The Muscular System
§ Muscles are responsible for all types of body ______
§ Three basic muscle types are found in the body
§ ______muscle
§ ______muscle
§ ______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
§ ______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