Intro to Muscles Flashcards
what are the 3 types of muscles and what are the difference between each?
Cardiac- Involuntary striated, single nuclei
Smooth- involuntary non striated, single nuclei
Skeletal- voluntary striated, multi nuclei
what are pacemaker cells and what types of muscle have them?
Pacemaker cells coordinate contractions that is separate from the nervous system
Cardiac muscle and some smooth muscle
Cardiac muscle cells form extensive connections with one another at specialized regions called
Intercalated discs
what are the 3 concentric layers/ wrappings of muscle from (outer to middle and inner)
Epimysium( outer layer covering muscle)
Perimysium(middle layer covering fascicle)
Endomysium (inner layer covering muscle fiber)
the ___ (lining of muscle) consists of a delicate network of reticular fibers
endomysium
the ___ (lining of muscle) contains collagen and elastic fibers
Perimysium
the __(lining of muscle is made of irregular connective tissue
epimysium
____cells lie between the endomysium and the muscle fibers are stem cells that repair damaged muscle tissue
these are found in what type of muscle?
Myosatellite
Skeletal
what is a tendon?
what is it made of ?
the collagen fibers of the epimysium, perimysium, and endomysium come together and form a tendon that attaches the muscle to bone, cartilage, skin, or another muscle
Dense Regular CT
Tendons that form thick, flattened sheets are called
aponeuroses.
Chemical communication between a neuron and a skeletal muscle fiber occurs at a site called the
the axon terminal attaches to the the ___ of the skeletal muscle fiber
neuromuscular junction (NMJ)
Motor End Plate
In a skeletal muscle cell, the plasma membrane
sarcolemma
Within the sarcolemma is the cytoplasm, which in a muscle cell is called
sarcoplasm
During development, groups of embryonic cells called___ fuse to form individual skeletal muscle fibers
Myoblasts
Some myoblasts do not fuse with developing muscle fibers, but remain in adult skeletal muscle tissue as stem cells called
myosatellite cells
Skeletal muscle cells feature intracellular ____ that extend the length of the cell
myofibrils
is a disorder characterized by widespread, chronic (more than three months) musculoskeletal pain
Fibromyalgia
Rank the terms from largest to smallest: Muscle fiber, muscle fascicle, myofibril, muscle
Muscle, fascicle, muscle fiber(muscle cell), and myofibril
Deep indentations in the sarcolemmal surface form a network of narrow tubules called______, that extend into the sarcoplasm. The sarcolemma and these_______conduct electrical impulses, called action potentials, to stimulate muscle fiber contraction.
Transverse Tubules (T tubules)
Myofibrils are organized in repeating units called ____
sarcomeres
____ are the smallest functional units of muscle fibers
Sarcomeres
in a sarcomere the dark band is called the ___
and the Light band is called the ___
1) A band (dArk)
2) Iband (lIGHT)
in a sarcomere the ___ filiment is composed of actin, tropomysosin and troponin
and the ___ filiment is composed of mysoin
Light
Dark
what are the 4 properties of muscle tissue
1) Excitability
2) Contractility
3) Extensibility
4) Elasticity
(EEEC)
property of muscle tissue: The ability to shorten actively and exert a pull or tension that is harnessed by connective tissues.
Contractility
The ability to contract over a range of resting lengths. For example, a smooth muscle cell can be stretched to several times its original length and still contract when stimulated.
Extensibility
The ability of a muscle to return to its original length after a contraction
Elasticity
The ability to respond to stimulation. For example, skeletal muscles respond to stimulation by the nervous system, and some smooth muscles respond to circulating hormones.
Excitability
can damaged cardiac muscle regenerate? why?
No
they lack myosatellite cells
this type of muscle cells are small with tapering ends
smooth
this type of muscle cell is the only type of muscle cell that can divide to regenerate after an injury
smooth muscle tissue
In regards to a tendon what are Sharpey’s Fibers?
Collagen fibers that penetrate deep into cortical bone
In regards to anatomy what is a motor unit?
1) single motor Neuron
2) all of the muscle fibers it controls
what does a larger motor unit mean? and does this mean we have more or less control over that muscle?
1) the more muscle fibers we have synapsed per motor neuron
3) less control
what is the All or None principle
If a signal travels through a motor neuron to muscle fibers, all of those muscle fibers synapsed will contract together completely or they will not contract at all.
what are the 3 types of skeletal muscle fibers
1) slow oxidative fibers
2) Fast Oxidative
3) Fast Glycolytic Fibers
this type of muscle fiber: (Aerobic endurance) meant to contract over a longer period of time
what type of muscles would we find more of these in?
Slow Oxidative
Postural muscles
this type of muscle fiber: (Aerobic Instantaneous power)
Fast Glycolytic
this type of muscle fiber: intermediate
Fast Oxidative
can a single motor unit control more than one type of muscle fiber (SO , FO, FG fibers )?
NO
increase i the size of muscle fiber
how does this happen?
Hypertrophy
Both myofibrils and myofilaments increase in size
what are the 4 main fascicle arrangements ? what do they mean
1) Parallel ( all fibers are lined up in same direction)
2) Convergent (begin fanned out and converge into one tendon
3) Pennate (fibers enter tendon from an angle)
4) circular (mouth and sphincters)
