Answer:
It allows information to go from one neuron to another through neurotransmitters.
The cell cannot go through mitosis and will not produce a new cell
Answer:
hey have long, lanky arms and prehensile (gripping) tails that enable them to move gracefully from branch to branch and tree to tree. These nimble monkeys spend most of their time aloft, and maintain a powerful grip on branches even though they have no thumbs.
These New World primates are social and gather in groups of up to two- or three-dozen animals. At night, these groups split up into smaller sleeping parties of a half dozen or fewer. Foraging also occurs in smaller groups, and is usually most intense early in the day. Spider monkeys find food in the treetops and feast on nuts, fruits, leaves, bird eggs, and spiders. They can be noisy animals and often communicate with many calls, screeches, barks, and other sounds.
Explanation:
Answer:
In muscles contraction the correct order of the steps are: A (Nerve impulse reaches the muscle), B (Action potential travels down T-tubules), C (Calcium binds to troponin), D (Tropomyosin moves).
Explanation:
Skeletal muscle contractions are based on different physiological and biochemical phenomena that happen in every cell. These phenomena are due to stimulation produced by somatic motor neurons, which axons get in contact with muscle fibers through a neuromuscular synapse. In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When an action potential is originated in the central nervous system, it travels to the somatic motor neuron membrane: the muscle fiber, and activates the calcium channels releasing it in the neuron. Calcium makes vesicles to fuse with the membrane and release the neurotransmitter named acetylcholine (Ach) into the synaptic space in the juncture. Then, Ach binds to its receptors on the skeletal muscle fiber. This causes the ion channels to open, and positively charged sodium ions cross the membrane to get into the muscle fiber (sarcoplasm) and potassium get out. The difference in charges caused by the migration of sodium and potassium makes the muscle fiber membrane to become more positively charged (depolarized). The action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane, that make the calcium be released into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin binds to the uncovered actin-binding sites, and while doing it ATP is transformed into ADP and inorganic phosphate. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
