Muscular Tissue (Skeletal Muscles with Introduction) Flashcards
It is one of the four primary tissue types.
Muscle
These are the largest soft tissues of the musculoskeletal system.
Muscle
3 types of muscle tissue
skeletal muscle
cardiac muscle
smooth muscle
wave-like pattern is know as…
action potential
Skeletal muscle depends on the nervous system to work properly. This is referred to as a ___________.
voluntary motion
both cardiac muscle and smooth muscle can respond to other stimuli, what are these stimuli?
• catecholamines (epinephrine and norepinephrine) from the blood
• hormones
• local stimuli
The muscle cell, muscle fiber, contains protein filaments of _______ and _______ that slide past one another, producing contractions that move body parts, including internal organs.
actin and myosin
These contains protein filaments of actin and myosin that slide past one another, producing contractions that move body parts, including internal organs
muscle cell and muscle fiber
A type of striated muscle found specifically in the heart or myocardium.
Cardiac muscle
A structure specific to cardiac muscle formed from gap junctions and desmosomes that allow cardiac muscle cells to contract in a coordinated fashion.
Intercalated disc
The term for a muscle cell that applies to skeletal muscle, cardiac muscle and smooth muscle.
Myofibers
The tube like organelle present in skeletal muscle and cardiac muscle that coordinates contraction of the cell.
Myofibrils
Modified cardiomyocytes that propagate electrical signals through the cardiac muscle of the myocardium allowing coordinated contraction.
Purkinje fibers
The basic functional unit of striated muscle that is composed of myofilaments.
Sarcomere
The organelle that is responsible for the storage and release of calcium into the cytosol of the myofiber.
Sarcoplasmic reticulum
A type of striated muscle responsible for voluntary movement.
Skeletal muscle
Non-striated muscle that is responsible for involuntary movement within several organ systems.
Smooth muscle
Invaginations of the sarcolemma (cell membrane) into the cell that allows for the
conduction of depolarization impulses from the outside of the cell to around the sarcomeres.
T tubules
It is one of the four primary tissue types.
Muscle
3 types of muscle tissue
Skeletal muscle
Cardiac muscle
Smooth muscle
It move bones and other structures (e.g. the eyes)
Skeletal muscle
Example of skeletal muscle
Eyes
It form most of the walls of the heart and adjacent great vessels, such as the aorta.
Cardiac muscle
Example of a cardiac muscle
Aorta
Smooth muscle is also present in what organs?
blood vessels and intestines
involuntary and non-striated muscle
Smooth muscle
Muscles are classified histologically into ________ and ________ based on the structural characteristic called “striations” which is due to the arrangement of the muscle fiber’s actin and myosin filaments.
striated muscles and non-striated muscle
Muscles are classified histologically into striated muscles and non-striated muscles based on the structural characteristic called ________ which is due to the arrangement of the muscle fiber’s actin and myosin filaments.
striations
It is due to the arrangement of the muscle fiber’s actin and myosin filaments.
striations
Based on this microscopic classification, skeletal and cardiac muscles are grouped as what?
striated muscles
Visceral muscle is classified as what?
non-striated
Four main properties of Muscle tissues
Excitability
Contractility
Extensibility
Elasticity
The ability to respond to stimuli
Excitability
The ability to contract
Contractility
The ability of the muscle to be stretched without tearing
Extensibility
The ability to return to its normal shape
Elasticity
It depends on the nervous system to work properly.
Skeletal muscle
Skeletal muscle depends on the ________ to work properly.
nervous system
Skeletal muscle depends on the nervous system to work properly. This is referred to as a __________.
voluntary motion
These are specialized types of epithelium and fibroblasts, respectively, that have the contractile ability.
Myoepithelium and myofibroblasts
These are often located in and around glands where extracellular product produced by the epithelial cells needs to be moved by contractile action towards the duct system.
Myoepithelial cells
These are often seen in healing wounds and assist in the maturation and contraction of the granulation tissue (immature fibrous connective tissue) as it matures and contracts.
Myofibroblasts
Through contraction, the muscular system performs the following important functions:
a. production of force and movement
b. support of the body
c. stability of joints
d. production of body heat
e. provision of form to the body
These are predominantly powered by the oxidation of fats and carbohydrates, but anaerobic chemical reactions are also used.
Muscles
These chemical reactions produce adenosine triphosphate (ATP) molecules that are used up by myosin filaments during muscle contractions.
anaerobic chemical reactions
It develops from the mesoderm layer (except for the muscles of the iris which develop from neuro-ectoderm, and the muscles of the esophagus which are believed to develop by transdifferentiation from smooth muscle) and consists of cardiac, smooth, and skeletal muscles.
muscular system
muscular system develops from what layer?
mesoderm
The muscular system develops from the mesoderm layer (except for the muscles of the _______ which develop from neuro-ectoderm, and the muscles of the ________ which are believed to develop by transdifferentiation from smooth muscle) and consists of cardiac, smooth, and skeletal muscles.
iris
esophagus
The muscles of the iris develop from ____________.
neuro-ectoderm
The muscles of the esophagus which are believed to develop by transdifferentiation from __________.
smooth muscle
(embryonic muscle cells) are derived from mesenchyme (embryonic connective tissue).
