Question

(9/25/25) formative assessment assignment: chapter 6 the muscular system part i (suggested
5 of 16
cardiac muscle
cardiac muscle is found in only one place in the body—the heart, where it forms the bulk of the (1 ) walls. the heart serves as a pump,
propelling blood through blood vessels to all body tissues. like skeletal muscle, cardiac muscle is striated, and like smooth muscle, it is uninucleate and its
control is involuntary. important key words for this muscle type are cardiac, striated, and involuntary.
the cardiac cells are cushioned by small amounts of (2 ) and are arranged in spiral or figure 8 - shaped bundles (figure 6.2b). when the heart
contracts, its internal chambers become smaller, forcing blood into the large arteries leaving the heart. cardiac muscle fibers are branching cells joined by
special gap junctions called (3 ) discs (see figure 3.20 on p. 99 and chapter 3, p. 98). these two structural features and the spiral
arrangement of the muscle bundles in the heart allow heart activity to be closely coordinated.
cardiac muscle usually contracts at a fairly steady (4 ) set by the heart’s “in - house” pacemaker. however, the nervous system can also
stimulate the heart to shift into “high gear” for short periods, as when you run to catch a bus.
as you can see, each of the three muscle types has a structure and function well suited for its job in the body. but because the term muscular system
applies specifically to (5 ) muscle, we will concentrate on this muscle type in this chapter.
o 1 intercalated 2 rate 3 skeletal 4 heart 5 endomysium
o 1 heart 2 endomysium 3 intercalated 4 rate 5 skeletal
o 1 skeletal 2 heart 3 endomysium 4 intercalated 5 rate
o 1 rate 2 skeletal 3 heart 4 endomysium 5 intercalated
o 1 endomysium 2 intercalated 3 rate 4 skeletal 5 heart

Explanation:

1. Cardiac muscle forms the bulk of the heart walls.
2. Cardiac cells are cushioned by endomysium.
3. Special gap - junctions in cardiac muscle are intercalated discs.
4. Cardiac muscle usually contracts at a fairly steady rate.
5. The muscular system specifically applies to skeletal muscle.

Answer:

1. heart 2. endomysium 3. intercalated 4. rate 5. skeletal