consider a muscle cell is changing from relaxtion to contraction. 1) is the length of the thick filaments changing  2) is the length of the thin filaments changing

Pick the list that has the order from the smallest to the larges a) Sarcomere , Myofibrilactin , myosin b) Actin, Sarcomere, Myofibril, Muscle fiber c) Actin Sarcomere, Myofibril , Muscle, Myosin d) Muscle fiber, myofibril, actin, myosin , sarcomere

One of the primary characteristics of all muscle tissue is contractility, the ability to shorten (contract) and lengthen (relax). You've identified the various components of a myofibril above. Now, use the table below to indicate what occurs to each band, line, or zone when the muscle contracts vs. relaxes. What occurs to this region / structure during contraction/relaxation? Region / Structure A-Band H-Band I-Band M-Line Z-Line Zone of Overlap Sarcomere No change Shortens Lengthens Muscle Contraction Muscle Relaxation

Distinguish between skeletal, smooth, and cardiac muscle in terms of location and whether they have sarcomeres. Use the sliding filament model to draw how thin filaments, thick filaments, and Z lines move during muscle contraction. Predict how perturbations of acetylcholine release, reception, or breakdown will influence muscle contraction. Predict how perturbations of actin, troponin, tropomyosin, myosin, or calcium would influence muscle contraction. Distinguish between the sympathetic and parasympathetic nervous system. Predict how changes in stress levels or situations would affect activation of the sympathetic and parasympathetic nervous system, levels of epinephrine and norepinephrine, and blood pressure.

Which of the following step(s) about the excitation of skeletal muscle is/are incorrect?   1. Acetylcholine is released and binds to motor end plate receptors   2. An action potential is created and moves down T-tubules   3. Calcium is released from the sarcoplasmic reticulum   4. Calcium ions bind to tropomyosin to shift troponin off the binding sites for cross-bridging   5. Myosin forms cross-bridges and binds with actin to pull it towards middle of sarcomere

Skeletal muscle cells undergo contractions based on a molecular mechanism involving: 1)the sliding of actin and myosin filaments past each other without any change in filament length  2) the shortening of actin filaments following direct interaction with myosin  3) dynamic instability of microtubules 4)none

Choose the best description of how myosin and actin are arranged within the two types of protein filaments in myofibrils. a.) Actin makes up the think filaments, and myosin makes up the thin filaments. b.) Myosin makes up the think filaments, and actin makes up the thin filaments. c.) Myosin and actin are randomly interspersed in the think filaments but are absent from the thin filaments. d.) Myosin and actin overlap with each other to make up both the think and thin filaments.

In an isometric contraction, how can the muscle stay the same length when the muscle is contracting? Can choose more than one   - The muscle is not able to generate more (or the same amount) force than the load, preventing shortening of the muscle. - Calcium stops entering the sarcoplasm when the desired length is reached.   - Elastic elements of the muscle stretch in response to the contraction of the muscle, so that the muscle stays the same size despite shortening sarcomeres. - The myosin heads detach from actin when they reach the desired length.

A. nerve cell releases neurotransmitter which stimulates the muscle cell: B. calcium is released from sarcoplasmic reticulum and floods sarcoplasm; C. sarcolemma is permeable to sodium allowing sodium to rush into cell; D. myosin forms cross-bridges to pull actin into the center of the sarcomere; E. sarcolemma depolarizes and conducts an action potential    Put them in order

Complete the following analogies: Troponin is to skeletal muscle as tropomyosin is to smooth muscle Neuromuscular junction is to skeletal muscle as striations is to smooth muscle Oxidative metabolism is to slow twitch fibers as sliding filament theory is to fast twitch fibers if it is wrong let me know what might be the correct answer.