The Muscular System

§ Muscles are responsible for all types of body ______

§ Three basic muscle types are found in the body

§ ______muscle

Characteristics of Muscles

§ and muscle cells are __(muscle cell = muscle fiber)

§ of muscles is due to the movement of

§ All muscles share some terminology

§ Prefixes and refer to “__”

§ Prefix refers to “”

Comparison of Skeletal, Cardiac, and Smooth Muscles

Skeletal Muscle Characteristics

§ Most are attached by ______to bones

§ Cells are ______

§ ______—have visible banding

§ ______—subject to conscious control

Connective Tissue Wrappings of Skeletal Muscle

§ Cells are surrounded and bundled by ______tissue

§ ______—encloses a single muscle fiber

§ ______—wraps around a fascicle (bundle) of muscle fibers

§ ______—covers the entire skeletal muscle

§ ______—on the outside of the epimysium

Skeletal Muscle Attachments

§ ______blends into a connective tissue attachment

§ ______—cord-like structures

§ Mostly ______fibers

§ Often cross a due to toughness and size

§ ______—sheet-like structures

§ Attach muscles ______to bones, cartilages, or connective tissue coverings

§ Sites of muscle attachment

§ ______

§ ______tissue coverings

Smooth Muscle Characteristics

§ Lacks ______

§ ______-shaped cells

§ ______nucleus

§ ______—no conscious control

§ Found mainly in the ______of ______organs

Cardiac Muscle Characteristics

§ ______

§ Usually has a ______nucleus

§ ______cells

§ Joined to another muscle cell at an ______disc

§ ______

§ Found only in the ______

Skeletal Muscle Functions

§ Produce ______

§ Maintain ______

§ Stabilize ______

§ Generate ______

Microscopic Anatomy of Skeletal Muscle

§ ______—specialized plasma membrane

§ ______—long organelles inside muscle cell

§ ______reticulum—specialized smooth endoplasmic reticulum

§ ______are aligned to give distinct ______

§ I band = ______band

§ Contains only ______filaments

§ A band = ______band

§ Contains the entire length of the ______filaments

§ ______—contractile unit of a muscle fiber

§ Organization of the sarcomere

§ ______

§ filaments = filaments

§ Thick filaments = ______filaments

§ Composed of the ______myosin

§ Has ______enzymes

§ Myosin filaments have ______(______, or cross bridges)

§ Myosin and actin ______somewhat

§ Thin filaments = ______filaments

§ Composed of the ______actin

§ Anchored to the ______

§ At ______, there is a ______zone that lacks ______filaments called the ______

§ Sarcoplasmic ______(SR)

§ Stores and releases ______

§ ______the myofibril

Stimulation and Contraction of Single Skeletal Muscle Cells

§ ______(also called ______or irritability)—ability to ______and ______to a stimulus

§ ______—ability to ______when an adequate stimulus is received

§ ______—ability of muscle cells to be ______

§ ______—ability to ______and resume resting ______after stretching

The Nerve Stimulus and Action Potential

§ Skeletal muscles must be stimulated by a motor ______(nerve cell) to ______

§ ______unit—one motor ______and all the ______muscle cells stimulated by that neuron

§ ______junction

§ Association site of ______terminal of the motor neuron and muscle

§ ______cleft

§ Gap between ______and ______

§ Nerve and muscle do not make ______

§ Area between nerve and muscle is filled with ______fluid

Transmission of Nerve Impulse to Muscle

§ ______—______released by nerve upon arrival of nerve impulse

§ The neurotransmitter for skeletal muscle is ______(ACh)

§ Acetylcholine attaches to ______on the ______

§ Sarcolemma becomes ______to ______(Na+)

§ ______rushes into the cell generating an ______

§ Once started, muscle ______cannot be ______

The Sliding Filament Theory of Muscle Contraction

§ Activation by nerve causes ______heads (______bridges) to attach to ______sites on the ______filament

§ ______heads then bind to the next site of the ______filament and pull them ______the center of the ______

§ This continued action causes a ______of the ______along the ______

§ The result is that the muscle is ______(______)

Contraction of Skeletal Muscle

§ Muscle fiber contraction is “______”

§ Within a skeletal muscle, not all fibers may be ______during the same ______

§ Different combinations of muscle fiber contractions may give differing responses

§ ______responses—different ______of skeletal muscle ______

§ Graded responses can be produced by changing

§ The ______of muscle stimulation

§ The ______of muscle cells being stimulated at one time

Types of Graded Responses

§ ______

§ Single, brief contraction

§ Not a normal muscle function

§ ______(summing of contractions)

§ One contraction is immediately followed by another

§ The muscle does not completely return to a resting state

§ The effects are added

§ ______(incomplete) ______

§ Some relaxation occurs between contractions

§ The results are summed

§ ______(complete) ______

§ No evidence of relaxation before the following contractions

§ The result is a sustained muscle contraction

Muscle Response to Strong Stimuli

§ Muscle force depends upon the ______of fibers stimulated

§ More fibers contracting results in ______muscle tension

§ Muscles can continue to contract unless they run out of ______

Energy for Muscle Contraction

§ Initially, muscles use stored ______for energy

§ ATP bonds are ______to release energy

§ Only ______worth of ATP is stored by muscles

§ After this initial time, other ______must be utilized to produce ATP

§ Direct ______of ADP by ______phosphate (CP)

