9. Muscle Tissue

Question 1

What is muscle tissue?

Answer 1

Muscles have specialized cells (muscle fibers) that respond to stimulation

Internal changes that shorten the cells

Question 2

Muscle functions

Answer 2

Facilitates movement, open and close body passageways, thermoregulation, and maintain posture and support for joints

Question 3

How do muscles facilitate movement?

Answer 3

As cells shorten (contract), they exert physical forces on attached tissues and produce movement

Question 4

Types of movement facilitated by muscle

Answer 4

Voluntary motion, blood circulation, respiratory activities, propulsion of materials through digestive tract, and waste elimination

Question 5

What muscles control the opening and closing of body passageways

Answer 5

Sphincter muscles

Question 6

How do muscles thermoregulate?

Answer 6

Contraction and relaxation produce heat

Question 7

Basis of muscle types

Answer 7

Cells- myocytes (or myofibers or muscle fibers)

Muscle types differ in structure and function

Question 8

Types of muscles

Answer 8

Skeletal, smooth, and cardiac

Question 9

Location, function, shape, and length of skeletal muscle

Answer 9

Location: throughout body
Function: movement, etc
Shape: cylindrical cells (muscle fibers)
Length: long (super long) cells

Question 10

Characteristics of skeletal muscle

Answer 10

Striated cells
peripherally located multinucleated cells
under voluntary control

Question 11

Location, function, shape, and length of smooth muscle

Answer 11

Location: GI, urinary, vascular tissues
Function: contraction causes controlled movement of material
Shape: fusiform (spindle-shaped)
Length: short

Question 12

Characteristics of smooth muscle

Answer 12

Lacks striation
Single, central nucleus
Involuntary

Question 13

Location, function, shape, and length of cardiac muscle

Answer 13

Location: confined to myocardium (muscle of the heart)
Function: contracts heart to pump blood
Shape: bifurcated (Y-shaped)
Length: short

Question 14

Characteristics of cardiac muscle

Answer 14

Striated
Central,y located mono- or binculeated
Involuntary
Intercalated discs - rapid transport of nervous stimulus

Question 15

Skeletal muscle organization

Answer 15

Muscle
Fascicle
Muscle fiber (cell)
Myofibrils (repeating sarcomeres)
Myofilaments (actin/myosin)

Question 16

Epimysium

Answer 16

Surrounds muscle
Dense irregular connective tissue

Question 17

Perimysium

Answer 17

Surrounds fascicles
Dense irregular connective tissue

Question 18

Endomysium

Answer 18

Surrounds muscle fibers
Areolar connective tissue

Question 19

Myofibrils contain repeating contractile units known as

Answer 19

Sarcomeres

Question 20

What do sarcomeres do and contain

Answer 20

Repeating sarcomeres give striated appearance

Sarcomeres contain myofilaments: myosin and actin

Question 21

Thick filament

Answer 21

Myosin

Question 22

Thin filament

Answer 22

Actin

Question 23

Linear contraction achieved by thick and thin myofilaments sliding against each other

Answer 23

Contractile mechanism or sliding filament mechanism

Question 24

Types of motor units

Answer 24

Large and small

Question 25

Large motor unit function for:

Answer 25

Strength and power movements

Question 26

Small motor units function for:

Answer 26

Fine and precision movements

Question 27

How do muscles move bone?

Answer 27

Over at least one joint and bring insertion to origin

Question 28

Origin

Answer 28

Less mobile attachment
Attaches to axial skeleton when crossing from axial to appendicular skeletons
Is the proximal attachment when in extremities

Question 29

Insertion

Answer 29

More mobile attachment
Attaches to appendicular skeleton when crossing from axial to appendicular skeleton
Is the distal attachment when in extremities

Question 30

How are muscles grouped:

Answer 30

Similar function and/or similar innervation and/or similar blood supply

Question 31

What is a motor unit?

Answer 31

A motor neuron and all muscle fibers it innervates