Muscles Flashcards
Is a contractile tissue that has the capacity of becoming short in response to an
appropriate stimulus.
Muscle
Muscle is the tissue of the body which primarily functions as a
source of power
Functions of Muscle Tissue
1. To produce movement by working with bones, ligaments and tendons. 2. Maintenance of posture. 3. Stabilization of joints. 4. Production of heat.
There are three types of muscle:
Cardiac muscle Smooth muscle Skeletal muscle
Cardiac Muscle site?
it is found only in the myocardium of the heart.
Cardiac Muscle special Characteristics?
- Cells within a fiber often branch and bind to cells in adjacent fibers to form a network to contract as a one unit.
- There are intercalated discs between the connecting branches of cells.
Cardiac Muscle all Characteristics?
1- Made up of bundles of cells. 2- Each cell has one or two centrally placed nucleus. 3- Cells within a fiber often branch and bind to cells in adjacent fibers to form a network to contract as a one unit. 4- There are intercalated discs between the connecting branches of cells. 5- Striated. 6- Involuntary.
Smooth Muscle Site?
walls of hollow organs and blood vessels.
Smooth Muscle special Characteristics?
- In the walls of the blood vessels, the smooth muscle fibers are arranged circularly and serve to modify the caliber of the lumen.
- In walls of digestive system arranged longitudinally and circularly that help movement of ingested food by a wave of contraction referred to as peristalsis.
Smooth Muscle Characteristics?
1- consists of long, spindle-shaped cells with single central nuclei. 2- Its muscle fibers are not striated. 3- Involuntary. 4- In the walls of the blood vessels, the smooth muscle fibers are arranged circularly and serve to modify the caliber of the lumen. 5- In walls of digestive system arranged longitudinally and circularly that help movement of ingested food by a wave of contraction referred to as peristalsis.
Skeletal Muscle Site ?
attached to the skeleton and hence its name (skeletal).
Skeletal Muscle special Characteristics?
- Consists of multi-nucleated, long and cylindrical muscle fibers . The nuclei of the cells are situated peripherally near the surface of the fiber.
Skeletal Muscle Characteristics?
- Composed of muscle cells (fibers), connective tissue, blood vessels and nerves. 2. Consists of multi-nucleated, long and cylindrical muscle fibers . The nuclei of the cells are situated peripherally near the surface of the fiber. 3. The fibers to be smaller diameter in small muscles and larger in large muscles (1 mm- 4 cm in length) 4. Striated. 5. Contracts under Voluntary control.
surrounds the individual muscle fiber/cell. ?
Endomysium
surrounds the whole bundle of muscle fibers
(fascicle). ?
Perimysium
surrounds the whole muscle. The epimysium is
covered with fascia.
Epimysium
most important
component of skeletal muscles. ?
Skeletal muscle fiber
Muscle growth occurs through ?
hypertrophy
enlargement of existing muscles
Nuclei are present just beneath the ?
sarcolemma
specialized plasma membrane.
?
Sarcolemma
specialized smooth endoplasmic reticulum.?
Sarcoplasmic reticulum
Bundles of myofilaments separated by sarcoplasmic
reticulum. ?
Myofibril
Contains contractile organelles of skeletal muscle. ?
Myofibril
Extends through the entire length of a muscle fiber.
?
Myofibril
Myofibrils are composed of functional units called
?
Sarcomere
responsible for the striations. ?
Sarcomere
Each sarcomere is separated from the next by ?
z discs.
Sarcomeres are composed of ?
thick (myosin) and thin
(actin) filaments.
A band is the part of the sarcomere composed of thick (myosin) and thin (actin) filaments . ?
A Band
Has dark striation seen under the microscope.
A band
full length of the thick filament; includes inner end of thin filaments (thus, there is overlap of thin and thick filaments).
A band
Band is the part of the sarcomere that contains only thin (actin) filaments.
I band
Has light striation seen under the microscope. ?
I band
is the center part of A band where no thin filaments occur (thus, there is no overlap of thin and thick filaments)
>?
A band - h zone
is the part of the A band that contains only thick filaments (myosin).
H zone
It is the middle of the sarcomere and is composed of supporting proteins that hold the thick filaments together. ?
M line
form the boundaries of each sarcomere. ?
Z discs or z lines
Extend from Z disc toward the center of the sarcomere.
Thin ( actin ) filaments
Located in the center of the sarcomere; overlap with the inner ends of the thin filaments.
Thick ( myosin ) filaments
They are invaginations of the sarcolemma that penetrate deeply into the muscle fiber around all
myofibrils. ?
Transverse tubules
They permit rapid transmission of the action potential into the cell and play an important role in
regulating cellular calcium concentration, increasing the efficiency of muscle contraction.
?
Transverse tubules
Myofibrils are built of 3 kinds of proteins:
?
Contractile proteins “myosin and actin”. Regulatory proteins which turns contraction on
& off “troponin and tropomyosin”. Structural proteins which provide proper
alignment, elasticity and extensibility “titin,
myomesin, nebulin and dystrophin”.
Contractile proteins ?
myosin and actin”.
Regulatory proteins which turns contraction on
& off?
troponin and tropomyosin”.
Structural proteins which provide proper
alignment, elasticity and extensibility ?
titin,
myomesin, nebulin and dystrophin”.
any disease that affects the
muscles that control voluntary movement in the body. ?
Myopathy
Patients experience muscle weakness due to a dysfunction of the
muscle fibers. ?
Myopathy
chronic autoimmune disorder in which antibodies destroy
the communication between nerves and muscle, resulting in
weakness of the skeletal muscles. ?
Myasthenia Gravis:
affects the voluntary muscles of the body,
especially those that control the eyes, mouth, throat and limbs.?
Myasthenia Gravis:
