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Contraction and Relaxation Animation

By: Administrator, Views: 10631

Muscles are responsible for movement. The types of movement are: - Locomotion, when chemical energy is changed into mechanical energy. - Propulsion of substances through tubes, as in circulation and digestion. - Changes in the sizes of openings, as in the contraction and relaxation of the iris...

Structures that affect circulation - heart and systolic/diastolic BP

By: HWC, Views: 7632

• Heart generates blood pressure. • Arterioles produce resistance thereby regulating blood flow to tissues. • Veins store blood; kidneys regulate blood volume; both affect venous return and cardiac output. ■ Contractions of the ventricles determine blood pressure, which drives th...

Frequency of stimulation and force (Recruitment of motor units and force)

By: HWC, Views: 8042

• Muscle tension depends on the frequency of stimulation. • Muscle twitch: First stimulus. • Wave summation: When a second stimulus excites a partially relaxed muscle, producing a stronger contraction. • Unfused tetanus: Successive stimulations at the same frequency, producing a se...

Five phases of cardiac cycle & Atrial contraction

By: HWC, Views: 7759

1. Atrial contraction (atrial systole). 2. Isovolumetric (ventricular) contraction. 3. Ventricular ejection. 4. Isovolumetric (ventricular) relaxation. 5. Passive ventricular filling. Beginning of cardiac cycle • Prior to atrial contraction: • Atria and ventricles are relaxed....

Haustral churning, Gastrocolic reflex and mass peristalsis & Defecation

By: HWC, Views: 7900

• As the cecum becomes filled and distends, a local reflex causes: • Closure of the ileocecal valve. • Activation of haustral churning. • Haustral churning mixes the chyme, which helps absorption of water, salts, and vitamins. • Haustral churning propels the contents of the colo...

Interview with Person who has Panic Attacks

By: Administrator, Views: 10736

Panic attacks are sudden periods of intense fear that may include palpitations, sweating, shaking, shortness of breath, numbness, or a feeling that something bad is going to happen. The maximum degree of symptoms occurs within minutes. Typically they last for about 30 minutes but the duration can...

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

By: HWC, Views: 8155

• 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...

Isovolumetric VC, Ventricular ejection, Isovolumetric & Passive ventricular filling

By: HWC, Views: 7683

• 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...

Muscle Twitch and Muscle Tension - Motor unit size and force

By: HWC, Views: 7964

• A motor unit is a group of muscle cells controlled by a single neuron. • A stimulus of sufficient intensity will cause all the cells in the motor unit to contract. • A single contraction, caused by a single action potential, is called a muscle twitch. • Latent period: A brief per...