L3 MUSCLE TISSUE

Question 1

Describe muscle tissue?

Answer 1

One of the basic tissues of the body

Cells (Fibers) are long and narrow

Question 2

Functions of muscle tissue?

Answer 2

Responsible for movements

Maintain posture

Transforms chemical energy into mechanical
energy, therefore, producing force

Stabilize joints

Thermogenesis

Increase muscle mass, increases immune system

Question 3

Four properties of muscle tissue?

Answer 3

Excitability; respond to nerve cells by
generating electrical signals
• Contractility; get shorten and generate force
• Extensibility; can be stretched
• Elasticity; returning back to its original shape

Question 4

What are three types of muscle tissue?

Answer 4

Skeletal muscle
Smooth muscle
Cardiac muscle

Question 5

What is skeletal muscle?

Answer 5

These are most abundant, found
attached to skeleton

Exhibit cross striations under microscope

Respond quickly to stimuli

Are supplied by somatic nerves

Are under voluntary control

E.g., Muscles of the limbs and
body wall

Question 6

Parts of a muscle?

Answer 6

Belly (fleshy part)

Tendons (fibrous part)

Question 7

What is the belly of the muscle?

Answer 7

• highly vascular and

contractile part

Question 8

What is the tendon?

Answer 8

part which is attached
to the bones or cartilages
made of collagen
fibres, less vascular and non
elastic

Question 9

What is aponeurosis?

Answer 9

The fibrous part present in the flat muscles

Question 10

What are the two attachments of muscles?

Answer 10

origin and insertion

Question 11

What is the origin attachment of muscles?

Answer 11

Attachment of a muscle that remains relatively fixed during
muscular contraction

Generally the proximal part

Question 12

What is the insertion attachment of muscles?

Answer 12

Attachment of a muscle that moves during muscular
contraction

Generally the distal part

Question 13

What are the four muscle organization? (arrangement of muscle fibres?)

Answer 13

Parallel
Convergent
Pennate
Circular

Question 14

What is the parallel arrangement of muscles?

What are the different types?

Example of each type and their location?

Answer 14

Muscle fibres run parallel to length of muscle

Most of the skeletal muscle are of this type

Different types – fusiform, strap, quadrilateral
• eg. biceps brachii, sartorius, pronator quadratus

Question 15

What is the convergent arrangement of muscles?

Example and location?

Answer 15

Muscle fibres spread out like fan on one end and
converge to single point on other end

eg. Pectoralis major

Question 16

What is the Pennate (feather like) arrangement of muscles?

Answer 16

Muscle fibres are arranged at an angle to tendon

Question 17

What are the three types of pennate muscle arrangements?

Answer 17

Unipennate
Bipennate
Multipennate

Question 18

What is the Unipennate arrangement of muscles?

Answer 18

Muscle fibres
angled on one side of tendon
(eg. palmar interossei)

Question 19

What is the Bipennate arrangement of muscles?

Answer 19

Tendon in the
middle with angled muscle
fibres on each side (eg dorsal
interossei)

Question 20

What is the multipennate arrangement of muscles?

Answer 20

Branched
tendon with muscle fibres
organised around each
branch (eg. Deltoid)

Question 21

What is circular muscle arrangement?

Answer 21

Concentric arrangement of muscle fibres

Guard the openings and decrease the diameter of openings

eg. Orbicularis oculi, orbicularis oris

Question 22

What are the eight Nomenclature of muscles?

Answer 22

shape, size, number of heads of origin, location, relative position, attachment, function, direction of fibres

Question 23

What are the four actions of skeletal muscles?

Answer 23

Agonist
Antagonist
Synergist
Fixator

Question 24

What is synergistic?

Answer 24

Muscle(s) that stabilises a
joint around which
movement is occurring,
which in turn helps the
agonist function effectively

n the biceps curl the 
synergist muscles are the 
brachioradialis and 
brachialis which assist the 
biceps to create the 
movement and stabilise 
the elbow joint

Question 25

Fixator?

