MUSCLE TISSUE AND MUSCULOSKELETAL SYSTEM

Question 1

3 Types of muscle tissue

Answer 1

 Skeletal
 Smooth
 Cardiac

Question 2

Similarities among 3 types(3)

Answer 2

 Mesoderm-derived
 Possess numerous mitochondria to accommodate their high energy requirements
 All contain contractile elements known as myofilaments

Question 3

SINGLE-CELL CONTRACTILE UNITS (3)

Answer 3

Myoepithelial cell
Pericyte
Myofibroblast

Question 4

 Important component of secretory glands

Answer 4

Myoepithelial cell

Question 5

 Smooth muscle-like cell that surrounds blood vessels

Answer 5

Pericyte

Question 6

Has a contractile role; secretes collagen; predominant during repair

Answer 6

myofibroblast

Question 7

Striation and function of skeletal, smooth, and cardiac muscles

Answer 7

skeletal: striated, voluntary
smooth: non-striated, involuntary
cardiac: striated, involuntary

Question 8

Long, unbranched, cylindrical with blunt ends and cross-striations
Multinucleated cells
= Large and peripherally located
Contraction: quick, forceful, and under voluntary control

Answer 8

SKELETAL MUSCLE

Question 9

cylindrical → middle and terminal parts have the same size

Answer 9

LS of skeletal

Question 10

polygonal in outline with dark blue or ovoid nuclei at the periphery

Answer 10

CS of Skeletal

Question 11

ORGANIZATION OF SKELETAL MUSCLE (7)

Answer 11

Epimysium
Perimysium
Endomysium
Muscle cells
Myofibrils
Myofilaments
SARCOMERE

Question 12

 External sheath of irregular DWFCT
 Surrounds the entire muscle

Answer 12

Epimysium

Question 13

 Thin CT layer
 Immediately surrounds each bundle of muscle fibers (fascicle)

Answer 13

Perimysium

Question 14

 Thin layer of reticular CT and scattered fibroblasts
 Surrounds individual muscle fibers

Answer 14

Endomysium

Question 15

aka muscle fibers, myofibers, myocytes
 _______(2)= muscle cell membrane
 _______(3) = cytoplasm
 ______(4) = endoplasmic reticulum

Answer 15

Muscle cells
Sarcolemma
Sarcoplasm
Sarcoplasmic reticulum

Question 16

Chain of sarcomeres

Answer 16

Myofibrils

Question 17

Region between two Z-lines
Regular light and dark bands are visible
 These stripes crossing each fiber = cross striations

Answer 17

SARCOMERE

Question 18

A band (dark band): thick filaments; ___ (2) is the predominant component; may overlap
with actin filaments
 _____(3): bisects A band; zone of myosin filaments only
 ____(4): middle of H zone; point of interconnection of thick myofilaments; does not contain actin
_____(5) (____(6) band): thin filaments; actin is the predominant component
____(7): zone of apposition of actin filaments belonging to two neighboring _______(1)

Answer 18

SARCOMERE
myosin
H zone:
 M line:
I band (light band)
Z line

Question 19

Capable of slow yet sustained contraction (little ATP usage)
Individual smooth muscle fibers contain contractile actin and myosin filaments
crisscross the sarcoplasm obliquely

Answer 19

SMOOTH MUSCLE

Question 20

Spindle shaped with tapered ends and centrally located nucleus

Answer 20

LS Smooth muslce

Question 21

Size are variable due to tapered shape of cells

Answer 21

CS smooth muscle

Question 22

Found in walls of tubular organs
and blood vessels

Answer 22

SMOOTH MUSCLE

Question 23

Tubular organs of smooth mm (2)

Answer 23

Tunica mucosa
 Muscularis mucosae

Question 24

Tunica muscularis of smooth mm (2)

Answer 24

 Inner circular
 Outer longitudinal

Question 25

1. Ordinary cardiac muscle cell

Answer 25

myocardium of the heart

Question 26

Long, branched with many centrally located oval nuclei, cross striations and perinuclear halo

Answer 26

LS of cardiac mm

Question 27

Polygonal with centrally located nuclei

Answer 27

CS of cardiac mm

Question 28

Similar to skeletal except: a. Highly vascular (in between) b. LS: anastomosing network of long branching cardiac cells  in between branches are loose connective tissue c. Tissue is crossed regularly by _____(2) represents points of end-end contact between contiguous muscle fiber

Answer 28

CARDIAC MUSCLE intercalated disks

Question 29

Special cardiac muscle cell (1)

Answer 29

Purkinje Fiber

Question 30

 Impulse conducting cell within the heart  Pale-staining, larger, and wider than ordinary w/ peripheral disposition of myofibrils  Mingle distally with contractile muscle fibers of each ventricle and trigger waves of contraction through both ventricles simultaneously

