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Contraction cycle of a sarcomere

By: HWC, Views: 8213

• 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...

Wrist Flexion and Extension Animation

By: Administrator, Views: 562

Flexion describes the movement of bending the palm down, towards the wrist. Extension describes the movement of raising the back of the hand.

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

By: HWC, Views: 8082

• 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...

Head and Neck Movement Animation

By: Administrator, Views: 334

Interestingly, head and neck muscles are the first ones that the baby can control. A baby can hold his head up before he can sit erect. The muscles of the head and neck perform many important tasks, including movement of the head and neck, chewing and swallowing, speech, facial expressions, an...

Humerus Adduction Animation

By: Administrator, Views: 10297

Types of body movement that occur at the diarthrotic joints: - Abduction - Adduction - Circumduction - Dorsiflexion Movement can occur in one plane, like with a knee bend, or in multiple planes such as with a shoulder roll. Adduction occurs when a joint moves a part of the body toward the ...

Gastrin (protein digestion)

By: HWC, Views: 7764

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone after b...

Elbow Pronation Animation

By: Administrator, Views: 473

The elbow pronation test is performed by placing a hand on the elbow, flexing the carpus to 90 degrees, and rotating the toes out (thus inwardly rotating the antebrachium), which places stress on the medial compartment of the elbow. Pronation – Lying prone (face downward); also turning the p...

Secondary and tertiary levels of protein structure Animation

By: HWC, Views: 1669

Amino acid sequence dictates a protein's final shape. The presence of certain amino acids favors a pattern of hydrogen bonding that causes part of the polypeptide chain to coil and twist into an alpha helix. The presence of other amino acids enables hydrogen bonding between strand like re...

Wrist Circumduction Animation

By: Administrator, Views: 1240

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...