Muscular system

Question 1

Main muscle functions

Answer 1

1. produce movement of the skeleton : by pulling tendons attached to the bones
2. Mantain posture and body position- even when we are not moving
3. Support soft tissue
4. Guard entrances and exits: in the form of sphincters
5. Maintain body temperature

Question 2

How do muscles maintain body temperature?

Answer 2

When contraction occurs, energy is used and converted to heat

Question 3

Muscles are attached to at least two points of a bone :

Answer 3

1. oRIGIN

2. Insertion

Question 4

Origin

Answer 4

attachment to a immoveable bone

Question 5

insertion

Answer 5

attachment to a movable bone

Question 6

The muscle usually involved in a moving bone , will

Answer 6

cross over a joint and upon contraction it bring about a movement at the joint

Question 7

The basic muscle types are found in the body

Answer 7

1. Skeletal muscle
2. Cardiac muscle
3. Smooth muscle

Question 8

Cell shape and appearance of skeletal muscle

Answer 8

Single, very long, cyndrical, multinucleate cells with very obvious striations

Question 9

Body location of skeletal muscle

Answer 9

Attached to bones or for some facial muscles to skin

Question 10

Body location of cardiac muscle

Answer 10

walls of the heart

Question 11

Cell shape and appearance of cardiac muscle

Answer 11

Branching chains of cells; uninucleate, striations; intercalated discs

Question 12

Body location of smooth muscle

Answer 12

Mostly in walls of hollow visceral organs

Question 13

Skeletal muscle must stimulated by

Answer 13

the central nervous system

Question 14

Skeletal muscle help in

Answer 14

voluntary movement and therefore, skeletal muscles are subject to conscious control

Question 15

Aponeurosis

Answer 15

A broad sheet of collagen fibers that connects muscles to each other

Similar to tendons, but do not connect to bone

Question 16

What are tendons

Answer 16

• Cordlike structures
• Mostly collagen fibers
• often cross a joint because of their toughness and small size

Question 17

A tendon consists of 3 layers

Answer 17

• Epimysium
• Perimysium
• Endomysium

Question 18

Ligament

Answer 18

Short band of tough, flexible fibrous connective tissue which connects two bones or cartilages or holds together a joint

Question 19

Differences between tendon vs ligament

Answer 19

tendon attaches muscle to bone (sprain)

Ligaments- attach bone to bone (strain)

Question 20

Smooth muscle - characteristics

Answer 20

• lack striations
• spindle-shaped cells
• single nucleus
• Involuntary- no conscious control
• found mainly in the walls of hollow visceral organs such as stomach, urinary bladder , respiratory)

Question 21

Cardiac muscle tissue is only found in the

Answer 21

heart

Question 22

Cardiac muscle cells communicate through

Answer 22

gap junctions, allowing all the fibers to work together

Question 23

(cardiac muscle cells ) intercalated discs

Answer 23

which connect cells to other cells

Question 24

(cardiac muscle cells ) Communicate through _____________________

Answer 24

gap junctions, allowing all the fibers to work together

Question 25

Pacemaker

Answer 25

a small device that is placed in the chest or abdoment to help control heart rhythms

Question 26

Irritability

Answer 26

ability to receive and respond to a stimulus

Question 27

Contractility

Answer 27

ability to shorten when an adequate stimulus is received

Question 28

Extensibility

Answer 28

ability of muscle cells to be stretched

Question 29

Elasticity

Answer 29

ability to recoil and resume resting length after stretching

Question 30

heart conditions where impulses are irregular

Answer 30

Bradycardia and heart block aRRHYTHMIAS (PATIENT NEED PACEMAKER)

Question 31

muscle twitch

Answer 31

a single stimulus-contraction-relaxation cycle in a muscle fiber or whole muscle

Question 32

muscle twitch is represented by

Answer 32

a myogram

Question 33

myogram

Answer 33

a graphic representation of the phenomena | (as velocity and intensity) of muscular contractions

Question 34

The three phases of a muscle twitch

Answer 34

- latent period - period of contraction - period of relaxation

Question 35

Latent period

Answer 35

first few msec after stimulus; Excited-contraction coupling taking place

Question 36

period of contraction

Answer 36

cross bridges from ; muscle shortens

Question 37

Period of relaxation

Answer 37

Ca2+ reabsorbed; muscle tension goes to zero

Question 38

Skeletal muscle must be stimulated by

Answer 38

a motor neuron to contract

Question 39

Motor unit

Answer 39

one motor neuron and all the skeletal muscle cells stimulated by that neuron

Question 40

Neuromuscular junction

Answer 40

Association site of axon terminal of the motor neuron and sarcolemma of a muscle

Question 41

Neurotransmitter

Answer 41

Chemicals are released by nerve upon arrival of nerve impulse in the terminal

Question 42

__________ is the neurotransmitter that stimulates skeletal muscle

Answer 42

acetylcholine

Question 43

Graded responses

Answer 43

different degrees of skeletal muscle shortening

Question 44

Graded responses can be produced by changing

Answer 44

The frequency of muscle stimulation the number of muscle cells being stimulate at one time

Question 45

Primary function of muscle tone

Answer 45

stabilization of joints and posture

Question 46

If the nerve supply is destroyed,

Answer 46

the muscle loses tone, becomes paralyzed and undergoes atrophy

Question 47

Atrophy

Answer 47

Occurs in a muscle that is not regularly stimulated or nerve supply is cut off Muscle becomes small and weak

Question 48

Effect of exercise on muscles

Answer 48

- exercise increases muscle size and strength and endurance - makes body metabolism more efficient - improves digestion, coordination

Question 49

Action and remarks brachialis

Answer 49

action - Prime mover, or agonist remarks - the muscle that is chiefly responsible for producing a movement

Question 50

Action and remarks triceps

Answer 50

action- antagonist remarks- a muscle that opposes another muscle

Question 51

action and remarks biceps

Answer 51

action- synergist remarks: a muscle that helps the prime mover

Question 52

primary actions of prime mover, or agonist

Answer 52

the muscle that is chiefly responsible for producing a movement

Question 53

primary actions of antagonist

Answer 53

a muscle that opposes another muscle

Question 54

primary actions of synergist

Answer 54

A muscle that helps the prime mover

Question 55

(muscle actions across elbow) the _____ is the prime mover, the _______ is the antagonist, and the __________ is the synergist

Answer 55

brachialis, tricpes brachii , biceps brachii

Question 56

Axial Muscles

Answer 56

these are the muscles that have both their origins and insertions on parts of the axial skeleton

Question 57

Appendicular muscles

Answer 57

- control the movements of the upper and lower limbs, and stabliize and control the movements if the pectoral and pelvic girdles

Question 58

Four effects of aging on skeletal muscle

Answer 58

1. muscle fibers become smaller 2. muscles become less elastic and more fibrous 3. tolerance for exercise decreases due to a decrease in thermoregulation 4. ability to recover from injury is reduced

Question 59

Thermoregulation

Answer 59

- ability of smooth muscles of the blood vessel walls to dilate and contract allows good thermoregulation

Question 60

in older individuals due to aged muscles and poor elasticity of the smooth muscles, __________

Answer 60

the ability of blood vessels to constrict/ dilate is reduced, thus tolerance to temperature changes is decreased