What have we been learning?? Types of Muscle Muscle Structure Muscle Stimulation

Types of Muscle

What are the 3 types of muscle?

Muscle Structure

Put these in order from outer to inner Connective Tissue Perimysium Fascia Epimysium Endomysium Muscle Groups Fascicles Muscle Fibers Myofilaments Myofibrils CHECK WITH A PARTNER

Muscle Structure What is this?

Let’s look inside a myofibril

Inside a Myofibril

Muscle Stimulation

What’s the difference between motor unit & neuromuscular junction? Motor Unit: one neuron & the muscle fibers it controls Neuromuscular Junction: one neuron and one muscle fiber.

Let’s Label the Neuromuscular Junction CHECK WITH A PARTNER

Can a neuron contain muscle fibers?? What are the circle like structures in the neuron? What is the muscle fiber in this picture?

Muscle Stimulation Process Ca++ Impulse travels down neuron Once an impulse travels down the neuron, where does Calcium (Ca++) enter the neuron? What does the Calcium do?

Muscle Stimulation Process 3. The neurotransmitters released from the vesicles do what? Attach to muscle fiber receptors

Muscle Stimulation Process 4. What is entering the muscle fiber? Sodium (Na+)

Muscle Stimulation Process 5. What happens to the neurotransmitters after sodium enters the muscle cell? - Travel back into vesicles

Muscle Stimulation Process 6. Muscle Impulse travels INSIDE muscle fiber to myofibril. 7. What is released from Sarcoplasmic Reticulum (SR)? Calcium

Muscle Stimulation Process: Sliding Filament Theory 1. Ca++ released from SR attaches to what myofilament? - actin

Muscle Stimulation Process: Sliding Filament Theory 2. Myosin heads attach to actin at binding sites

Muscle Stimulation Process: Sliding Filament Theory 3. Myosin pushes actin back (Walk along actin)