Histology Chapter 11
Which disease listed below is an autoimmune disease in which the body produces antibodies to the acetylcholine receptors on the muscle sarcolemma. 1. acute inflammatory demyelinating polyradiculoneuropathy 2. Multiple sclerosis 3. Guillain-Barre syndrome 4. Myasthenia gravis
4. Myasthenia gravis
When the action potential or stimulus for contraction reaches the muscle fiber, the first thing that happens is: Myosin molecule begins to undergo a conformation change Calcium ions are taken back up into sarcoplasmic reticulum Myosin ATPase begins to break down ATP releasing energy Calcium ions are released from the sarcoplasmic reticulum
Calcium ions are released from the sarcoplasmic reticulum
Large terminal cisternae are found in the sarcoplasmic reticulum of heart muscle fibers. False True
False
Muscle tissue is highly vascularized and innervated but does not have much connective tissue associated with it for its functional activity. True False
False
Placing heart muscle fibers in solutions lacking calcium ions can cause the gap junctions present in the intercalated disk area to fall apart. True False
False
The actin filaments contain club-shaped extensions that contain ATPase which is utilized to break down ATP for muscle contraction. True False
False
The major function of the sarcoplasmic reticulum is to sequester phosphate ions for the production of ATP. 1.True 2.False
False
The process of forming G-actin from F-actin requires the presence of potassium and magnesium ions and also energy from the breakdown of ATP to ADP. True False
False
When Calcium activates ATPase on the actin molecule, the actin undergoes a conformation change. True False
False
Intercalated disks are junctions of two cardiac muscle fibers which occur only at the: A Band H Band Z line I Band
I Band
A motor unit is considered to be a nerve fiber and all the muscle fibers it innervates. True False
True
Smooth muscle fibers normally are arranged in bundles such that the thick portion of the fiber lies alongside the thin portion of the next fibers. False True
True
The shortening of the distance between Z lines in a sarcomere is another way of defining muscle fiber contraction. True False
True
Troponin and tropomyosin on the thin actin filament move away in presence of Calcium to permit myosin attachment. False True
True
Choose the fiber type which is slow twitch, fatigue-resistant and found in high number in the long muscles of the human back which help maintain posture. Type III (intermediate anaerobic fibers) Type IIa (fast oxidative glycolytic fibers) Type IIb (fast glycolytic fibers) Type I (slow oxidative fibers)
Type I (slow oxidative fibers)
Which skeletal muscle fiber type below is not found in human skeletal muscles. Type I (slow oxidative fibers) Type III (slow glycolytic fibers) Type IIb (fast glycolytic fibers) Type IIa (fast oxidative glycolytic fibers)
Type III (slow glycolytic fibers)
The sarcomere is the area on a skeletal muscle fiber which is located between two: Z lines A Bands I Bands M Lines
Z lines
The function of the T-Tubule system is to: better enable action potential to reach center of muscle fiber release energy from ATP make an easier connection to external connective tissue sequester Calcium ions
better enable action potential to reach center of muscle fiber
During contraction of a sarcomere, what happens to the I Band? becomes smaller in width disappears stays same width becomes smaller in width
disappears
The lumen of the T-tubule is considered to be an inner extension of the external environment because: ferritin-soaked muscles show ferritin inside T-Tubule it opens up into the terminal cisternae it and two terminal cisternae form a triad it is wrapped around the myofibrils like a net
ferritin-soaked muscles show ferritin inside T-Tubule
ATP is a necessary component for: release of Calcium ions from sarcoplasmic reticulum muscle fiber contraction Rigor Mortis muscle fiber relaxation
muscle fiber relaxation
The individual contractile unit of a muscle cell that can be viewed with a light microscope is called the: myofibril sarcoplasmic reticulum sarcoplasm sarcolemma
myofibril
The elongated inelastic protein which assists in anchoring the thin filaments to the Z-line is called what? tropomodulin titin nebulin
nebulin
For a relaxed sarcomere, choose the answer below that would fit for being present in the I Band region. some myosin and all of actin filaments only myosin filaments some actin and all of myosin filaments only actin filaments
only actin filaments
For a relaxed sarcomere, choose the answer below that would fit for being present in the H Zone region. only myosin filaments only actin filaments some myosin and all of actin filaments some actin and all of myosin filaments
only myosin filaments
For a relaxed sarcomere, choose the answer below that would fit for being present in the H Zone region. only myosin filaments some myosin and all of actin filaments only actin filaments some actin and all of myosin filaments
only myosin filaments
Which hormone listed below causes contraction of the smooth muscle of the uterus in terminal stages of pregnancy. vasopressin oxytocin glucagon erythropoeitin
oxytocin
Which connective tissue fibers form a network which wraps itself around individual muscle fibers where smooth muscle fibers are arranged in bundles such as in the intestine. elastic fibers collagen fibers endothelial fibers reticular fibers
reticular fibers
The plasma membrane of a muscle cell is called the: myofibril sarcolemma sarcoplasm sarcoplasmic reticulum
sarcolemma
The contractile unit of a muscle is called a: sarcolemma bundle sarcomere fiber
sarcomere
The contractile unit of a muscle is called a: bundle fiber sarcolemma sarcomere
sarcomere
The cytoplasm of a muscle cell is called the: sarcoplasmic reticulum sarcoplasm sarcolemma myofibril
sarcoplasm
Individual muscle cells of this type have many nuclei per muscle fiber (multinucleated). rough muscle smooth muscle skeletal muscle cardiac muscle
skeletal muscle
Which muscle type below is voluntary and makes up most of the flesh of our limbs and also the covering musculature of our body. smooth muscle skeletal muscle cardiac muscle rough muscle
skeletal muscle
Individual muscle cells of this type have only one nucleus per cell and usually display a long slender form rough muscle smooth muscle cardiac muscle skeletal muscle
smooth muscle
Which muscle type below is categorized as involuntary and forms the musculature of most hollow organs such as the bladder and alimentary canal. skeletal muscle smooth muscle rough muscle cardiac muscle
smooth muscle
For a relaxed sarcomere, choose the answer below that would fit for being present in the A Band region. some myosin and all of actin filaments some actin and all of myosin filaments only myosin filaments only actin filaments
some actin and all of myosin filaments
During contraction of a sarcomere, what happens to the A Band? stays same width disappears becomes smaller in width becomes smaller in width
stays same width
The large elastic accessory protein in the muscle sarcomere which anchors the thick myosin filament to the Z-line is: tropomyosin titin nebulin tropomodulin
titin
Which accessory protein in the sarcomere caps actin and regulates the length of the thin filaments? nebulin tropomodulin titin tropomyosin
tropomodulin
Which accessory protein in the sarcomere stabilizes the thin filaments and helps regulate binding of Calcium ions? tropomodulin nebulin titin tropomyosin
tropomyosin
Which accessory protein in the sarcomere stabilizes the thin filaments and helps regulate binding of Calcium ions? tropomyosin tropomodulin titin nebulin
tropomyosin
Which hormone causes contraction of the smooth muscle surrounding walls of arterioles to increase blood pressure. vasopressin glucagon erythopoeitin oxytocin
vasopressin
