Sequence of Events at the Neuromuscular Junction The site where a motor neuron excites a skeletal...
Choc Muscle fiber nucleus Myofibrilot muscle fiber Figure 10.15. Details of the neuromuscular junction. Label the structures labeled with capital letters. The numbers 1-4 indicate the chain of events that occur at the neuromuscular junction. Put these events in chronological order by placing a l in the blank before the first event, etc. Refer back to Figure 10.15 for information. Acetylcholine diffuses across the synaptic cleft. Nerve impulse reaches the axon terminal. Synaptic vesicles release acetylcholine into the synaptic cleft....
90) The motor end plate is A) the same as the neuromuscular junction. B) formed by the membrane of enlarged axon terminals, or boutons, that lie on the surface of skeletal muscle cells. C) a special fibrous matrix whose collagen fibers hold the axon terminal in proper position. D) a folded area of muscle cell membrane with ACh receptors clustered at the top of each fold. E) the same as the synaptic cleft.
Put these steps in neuromuscular junction synaptic transmission and excitation-contraction coupling in chronological order. A. Ryanodine receptors open B. Voltage-gated Na+ channels open in the muscle cell membrane near the neuromuscular junction C. Tropomyosin rotates into the groove of the thin filament (out of the way of the myosin binding site) D. Depolarization of motoneuron axon terminal E. Ca2+ dissociates from troponin F. [Ca2+] rises in the muscle cell cytoplasm G. An EPSP occurs in the muscle cell H. Myosin...
6. Draw the Neuromuscular junction and label the Following structures. Include the three substances that interfere with normal muscle contraction (both toxic and therapeutic). ID synapse, neurotransmitter synaptic cleft, axon terminal, synaptic bulb, synaptic vesicles, motor end plate, acetylcholine receptors, Junctional folds, acetylcholinesterase. 7. Describe or draw each of the contractile proteins (actin/myosin) and regulator proteins (troponin & tropomyosin). Explain the set up and how each participate in muscle contraction. Name the protein that attaches the sarcomere to the sarcolemma...
B C). F Fotch G I Anind A [Choose) B [Choose ] Acetyl-choline gated sodium channels open, causing a graded potential on the sarcolemma An action potential moves across the sarcolemma and down the t-tubules An action potential arrives in the muscle cell via gap junctions The calcium ATPase is always active Ca++ is released from the sarcoplasmic reticulum through the opening of voltage gated calcium channels (DHP- Calcium diffuses through the cytosol and binds with troponin Acetylcholine binds with...
True or False: The striations in skeletal muscle are formed by the arrangement of thick and thin filaments. 2. True or False: In skeletal muscle cells, the sarcoplasmic reticulum is continuous with the sarcolemma. 3. The interval between two Z lines is called a ________________. 4. At a neuromuscular junction, the space between the plasma membrane of the synaptic terminal and the motor end plate is the __________________. 5. An action potential (electric impulse) is transferred from a...
Answer Thi Q. thank You The Nervous System edit) 1. The junction between one neuron and the next, or between a neuron and an effector is called: A) A synapse 8) A dendrite C) A neuotransmiter D ) A ventricle E) None of the above 2. A fast excitatory synapses follows this order A) (1) neurotransmiter released (2) diftused across the synaptic cleft to a receptor protein (3) binding of the transmitter opens pores in the ion channels and positive...
The Brain on Mind Altering Drugs Psychoactive drugs alter brain function by acting at synapses in the brain, where they may mimic, enhance, or block the effects of natural signaling molecules (neurotransmitters). The neurotransmitter dopamine plays a particularly important role in creating the dependency aspect of both drug and behavioral addictions. Natural behaviors which enhance survival and/or reproduction, such as eating or engaging in sex, result in a surge of dopamine. Normally, this response helps individuals learn to repeat beneficial...