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How is the heart beat controlled?

Cardiac muscle is myogenic i.e has the ability to contract naturally, without external stimuli, such as action potentials arriving via nerves. For the whole heart to contract in an organised manner, there ne...
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Answered by Cezar B. Biology tutor
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Describe the process of cyclic photophosphorylation?

Inside a chloroplast, there are thylakoid disks, that have their own phospholipid bilayer membrane, which contains embedded protiens, which allow the process of cyclic ad non-cyclic photophosphorylation to h...
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Answered by Samuel H. Biology tutor
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Briefly describe how the autonomic nervous system returns internal body temperature to normal following a rise in body temperature

Body temperature in mammals is controlled and maintained by a small part of the brain called the hypothalamus. Information about the temperature both inside and outside of the body is detected by thermoregul...
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Answered by Chantal R. Biology tutor
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How is heart rate controlled?

It can be controlled by hormonal or neuronal (from the nervous system) input. To increase the heart rate, during a fight or flight situation for example, adrenaline may be released from the adrenal glands an...
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Answered by Grace M. Biology tutor
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Explain the series of events at a synapse between 2 neurons.

An impulse travels along the pre-synaptic neurone, and when it reaches the axon ending it stimulates calcium channles to open on the pre-synaptic membrane. This allows calcium ions to rush into the neurone c...
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Answered by Jim L. Biology tutor
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