TOPIC 7 - MUSCLE TISSUE Flashcards
“Sarco-“ is from what Greek word ?
“Sarx”
What is the meaning of the Greek word “Sarx”?
Flesh
“Myo-“ is from what Greek word?
“Mys”
What is the meaning of Greek word “Mys”?
Muscle
What are the 3 types of muscle?
- Smooth muscle
- Skeletal muscle
- Cardiac muscle
Give the type of muscle that is non-striated.
Smooth muscle
Give the type of muscle that is striated.
- Skeletal muscle
- Cardiac muscle
Give the type of muscle that is voluntary.
Skeletal muscle
Give the type of muscle that is involuntary.
- Cardiac muscle
- Smooth muscle
Muscle tissues contract in response to ?
Stimulation
Muscles can lengthen by itself. True or False?
False
How can muscles be lengthened?
Through contractions
Give 3 functions of muscles.
- Locomotion
- Food movement
- Heat production
The ends of the smooth muscles are?
Tapered
This type of muscle surrounds the gut and moves food through the digestive tract.
Smooth muscle
This type of muscle surrounds blood vessel where it controls distribution of blood.
Smooth muscle
After meals, blood vessels in the gut are ____ while those in the skeletal muscles ____.
Filled, contract
There is not enough blood in the body to fill all blood vessels so some must be ____ while others are filled.
Contracted
This type of muscle has cells that are long, extending the length of muscle.
Skeletal muscle
This type of muscle is multinucleated and striated.
Skeletal muscle
Striations are seen as a result of what ?
Orderly arrangement of actin and myosin filaments within the muscle cell.
The skeletal muscle cells are arranged into bundles called ?
Fascicles
Fascicles are surrounded by thin layers of connective tissue. True or False?
True
Fascicles can still be arranged into larger bundles. True or Falase?
True
If bundled skeletal muscle cells are arranged into fascicles, fascicles are arranged into ?
Particular muscular organ (e.g. biceps)
The connective tissues surrounding fascicles extends into what type of connective tissue?
Dense regular connective tissue (e.g. tendon)
This type of muscle is found in the heart.
Cardiac muscle
This type of muscle is striated and branched.
Cardiac muscle
What do you call the structure that connects the branches of muscle cells in the cardiac muscle?
Intercalated discs
This type of muscle has strong and quick discontinuous contraction.
Skeletal muscle
This type of muscle has strong and quick continuous contraction.
Cardiac muscle
This type of muscle has weak and slow contraction.
Smooth muscle
Give the locations of each type of muscle. (Skeletal - cardiac - smooth respectively)
- Near bones
- Heart wall
- Walls of hollow organs and blood vessels
What are the characteristics of skeletal muscle nuclei?
Many, flat, peripheral
What are the characteristics of cardiac muscle nuclei?
1-2 per cell, plump, central
What are the characteristics of smooth muscle nuclei?
One per cell, central
Among the types of muscle, which has sarcoplasmic reticulum?
- Skeletal muscle
- Cardiac muscle
- Smooth muscle (less developed)
Among the types of muscle, which has T-tubules?
- Skeletal muscle
- Cardiac muscle
Where do you find the T-tubules in skeletal muscle?
At the junction of A-I bands.
Where do you find the T-tubules in cardiac muscle?
At the Z lines.
The T-tubules in skeletal muscle forms what?
Forms triads
(Triads - t-tubule (transverse tubule) flanked by two sarcoplasmic reticulum (SR) terminal cisternae)
The T-tubules in cardiac muscle forms what?
Forms diads
(Diads - single t-tubule paired with one sarcoplasmic reticulum terminal cisternae)
This type of muscle has cells overlapping each other.
Smooth muscle
This type of muscle has moderate blood supply.
Skeletal muscle
This type of muscle has extensive blood supply.
Cardiac muscle
This type of muscle has less abundant blood supply.
Smooth muscle
Skeletal muscle cells is derived from?
(Hint: Embryonic)
Mesenchymal cells
A precursor of muscle cell that is fused to form multi-nucleated myotubes which elongate.
Myoblast
What are the components of sarcoplasm?
- Ton of mitochondria
- Glycogen granules
- Myoglobin
In mature skeletal muscles, its tubes are long and branched. True or False?
False, unbranched.
Mature skeletal muscle cells can still divide. True or False?
False
There is abundant basophilic cytoplasm in skeletal muscle. True or False?
False, eosinophilic.
It is a delicate connective tissue that surrounds muscle fibers (myofibrils).
Endomysium
It is a connective tissue that surrounds each fascicle.
Perimysium
It is a dense layer of connective tissue that surrounds entire muscle.
Epimysium
Sarcomere is derived from what Greek words?
“Sarx” and “Meros”
The Greek word “Meros” means?
