Lecture 4 - Muscle Tissue Flashcards
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
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
the ability to return to its normal shape
elasticity
ability to respond to stimuli
excitability
ability to contract
contractility
ability of the muscle to stretch without tearing
extensibility
Skeletal muscle depends on the nervous system to work properly referred to as?
a voluntary motion
cardiac muscle and smooth muscle can respond to other stimuli, such as catecholamines _________ from the blood, hormones and local stimuli.
epinephrine and norepinephrine
are specialized types of epithelium and fibroblasts, respectively, that have the contractile ability.
myoepithelium and myofibroblasts
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
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
what are the functions muscular system is able to perform through contraction?
a. production of force and movement
b. support of the body, change of body posture
c. stability of joints
d. production of body heat (to maintain normal body temperature)
e. provision of form to the body
Myoblasts (embryonic muscle cells) are derived from?
Mesenchyme
Cardiac and smooth muscle tissues develop from local populations of?
Splanchnic mesoderm
skeletal muscles develop from mesoderm within ____ ?
somites
This muscle allows voluntary control of specific functions, such as swallowing, urination, and defecation.
skeletal muscles
What are the various integrated tissues that compose skeletal muscle?
a. the skeletal muscle fibers
b. blood vessels
c. nerve fibers
d. connective tissue.
Each large muscle is wrapped in a sheath of dense, irregular connective tissue called the ______ which holds muscle fascicles in a group and also allows a muscle to contract while maintaining its structural integrity.
epimysium
a term synonymous with muscle cell; 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), by an intermediate layer of connective tissue
perimysium
Inside each fascicle, each muscle fiber is encased in an extremely thin connective tissue layer
endomysium
The plasma membrane of muscle fibers is called the __________, the cytoplasm is referred to as __________, and the specialized smooth endoplasmic reticulum that stores and controls the release of calcium ions (Ca++) is called the ______________.
sarcolemma, sarcoplasm, sarcoplasmic reticulum
What is the function unit of skeletal muscle fiber?
sarcomere
Cardiac muscle tissue is located in?
in the heart or in myocardium
is a cell structure that anchors the ends of cardiac muscle fibers together so the cells do not pull apart during the stress of individual fibers contracting
desmosome
Contractions of the heart (heartbeats) are controlled by specialized cardiac muscle cells called __________ that directly control heart rate
pacemaker cells
This group of cells is self-excitable and able to depolarize to threshold and fire action potentials on their own
autorhythmicity
regulatory protein that facilitates contraction in smooth muscles
calmodulin
sarcoplasmic structure that attaches to the sarcolemma and shortens the muscle as thin filaments slide past thick filaments
dense body
process in which one cell splits to produce new cells
hyperplasia
subset of a cross-bridge in which actin and myosin remain locked together
latch bridges
cell that triggers action potentials in smooth muscle
pacesetter cells
relaxation of smooth muscle tissue after being stretched
stress-relaxation response
enlargement of neurons that release neurotransmitters into synaptic clefts
varicosity
Smooth muscle found in the walls of visceral organs
visceral muscle
Where can we located smooth muscles?
urinary bladder, uterus, stomach, and intestines, and in the walls of large vascular tubes, such as the arteries and veins
Muscles are predominantly powered by
Oxidation of fats
Carbohydrates
Anaerobic chemical reactions
Molecules that are used up by myosin filaments during muscle contractions
Adenosine triphosphate (ATP)
Muscular system develops from the?
Mesoderm layer
The muscles from the iris is developed from?
Neuro-ectoderm
Muscles of the esophagus are developed by?
Transdifferentiation from smooth muscle
Three levels of connective tissue that encloses the skeletal muscle
a. Epimysium
b. Perimysium
c. Endomysium
2 types of myofilaments
Myosin and actin
Proteins of thin filament
Actin
Tropomyosin
Troponin
