Chapter 9 terms Flashcards
Definition: calat-
Something inserted
Definition: erg-
Work
Definition: fasc-
Bundle
Definition: -gram
Something written
Definition: hyper-
Over, more
Definition: inert-
Between
Definition: iso-
Equal
Definition: laten-
Hidden
Definition: myo-
Muscle
Definition: reticul-
A net (network)
Definition: sarco-
Flesh
Definition: syn-
Together
Definition: tetan-
Stiff
Definition: -tonic
Stretched
Definition: -troph
Well fed
Definition: voluntar-
Of one’s free will
Fascia
Layers of dense connective tissue; surrounds each muscle and may project beyond the ends of its muscle fibers, forming cordlike tendon.
Tendon
A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
Aponeurosis (plural: aponeuroses)
A sheet of pearly-white fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.
Myofibrils
Any of the elongated contractile threads found in striated muscle cells.
Myosin
A fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cells.
Actin
A protein that forms (together with myosin) the contractile filaments of muscle cells, and is also involved in motion in other types of cells.
Sarcomere
A structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band
Titin
A protein important in the contraction of striated muscle tissues
Troponin
A globular protein complex involved in muscle contraction. It occurs with tropomyosin in the thin filaments of muscle tissue
Tropomyosin
A protein involved in muscle contraction. It is related to myosin and occurs together with troponin in the thin filaments of muscle tissue
Sarcoplasmic reticulum
A specialized form of endoplasmic reticulum surrounding myofibers. A membrane system responsible for storing, releasing, and resequestering calcium in response to an action potential.
Transverse tubule
a deep invagination of the sarcolemma, which is the plasma membrane, only found in skeletal and cardiac muscle cells
Cisternae
a sac or cavity containing fluid.
Triad
The structure formed by a T tubule with a sarcoplasmic reticulum (SR) known as the terminal cisterna on either side.
Synapse
A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter
Neurotransmitters
A chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure
Motor neurons
A nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland
Neuromuscular junction
A neuromuscular junction (NMJ) is the synapse or junction of the axon terminal of a motoneuron with the motor end plate
Motor end plate
the flattened end of a motor neuron that transmits neural impulses to a muscle
Synaptic cleft
The space between a presynaptic and postsynaptic membrane, containing extracellular fluid (ECF). Neurotransmitters must diffuse across this cleft to activate postsynaptic receptors.
Acetylcholine (ACh)
A compound that occurs throughout the nervous system, in which it functions as a neurotransmitter.
ATPase
ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion.
Sliding filament model
When sarcomeres shorten, the thick and thin filaments do not change length. They slide past one another, with the thin filaments moving toward the center of the sarcomere from both ends.
Acetylcholinesterase
An enzyme that causes rapid hydrolysis of acetylcholine. Its action serves to stop excitation of a nerve after transmission of an impulse
Creatine phosphate
A compound produced in the body, stored in the muscle fibers, and broken down by enzymes to quickly replenish the adenosine-triphosphate stores.
Myoglobin
A red protein containing heme that carries and stores oxygen in muscle cells. It is structurally similar to a subunit of hemoglobin
Lactic acid threshold
amount of effort it takes before the body switches from aerobic exercise to anaerobic.
Oxygen debt
a cumulative deficit of oxygen resulting from intense exercise; the deficit must be made up when the body returns to rest
Twitch
The contractile response of a single muscle fiber to a muscle impulse.
Threshold stimulus
The weakest stimulus capable of producing an action potential in an excitable cell.
Summation
Summation is a method of achieving or inhibiting action potential in the postsynaptic neuron, when one presynaptic neuron does not generate enough neurotransmitter.
Tetanic contraction
Occurs when a motor unit has been maximally stimulated by its motor neuron.
Recruitment (multiple motor unit summation)
The combined effect of a number of motor units acting within a muscle at any given time.
Muscle tone
The tension present in resting muscles.
Isotonic contraction
The force of the muscle fibers remains constant but the speed may vary.
Concentric contraction
Shortening
Eccentric contraction
Lengthening; occurs when the force a muscle generates is less than that required to move or lift an object.
Isometric contraction
When a muscle strains against a resistance but does not change in length; the length stays the same but the force changes.
Multiunit smooth muscle
Smooth muscle containing few tight junctions, but richly innervated; responds as individual motor units, not as a single unit.
Visceral smooth muscle (single-unit smooth muscle)
Smooth muscle containing many tight junctions that contracts as a unit and responds to stretch.
Peristalsis
The involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wavelike movements that push the contents of the canal forward
Levers
Simple mechanical devices
Origin of skeletal muscle
The less movable end of a joint.
Insertion of skeletal muscle
The more movable end.