Answer 25

``` Stabilize the proximal joints to allow the movements at the distal joints ``` E.g. deltoid muscle during biceps curl

Question 26

What is epimysium tissue?

Answer 26

A connective tissue that surrounds the muscle.

Question 27

What are fascicles?

Answer 27

Also known as bundles. Several cylindrical muscle cells or muscle fibres that make up the muscle

Question 28

What is perimysium tissue?

Answer 28

A connective tissue sheath that surrounds bundles or fascicles.

Question 29

What is endomysium tissue?

Answer 29

A connective tissue sheath that surrounds muscle cell.

Question 30

What does each muscle cell or fiber contain?

Answer 30

all of the organelles that we find in other cell types multiple peripherally placed flat nuclei Under the microscope, stripes called striations

Question 31

What are T-Tubules?

Answer 31

Invaginations of sarcolemma at A Band and I Band junction (permit rapid transmission of the action potential into the cell)

Question 32

What is Sarcolemma?

Answer 32

Plasma membrane of the | muscle cell

Question 33

What is Sacroplasma?

Answer 33

Cytoplasm of the muscle | cell

Question 34

What is Sarcoplasmic reticulum? | Contains?

Answer 34

the smooth endoplasmic reticulum of the muscle cell containing calcium

Question 35

What are terminal cisternae?

Answer 35

``` Terminal cisternae are enlarged areas of the sarcoplasmic reticulum surrounding the transverse tubules- store calcium ```

Question 36

What is a triad?

Answer 36

2 terminal cisterna | and 1 T-tubule

Question 37

What is myoglobin?

Answer 37

red pigment that stores oxygen within muscle

Question 38

What are glycosomes?

Answer 38

granules of stored glycogen within the muscle

Question 39

Where are myofibrils found?

Answer 39

Muscle fiber or cell

Question 40

What are myofibrils?

Answer 40

cylindrical bundle of contractile proteins contains several sarcomeres

Question 41

What are sacromeres?

Answer 41

``` the functional or contractile units of muscle One sarcomere is separated from the other by the Z line ```

Question 42

What do sacromeres of myofibrils contain?

Answer 42

Myofilaments

Question 43

What are thin myofilaments composed of ?

Answer 43

Thin myofilaments are composed mainly of a protein | known as actin

Question 44

What are thick myofilaments composed of?

Answer 44

composed mainly of the protein myosin

Question 45

What does the striated | appearance (light and dark bands) of skeletal muscles result from?

Answer 45

the orderly overlapping of the actin and myosin | filaments

Question 46

What is an I band?

Answer 46

I Band contains only thin (actin) myofilaments | isotropic; light band

Question 47

What is an A band?

Answer 47

A Band contains thick and thin (actin and myosin) (anisotropic; not isotropic; dark band)

Question 48

What is H zone?

Answer 48

middle of A, only myosin

Question 49

What is smooth muscle? | Where is it found?

Answer 49

Found in the walls of the hollow viscera (stomach) and walls of blood vessels • Muscle fiber is an elongated, spindle (fusiform) shaped cell • Contains centrally placed spindle shaped nucleus • Do not exhibit cross or transverse striations under microscope, being plane and smooth in form • Supplied by autonomic nerves, not under voluntary control

Question 50

What is cardiac muscle? | Where is it found?

Answer 50

Striated (transverse) but involuntary muscle Consists of short, cylindrical muscle fibers It is present exclusively in the heart and is also called myocardium of heart Each muscle fiber contains many muscle cells (cardiomyocytes) which are united by intercalated discs Each muscle cell contains centrally placed, single oval or round nucleus Muscle fibers branch

Question 51

Functions of cardiac muscle

Answer 51

Automatic and rhythmic contractions

Question 52

What do muscle fiber of cardiac muscle contain?

Answer 52

contains many muscle cells (cardiomyocytes) which are united by intercalated discs Muscle fibers branch and anastomose with the neighboring fibers Each muscle cell contains centrally placed, single oval or round nucleus Transverse striations are present