Musclar System Structure

Question 1

Skeletal Muscles System

Answer 1

Striated, Somatic, Voluntary

Function- To move & stabilize bones

Question 2

Cardiac Muscles

Answer 2

Striated, Visceral, involuntary

Forms the heart- Myocardium

Function- Pump the blood

Question 3

Smooth Muscles

Answer 3

Smooth, Visceral, Involuntary

Forms the walls of blood vessels and viscera.

Function- Movement (peristalsis) Controls flow.

Question 4

Head or Bellies of Muscles

Answer 4

Fleshy, reddish, contractile portion composed of skeletal muscle.

Question 5

Tendon

Answer 5

White, non-contractile portions composed of organized collagen.

Attaches muscles to the bones

***Continuation of CT (Connective Tissue) that surrounds each muscles.

***Included when measuring the length of a muscle.

Question 6

Aponeurosis

Answer 6

Flattened tendon that attaches muscles to bones and other muscles.

Question 7

Naming of Muscles

Answer 7

Named by bones to which they are attached.

Size – gluteus maximus m.
Shape – trapezius, rhomboid, deltoid mm.

Location – rectus abdominis, occipitalis and subclavius mm.

Action – abductor digiti minimi and adductor pollicis mm.

Length – extensor carpi radialis longus and flexor pollicis brevis mm.

Question 8

Flat Muscles

Answer 8

Flat has parallel fibers, often with an aponeurosis

Question 9

Fusiform

Answer 9

spindle shaped with a round, thick belly (bellies) and tapered ends

Question 10

Pennant Muscles:

Unipennate

Bipennate

Multipennate

Answer 10

feather-like in arrangement. May be:

o Unipennate – fibers on one side of tendon

o Bipennate – fibers on both sides of tendon

o Multipennate – radiating fibers that converge on a central tendon

Question 11

Quadrate

Answer 11

Have four equal side

Question 12

Circular (Sphincteral)

Answer 12

surround body opening or orifice, constricting it when contracted

Question 13

Multi-headed (Multi-bellied)

Answer 13

have more than one head of attachment or more than one

contractile belly

Question 14

Attach of Muscles:

Origin-

Insertion-

Answer 14

O- Proximal attachment and usually remains fixed during muscular contraction.

I- distal attachment and some muscles have dual origin and insertions

Question 15

Reflexive Contraction

Answer 15

automatic aspect of certain skeletal muscle activity

Question 16

Myotatic Reflex

Answer 16

movement of a muscle after a stretch to tendon has been induced by tapping with a hammer

Question 17

Tonic Contraction

Answer 17

slight contraction present in muscles even when “relaxed”.

Does not produce movement or active resistance

Gives muscle a certain firmness to stabilize joints and maintain posture

Keeps muscles ready to respond

Absent when in deep sleep, under anesthesia and after paralysis

Paralysis would result in atrophy (wasting) of the muscle

Question 18

Isometric Contraction

Answer 18

Muscle length remains the same.

Muscle tension is increased above tonic levels.

Resists gravity or other antagonistic force

Question 19

Isotonic

2 types:

Answer 19

Muscle changes length in relationship to production of movement.

Concentric- movement occurs as a result of muscle shortening.

Eccentric- Lengthening of a contracting muscle.

Question 20

Flat Muscles

Answer 20

Flat has parallel fibers, often with an aponeurosis