Muscle (*)

Question 1

what are the 3 types of muscle?

Answer 1

skeletal muscle, cardiac muscle and smooth muscle

Question 2

describe skeletal muscles

Answer 2

is composed of large, elongated, multinucleated fibers that show strong, quick, voluntary contractions

Question 3

describe cardiac muscles

Answer 3

composed of irregular branched cells bound together longitudinally by intercalated discs and shows strong, involuntary contractions

Question 4

describe smooth muscle

Answer 4

composed of grouped, fusiform cells with weak, involuntary contractions. The density of intercellular packing seen reflects the small amount of extracellular connective tissue present

Question 5

An entire skeletal muscle is enclosed within a thick layer of dense connective tissue called the ________

Answer 5

epimysium

Question 6

Large muscles contain several _____ each wrapped in a thin but dense connective tissue layer called the ________

Answer 6

fascicles, perimysium

Question 7

Within fascicles individual muscle fibers (elongated multinuclear cells) are surrounded by a delicate connective tissue layer, the __________

Answer 7

endomysium

Question 8

endomysium, perimesium and epimysium contains _________

Answer 8

collagen type I and II

reticulin

Question 9

a giemsa stain with polarized light can reveal what is muscle?

Answer 9

network of capillaries in endomysium surrounding muscle fibers

Question 10

what is the myotendinous junction?

Answer 10

Tendons develop together with skeletal muscles and join muscles to the periosteum of bones. The collagen fibers of a tendon are continuous with those in the connective tissue layers around muscle fibers, forming a strong unit that allows muscle contraction to move the skeleton

Question 11

________ are cylindrical bundles of thick and thin myofilaments that fill most of each muscle fiber

Answer 11

Myofibrils

Question 12

that each muscle fiber contains several parallel bundles called _________

Answer 12

myofibrils.

Question 13

Each myofibril consists of a long series of ________, separated by Z discs and containing thick and thin filaments that overlap in certain regions.

Answer 13

sarcomeres

Question 14

Thick filaments are bundles of myosin, which span the entire A band and are bound to proteins of the M line and to the Z disc across the I bands by a very large protein called________, which has springlike domains.

Answer 14

titin

Question 15

Thin filaments are actin filaments with one end bound to ________ in the Z disc

Answer 15

α-actinin

Question 16

A thick myofilament contains 200-500 molecules of ______

Answer 16

myosin

Question 17

A thin filament contains ________ _________ and_________

Answer 17

F-actin, tropomyosin, and troponin.

Question 18

Transverse tubules are invaginations of the _________ that penetrate deeply into the muscle fiber around all myofibrils.

Answer 18

sarcolemma

Question 19

what is the rolde of componants of the triad?

Answer 19

cyclic release of Ca2+ from the cisternae and its sequestration again that occurs during muscle contraction and relaxation

Question 20

______ _______ -________under acidic conditions reveals slow type oxidative fibers (type I)- darkest. Fast, oxidative-glycolytic (Type IIa) have intermediate staining. Fast, glycolytic fibers (Type IIb) have weakest staining.

Answer 20

ATPase enzyme histochemistry

Question 21

in general what is the function of muscle?

Answer 21

contraction

Question 22

in general what is the organization of skeletal muscle?

Answer 22

fascicles surrounded by connective tissue banding pattern from sacromeres

Question 23

the transverse tubule system is for

Answer 23

AP propagation

Question 24

the sarcoplasmic reticulum is used to ?

Answer 24

store calcium

Question 25

what is the mechanism of contraction

Answer 25

Sliding filament theory, Calcium

Question 26

innervation icnludes

Answer 26

motor neuron, motor end plate, excitation-contraction coupling.

Question 27

name the muscle fibre types and relative stain speed?

Answer 27

slow oxidative (Type I), intermediate oxidative-glycolytic (Type IIa), fast, glycolytic (Type IIb).

Question 28

What are intercalated discs?

Answer 28

fibers consist of separate cells in a series with interdigitating processes where they are held together. These regions of contact are called the intercalated discs, which cross an entire fiber between two cells

Question 29

transverse regions of the steplike intercalated disc have abundant __________

Answer 29

desmosomes

Question 30

longitudinal regions of the discs contain many physiologically important ________ ___________

Answer 30

gap junctions

Question 31

Transverse regions of the disc have many desmosomes and adherent junctions called ________ __________

Answer 31

fascia adherentes

Question 32

the heart is composed of what 3 main things ?

Answer 32

endocardium, myocardium and purkinji fibres

Question 33

what does the endocardium consist of?

Answer 33

consists of the endothelium, a thin layer of connective tissue with smooth muscle cells, and a layer of variable thickness lacking smooth muscle called the subendocardial layer.

Question 34

The atrial granules contain the precursor of a polypeptide hormone called ______ -_______ -_____

Answer 34

atrial natriuretic factor (ANF)

Question 35

what does ANF do?

Answer 35

targets cells of the kidneys to bring about sodium and water loss

Question 36

what is smooth muscle specialzed for and what is it controlled by?

Answer 36

specialized for slow steady contraction and controlled by involuntary mechanisms

Question 37

_______ __________ associated with the basal laminae of smooth muscle cells help hold the cells together as a functional unit during the slow, rhythmic contractions of this tissue

Answer 37

Reticulin fibres

Question 38

what are dense bodies?

Answer 38

attachment points for intermediate filaments and thin filaments. Associated with adherens junctions in sarcolemma for transmitting tension between neighbouring cells.

Question 39

what is the function of caveolae?

Answer 39

regulate release of ca from sarcoplasmic reticulum

Question 40

what are gap junctions?

Answer 40

electrical coupling of cells , form a syncytium

Question 41

where is smooth muscle located ?

Answer 41

1. Viseral organs (digestive tract, urinary tract (bladder). 2. Respiratory airways (spincters control air flow) 3. Circulatory system (blood vessel walls, spincters) control blood flow.

Question 42

smooth muscle isnt voluntary, why?

Answer 42

lack MEPs

Question 43

what are 3 areas that smooth muscle controls?

Answer 43

1. Nervous: autonomic nervous system, sympathetic and parasympathetic. 2. Hormonal: Adenaline/epinephrine 3. Physiological conditions : stretch, or local oxygen levels.

Question 44

describe cardiac muscle

Answer 44

Striated muscle, interwoven network of electrically coupled cells (syncytium). Myogenic and autorhythmic. Highly aerobic.

Question 45

describe smooth muscle

Answer 45

- Non-striated, small fusiform cells which lack T-tubule system and organization of myofilaments. Dense bodies function like Z-disks as well as points for cell to cell contact. - Can synthesize ECM. - Found in Visceral organs, respiratory tract and blood vessels.