Chapter 7 - The Muscular System
Red muscles are slower than white muscles
True
Skeletal muscles contain blood vessels
True
Resting slow muscle fibers contain oxygen reserves, bound to myoglobin
True of slow fibers
In infants, which muscle allows for the mouth to form a tight fit around the nipple?
orbicularis ortis
The less moveable end of a skeletal muscle is the
origin
Quadriceps group contains
rectus femoris, vastus intermedius, vastus lateralis and vastus medialis
Each myofibril consists of approximately how many sarcomeres
10,000
Rigor mortis occurs due to lack of what molecule
ATP
If ACh is not released at axon terminals, what happens
Muscles are not capable of contracting
Action of the deltoid
abduct the arm
Myofibrils are made primarily of
actin and myosin
The striated appearance of skeletal muscle results from
actin and myosin arrangement
Muscles whose actions oppose one another
antagonists
Contains vesicles filled with acetylocholine
axon terminal
Muscle that allows you to do a pull up
biceps brachii
The enzyme acetylcholinesterase causes aceylcholine to
break down
In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases
calcium ions
A muscle that inserts on the radial tuberosity or the ulnar tuberosity is most likely involved in
elbow flexion
Action of the trapezius
elevates, adducts, depresses or rotates the scapula
A layer of collagen fibers that surrounds and entire muscle
epimysium
Layer of collagen fibers that surrounds and entire muscle
epimysium
Action of the vastus lateralis and other quadriceps muscles
extension of the knee
Biceps femoris, semitendinosus and semimembranosus make up
hamstrings
Cardiac muscle tissue is
involuntary, contains branched cells and intercalculated discs
Characteristics of smooth muscle tissue
involuntary, lacks sarcomeres and is not striated
Where is the latissimus dorsi located?
lower back
Function of skeletal muscles
maintain body posture, produce bone movement, maintain body temperature
The specialized sarcolemma that contains acetylcholine receptors is the
motor end plate
The term for a single motor neuron and all the muscle fiber it controls
motor unit
The area between Z lines is the
sarcomere
The skeletal muscles store calcium ions in the terminal cisternae of the
sarcoplasmic reticulum
The muscle that produces the action of standing on tip toes
soleus
What is the function of a transverse tubule
transmit electrical impulses to the cell's interior
Large, superficial muscle covering the upper back and portions of the neck
trapezius
What muscle extends the elbow during a pushup?
triceps brachii
Tropomyosin strands are held in position by
troponin molecules
The muscle that originates along the entire length of the linea aspera of the femur
vastus medialis