Part
It is the basic functional unit of a muscle.
Sarcomere
It is composed of tubular muscle cells formed in the process of myogenesis.
Sarcomere
It is composed of repeating sections of sarcomeres which appear under the microscope as dark and light bands.
Myofibrils
It is the thick filament of myofibrils.
Myosin
It is the thin filament of myofibrils.
Actin
Myosin can only bind to actin when binding sites are exposed to ?
Calcium ions
Myosin head binds to ___ which is the source of energy for muscle movement.
ATP
What forms the borders of sarcomeres?
Actin molecules bound to Z lines
It gives skeletal and cardiac muscles their striated appearance.
Organized arrangement of sarcomeres
A sarcomere is defined as running from ___ ___ to ___ ___.
Z line to Z line
When muscles contract, sarcomeres ____.
Shorten
In a contraction, actin filaments get pulled ___ each other. The distance between the Z lines ___, and the H band ___.
toward, shorten, disappears
Sarcomere structures: It is composed of myosin filaments overlapping actin filaments. `
A bands
Sarcomere structures: It is in the center of A bands, They lie between the free ends of the thin filaments and contain only myosin filaments.
H bands
Sarcomere structures: It bisect H bands. They are where adjacent thick filaments connect.
M lines
Sarcomere structures: It contain only thin filaments.
I bands
Sarcomere structures: It bisect I bands.
Z lines (disks)
This is a structural protein that attaches actin filaments to the Z line.
Alpha actinin
It is the counterpart of endoplasmic reticulum in muscle cells.
Sarcoplasmic reticulum
Sarcoplasmic reticulum is specialized requester that releases sodium ions. True or False?
False, calcium ions.
Sarcoplasmic reticulum surrounds each myofibril. True or False?
True
At each A-I band junction. a tubular invagination of the sarcolemma termed ____ ____ penetrates the muscle fiber and lies next to the surface of myofibrils.
Transverse (T) tubule
It is an expansion of the sarcoplasmic reticulum called a ___ ___ lying on each side of the T-tubule.
Terminal cisterna
It is a complex of 2 terminal cisternae with a T-tubule in between.
Triad
What glue adjacent cells together in cardiac muscle?
Intercalated disks
Sarcoplasmic reticulum is abundant and prominent in cardiac muscle cells. True or False?
False
If the T-tubules occurs at A-I bands in skeletal muscle, where does it occur in cardiac muscle?
At Z lines
T-tubules form triads with adjacent sarcoplasmic reticulum. True or False?
False, diads.
Intercalated disks are complexes of several types of cell-cell junctions. True or False?
True
In cardiac muscle, this anchors actin filaments.
Fascia adherens
In cardiac muscle, this prevent cardiac muscle fibers from tearing apart during contraction.
Macula adherens (spot desmosomes)
In cardiac muscle, this allows electrical stimuli to be passed from cell to cell.
Gap junctions
Smooth muscle is also present in the eye. True or False?
True
In addition to their contractile properties, smooth muscle cells produce ____, ____, and ____.
Collagen, elastin, and proteoglycans.
Smooth muscle cells are in what shape?
Fusiform (spindle-shaped)
The width of the fiber or cell of smooth muscle is only slightly lesser than the width of the nucleus. True or False?
False, slightly greater
Smooth muscle cells are packed together tightly. True or False?
True
In smooth muscle cell, there is lesser mitochondria. True or False?
False, abundant mitochondria.
In smooth muscle cell, rough ER is abundant. True or False?
False, lesser RER.
In smooth muscle cell, golgi complex is smaller. True or False?
False, large golgi complex.
Each smooth muscle cell is surrounded by a thin layer of ____ fibers.
Reticular
Actin and myosin filaments in smooth muscle are not tightly arranged but just crisscross through cell. True or False?
True
What are the intermediate filaments present in smooth muscle?
Desmin and vimentin
These are anchor sites for actin-myosin filament bundles.
Dense bodies
Smooth muscle: Counterpart of Z-disks of skeletal and cardiac muscle.
Dense bodies
Dense bodies are located outside the sarcolemma. True or False?
False, inside.
All types of muscle has regenerative ability. True or False?
False
Among the 3 types of muscle, which has no regenerative ability?
Cardiac muscle
Death of cardiac muscle leads to replacement by?
Dense connective tissue scar
Both skeletal muscle and smooth muscle has “active” regeneration. True or False?
False, only smooth muscle.
Skeletal muscle can only undergo limited regeneration. True or False?
True
In the case of an injury in skeletal muscle, these are activated to proliferate and fuse.
Satellite cells
What type of cell is a satellite cell?
Myoblast
In the case of an injury in smooth muscle, muscle fibers undergo ____ and replace damaged tissue.
Mitosis