Module 4 Muscular Tissue Flashcards
Bundle of muscle fiber
Fascicle
thread like structures w/
contractile function
Myofibrils
finer structure inside myofibrils
Myofilaments
dense CT, surrounds whole muscle
Epimysium
thinner covering around fascicle or
a bundle of muscle fiber
Perimysium
delicate layer of reticular fibers
around each muscle fiber
Endomysium
cytoplasm of a muscle fiber
(acidophilic)
Sarcoplasm
plasma membrane of a muscle cell
Sarcolemma
linear unit, basic functional unit
of myofibril
Sarcomeres
granules in the sarcoplasm (under
EM is actually mitochondria)
Sarcosome
endoplasmic reticulum,
membranous sacs which encircles
each myofibril
Sarcoplasmic reticulum (SR)
Muscular Tissues: General Characteristics:
- Cells elongated (called fibers)
- Sarcoplasm
- Plasma membrane
- Acidophilic staining
- Contraction depends on
myofilaments
6.Cells held together by loose areolar
Connective Tissue containing blood
vessels and nerves
appears fibular
due to myofibrils
Sarcoplasm
Muscular Tissues: General Functions:
- Movement
- Posture maintenance
- Joint stabilization
- Heat generation
skeletal and smooth muscle aid in movement of
bones and fluids
Movement
skeletal muscles contract to maintain the body
position
Posture maintenance
tendons that cross over stabilize joint as the
muscle tone (constant low level contraction)
places tension on the tendon
Joint stabilization
muscular contractions generate heat influencing
body temperature
Heat generation
Muscular Tissues: Special Functions:
- Contractility (able to contract)
- Extensibility (able to extend)
- Excitability (able to become excitable)
- Elasticity
when long cells shorten simultaneously, pulling force is
created, contracts the muscle reduce overall size then
cause movement or stabilization
Contractility
at the end of contraction, muscle may return to
original length by relaxing or extending with the aid of
opposing muscle
Extensibility
muscle cells respond to nerve impulses
Excitablity
Recoils (back to it’s normal size) after stretch
Elasticity
Muscular Tissues: Composition
- Muscle fibers
- Loose areolar CT
outermost layer, a sheath of
dense connective tissue (CT) externally
surrounds the entire muscle
Epimysium
a sheath of fibrous CT
surrounding fascicles
Perimysium
a sheath of reticular fibers
surrounding the bundles within the fascicles
Endomysium
intercellular substance
that held together muscle fibers
Loose areolar CT
Types of Muscle tissue
- Skeletal muscle
- Smooth muscle
- Cardiac muscle
somatic
striated and voluntary muscles
Skeletal muscle
Have Intercalated disk
striated involuntary muscles
Cardiac muscle
plain/visceral or
non-striated/involuntary muscles
Smooth muscle
plain/visceral or
non-striated/involuntary muscles
Smooth muscle
walls of hollow organs
Smooth muscle
only in the wall of
the heart
Cardiac muscle
Attach to and move skeleton
Skeletal muscle
It is 40% of body weight
Skeletal muscle
Fibers = multinucleate cells (embryonic cells fuse)
Skeletal muscle
Cells obviously striated
*Contractions are
voluntary
Skeletal muscle
It is spindle or fusiform shaped
Smooth muscle
not branched and no striations
Smooth muscle
Cells somewhat compact in
arrangement
Smooth muscle
It has very scanty intercellular
subs (has least amount of
Loose areolar CT)
Smooth muscle
Few long slender
mitochondria
Smooth muscle
Scanty ribosomes and ER
*
Smooth muscl
Scanty ribosomes and ER
*
Smooth muscle
Sarcolemma showing pinocytic
vesicles
Smooth muscle
Single nucleus - bulging and
centrally located
Smooth muscle
Myofibrils of smooth muscle IS
non-stiriated
myofilaments of smooth muscle
not distinct
cannot consciously control movement
Involuntary
very slow and sustained
Is very fatigue resistant
Contraction
Distribution of smooth muscle
mainly in the walls of hollow visceral organs
-In blood vessels: walls of vein and arteries
-In reproductive and glandular systems
-in digestive and urinary systems:
-In integumentary system
smooth muscle In blood vessels: walls of vein and arteries
To regulate blood pressure and flow
smooth muscle in reproductive and glandular systems
To produce movements
Smooth muscle in digestive and urinary systems:
- forms internal sphincters of anus
- produces contractions
What causes goose bumps?
Arrestores pitorum or arrector pili muscles
Smooth muscle distribution
and its MAJOR LOCATION
- Inside the eye
- Respiratory tubes
- Urinary organs
- Reproductive organs
- Digestive organs
- Walls of vessels
NEED BASAHIN THIS
Lining of hollow visceral organs
* the walls of the digestive system ex. stomach,
bladder, respiratory passages
* Middle to lower part of esophagus
* Walls of ducts and glands associated with alimentary tract
* Walls of respiratory passages (trachea to alveolar ducts
urinary & genital ducts)
* Walls of arteries, veins & larger lymphatics
* Spleen
* Arrestores pitorum or arrector pili muscle (goose flesh)
* Iris & ciliary body of the eye concerned with accomodation,
constriction & dilation of pupil
* Areola of mammary gland
* Subcutaneous tissue of scrotum
Smooth Muscle: Functions MAJOR
To alter activity of various body parts to meet
needs of the body
SMOOTH MUSCLE: FUNCTIONS SPECIFIC
- Contraction of the bladder
- Move food through the intestines (peristalsis)
- Peristaltic movement to move feces down the
digestive system - Contraction of smooth muscle in the trachea and
bronchi w/c decreases the size of the airways - Constriction and dilation of blood vessels
- Constriction, accomodation and dilation of pupil
- Uterine contraction during birthing
It has characteristics of both
skeletal and smooth muscle
CARDIAC MUSCLE
Contractions lasts longer than
a skeletal muscle twitch
CARDIAC MUSCLE
It depends on aerobic
respiration to generate ATP
CARDIAC MUSCLE