Myoblasts
Myoblasts (embryonic muscle cells) are derived from ________.
mesenchyme (embryonic connective tissue).
It is developed from local populations of mesenchymal cells (splanchnic mesoderm)
Cardiac and smooth muscle tissues
It is developed from mesoderm within the somites.
skeletal muscles
Cardiac and smooth muscle tissues develop from local populations of __________________.
mesenchymal cells (splanchnic mesoderm)
skeletal muscles develop from __________.
mesoderm within the somites.
Functions of skeletal muscle
To contract and cause movement
Stop movement
Hold a body
Maintaining skeletal stability and preventing skeletal structure damage or deformation.
Control movement
Protect internal organs
Generate heat
One of the most important functions of skeletal muscle is _________.
To contract and cause movement.
It act not only to produce movement but also to stop movement.
Skeletal muscles
It prevent excess movement of the bones and joints, maintaining skeletal stability and preventing skeletal structure damage or deformation.
Skeletal muscles
It is located throughout the body at the openings of internal tracts to control the movement of various substances.
Skeletal muscles
These allows voluntary control of specific functions, such as swallowing, urination, and defecation.
Skeletal muscles
It protect internal organs (particularly the abdominal organs) by acting as an external barrier or shield to external trauma and by supporting the weight of the organs.
Skeletal muscles
It contribute to the generation of heat, primarily by shivering or intense bursts of movement.
Skeletal muscles
It requires energy, and when ATP is broken down, heat is produced.
Muscle contraction
When ATP is broken down, ________ is produced.
heat
Enumerate skeletal muscles voluntary control of specific functions.
swallowing, urination, and defecation
integrated tissues of skeletal muscles
a. the skeletal muscle fibers
b. blood vessels
c. nerve fibers
d. connective tissue
3 levels of connective tissue of skeletal muscle
a. Epimysium
b. Perimysium
c. Endomysium
Each large muscle is wrapped in a sheath of dense, irregular connective tissue called the __________.
epimysium
It holds muscle fascicles in a group and also allows a muscle to contract while maintaining its structural integrity. This membranous envelope, is impervious to the spread of fluid such as pus.
epimysium
This membranous envelope, is impervious to the spread of fluid such as pus.
Epimysium
It also allows the muscle to move independently from other muscle groups and other types of tissue. Most individual muscles that you learn in gross anatomy are surrounded by this.
epimysium
It is a term synonymous with muscle cell.
muscle fiber
It is a cell with multiple peripherally located nuclei that runs the ENTIRE length of the actual muscle.
muscle fiber
Inside each skeletal muscle, muscle fibers are organized into individual bundles called ________.
fascicles
Inside each skeletal muscle, muscle fibers are organized into individual bundles (called fascicles), by an intermediate layer of connective tissue called the ________.
perimysium
Inside each fascicle, each muscle fiber is encased in an extremely thin connective tissue layer called the __________.
endomysium
Some terminology associated with muscle fibers is rooted in the _________&.
Greek sarco
sarco, which means _________
flesh
plasma membrane of muscle fibers is called the ____________
sarcolemma
The cytoplasm of muscle fiber is referred to as _____________.
sarcoplasm
The specialized smooth endoplasmic reticulum that stores and controls the release of calcium ions (Ca++) is called the ____________.
sarcoplasmic reticulum (SR)
The functional unit of a skeletal muscle fiber is the ___________.
sarcomere
It is a highly organized arrangement of the contractile myofilaments actin (thin filament) and myosin (thick filament), along with other support proteins.
sarcomere
myofilaments
actin (thin filament) and myosin (thick filament)
Individual sarcomeres are joined together in a long chain called a __________ and attach to the sarcolemma at its end.
myofibril
These are bundled together within the sarcoplasm.
Myofibrils
In addition, there are invaginations of the sarcolemma into the sarcoplasm that surround the myofibrils. These are referred to as ____________.
t-tubules
These are also known as striated muscle.
skeletal muscle and cardiac muscle
strands that are thinner than the myosin, together it is called the _________
thin filament of the sarcomere.
Because the myosin strands and their multiple heads (projecting from the center of the sarcomere, toward but not all to way to, the Z-discs) have more mass and are thicker, they are called __________.
thick filaments
In order for a sarcomere to contract, this is released from the sarcoplasmic reticulum after a stimulatory action potential from the T-tubules is generated.
calcium
