Final studying: Lecture 5 (on its own bc it's huge) Flashcards
(46 cards)
1) What kind of movement does skeletal muscle do?
2) What is abundant in skeletal muscle cells?
3) What two things do they provide?
1) Both voluntary and reflex control
2) Abundant mitochondria
3) Movement and production of heat
Skeletal muscle:
1) What does endomysium bind?
2) What does perimysium bind? What is in this layer?
3) What does epimysium bind?
1) Muscle fibers
2) Fascicles; nerves and blood vessels
3) Muscles
1) What maintain skeletal muscle?
2) List them
1) Cytoskeletal proteins
2) A band, H zone, M line, I band, & Z line
1) What is the functional unit of skeletal muscle?
2) How is it defined?
1) Sarcomere
2) Area between Z lines
What 3 things make up thin filaments? [of skeletal muscle]
1) Actin
2) Tropomyosin
3) Troponin
1) What is tropomyosin shaped like?
2) What does it do [in skeletal muscle]?
1) Threadlike
2) Wraps around helix and covers binding sites
What makes up troponin?
3 small spherical subunits
1) When skeletal muscle is at rest, what is troponin doing?
2) At rest, what blocks actin binding sites?
1) Not bound to calcium
2) Tropomyosin ribbon
1) What branches into the NMJ (neuromuscular junction)?
2) What does it contain?
1) Motor neuron
2) Acetylcholine
Muscle relaxation is facilitated by what?
Calcium’s return to the lateral sacs
What are the 3 types of contraction? Describe and give an example of each
1) Isotonic
-Muscle changes length, load remains constant
-Ex: Lifting weights
2) Isokinetic
-Muscle changes length, velocity remains constant
-Ex: riding elliptical
3) Isometric
-Muscle prevented from changing length, tension develops
-Ex: Holding a weight with your arm still
1) When is asynchronous recruitment possible?
2) Why?
1) Only possible for submaximal contractions
2) Maximal contractions recruit all motor units (by definition)
What causes a stretch reflex?
Muscle spindles sense a change in length
What are the 3 classes of motor activity? Give an example of each
1) Reflex: Patellar reflex
2) Voluntary: Choosing to move your arm
3) Rhythmic: Walking or chewing
1) What are slow-oxidative (type I) muscle fibers good for?
2) Give 2 examples of where they’re prolific
1) Low intensity contractions for longer periods without fatigue
2) Back and leg muscles
1) What do satellite cells do?
2) What are their limitations?
1) Local damage activates them, and this gives rise to myoblasts which can fuse to form a muscle fiber
2) Cannot repair extensive damage
1) What fibers are most affected by age-related atrophy?
2) What occurs during age-related atrophy?
3) Why does this happen?
4) What can delay this type of atrophy?
1) Fast-glycolytic fibers
2) Reduced rates of protein synthesis
3) Lower rates of growth hormone,testosterone, and IGF-1
4) Diet and training
How do cardiac and smooth muscle contract? Describe
Similarly to skeletal muscle:
1) Actin filaments slide over myosin filaments after Ca+ rise
2) Use ATP for cross-bridge cycling
1) When is tonic smooth muscle contracted?
2) Where is it found?
1) Usually contracted to some degree at all times, but resting tone that can incrementally increase or decrease
2) Arteriole walls
Name 3 things skeletal and cardiac muscle have in common
1) Striated
2) Filaments organized into bands
3) Contain troponin and tropomyosin
Name 2 things smooth and cardiac muscle have in common
1) Have gap junctions that enhance spread of action potentials
2) Innervated by autonomic system
Name 2 characteristics unique to cardiac muscle
1) Fibers joined in branching network
2) Action potentials last much longer after depolarizing
1) What is hematocrit (Ht, HTC) ?
2) What is the average in both males and females?
1) The percent volume of red blood cells per volume of whole blood
2) 42% avg in females, 45% for males
