Ch. 8 Test Flashcards
How are muscle fibers arranged in skeletal muscle tissue
Parallel
Which molecular component of blood provides the reddish pigment in skeletal muscle
Myoglobin
What are the two types of protein filaments that make up the myofibrils of muscle fibers
Thin filaments
Thick filaments
Which protein or thick filaments composed of
Myosin
Which protein or thin filaments composed of
Actin
During muscle contractions what causes the thin filaments to slide toward the center of a sarcomere
Myosin heads of the thick filaments pull on the thin filaments
As thin filaments slide what part of the muscle fibers become narrower and eventually disappear
I bands and H zones
What causes the shortening of the sarcomere during muscle contraction
Increased overlap of thin and thick filaments
What type of neuron delivers the electrical signal necessary for a skeletal muscle fiber to contract
Motor neuron
What are the swelling is at the end of the axon terminal’s of motor neurons called
Synoptic end bulbs
What is the concentration level of calcium ions in the Sarco plasmic reticulum in muscle fibers are relaxed
Low concentration
What is the concentration level of calcium ions in the sarcoplasmic reticulum one muscle fibers contract
High concentration
What are the four repeating events (in order) of the contraction cycle
- Splitting ATP
- Forming cross bridges
- Power stroke
- Binding ATP and detaching
What type of skeletal muscle changes can various types of exercise induce
Changes in the muscle fibers
What to major changes do endurance exercise results in
Cardiovascular
Respiratory
What do the changes listed in question above call skeletal muscle to do? What do they not do?
Receive better supply of oxygen and nutrients
Increase muscle mass
List the three differences between cardiac muscle fibers and skeletal muscle fibers
Source of stimulation
Involuntary
Larger in diameter
What term is given to the intrinsic rhythm of heart contractions
autorhythmicity
How many times per minute does cardiac muscle tissue relax and contract under normal resting conditions
75
What are the two kinds of smooth muscle tissue
Visceral
Multiunit
Which type of hollow viscera are good examples of organs made up of visceral muscle tissue
Stomach
Uterus
Intestines
Urinary bladder
List the three things that stimulate smooth muscle fibers in visceral muscle tissues
Neurotransmitter
Hormones
Auto rhythmic signal
What characteristic of multi units me with muscle tissue permits hollow organs such as the uterus and urinary bladder to expand and contract
Stretchiness
At what age do humans undergo a slow, progressive loss of skeletal muscle mass
30
