Muscle Tissue Property: Electrical Excitability - ANSions are charged molecules that have
different concentrations between a semipermeable membrane
Muscular Tissue Property: Contractility - ANSthe ability to forcefully contract
Muscular Tissue Property: Extensibility - ANSthe ability to stretch
Muscular Tissue Property: Elasticity - ANSthe ability to return to your original shape
Microscopic Anatomy of a Skeletal Muscle Fiber - ANS-each mature skeletal muscle fiber has
100+ nuclei
-once fusion has occurred the muscle fiber loses its ability to undergo cell division
-skeletal muscles are set before you are born and last a life time
Control of Muscle Tension: Sliding Filament Mechanism - ANS-myosin pulls on actin, causing
thin filament to slide forward
-consequently, Z discs move toward each other and the sarcomere shortens
-thanks to structural proteins, there is a transmission of force throughout the entire muscle
***Filaments do not change in length
Isotonic - ANStension is constant while muscle length changes
-concentric=picking up book
-eccentric=lowering book
Isometric - ANSmuscle contracts but does not change length
-holding a book out steady
actin - ANSDuring active muscle contraction, myosin heads bind to the protein
_______________.
calcium - ANS________________ is released from the sarcoplasmic reticulum and plays a key
role in active muscle contraction
Functions of Skeletal System - ANS1. facillitating movement
2. generating heat (thermogenesis)
3. Storing glycogen
4. maintaining body posture
How individual muscle fibers generate ATP - ANS1. glycolysis (anaerobic respiration)
2. hydrolysis of creatine phosphate
, 3. krebs cycle/electron transport chain (aerobic respiration)
actin,myosin - ANSIn a given muscle fiber, the thin filaments are known as _____________, and
the thick filaments are known as _____________.
Sarcolemma - ANScell membrane of individual muscle cell
Origin - ANSthe attachment to the stationary bone (bone that does not move) Proximal
Insertion - ANSthe attachment to the movable bone (distal)
Fulcrum - ANSelbow joint
Effort - ANSamount of force
ex: contraction of biceps brachii
Load - ANSweight of object plus forearm (resistance)
(opposes movement)
Muscles of the thigh that move the femur, tibia and fibula:
Quadriceps Femoris = Four heads
1. Rectus femoris
2. Vastus lateralis
3. Vastus medialis
4. Vastus intermedius - ANSall four heads extend leg at knee joint; rectus femoris muscle acting
alone also flexes thigh at hip joint
Muscles of the thigh that move the femur, tibia and fibula:
Sartorius - ANSweakly flexes leg out at knee joint; weakly flexes, abducts, and laterally rotates
thigh at hip joint
Muscles of the thigh that move the femur, tibia and fibula:
Hamstrings:
1. Biceps femoris
2. Semitendinosus
3. Semimembranosus - ANSflexes leg at knee joint and extends the thigh at hip joint
Muscles of the thigh that move the femur, tibia and fibula:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Ashley96. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.