Quiz 4
For multiple choice and T/F, circle the best answer
NAME:
SID#:
1. The neurotransmitter released at the neuromuscular junction:
a. Depends on the specific type of skeletal muscle cell.
b. Depends on the type of nerve that is innervating the muscle.
c. Determines the strength of contraction.
d. Is acetylcholine.
2. The strength of skeletal muscle contraction is determined by all of the following except:
a. The length of the muscle
b. The number of motor units.
c. The kind of neurotransmitter released.
d. The rate of stimulation by the nerve.
3. Bone is made up of:
a. Fibroblasts and calcium hydroxide
b. Collagen and carboxycartilage.
c. Collagen and hydroxyapatite
d. Fibrinogen and hydroxyapatite
4. Put in order from smallest unit to largest unit (WRITE letters in order): _____, _____, _____, _____
a. Muscle cell
b. Myofibril
c. Sarcomere
d. Motor unit
5. Tetany is caused by:
a. Increased amplitude of action potentials.
b. Increased frequency of action potentials.
c. Is a result of abnormal homeostasis in the motor unit.
d. Stimulation of the muscle by multiple nerves.
6. T
/ F
Muscle cells get input from multiple nerves, whose effects summate to produce contraction.
7. T
/ F
Cartilage is made by cells called chondrocytes and cushion joints.
8. T / F
Calcium involved in smooth muscle contraction comes from both the sarcoplasmic reticulum
and from outside the cell.
9. T
/ F
Myosin light chain is involved in regulation of cardiac muscle contraction.
Please answer the following questions BRIEFLY!
10. When skeletal muscle is at rest, what prevents actin and myosin from initiating contraction?
_________________________________________________________________________________________
11. ATP has many roles in skeletal muscle contraction, including setting up the ion gradients that allow action
potentials to happen. Name two other ways ATP is important for the actin and myosin cycling (answer briefly!:
________________________________________________________________
________________________________________________________________
12. At the level of the sarcomere, what is rigor mortis and what causes it?
__________________________________________________________________________________________
13. Osteoporosis is a common bone disorder in postmenopausal women that results in brittle bones. The
overactivity of what type of cell may be responsible for this disease?__________________________________
14. The ability to fully relax between contractions is essential in cardiac muscle because the heart must fill with
blood. What prevents cardiac muscle from tetanizing like skeletal muscle?
__________________________________________________________________________________________
15. The name of the receptor on the sarcoplasmic reticulum of skeletal and cardiac muscle that is involved in
calcium release_____________________________________
16. Name two places in the body where you would find smooth muscle:
_____________________________, ____________________________
17. What structures allow electrical activity to spread from cell to cell in cardiac and smooth muscle?
_____________________________________
18. Which one of the three methods of resynthesizing ATP do cardiac and smooth muscles use?
________________________________________________________________________________________
Extra Credit (2 pts):
Put the following in order of circulation through the body, starting from the Right Atrium:
This is not as hard as you think!!! Walk through the circulation
Right Atrium
A. Lungs
B. Systemic Arteries
C. Systemic Capillaries
D. Left Ventricle
E. Left Atrium
F. Aorta
G. Right Ventricle
H. Systemic Veins
Put in order of length of time it takes to complete
one muscle cell twitch
A. Skeletal muscle,
B. cardiac muscle,
C. smooth muscle