§ Muscle cells store ______

§ CP is a ______-energy molecule

§ After ATP is depleted, ADP is left

§ CP transfers energy to ADP, to regenerate ATP

§ CP supplies are exhausted in less than ______seconds

§ ______respiration

§ ______is broken down to carbon dioxide and water, releasing energy (______)

§ This is a slower reaction that requires continuous ______

§ A series of metabolic pathways occur in the ______

§ ______glycolysis and lactic acid formation

§ Reaction that breaks down glucose ______oxygen

§ Glucose is broken down to pyruvic acid to produce some ATP

§ Pyruvic acid is converted to lactic acid

§ This reaction is not as ______, but is fast

§ Huge amounts of ______are needed

§ Lactic acid produces muscle ______

Muscle Fatigue and Oxygen Deficit

§ When a muscle is fatigued, it is unable to ______even with a ______

§ Common cause for muscle fatigue is ______debt

§ Oxygen must be “______” to tissue to remove oxygen deficit

§ Oxygen is required to get rid of accumulated ______acid

§ Increasing ______(from lactic acid) and lack of ______causes the muscle to contract less

Types of Muscle Contractions

§ ______contractions

§ ______are able to slide past each other during contractions

§ The muscle ______and ______occurs

§ ______contractions

§ Tension in the muscles ______

§ The muscle is ______to shorten or produce movement

Effect of Exercise on Muscles

§ Exercise increases muscle ______, ______, and ______

§ Aerobic (______) exercise (biking, jogging) results in ______, more ______muscles with greater resistance to ______

§ Makes body metabolism more ______

§ Improves ,

§ Resistance (______) exercise (weight lifting) increases muscle ______and ______

Muscles and Body Movements

§ Movement is attained due to a muscle moving an attached ______

§ Muscles are attached to at least ______points

§ ______

§ Attachment to a ______bone

§ ______

§ Attachment to an ______bone

Types of Muscles

§ ______mover—muscle with the ______responsibility for a certain movement

§ ______—muscle that ______or reverses a prime mover

§ ______—muscle that ______a prime mover in a movement and helps prevent rotation

§ ______—______the origin of a prime mover

Naming Skeletal Muscles

§ By ______of muscle fibers

§ Example: Rectus (______)

§ By relative ______of the muscle

§ Example: Maximus (______)

§ By ______of the muscle

§ Example: Temporalis (______bone)

§ By number of ______

§ Example: Triceps (______heads)

§ By ______of the muscle’s origin and insertion

§ Example: Sterno (on the ______)

§ By ______of the muscle

§ Example: Deltoid (______)

§ By ______of the muscle

§ Example: Flexor and extensor (flexes or extends a bone)

Head and Neck Muscles

§ Facial muscles

§ ______—raises eyebrows

§ ______oculi—closes eyes, squints, blinks, winks

§ ______oris—closes mouth and protrudes the lips

§ ______—flattens the cheek, chews

§ ______—raises corners of the mouth

§ Chewing muscles

§ ______—closes the jaw and elevates mandible

§ ______—synergist of the masseter, closes jaw

§ Neck muscles

§ ______—pulls the corners of the mouth inferiorly

§ ______—flexes the neck, rotates the head

Muscles of Trunk, Shoulder, Arm

§ Anterior muscles

§ ______major—adducts and flexes the humerus

§ Intercostal muscles

§ External ______—raise rib cage during inhalation

§ Internal intercostals—______the rib cage to move air out of the lungs when you exhale forcibly

§ Muscles of the abdominal girdle

§ Rectus ______-—flexes vertebral column and compresses abdominal contents (defecation, childbirth, forced breathing)

§ External and internal ______—flex vertebral column; rotate trunk and bend it laterally

§ ______abdominis—compresses abdominal contents

§ Posterior muscles

§ ______—elevates, depresses, adducts, and stabilizes the scapula

§ ______dorsi—extends and adducts the humerus

§ Erector ______—back extension

§ ______lumborum—flexes the spine laterally

§ ______—arm abduction

Muscles of the Upper Limb

§ ______brachii—supinates forearm, flexes elbow

§ ______—elbow flexion

§ ______—weak muscle

§ ______brachii—elbow extension (antagonist to biceps brachii)

Muscles of the Lower Limb

§ ______—hip extension

§ Gluteus ______—hip abduction, steadies pelvis when walking

§ ______—hip flexion, keeps the upper body from falling backward when standing erect

§ ______muscles—adduct the thighs

§ Muscles causing movement at the knee joint

§ ______group—thigh extension and knee flexion

§ Biceps ______

§ ______

§ Muscles causing movement at the knee joint

§ ______—flexes the thigh

§ ______group—extends the knee

§ Rectus ______

§ Vastus muscles (______)

§ Muscles causing movement at ankle and foot

§ ______anterior—dorsiflexion and foot inversion

§ Extensor ______longus—toe extension and dorsiflexion of the foot

§ ______muscles—plantar flexion, everts the foot

§ ______—plantar flexion

The Muscular System