Question

Drag the appropriate events of excitation-contraction coupling to their respective locations (bins). View Available Hint(s) Rose 12in Motor neuron signais muscle fiber confraction Action potential is conducted along T tubule Tropomyosin shifts pooition Calciun fons bind to troponin Caicium ions are released Sodium channels open along sarcolemma Myosin forms cross bridges with actin

Answer 1

Excitation-contraction coupling is the process that links the action potential generated in the sarcolemma with muscle contraction. It involves a series of events: motor neuron stimulation, action potential conduction, calcium release, tropomyosin shift, and myosin cross-bridge formation.

Step-by-step explanation:

Excitation-contraction coupling is the process that links the action potential generated in the sarcolemma with muscle contraction. It involves a series of events:

1. The motor neuron stimulates the muscle fiber to contract.
2. The action potential is conducted along the T-tubule.
3. The T-tubules trigger the release of calcium ions (Ca++) from the sarcoplasmic reticulum (SR).
4. The calcium ions bind to troponin, causing tropomyosin to shift position and expose the actin-binding sites.
5. Myosin forms cross bridges with actin, leading to muscle contraction.

Answer 2

This is the list of events and their corresponding bins:

• Action potential is conducted along T tubule ⇒ Excitation
• Sodium channels open along sarcolemma ⇒ Excitation
• Calcium ions are released from the sarcoplasmic reticulum ⇒ Excitation
• Calcium ions bind to troponin ⇒ Contraction
• Tropomyosin shifts position ⇒ Contraction
• Myosin forms cross bridges with actin ⇒ Contraction

What is are these events?

Depolarization: An action potential travels along the sarcolemma, causing sodium channels to open. This influx of sodium ions depolarizes the sarcolemma, triggering the release of calcium ions from the sarcoplasmic reticulum.

Calcium Release: Calcium ions bind to troponin, a protein on the actin filaments. This binding causes tropomyosin to shift position, exposing binding sites on the actin filaments for myosin heads.

Excitation-Contraction Coupling: Myosin heads attach to actin filaments and form cross-bridges. These cross-bridges undergo a power stroke, pulling the actin filaments towards the center of the sarcomere, leading to muscle contraction.

Complete question:

Drag the appropriate events of excitation-contraction coupling to their respective locations (bins). View Available Hint(s)

Motor neuron signals muscle fiber contraction

Action potential is conducted along T tubule

Tropomyosin shifts position

Calcium ions bind to troponin

Calcium ions are released

Sodium channels open along sarcolemma

Myosin forms cross bridges with actin