11.7 – Cardiac and smooth muscle

Question 1

walls of the heart consist of ___ muscle tissue

Answer 1

cardiac

Question 2

which describes cardiac muscle tissue?

Answer 2

striated, usually uninucleate, branching

Question 3

skeletal muscles contain which of the following?

Answer 3

both slow oxidative and fast glycolytic fibers

Question 4

which structures coordinate contraction in cardiac muscle cells?

Answer 4

gap junctions

Question 5

cardiac muscle tissue is autorhythmic but the ___ can increase or decrease the heart rate and contraction strength

Answer 5

autonomic nervous system

Question 6

cardiac and smooth muscle are both considered which of the following?

Answer 6

involuntary

Question 7

where is cardiac muscle found?

Answer 7

in the heart wall only

Question 8

in the heart, what triggers the wave of electrical excitation that causes the heart to contract?

Answer 8

pacemaker

Question 9

___ discs are the thickened notched ends of cardiac muscle cells which contain gap junctions

Answer 9

intercalated

Question 10

intercalated discs contain ___ that prevent cardiac cells from pulling apart during contraction

Answer 10

mechanical junctions

Question 11

which muscle type is resistant to fatigue, contracts w/ a regular rhythm, and functions 24 hrs a day?

Answer 11

cardiac

Question 12

the autonomic nervous system is important int the control of which 2 types of muscle tissue?

Answer 12

cardiac
smooth

Question 13

cardiac muscle cells are considered ___ because they contract rhythmically and independently.

Answer 13

autorhythmic

Question 14

what is the function of the cardiac pacemaker?

Answer 14

it triggers contraction in the heart muscle

Question 15

which muscle tissue is rich in myoglobin, mitochondria, glycogen, and uses aerobic respiration almost exclusively for its energy needs?

Answer 15

cardiac

Question 16

which describes cardiac muscle tissue?

Answer 16

striated, usually uninucleate, branching

Question 17

what are the swellings along the length of a nerve fiber that innervates smooth muscle called?

Answer 17

varicosities

Question 18

why are gap junctions important?

Answer 18

they allow the cells to contract in a coordinated fashion

Question 19

which tissue makes up the piloerector muscle of a hair follicle?

Answer 19

smooth muscle

Question 20

which are the characteristics of cardiac muscle cells?

Answer 20

they contract nearly in unison
they contract w/ regular rhythm
they are resistant to fatigue

Question 21

which describe smooth muscle?

Answer 21

smooth muscle has no T-tubules
smooth muscle is uninucleate
smooth muscle has little SR

Question 22

what does it mean that cardiac cells are autorhythmic?

Answer 22

they contract rhythmically and independent of nervous stimulation

Question 23

where is single-unit smooth muscle found?

Answer 23

wall of uterus
wall of bladder
wall of stomach

Question 24

which statement explains why cardiac muscle is resistant to fatigue?

Answer 24

cardiac muscle uses little anaerobic fermentation

Question 25

the varicosities of the autonomic neurons that innervate smooth muscle release what when stimulated?

Answer 25

neurotransmitters

Question 26

how does smooth muscle differ from skeletal muscle?

Answer 26

smooth muscle can be excited in a multitude of ways while skeletal muscle is excited by a neuron

Question 27

what are the functions of smooth muscle?

Answer 27

to regulate pupil diameter
to move material thru the digestive tract
to constrict or dilate blood vessels to control blood pressure

Question 28

which 2 types of muscle tissue can be autorhythmic?

Answer 28

cardiac
smooth

Question 29

how do smooth muscle myocytes differ from cardiomyocytes?

Answer 29

smooth muscle myocytes have no T tubules while cardiac muscles do

Question 30

what type of smooth muscle is found in the digestive tract, respiratory tract, and urinary tract?

Answer 30

single-unit

Question 31

what is calmodulin?

Answer 31

a protein that replaces troponin in smooth muscle cells

Question 32

which are characteristics of cardiac muscle?

Answer 32

it has large stores of glycogen
it is rich in myoglobin
it uses aerobic respiration almost exclusively

Question 33

the sarcolemma of smooth muscle cells has pockets called ___ that contain calcium channels

Answer 33

caveolae

Question 34

excitation can be non-electrical in what type of muscle tissue?

Answer 34

smooth

Question 35

T or F:

smooth muscle often fatigues

Answer 35

false

(consider the consequences of smooth muscle of the gut adn blood vessels fatiguing)

Question 36

the presence of material in the stomach and urinary bladder stretches the wall, stimulating what type of muscle contraction?

Answer 36

smooth

Question 37

in which situation would mechanically-regulated calcium gates n smooth muscle cells open?

Answer 37

the tissue is stretched

Question 38

which describe smooth muscle?

Answer 38

smooth muscle has no T-tubules
smooth muscle is uninucleate
smooth muscle has little SR

Question 39

what regulatory protein is associated w/ the thick filament of smooth muscle and activates myosin light-chain kinase?

Answer 39

calmodulin

Question 40

what is the immediate trigger for the contraction of smooth muscle?

Answer 40

calcium ions

Question 41

which muscle tissue frequently exhibits tetanus and is resistant to fatigue?

Answer 41

smooth

Question 42

how can the stretching of smooth muscle lead to smooth muscle contraction?

Answer 42

stretching causes the opening of mechanically gated calcium ion channels in the sarcolemma

Question 43

___ muscle cells have a fusiform shape and taper to a point at the ends

Answer 43

smooth

Question 44

what is calmodulin?

Answer 44

a protein that replaces troponin in smooth muscle cells

Question 45

T or F:
smooth muscle often fatigues

Answer 45

false

(consider the consequences of smooth muscle of the gut and blood vessels fatiguing)

Question 46

in smooth muscle, which protein does calcium bind to?

Answer 46

calmodulin