they absorb
Define Term: Endergonic Reaction
chemical reactions that absorb more energy than they release
Define Term: Cellular Respiration
the process by which glucose provides the energy to make ATP. Cellular repiration as two phases: anaerobic and aerobic. In the anaerobic phase, glucose is partially broken down into pyruvie aold by a series of reactions that do not require energy. In the aerobic phase, glucose is completely broken down to CO2 and H2O. Oxygen is required for this process.
Understand how different joints mimic different types of levers [NEED TO INCLUDE DIFFERENT LEVEL SLIDES]
Bnes at as levers, a ridgid structure that can move around a fixed point (the fulcrum). The joint functions as the fulcrum of the lever. Two forces come into play: 1) Effort which cases movement and 2) Load or resistance which opposes movement.
Understand how the muscle uses ATP to produce energy necessary for muscle contraction.
Muscle stores energy in ATP in mitochondria (in 3rd phosphate bond). Myosin head (myosin = thick filament) has an ATP-binding site and an ATPase (enzyme that converts ATP to ADP). Energy provided results in change of position of head (breaks the crossbridges) ATP is thus required for both formation of crossbridges and detachment of crossbridges.
Understand how energy obtained from glucose is stored in the covalent bonds of ATP ready for future use.
The process by which glucose provides the energy to make ATP is called cellular respiration. Cellular respiration has two phases: anaerobic and aerobic. In the Anaerobic phase, glucose is partially broken down into pyruvic acid by a series of reactions that do not require energy. In the aerobic phase, glucose is completely broken down to CO2 and H2O. Oxygen is required for this process.
How the distinguising histological features and functions of the three muscle types: Skeletal
-Long striated fibers -Peripheral Nuclei -Voluntary Control -Usually attached to bones via tendons -Important in motion, posture, heat production, and protection
How the distinguising histological features and functions of the three muscle types: Cardiac
-Branched, striated fibers -Involuntary Control -Centrally located nuclei -Pound in heart wall -Pumps blood to all parts of the body
How the distinguising histological features and functions of the three muscle types: Smooth
-Spindle-shaped, non-striated with centrally located nuclei -Involuntary Control -Walls of internal organs such as blood vessels, GI tract, airways to lungs. Gall bladder, urinary bladder, uterus. -Motion, e.g. contriction of blood vessels, movement of food through GI, contraction of bladder, uterus
Understand how muscle achieves each of the following functions: Producing body movement
relies on integrated functioning of bones, joints, muscles and nervous system. Muscle contractions on bones create movement.
Understand how muscle achieves each of the following functions: Stabilizing body positions
Skeletal muscles stabilize joints and help maintain body positions. Postural muscles contract continually when you are awake.
Understand how muscle achieves each of the following functions: Storing and moving substances within body
-Smooth muscle allows for continual contraction of ringlike bands of muscle (sphincters), e.g. storage of food in stomach - Contraction and relaxation of smooth muslce walls of blood vessels allows for storage of blood.
Understand how muscle achieves each of the following functions: Generating heat
As muscle contracts it generates heat in a process known as thermogenesis – this heat is used to maintain normal body temperature. Involuntary contractions of skeletal muscle (shivering) can generate more heat.
What are the properties of musle tissue?
Excitability, contractibility, extensibility, elasticity
Define Term: Fascia
means a broad band of connective tissue that surrounds muscle or other organs
Define Term: Epimysium
Three distinct layers of connective tissue surround and protect skeletal muscle. The epimysium is the layer that encircles the entire muscle.
Define Term: Perimysium
Three distinct layers of connective tissue surround and protect skeletal muscle. The perimysium sorrounds groups of 10-100 or more muscle fibers. This separates them into bundles called fascicles.
Define Term: Endomysium
Three distinct layers of connective tissue surround and protect skeletal muscle. The Endomysium separates individual muscle fibers within fascicles.
Define Term: Fascicle
Bundles of approx 10-100 or more muscle fibers within a muscle, surrounded by the Perimysium. Some Fasicles large enough to be seen with the naked eye.
Define Term: Tendon
Epimysium, perimysium, and endomysium are continuous with the connective tissue that connects muscles to other organs. When they extend in long parallel bundles to attach a muscle to a bone, they are called a tendon.
Define Term: Aponeurosis
A tendon that extends in a broad flat layer. E.g. how the occipitofrontalis muscles attach to the skull.
Define Term: Muscle fiber
Muscle cells are called muscle fibers. Mutlinucleat and formed from many myoblasts.
Define Term: Myoblast
Embryonic cells called myoblasts fuse to form muscle fibers.
Define Term: Satellite cell
some myoblast-derived cells called satelite cells remain in the adult, and can accomplish some muscle regeneration, though the number of muscle fibers in set before you are born.
Define Term: Sacolemma
the plasma membrane of the muscle fiber
Define Term: Transverse tubule
tiny structures of the sarcolemma (plasma membrane in muscle), which tunnel in from the surface toward the center of the cell
Define Term: Triad
a group consisting on a T-Tubule and the terminal cisternae of the two adjastent sarcoplasmic reticulums
Define Term: Sarcoplasm
the cytoplasm of muscle cells
Define Term: Myoglobin
An oxygen-binding protein found only in the sarcoplasm of skeletal muscle
Define Term: Myofibril
-Small structures that run through the sarcoplasm of muscle fibers. -Specialized contractile organelles of muscle fibers
Define Term: Sarcoplasmic reticulum
the endoplasmic reticulum of muscle fibers. abundant and encircles each myofibril
How are mutlinucleated muscle fibers formed?
fusion of myoblasts
Know the organization and components of thin and thick filaments.
Thick filaments are composed on Myosin. Thin filaments are mainly composed of Actin, but also contain two regulatory proteins – tropomyosin and troponin. Individual actin molcules form a twisted helical filament.
Know the organization of a sarcomere
One sacromere goes from Z disc to Z disc, with the M line at the center. Thin filaments are on both sides of the thick filaments. The I band is the zone of thin filament before the thick filament. the H zone is the zone of thick filament and no thin filament (both H zone and I band shrink during contraction). A band is length of thick filament (length of thin and thick filaments remain the same during contraction.
Know the structure of actin and myosin
Mysoin is composed of a head and tail component Myosin molecules look like two golf clubs with the long ends twisted together. Individual actin molcules form a twisted helical filament, with myosin binding heads of actin attached to tropomyosin. Actin molecules look like little balls.
Know the function of myosin
-Myosin is a “motor protein” - a protein capable of pushing or pulling cellular structures. -Movement requires ATP, and chemical energy is converted to mechanical energy.
