Chapter 6: The Muscular System Flashcards

Skeletal & smooth muscle cells are elongated, not cardiac muscle cells.

Packaged into the organs & attach to the body's skeleton.

Also skeletal muscle, its fibers have obvious stripes.

The only muscle type subject to conscious control.

A delicate connective tissue sheath

A coarser fibrous membrane.

A tougher "overcoat" of connective tissue fibers.

Cord of dense fibrous tissues attaching muscle to bone.

Attach muscles indirectly to bone, cartilages, or connective tissue coverings.

Has no striations & is involuntary, cannot consciously be controlled. Found mainly within the walls of the stomach, urinary bladder & respiratory passages.

Found in ONLY one place within the body, in the heart.

Plasma membrane in muscle cells

Long ribbon like organelles.

Filaments composing the myofibrils. 2 types: Myosin & Actin

Composed of contractile protein called actin.

A specialized smooth ER.

1 neuron & all the skeletal muscle cells it stimulates.

A long threadlike extension of neurons, AKA nerve fibers

When an "upset" generates an electrical current.

Contain vesicles filled with a chemical called neurotransmitter

Chemical released by neurons that may stimulate or inhibit them.

A response that varies directly with the strength of the stimulus.

-Produced 2 ways:

• by changing the frequency of muscle stimulation
• by changing the # of muscle cells being stimulated at 1 time

Single, brief, jerky contraction; sometimes result from certain nervous system problems, NOT the way muscles normally operate.

When the muscle is stimulated so rapidly that no evidence of relaxation is seen & the contractions are completely smooth & sustained.

The product of anaerobic metabolism, especially in muscle.

When we exercise our muscles strenuously for a long time, when a muscle is no longer able to contract.

Occurs when a person is not able to take in oxygen fast enough to keep the muscles supplied with all the oxygen needed when working vigorously.

Myofilaments are successful in their sliding movements, the muscle shortens, movement occurs.

Ex: bending the knee, rotating the arms & smiling.

Contractions in which the muscles do not shorten

Sustained partial contraction of a muscle in response to stretch receptor inputs; keeps the muscle healthy and ready to react.

Is attached to the immovable or less moveable bone.

Is attached to the moveable bone & when the muscle contracts it moves toward the origin.

Movement, generally in the sagittal plane, that decrease the angle of the joint & brings 2 bones closer together.

Ex: bending the knee or elbow, or bending forward at the hip.

Opposite of flexion; movement that increases the angle or distance between 2 bones or parts of the body.

Ex: straightening the knee or elbow.

Movement of a bone around its longitudinal axis.

Ex: shaking your head "no"

Moving a limb away (generally on the frontal plane) from the midline or median plane of the body.

Opposite of abduction: moving the limb toward the body midline.

Combination of flexion, extension. abduction and adduction commonly seen in ball-and-socket joints such as the shoulder.

Lifting the foot so the it superior surface approaches the shin.

Ex: Standing on you heels.

Depressing the foot.

Ex: pointing the toes.

Turn the sole medially.

Turn the sole laterally.

Occurs when the forearm rotates laterally so that the palm faces anteriorly & the radius & ulna are parallel, "turning backward"

Occurs when the forearm rotates medially so that the palm faces posteriorly, bring the radius across the ulna forming a X. "turning forward"

Action which you move your thumb to touch the tips of the other fingers on the same hand.

Muscle that has the major responsibility for causing a particular movement.

Muscles that oppose or reverse a movement.

Help prime movers by producing the same movement or by reducing undesirable movements.

Specialized synergists, had a bone still or stabilize the origin of a prime mover so all the tension can be used to mover the insertion bone.

rectus (straight), its fibers run parallel to that imaginary line; oblique (at a slant), muscle fibers run at a slant to the imaginary line.

Maximus (largest), Minimis ( smallest), and longus (long).

Ex: gluteus Maximus (largest muscle of the gluteus group).

Named for bone which they are associated.

Ex: temporalis & Frontalis muscles overlie the temporal & frontal bones of the skull.

When the pre-fix bi- (2), tri- (3), & quad- (4) form part of a muscle name you can assume that muscle has 2,3,4 origins

Ex: Bicep has 2 heads or origin.

Muscles are named for their attachment site.

