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Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 6789

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...

Energy sources - types

By: HWC, Views: 6897

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...

Role of ATP in muscle movement

By: HWC, Views: 6838

• Muscle cells use ATP to power contraction and movement. • The hydrolysis of ATP to ADP releases • ATP can be regenerated by adding to ADP. • During muscular contraction, ATP molecules: • Energize the myosin head • Detach myosin from actin • ATP must be then regenerat...

Stretch reflex & Tendon reflex

By: HWC, Views: 6398

• The stretch reflex is a response to the stretching of muscles. It is monosynaptic and ipsilateral. • Stretching stimulates receptors in the muscle spindle of the agonist (stretched) muscle. • One or more action potentials are generated by the receptors and propagate along the axon of ...

Contraction cycle of a sarcomere

By: HWC, Views: 7185

• 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...

Nervous pathway to the Neuromuscular (NMJ)

By: HWC, Views: 7187

• A nervous impulse, also called an action potential, starts from the brain or spinal cord to signal skeletal muscle cell contraction. Action potentials continue along a motor neuron to the muscle cell. • The signal to contract must cross a synapse - the neuromuscular junction (NMJ) - betwe...

Structures that affect circulation - kidneys and blood volume and skeletal muscle pumping

By: HWC, Views: 7231

• 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...

Structures that affect circulation - arterioles and vasomotor responses

By: HWC, Views: 6367

■ 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 ...

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

By: HWC, Views: 6749

■ 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 ...