Answer 30

Purkinje Fiber)

Question 31

Where is Purkinje Fiber found in the cardiac mm

Answer 31

inner ventricular wall beneath the endocardium

Question 32

1. Produce myoblasts that can replace damaged fibers 2. Undergo self-renewal to replenish their pool

Answer 32

Satellite cells

Question 33

Response to increased load of skeletal mm and cardiac mm

Answer 33

Hypertrophy

Question 34

Response to increased load of Smooth mm

Answer 34

Hypertrophy and hyperplasia

Question 35

Capacity for regeneration of skeletal mm

Answer 35

Limited Mainly involves satellite cells

Question 36

Capacity for regeneration of Smooth

Answer 36

Good Involves mitotic activity of muscle cells

Question 37

Capacity for regeneration of Cardiac

Answer 37

Very poor

Question 38

MUSCULOSKELETAL SYSTEM structure (5)

Answer 38

TENDON JOINTS DIARTHROSIS SYNOVIAL FLUID LIGAMENTS

Question 39

Attaches muscle organ to the bone  Tremendous tensile strength Composed of:  Few cells called ____(2)  Regular DWFCT Collagenous fibers of a tendon extend into the bone as _____(3)

Answer 39

TENDON tenocytes Sharpey's fibers

Question 40

Tendon sheath

Answer 40

epitendineum

Question 41

epitendineum parts (2)

Answer 41

 Parietal (outer)  Visceral (inner)

Question 42

surrounds bundles of fibers (fascicles); continuous with epitendineum

Answer 42

Peritendineum

Question 43

surrounds individual collagen fibers

Answer 43

Endotendineum

Question 44

gap between the opposing edges of the synovial sheath where blood vessels supplying the tendon pass through

Answer 44

Mesotendineum

Question 45

Regions where adjacent bones are capped and held together firmly by other connective tissues

Answer 45

JOINTS

Question 46

HISTOLOGICAL CLASSIFICATION OF JOINTS (3)

Answer 46

Fibrous Cartilaginous Synovial

Question 47

 ____(2) – held together by collagenous or elastic dense connective tissue Examples:  Fibrous articulation between the radius and ulna  Sutures of the skull

Answer 47

Fibrous Syndesmosis

Question 48

 ___(2) – connected by cartilage  Physis  ____(3) – thick pad of fibrocartilage between the thin articular cartilage covering the ends of the bones  Intervertebral disc, pubic symphysis

Answer 48

Cartilaginous Synchondrosis Symphysis

Question 49

 Diarthrosis  Characterized by:  presence of articular cartilage on the opposing bony surfaces  a lubricating synovial fluid within the closed joint cavity  joint capsule enclosing the entire joint  Elbow, knee

Answer 49

Synovial

Question 50

Joint capsule

Answer 50

DIARTHROSIS

Question 51

Outer fibrous layer of DIARTHROSIS

Answer 51

 Irregular DWFCT

Question 52

Covered by 1-2 layers of synovial cells overlying the CT  Type A cells: _______(2)  Type B cells: ____(3)

Answer 52

 Inner synovial membrane of DIARTHROSIS macrophage-like synovial cells Fibroblastic synovial cells

Question 53

Combined product of the synovial cells and ultra-filtrate of capillaries

Answer 53

SYNOVIAL FLUID

Question 54

Components of synovial fluid (3)

Answer 54

 Hyaluronic acid  Glycoproteins Leukocytes

Question 55

 Contain a lower percentage of ground substance than tendons  Collagen fibers are organized more randomly

Answer 55

Collagenous ligaments

Question 56

Predominated by large elastic fibers that branch and interconnect  Fibers are surrounded by loose connective tissue Ligamentum nuchae, ligamenta flava

Answer 56

Elastic ligaments:

Question 57

NERVOUS STRUCTURES IN MUSCULOSKELETAL SYSTEM (2)

Answer 57

Motor unit: Neuromuscular junction (motor endplate)

Question 58

Nerve fiber + associated skeletal muscle fiber

Answer 58

Motor unit:

Question 59

 Point of junction between the nerve terminal and the muscle fiber  Site where the impulse from the axon is transmitted to the skeletal muscle fiber

Answer 59

Neuromuscular junction (motor endplate)

Question 60

where are axon terminals found? these are depression of the muscle fiber formed by deep infoldings of the sacrolemma

Answer 60

primary synaptic cleft

Question 61

these receptors are found at the crest bottom of the junctional folds or 2ndary synaptic clefts

Answer 61

acetylcholine

Question 62

a basal lamina associated with he sarcolemma contains _______

Answer 62

acetylcholinesterase