Lecture 4 - Muscle Tissue

Question 1

A type of striated muscle found specifically in the heart or myocardium.

Answer 1

cardiac muscle

Question 2

A structure specific to cardiac muscle formed from gap junctions and desmosomes that allow cardiac muscle cells to contract in a coordinated fashion.

Answer 2

Intercalated disc

Question 3

The term for a muscle cell that applies to skeletal muscle, cardiac muscle and
smooth muscle.

Answer 3

myofibers

Question 4

The tube like organelle present in skeletal muscle and cardiac muscle that coordinates contraction of the cell.

Answer 4

myofibrils

Question 5

Modified cardiomyocytes that propagate electrical signals through the cardiac muscle of the myocardium allowing coordinated contraction

Answer 5

purkinje fibers

Question 6

The basic functional unit of striated muscle that is composed of myofilaments.

Answer 6

sarcomere

Question 7

The organelle that is responsible for the storage and release of calcium into the cytosol of the myofiber

Answer 7

sarcoplasmic reticulum

Question 8

The organelle that is responsible for the storage and release of calcium into the cytosol of the myofiber

Answer 8

sarcoplasmic reticulum

Question 9

A type of striated muscle responsible for voluntary movement.

Answer 9

skeletal muscle

Question 10

Non-striated muscle that is responsible for involuntary movement within
several organ systems

Answer 10

smooth muscle

Question 11

Invaginations of the sarcolemma (cell membrane) into the cell that allows for the conduction of depolarization impulses from the outside of the cell to around the sarcomeres.

Answer 11

T tubules

Question 12

the ability to return to its normal shape

Answer 12

elasticity

Question 13

ability to respond to stimuli

Answer 13

excitability

Question 14

ability to contract

Answer 14

contractility

Question 15

ability of the muscle to stretch without tearing

Answer 15

extensibility

Question 16

Skeletal muscle depends on the nervous system to work properly referred to as?

Answer 16

a voluntary motion

Question 17

cardiac muscle and smooth muscle can respond to other stimuli, such as catecholamines _________ from the blood, hormones and local stimuli.

Answer 17

epinephrine and norepinephrine

Question 18

are specialized types of epithelium and fibroblasts, respectively, that have the contractile ability.

Answer 18

myoepithelium and myofibroblasts

Question 19

are often located in and around glands where extracellular product produced by the epithelial cells needs to be moved by contractile action towards the duct system.

Answer 19

myoepithelial cells

Question 20

are often seen in healing wounds and assist in the maturation and contraction of the granulation tissue (immature fibrous connective tissue) as it matures and contracts.

Answer 20

myofibroblasts

Question 21

what are the functions muscular system is able to perform through contraction?

Answer 21

a. production of force and movement
b. support of the body, change of body posture
c. stability of joints
d. production of body heat (to maintain normal body temperature)
e. provision of form to the body

Question 22

Myoblasts (embryonic muscle cells) are derived from?

Answer 22

Mesenchyme

Question 23

Cardiac and smooth muscle tissues develop from local populations of?

Answer 23

Splanchnic mesoderm

Question 24

skeletal muscles develop from mesoderm within ____ ?

Answer 24

somites

Question 25

This muscle allows voluntary control of specific functions, such as swallowing, urination, and defecation.

Answer 25

skeletal muscles

Question 26

What are the various integrated tissues that compose skeletal muscle?

Answer 26

a. the skeletal muscle fibers b. blood vessels c. nerve fibers d. connective tissue.

Question 27

Each large muscle is wrapped in a sheath of dense, irregular connective tissue called the ______ which holds muscle fascicles in a group and also allows a muscle to contract while maintaining its structural integrity.

Answer 27

epimysium

Question 28

a term synonymous with muscle cell; a cell with multiple peripherally located nuclei that runs the ENTIRE length of the actual muscle

Answer 28

muscle fiber

Question 29

Inside each skeletal muscle, muscle fibers are organized into individual bundles (called fascicles), by an intermediate layer of connective tissue

Answer 29

perimysium

Question 30

Inside each fascicle, each muscle fiber is encased in an extremely thin connective tissue layer

Answer 30

endomysium

Question 31

The plasma membrane of muscle fibers is called the __________, the cytoplasm is referred to as __________, and the specialized smooth endoplasmic reticulum that stores and controls the release of calcium ions (Ca++) is called the ______________.

Answer 31

sarcolemma, sarcoplasm, sarcoplasmic reticulum

Question 32

What is the function unit of skeletal muscle fiber?

Answer 32

sarcomere

Question 33

Cardiac muscle tissue is located in?

Answer 33

in the heart or in myocardium

Question 34

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

Answer 34

desmosome

Question 35

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

Answer 35

pacemaker cells

Question 36

This group of cells is self-excitable and able to depolarize to threshold and fire action potentials on their own

Answer 36

autorhythmicity

Question 37

regulatory protein that facilitates contraction in smooth muscles

Answer 37

calmodulin

Question 38

sarcoplasmic structure that attaches to the sarcolemma and shortens the muscle as thin filaments slide past thick filaments

Answer 38

dense body

Question 39

process in which one cell splits to produce new cells

Answer 39

hyperplasia

Question 40

subset of a cross-bridge in which actin and myosin remain locked together

Answer 40

latch bridges

Question 41

cell that triggers action potentials in smooth muscle

Answer 41

pacesetter cells

Question 42

relaxation of smooth muscle tissue after being stretched

Answer 42

stress-relaxation response

Question 43

enlargement of neurons that release neurotransmitters into synaptic clefts

Answer 43

varicosity

Question 44

Smooth muscle found in the walls of visceral organs

Answer 44

visceral muscle

Question 45

Where can we located smooth muscles?

Answer 45

urinary bladder, uterus, stomach, and intestines, and in the walls of large vascular tubes, such as the arteries and veins

Question 46

Muscles are predominantly powered by

Answer 46

Oxidation of fats Carbohydrates Anaerobic chemical reactions

Question 47

Molecules that are used up by myosin filaments during muscle contractions

Answer 47

Adenosine triphosphate (ATP)

Question 48

Muscular system develops from the?

Answer 48

Mesoderm layer

Question 49

The muscles from the iris is developed from?

Answer 49

Neuro-ectoderm

Question 50

Muscles of the esophagus are developed by?

Answer 50

Transdifferentiation from smooth muscle

Question 51

Three levels of connective tissue that encloses the skeletal muscle

Answer 51

a. Epimysium b. Perimysium c. Endomysium

Question 52

2 types of myofilaments

Answer 52

Myosin and actin

Question 53

Proteins of thin filament

Answer 53

Actin Tropomyosin Troponin