Ex: Sternum (sterno) and Clavicle (cleido) & inserts on the mastoid process of the temporal bone.

Muscles have a distinctive shape that helps identify them.

Ex: Deltoid is triangular (deltoid means triangular)

When muscles are named for their action, the terms flexor, extensor, and adductor appear.

when fascicles are arranged in rings.

Ex: the orbicularis muscles surrounding the eyes and mouth.

Fascicles converge toward a single insertion.

Length of fascicles run parallel to the long axis of the muscle.

(modification of parallel) Result in spindle-shaped muscle with an expanded belly (midsection)

Covers the frontal bone, runs from the cranial aponeurosis to the skin of the eyebrows, when it inserts. Allows you to raise your eyebrow & wrinkle your forehead.

Covers the posterior aspect if the skull and pulls the scalp posteriorly.

Has fibers that run in circles around the eyes. Allows you to close you eyes, blink, squint, & wink.

Is the circular muscle of the lips "kissing muscle"

Muscle runs horizontally across the cheek and inserts into the Orbicularis Oris. Also a chewing muscle because It compresses the cheek to hold food between the teeth while chewing.

Extends form the corner of the mouth to the cheekbone, "smiling muscle"

Covers the angle if the lower jaw. Closes the jaw by elevating the mandible.

Fan-shaped muscle overlying the temporal bone, inserts into the mandible and acts as a synergist of the masseter in closing the jaw.

A single sheet like muscle that covers the anterolateral neck.

Muscles are 2-headed, one found on each side of the neck. Heads fuse before inserting into the mastoid process of the temporal bone. "Prayer Muscles"

Is a large fan-shaped muscle covering the upper part of the chest.

Deep muscles found between the ribs

Run from the pubis to the rib cage, enclosed in an aponeurosis, main function is to flex the vertebral column.

Are paired superficial muscles that make up the lateral wall if the abdomen, their fibers run downward & medially from the last 8 ribs & insert into the ilium

Paired muscles deep to the external oblique, fibers run at right angles to those of external obliques.

The deepest muscle of the abdominal wall & has fibers that run horizontally across the abdomen.

The most superficial muscles of the posterior neck & upper trunk, form a diamond or kite-shaped muscle mass.

Muscles are 2 large flat muscles that cover the lower back.

Group is the prime mover of back extension, these paired muscles are deep muscles of the back.

Muscles form part of the posterior abdominal wall, acting separately each muscle of the pair flexes the spine laterally.

Are fleshy, triangle-shaped muscles that form the rounded shape of your shoulders

Muscle of the arm that bulges when the elbow is flexed

Lies deep to the bicep muscle & is as important as the biceps in elbow flexion.

A fairly week muscle that arises on the humerus & inserts into the distal forearm.

The ONLY muscle fleshing out the posterior humerus.

Is a superficial muscle of the hip that forms most of the flesh of the buttock. Most important muscle when extending the hip when power is needed.

Runs from the ilium to the femur, beneath the gluteus maximus for most of its length.

is a fused muscle composed of muscles, the iliacus and the psoas major.

From the muscle mass at the medial side of each thigh

The muscles forming the muscle mass of the posterior thigh.

• Biceps femoris
• semimembranosus
• semitendinosus

Thin, strap like muscle is not too important, but it is the most superficial muscle of the thigh and is rather hard to miss.

Consists of 4 muscles that flesh out the anterior thigh.

• The rectus femoris
• 3 Vastus Muscles

Is a superficial muscle on the anterior leg, arises from the upper tibia & then parallels the anterior crest as it runs to the tarsal bones, where it inserts by a long tendon.

Lateral to the tibialis anterior, arises from the lateral tibial condyle &proximal 3/4 of the fibula & inserts into phalanges of toes 2-5.

3 muscles are found on the lateral part of the leg- longus, brevis, & tertius, arise from the fibula & insert into the metatarsal bones.

is 2-bellied muscle that forms the curved calf of the posterior leg, arises by 2 heads, 1 from each side of the distal femur, & inserts through the large calcaneal (Achilles) tendon into the heel.

Deep to the gastrocnemius muscle, arises on the tibia & fibula (rather than the femus) it DOES NOT affect the knee movement and inserts into the calcaneal tendon & is strong plantar flexor of the foot.