Muscular Tissue (Cardiac Muscles)

Question 1

It is only found in the heart, specifically the myocardium.

Answer 1

Cardiac muscle tissue

Question 2

Cardiac muscle tissue is only found in what organ?

Answer 2

heart

Question 3

Cardiac muscle tissue is only found in the heart, specifically the ____________.

Answer 3

myocardium

Question 4

It is striated and organized into sarcomeres, possessing the same organization of myofilaments as skeletal muscle. However, cardiac muscle fibers are shorter than skeletal muscle fibers and usually contain only one nucleus, which is located in the central region of the cell.

Answer 4

Cardiac muscles

Question 5

It shorter than skeletal muscle fibers and usually contain only one nucleus, which is located in the central region of the cell.

Answer 5

cardiac muscle fibers

Question 6

It also contain many mitochondria. This is necessary as large amounts of ATP are required by the cells and this is produced primarily through aerobic metabolism.

Answer 6

Cardiac muscle fibers

Question 7

It allows the cardiac muscle cells to contract in a coordinated fashion so that the heart can work as a pump.

Answer 7

intercalated disc

Question 8

These are part of the sarcolemma and contain two structures important in cardiac muscle contraction: gap junctions and desmosomes

Answer 8

Intercalated discs

Question 9

2 structures important of intercalated discs in cardiac muscle contraction

Answer 9

gap junctions and desmosomes

Question 10

It form channels between adjacent cardiac muscle fibers that allow the depolarizing action potential to move between one cardiac muscle cell to the next.

Answer 10

Gap junction

Question 11

It allows the quick transmission of action potentials and the coordinated contraction of the entire heart. The remainder of the intercalated disc is composed of desmosomes.

Answer 11

Gap junctions

Question 12

It anchor the ends of cardiac muscle fibers together so the cells do not pull apart during individual fiber contraction.

Answer 12

Desmosomes

Question 13

Unlike skeletal muscle which is composed of a long row of cells with fused cytoplasm, this muscle is composed of multiple branching cells that are joined by specialized structures, including intercalated discs. These appear as very fine lines between the cardiomyocytes.

Answer 13

cardiac muscle

Question 14

This joining is called ______________, and in cardiac muscle, it allows the quick transmission of action potentials and the coordinated contraction of the entire heart.

Answer 14

electric coupling,

Question 15

This network of electrically connected cardiac muscle cells creates a functional unit of contraction called a __________.

Answer 15

syncytium

Question 16

It is a cell structure that anchors the ends of cardiac muscle fibers together so the cells do not pull apart during the stress of individual fibers contracting Cardiac Muscle.

Answer 16

desmosome

Question 17

Intercalated discs are part of the cardiac muscle sarcolemma and they contain these two.

Answer 17

gap junctions and desmosomes

Question 18

Contractions of the heart (heartbeats) are controlled by specialized cardiac muscle cells called ___________ that directly control heart rate.

Answer 18

pacemaker cells

Question 19

directly control heart rate

Answer 19

pacemaker cells

Question 20

It cannot be consciously controlled.

Answer 20

cardiac muscle

Question 21

It respond to signals from the autonomic nervous system (ANS) to speed up or slow down the heart rate.

Answer 21

pacemaker cells

Question 22

It can also respond to various hormones that modulate heart rate to control blood pressure.

Answer 22

pacemaker cells

Question 23

The wave of contraction that allows the heart to work as a unit is called a ____________.

Answer 23

functional syncytium

Question 24

It begins with the pacemaker cells

Answer 24

Functional syncytium

Question 25

This group of cells is self-excitable and able to depolarize to threshold and fire action potentials on their own, a feature called ______________; they do this at set intervals which determine heart rate.

Answer 25

autorhythmicity

Question 26

It is striated muscle that is present only in the heart.

Answer 26

Cardiac muscle

Question 27

intercalated discs that contain ___________ for between cells and __________ to hold the fibers together when the heart contracts.

Answer 27

gap junctions
desmosomes

Question 28

Depolarization

Answer 28

Gap junstion

Question 29

hold the fibers together when the heart contracts

Answer 29

Desmosomes

Question 30

Contraction in each cardiac muscle fiber is triggered by what?

Answer 30

Ca++ ions

Question 31

It stimulate the spontaneous contraction of cardiac muscle as a functional unit, called a syncytium.

Answer 31

Pacemaker cells

Question 32

Cardiac muscle cells may also be called what?

Answer 32

cardiocytes / cardiac myocytes / myocardial cells