Muscular System 5.1

​Muscular System​
5.1 Tissue and Function

5.2 ​Skeletal Muscle Action

5.3 Major Skeletal Muscles​

5.4 Injuries and Disorders​

Muscular System 5.1

​Characteristics of Muscles

• ​ Movement – both voluntary & involuntary

• Maintaining posture

• Supporting soft tissues within body cavities

• Guarding entrances & exits of the body

• Thermoregulation

  • Maintaining body temperature

• ​Glycemic Controls

  • Inulin-stimulated glucose disposal muscles uptake glucose from the blood and store ​it as glycogen.

​Types of Muscle Tissue

• ​Skeletal

  • ​Voluntary

  • ​striated

• ​Cardiac

  • ​Involuntary

  • ​striated

• ​Smooth

  • ​involuntary

  • ​non-striated

Multiple Choice

This type of muscle tissue is found only in the heart

• Skeletal
• Cardiac
• Smooth

Multiple Choice

This type of muscle tissue is found in the walls of hollow organs such as the stomach 

• Skeletal
• Cardiac
• Smooth

​Skeletal muscle

• ​Attaches to skeleton

• ​voluntary movement

• ​long cylindrical cells

  • ​forming striations

​Muscle Coverings and Connective Tissue Membranes

• ​Sarcolemma

  • ​plasma cell membrane surrounds the muscle cell

• ​Endomysium

  • ​Connective tissue membrane that surrounds the muscle cell fibers

  • creates space for​nourishment and nerve stimulation

Multiple Choice

the cytoplasm of a muscle cell is called the

• myosin

• actin

• fascia

• sarcoplasm

​​Connective Tissue and Fascicles

• ​​Perimysium

  • Surrounds muscle fibers together Fascicles

    ​visible to human eye

• ​Epimysium

  • ​surrounds the entire muscle, forms the tendon sheath

• ​​Fascia

  • ​separates neighboring muscles or muscle groups

Multiple Choice

The entire muscle is encased by connective tissue called the

• sacromere

• sarcoplasm

• myosin

• epimysium

Multiple Choice

The _______________ covers bundles of cells (fascicles) within the muscle.

• endomysium

• perimysium

• sarcoplasm

• tendon

​Tendons and Aponeurosis

• ​Extensions of epimysium beyond the muscle fibers

  • ​Tendon

    • ​rope or cord like

  • ​Aponeurosis

    • ​ broad sheet

Multiple Choice

the cordlike connective tissue that attaches a muscle to a bone is called

• a tendon

• a ligament

• a sarcomere

• a fascicle

​Muscle Shapes and Fascicles

• ​Orientation of fascicles determine shape and direction of pull

​Fusiform, Parallel, and Triangular

• Fusiform

  • ​Thick middle with tapered ends (bicep brachii)

• ​Parallel

  • ​uniform width with parallel fascicles. (Sartorius and rectus abdominis)

• ​Convergent (triangular)

  • ​fan shaped, broad at one end and tapered at the other (trapezius and pectoralis major)

Multiple Choice

Trapezium Muscle is an example of 

• Convergent/triangular

• Parallel

• Pennate

• Circular

• Fusiform

​Pennate and Circular

• ​Pennate

  • ​Feathered shaped, more muscle fibers equals more force (rectus femoris and deltoid)

• ​Circular

  • ​form rings to prevent or allow passage (orbicularis oris)

Multiple Choice

Rectus femoris is an example of

• fusiform 

• pennate

• circular

• convergent/triangular

• parallel

​Attachment Sites

• ​Origin

  • ​The bony attachment that is relatively stationary

• ​Insertion

  • ​The movement or mobile site

There are four characteristics associated with muscle tissue:

​

• ​Irritability

  • ​ Tissue can receive & respond to nerve stimulation

• Contractility

  • Tissue can shorten & thicken

• Extensibility

  • ​Tissue can lengthen

• ​Elasticity

  • ​ After contracting or lengthening, tissue always wants to return to its resting state

​Muscle Contractions

• ​When skeletal muscles contract, they produce an action:

  • Isometric contraction (stays the same length)

  • Isotonic concentric contraction (shorten)

  • Isotonic eccentric contraction (lengthen)

Multiple Choice

The type of muscle contraction where the muscle tenses but does not shorten.  

• Isometric
• Isotonic
• Contraction
• relaxation

Multiple Choice

When a muscle shortens under tension, it is called_______

• isotonic eccentric contraction
• isotonic concentric contraction
• isometric concentric contraction
• isometric eccentric contraction

​Functional Groups of Muscles

• ​Agonist

  • ​prime mover, produces most of the force

• ​Synergist

  • ​aids the prime mover

• ​Antagonist

  • ​opposes the prime mover, limits the range of the prime

• ​Antagonistic pair

  • ​pair that work on opposite sides of a joint