Search results for: 'Cardiac muscle sarcomeres'

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By: Administrator, Views: 9666

Cardiac dysrhythmias are a problem with the rate or rhythm of your heartbeat caused by changes in your heart’s normal sequence of electrical impulses. Your heart may beat too quickly, called tachycardia; too slowly, bradycardia; or with an irregular pattern. Dysrhythmias can range from complete...

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Structures that affect circulation - arterioles and vasomotor responses

By: HWC, Views: 6363

■ Small arteries and arterioles determine SVR. ■ Blood pressure drops significantly as blood passes through arterioles. ■ Decreasing arteriole radius and decreased wall elasticity are the main reasons for increased SVR. ■ Small changes in arteriole radius can cause large changes in ...

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Isovolumetric VC, Ventricular ejection, Isovolumetric & Passive ventricular filling

By: HWC, Views: 6642

• Isovolumetric means that blood volume does not change. • Ventricular blood volume and cell length remain constant. • With valves closed and contraction continuing, ventricular pressure continues to rise. • Ventricular pressure rises above arterial pressure. • Increased ventr...

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Heart sounds

By: HWC, Views: 6525

During a normal, healthy heartbeat, or what we call a cardiac cycle, the top two chambers of the heart, called the atria, contract simultaneously. Then, as they relax, the bottom two chambers, called the ventricles, contract. This explains what happens during a cardiac cycle, but what it doesn't ...

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Chemical Synapse Animation

By: HWC, Views: 4017

A neuromuscular junction is a chemical synapse between the axon endings of a motor neuron and a muscle cell. A narrow synaptic cleft separates the presynaptic cell (the motor neuron) from the postsynaptic cell (the muscle cell). The presynaptic cell contains vesicles filled with neurotransmitt...

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Automated external defibrillator (AED)

By: Administrator, Views: 9750

An automated external defibrillator (AED) is a portable electronic device that automatically diagnoses the life-threatening cardiac arrhythmias of ventricular fibrillation and pulseless ventricular tachycardia, and is able to treat them through defibrillation, the application of electricity which...

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Cardiac Cycle (Part 2 of 4)

By: Administrator, Views: 9698

Prior to atrial systole, blood has been flowing passively from the atrium into the ventricle through the open AV valve. During atrial systole the atrium contracts and tops off the volume in the ventricle with only a small amount of blood. Atrial contraction is complete before the ventricle begins...

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ATPase function - membrane transport, contractile proteins and synthesis

By: HWC, Views: 7052

• Energy from ATP is used to move ions across the cell membrane during active transport. • This membrane protein transports sodium out of the cell and potassium into the cell. As such, it is called a sodium-potassium pump. • Because this pump also acts as an enzyme to hydrolyze ATP it i...

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Regulation of GFR: three methods, autoregulation & autoregulation via myogenic mechanism

By: HWC, Views: 7077

• GFR can be regulated by adjusting: • Blood flow in and out of the glomerular capillaries. • Surface area of glomerular capillaries. • There are three main ways to make these adjustments: • Renal autoregulation. • Nervous regulation. • Hormonal regulation. • Ren...

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