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Muscles and Movement

Muscles and Movement

Skeletal muscle is a type of muscle which we use to move. Tendons attach
muscle to bones, whereas ligaments attach bones to other bones. Skeletal
muscle contracts and relaxes in order to move bones at a joint. Muscles work
in antagonistic pairs because they…

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muscle fibres contract. Sarcomeres return to their original length as the
muscle relaxes

Muscle Contractions

Myosin filaments have globular heads with binding sites on them, they are
hinged so they can move back and forth. Each myosin head has a binding site
for actin and a binding site of ATP.…

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Starting off with glucose (6C), this is split into 2x pyruvate (3C). This pyruvate
is taken into the mitochondria and enters the krebs cycle.

Glycose (6C) used 2 ATP to change into pyruvate (2X3C). This reaction is called
glycolysis. During the glycolysis 2 oxidised
NAD is used and changed to…

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electrons are moved along the electron transport chain ( made up of 3
electron carriers) losing energy at each stage. The energy lost from the
electrons is used to help pump the protons into the intermembrane space
from the mitochondrial matrix. This creates a higher concentration of protons
in the…

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1. The process starts in the sinoatrialo node (SAN), which is in the wall of
the right atrium.
2. The SNA is like the pacemaker of the heart, it sets the rhythm. This is
done by sending out regular waves of electrical activity into the atrial
walls (a wave of…

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P wave Depolarisation of the atria, leading to atria contraction
PR interval Time taken for the impulse to be conducted from the SAN
across the atria to the ventricles through the ANS
QRS complex The wave of depolarisation resulting in contraction of the
T wave Repolarisation of the ventricles…

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3. As the lungs inflate, stretch receptors in the lungs are stimulated. The
stretch receptors send a nerve impulse back to the medulla. These
impulses inhibit the action of the inspiratory centre.
4. The expiratory centre then sends nerve impulses to the diaphragm and
intercostals muscles to relax. This causes…

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1. Carbon dioxide dissolves in blood plasma making carbonic acid
2. Carbonic acid dissociated into hydrogen ions and hydroengcarbonates
ions which lowers the blood PH
3. Chemoreceptors sensitive to hydrogen ions are located in the
ventilation centre of the mendulla oblongata.
4. Impulses are sent to other parts of the…

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Exercise causes an increase in breathing rate and tidal volume. A spirometer
can be used to measure the change in breathing rate and tidal volume at rest,
during exercise and after exercise.


Homeostasis is the maintenance of a constant internal environment. Your
external environment and what you're doing will…

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the hypothalamus, which in turn sends impulses along motor neurons to
effectors. The effector responds to restore the body temperature back to
normal. The control of body temperature is called thermoregulation.

Hormones switch genes on to help regulate temperature. In a cell there are
proteins called transcription factors that control…


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