physiology - muscle contraction Flashcards
a defect in the signalling from nerve to muscle at the neruo muscular junction causes which condition
a. MS
b. marfans
c. myasthenia gravis
c.myasthenia gravis
muscle weakness in the muscles of the eyes, eyelids and face is the symptom of which autoimmune condition
a. MS
b. marfans
c. myasthenia gravis
c.myasthenia gravis
what does myasthenic crisis refer to?
a. heart problems due to myasthenia gravis
b. lack of oxygen to the brain due to myasthenia gravis
c. breathing difficulties due to myasthenia gravis
c.breathing difficulties due to myasthenia gravis
many muscle fibres are held within a …
a. connective tissue
b. tendon
c. fascicle
c.fascicle
whats the correct order of skeletal muscle organisation from largest to smallest
a. muscle, fasiculus, fibre/cell, myofibril, sarcomere, filaments
b. filaments, sarcomere, myofibril, fibre/cell,fasiculus, muscle
a.muscle, fasiculus, fibre/cell, myofibril, sarcomere, filaments
what happens to actin filaments in the contracted state?
a. ends of actin filaments from z discs barely overlap
b. actin filaments are pulled inward and overlap to max extent
b. actin filaments are pulled inward and overlap to max extent
a double stranded F actin molecule is formed from polymerised ……………… molecules
a. A actin
b. F actin
c. B actin
d. G actin
d. G actin
how many strnds of tropomyosin molecules are found bound to an actin filament
a. 1
b. 2
c. 3
d. 4
b.2
what binds ca2+
a. actin
b. tropomyosin
c. troponin
c.troponin
what type of proteins are troponin and tropomyosin
a. contractile
b. regulatory
c. structural
b. regulatory
what does binding of calcium ions to troponin cause
a. muscle relaxation
b. muscle contraction
b.muscle contraction
what causes the myosin head to be reorientated and energised
a. ATP binding
b. ADP released
c. ATP hydrolysis
c.ATP hydrolysis
what happens when the myosin head attaches to the myosin binding site on actin
a. ATP binding
b. ADP released
c. ATP hydrolysis
d. pi released
d.pi released
cross bridge formation and power stroke changes the angle of the myosin head from 90 - what?
a.30 degrees
b.35
degrees
c.40 degrees
d.45 degrees
d.45 degrees
halves
the cross bridge remains attached to actin until what occurs?
a. ATP binding
b. ADP released
c. ATP hydrolysis
d. pi released
a.ATP binding
myosin head then dettaches
the length tension relationships depends on sarcomere length …………….. contraction
a. before
b. during
c. after
a.before
what type of receptors on the t tubule membrane sense AP voltage
a. dihydropiyridine
b. ryanodine
c. voltage gated sodium channels
a. dihydropiyridine
what type of receptors on the sarcoplasmic reticulum open and release ca2+ into the sarcoplasm
a. dihydropiyridine
b. ryanodine
c. voltage gated sodium channels
b. ryanodine
active pumping of what substance causes muscle relaxation
a. Ach
b. na
c. ca
c. ca
rigor mortis is due to leaking of which substance into the cell
a. sodium
b. pottasium
c. ach
d. calcium
d.calcium
ATP no longer synthesised so cross bridges cannot dettach from actin
what causes rigor mortis to end?
a. lack of remaining calcium
b. crossbridge breakdown by proteolytic enzymes
c. actin breakdown by proteolytic enzymes
b.crossbridge breakdown by proteolytic enzymes
total force produced by a single muscle fibre depends on…
a. rate of muscle fibre stimulation
b. number of muscle fibres contracting together
a.rate of muscle fibre stimulation
total force produced by a muscle depends on…
a. rate of muscle fibre stimulation
b. number of muscle fibres contracting together
b.number of muscle fibres contracting together
what type of contraction happens to muscle when picking up an object?
a. concentric
b. eccentric
c. isometric
a.concentric
muscle shortens
isotonic as constant tension and change in length
a contraction that involves constant tension and a change in length is known as..
a. isotonic
b. isometric
a.isotonic
a contraction that involves constant length producing tension..
a. isotonic
b. isometric
b.isometric
lowering a book involves which type of muscle contraction
a. concentric
b. eccentric
c. isometric
b.eccentric
muscle lengthens
holding a book out with straight arms involves which type of contraction
a. isotonic
b. concentric
c. eccentric
d. isometric
d. isometric
the postural muscles of the back are examples pf what type of skeletal muscle fibres
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
a.slow twitch type 1
the soleus in the calf are examples pf what type of skeletal muscle fibres
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
b.fast twitch type 2A
the extraocular muscles are examples pf what type of skeletal muscle fibres
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
c.fast twitch type 2B
what type of muscle uses anaerobic glycolysis instead of oxidative metabolism
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
c.fast twitch type 2B
which type of muscle has few mitochondria
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
c.fast twitch type 2B
which muscle type contains red myoglobin
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
a.slow twitch type 1
which muscle type contains red pink myoglobin
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
b.fast twitch type 2A
which muscle type contains little myoglobin so appears white
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
c.fast twitch type 2B
which muscle type has glycogen content
a. slow twitch type 1
b. fast twitch type 2A
c. fast twitch type 2B
c.fast twitch type 2B
single unit and multi unit are the two types of which type of muscle
a. skeletal
b. smooth
c. cardiac
b.smooth
where do repetitive spikes potentials occur spontaneously in smooth muscle
a. uterus
b. intestinal walls
b. intestinal walls
action potential with a plateau occurs in which in smooth muscle
a. uterus
b. intestinal walls
a.uterus
what type of muscle can be triggered to contract by ca2+ release from the sarcoplasmic reticulum or through voltage gated calcium channels
a. skeletal
b. smooth
c. cardiac
b.smooth
in smooth muscle what does ca 2+ bind to?
a,troponin
b. tropomyosin
c. calmodulin
c.calmodulin
what is activated by the ca2+ calmodulin complex
a. ATP ase
b. ATP hydrolase
c. myosin light chain kinase
c. myosin light chain kinase
what does myosin light chain kinase do?
a. phosphorylates actin
b. phosphorylates myosin heads
c. phosphorylates tropomyosin
b. phosphorylates myosin heads
contraction velocity in smooth muscle is…………. than in skeletal
a,more
b,less
b,less
activity of smooth muscle contraction is modified by
a,neurotransmitters
b. hormomes
c. nerones
b.hormomes
t tubules are not found in which type of muscle
a. cardiac
b. skeletal
c. smooth
c.smooth
troponin and tropomyosinnare not found in which type of muscle
a. cardiac
b. skeletal
c. smooth
c.smooth
spontaneous activity cannot occur in which type of muscle
a. cardiac
b. skeletal
c. smooth
b.skeletal
what type of muscle has the highest contraction speed
a. skeletal
b. cardiac
c. smooth
a.skeletal
a decreased number of acetylcholine receptors due to antibodies binding to them is the cause of which disease
a. myasthenia gravis
b. marfans
c. MS
d. dystonia
d.dystonia
what does pyridostigime inhibit
in order to improve nerve muscle transmission and movement
a. myosin light chain kinase
b. acetylcholine esterase
c. ryanodine receptors
b. acetylcholine esterase
