Presentation on theme: "This will eventually lead to a muscle contraction if the stimulus is above the threshold."— Presentation transcript:
This will eventually lead to a muscle contraction if the stimulus is above the threshold.
What do we have in common? Puffer fish
Poison Arrow Frog
Neuromuscular Junction - The Real Thing! Botulinum toxin binds to pre-synaptic membranes at neuromuscular junctions, enters the neuron, and then a component of the toxin interferes with the release of neurotransmitter. Release of acetylcholine is blocked. No acetylcholine? No muscular contraction. (flaccid paralysis)
The Transverse (T) Tubules work with the sarcoplasmic reticulum to rapidly concentrate and move calcium ions throughout the sarcoplasm
Ca 2+ binds the troponin molecules on the thin actin myofilaments. This leads to the ability of the thick myosin filaments to bind the actin. The myosin heads pull the actin molecules inward, causing the whole fiber to shorten.
What is happening when ATP binds the myosin head? The cross-bridge is broken and the muscle relaxes!
A Body Temperature Rigor MortisTime since death WarmNot yet stiffDead not more than 3 hours WarmStiffness starting in head Dead 3 to 8 hours ColdStiffDead 9 to 36 hours ColdNo longer stiffDead more than 36 hours