Muscular System 1

• 1. Produce body movements
• 2. Stabilize body positions
• 3. Store/move substances within body
• 4. Produce heat

• 1. Electrical Excitability-
• 2. Contractility-
• 3. Extensibility-
• 4. Elasticity-

The ability of muscle tissue to respond to certain stimuli by producing electrical signals called action potentials (impulses, muscle action potentials).

The ability of muscle tissue to contract forcefully when stimulated by an action potential.

• The ability of muscular tissue to stretch, within limits, without being damaged.
• Connective tissue within the muscle limits the range of extensibility and keeps it within the contractile range of the muscle cells.

The ability of muscular tissue to return to its original length and shape after contraction or extension.

The site where the motor neuron makes contact with, and excites the skeletal muscle fibers.

The nerve cells (neurons) that transmit the electrical impulse from the central nervous system to groups of muscle fibers, causing muscles to respond (contract).

All of the muscle fibers excited by a motor neuron.

A muscle contraction/relaxation under conscious control.

A muscle contraction/relaxation not under conscious control.

• 1. Cramps-
• 2. Spasms-
• 3. Reflexes-

Alternating light and dark protein (contractile proteins/fibers) bands present in sarcomeres.

The contractile unit of a muscle fiber (cell).

The rate at which Ca²⁺ enters/exits the muscle fiber.

• 1. Slow
• 2. Moderate
• 3. Fast

Oxygen-binding protein found in muscle cells.

Cylindrical structures that extend the entire length of the cell within muscle fibers and are composed of thin and thick filaments (that do not extend the entire length) arranged into sarcomeres.

Bundles of 10 - 100 muscle fibers (cells).

• 1. Endomysium-
• 2. Perimysium-
• 3. Epimysium-
• 4. Tendon-
• 5. Fascia-

CT that lines each individual muscle fiber (cell).

CT that surrounds the fascicles.

CT that wraps around the entire muscle.

Parallel bundles of collagen connecting muscle to bone.

• Calcaneal tendon
• Bicep tendon

Fascia that connects bone to bone.

Dense irregular CT that lines the body wall and limbs, supports surrounding muscles, and other organs.

Twisting/wrenching of ligament.

Overstretching/tearing of tendon/muscle.

A muscle attachment site where the connected bone remains in place.

A muscle attachment site where the connected bone moves toward the origin (in most cases).

Movement of the insertion point towards the origin point.

• Origin-Coracoid process & supraglenoid tubercle
• Insertion-Radial tuberosity & bicipital aponeurosis
• Action-Elbow flexion, shoulder flexion, forearm supination.

Yes

• 1. Isotonic Contractions
• 2. Isometric Contractions

A contraction in which the muscle length changes as the force of contraction remains constant.

A muscle contraction in which the muscle length remains the same as the force of contraction increases.

• 1. Concentric isotonic contractions-
• 2. Eccentric isotonic contractions-

Muscle shortens as it contracts because the force it generates is greater than the resistance.

Muscle lengthens as it contracts because the force it generates is less than the resistance.

Biceps curl

• Lowering a heavy item slowly to the ground
• Negative repetitions in weight lifting

• Planks
• Wall-sits

The prime mover/leader responsible for most of the force generating a movement.

• The muscle whose contraction opposes that of the agonist.
• This muscle often relaxes when the agonist contracts.

Muscle that help the prime mover function more efficiently by reducing unnecessary movements.

Muscles that stabilize the origin of the prime mover so that the prime mover can act more efficiently.

• 1. Hamstrings
• 2. Quadriceps
• 3. Gastrocnemius
• 4. Adductors

• 1. Progressive loss of skeletal muscle (atrophy)
• 2. Decreased strength & flexibility
• 3. Slowing of reflexes
• 4. Regular aerobic and strength training can slow this process

• 1. Shape
• 2. Size
• 3. Fiber direction
• 4. Origin/insertion
• 5. Number of origins
• 6. Main action
• 7. Location/nearby structures

• Rectus
• Transverse
• Oblique

• parallel to midline
• Rectus Abdominus

• maximus/minimus
• longus
• latissimus
• longissimus
• magnus
• major/minor
• vastus

• largest/smallest
• Gluteus maximus/minimus

• widest
• latissimus dorsi

• longest
• Longissimus muscles of ESGs

• large
• Adductor Magnus

• larger/smaller
• Rhomboid major/minor
• Teres major/minor

great

• deltoid
• rhomboid
• orbicularis
• pectinate
• piriformis
• platys
• quadratus
• gracilis

• diamond-shaped
• Rhomboid major

• short
• Adductor brevis

• four-sided
• Quadratus lumborum

• circular
• Orbicularis oculi/oris

• makes something rigid
• tensor fascia latte

flexor H longus/extensor digitorum

• elevate
• Levator scapula