| A | B |
|---|
| The three types of muscles are ____, ____, and ____. | smooth, cardiac and skeletal (striated) |
| Smooth muscles can also be called _____ muscles. | involuntary |
| Smooth (involuntary) muscles line the walls of the _____ and the _____. | blood vessels, digestive tract |
| Smooth muscles are under the control of the _____. | autonomic nervous system (smooth muscles are also called involuntary muscles because they are controlled by a part of the nervous system that is not under the direct control of concious thought) |
| Which type of muscle is found in the heart? | cardiac |
| The _____ is modified plasma membrane that surrounds each muscle fiber and can propagate an action potential. | sarcolema |
| The _______ is modified ER that contains sacs of Ca++ ions necessary for normal muscle contraction. | sarcoplasmic reticulum,  |
| The _____ is the functional unit of the muscle fiber (cell). The boundaries are the _____, which give skeletal muscle its characteristic striated appearance. | sarcomere, Z-line,  |
| Within the cytoplasm of each muscle cell are thousands of fibers called ______ that run parallel to the length of the cell. | myofibrils |
| Myofibrils consist of ______. | thick and thin filaments, |
| Thin filaments consist of two chains of ____ wound around each other. | actin proteins,  |
| Each thick filament is composed of two chains of _____, each with a globular head at one end. | myosin molecules,  |
| Muscles contract as ____ and ____ slide over each other. | thick and thin filaments, |
| Which ion allows thick and thin filaments to develop cross bridges so they can interact?, | calcium ions (Ca++), |
| The axon of a motor neuron, synapses on a skeletal muscle at the _________. | neuromuscular junction |
| Which neurotransmitter stimulates muscle contraction? | acetylcholine (Ach),  |
| Acetylcholine released into the neuromuscular synapse binds to receptors on the _____, depolarizing the muscle cell membrane to set up an action potential. | sarcolema, |
| The ______ is a system of tubules that connects the sarcoplasmic reticulum to the extracellular fluid | T system, |
| _____ connects muscle to bone. | Tendons (ligaments connect bone to bone),  |
| A ____ consists of a single motor neuron and all the muscle fibers it controls. | motor unit, |
What does "A" refer to?,  | I - band,  |
| What does "B" refer to?, | A - band, |
| What does "C" refer to?, | Z - line, |
| What does "D" refer to?, | myofibril, |
| What does "E" refer to?, | sarcomere, |
| What does "F" refer to?, | H-zone, |
