Muscular System

What are the 3 types of muscle?

smooth, cardiac, and skeletal

Smooth muscle =

• involuntary

• non-striated

• generally found in digestive system

Cardiac muscle =

• involuntary

• striated

• only found in the heart

Skeletal muscle =

• voluntary

• striated

• attached to bones

Characteristics of Skeletal Muscle =

• elongated/cylindrical

• multi-nucleated

• attaches to bones via tendons

• enables movement

• peripheral nuclei

• fast action

What causes striations?

actin & myosin — band together and make the striated shape

Characteristics of Cardiac Muscle =

• elongated/branched

• one/two nuceli

• intercalated discs

• striated

• fast

Characteristics of Smooth Muscle =

• spindle shaped cells

• one nucleus

• center nuclei

• found in hollow structures (stomach, intestines)

ANS =

autonomic nervous system — involuntary control

SNS =

somatic nervous system — voluntary control

What are the 5 ways muscles are named?

• shape

• location

• attachment

• size

• orientation of fibers

Shape =

• ex. trapezius = trapezoid shape

• tricepts = 3 portions or number of origins

• biceps = 2 portions

Location =

• pectoralis — in the chest/pectus

• intercostal — between ribs

Attachment =

• ex. sternocleidomastoid — sternum, clavicle, and mastoid of the skull

Size =

• ex. Maximus — largest

• Minimus — smallest

• Longus — long

• Brevis — short

Orientation of Fibers =

• direction of the fibers

• rectus — straight, fibers run vertically

• transverse — across, fibers run horizontally

• ex. obliques — angled, fibers run diagonally

What is the Extensor Muscle Group?

• located in the upper body and along the front and top surfaces of the limbs

• their primary function is to straighten or extend a joint

What is this?

Brachiocephalicus

What is this?

Triceps

What is this?

Deltoid

What is this?

Trapezius

What is this?

Latissimus Dorsi

What is this?

Intercostals

What is this?

Abdominals

What is this?

Oblique

What is this?

Gluteus

What is this?

Biceps Femoris

What is this?

Semitendonosis

What is this?

Semimembranosus

What is this?

Masseter