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Structures that affect circulation - arterioles and vasomotor responses and venous return

By: HWC, Views: 6735

■ 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 ...

Introduction to Dysrhythmia

By: Administrator, Views: 9651

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...

Heart sounds

By: HWC, Views: 6512

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 ...

System organization - PPM system types (Somatic, Autonomic & Enteric) and Reflex arc types

By: HWC, Views: 6798

• The PNS consists of all nervous tissue outside of the CNS. • It is divided into three functional components: • Somatic nervous system (SNS) • Autonomic nervous system (ANS) • Enteric nervous system (ENS) • The SNS consists of: • Sensory neurons from skeletal muscles ...

Automated external defibrillator (AED)

By: Administrator, Views: 9734

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...

Cardiac Cycle (Part 2 of 4)

By: Administrator, Views: 9685

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...

Muscular System Animation

By: Administrator, Views: 9565

Three basic types of muscles: - Skeletal - Smooth - Cardiac Composed of striated or smooth muscle tissue and classified according to their functions and appearance. Skeletal Muscle: - Also known as voluntary or striated muscle. - Controlled by the conscious part of the brain and attach...

Electrical changes in the heart

By: HWC, Views: 6479

• ECG: Graph of the voltage changes that occur during the cardiac cycle. • Readings are taken by electrodes placed on the surface of the body. • Electrodes detect voltage changes caused by the electrical activity of the heart. • P wave = atrial excitation (atrial depolarization). ...

Structures that affect circulation - kidneys, blood volume and venous tone

By: HWC, Views: 6633

• Kidneys regulate blood volume and blood osmolarity via salt and water reabsorption. • Increased reabsorption increases blood volume and venous return (and CO). • Decreased reabsorption increases urine production, which decreases blood volume and venous return (and CO). • Systemi...