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Factors that influence muscle tension - Sarcomere length and force, understretched and overstretched

By: HWC, Views: 6657

• Muscle tension generated through the contraction of muscle cells provides the force necessary for the muscular system to function. • The amount of tension produced depends on several factors: • Sarcomere length Frequency of stimulation • Motor unit size • Recruitment of moto...

Stroke volume - preload, sarcomere length and Frank -Starling law

By: HWC, Views: 6297

• Sarcomere length affects muscle tension and the force of contraction. • Increased muscle stretch (increased sarcomere length) at the beginning of contraction increases tension produced during the contraction. • A more forceful contraction ejects more blood, thus increasing stroke volu...

Stroke volume

By: HWC, Views: 6645

Preload definition • Preload is the degree of stretch of cardiac muscles cells prior to contraction. • The amount of stretch is related to the end-diastolic volume[EDV]. • Increased return blood flow from the veins increases end-diastolic volume. Cardiac muscle sarcomeres stretch and ...

Contraction cycle of a sarcomere

By: HWC, Views: 7158

• A single nervous signal releases Ca2+ ions into the sarcoplasm and initiates the contraction cycle. step 1. ATP hydrolysis • ATP provides the to move myosin molecules back into the energized configuration necessary to perform the power stroke. Step 2. Crossbridge attachment • Myosin...

Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 6771

Once the muscle cell has been excited it will contract. • A muscle action potential will trigger the release Of Ca2+ ions into the sarcoplasm. • The Ca2+ ions bind to the regulatory proteins and trigger contraction. • Within skeletal muscle cells are structures that provide the ability...

Properties of macromolecules (Explained with No Audio)

By: HWC, Views: 5649

The term thermoplast refers to a plastic, which when heated is soft and deformable, but which rehardens when cooled. The molecular structure of the macromolecules is comparable to a cotton ball in which the individual fibers of the macromolecules are shown. The fibers of the cotton ball can s...

Fetal development - Weeks 9 to 38

By: HWC, Views: 6745

Weeks 9-12 • Fetal development during the third month includes: • A large head, about 1/2 the length of the fetus. • Visible eyes and ears. • A detectable heartbeat. • Kidneys that form urine. • Gender identification. • Weak, undetectable body movements. • By the e...

The primary factors that affect circulation - MABP, CO and SVR

By: HWC, Views: 6931

Introduction Blood flow is determined by the relative intensities of factors that drive and resist moving blood. • Cardiac output (CO) equals the mean arterial blood pressure (MABP, a driving force) divided by systemic vascular resistance (SVR, a resisting force). • Hormones and the cen...

Wrist Circumduction Animation

By: Administrator, Views: 1190

Circumduction is sometimes described as simply a "circular movement" because circumduction movements of (e.g. the arm and hand) result in the outer edge of the limb (e.g. the fingertips) tracing circles in space. Another way to express this is to say that circumduction is the movement of the dist...