Muscular system

Characteristics of Muscle Cell

• Excitability or irritability

• Contractility

• Extensibility

• Elasticity

Skeletal Muscle Tissue

Multinucleated, voluntary, striated, 40% of body weight

Cardiac muscle cell

Striated, one nucleus, involuntary intercalated discs, branched

Smooth muscle cell

One nucleus, involuntary, not striated

Location of smooth muscle cell

Walls of hollow organs, tracts, vessels

Location of skeletal muscle cell

Attached to bones

How do muscles attach to origins and insertions

Connective tissue

Origin

Less movable attachment

Flesh attachment

Short connective tissue at the origin

Insertion

More movable attachment (that is moving)

Indirect attachment

Long connective tissue (tendon) at insertion

Where do the tendons meet the bones

Bone markings

Functions of skeletal muscles

Locomotion and breathing, posture, heat production

The diaphragm is a skeletal muscle

True

How is the diaphragm a skeletal muscle

Upon its contraction and relaxation we are able to breath. However, if we stop taking in air, the diaphragm will stop as well, making the process voluntary

Why is muscle an organ

Because it has nerves and blood vessels

Muscle fiber

Muscle cell

Muscle fascicle

Multiple muscle cell

Skeletal muscle

Multiple muscle fascicles wrapped in connective tissue

What does a muscle consist of

Muscle tissue, nerve fiber, blood vessels, connective tissue

What are the three muscle connective sheaths

Endomysium, perimysium, epimysium

Where is the endomysium found

Around each muscle cell/fiber

What is the endomysium made up of

Reticular fibers

What is perimysium made of

Fibrous connective tissue

Location of cardiac muscle

Heart

Where is perimysium found

Around each fascicile

What is epimysium made of

Dense connective tissue

Where is the epimysium found

Around an entire muscle

Sarcolemma

Plasma membrane of the muscle cell

Which muscle cell is voluntary

Skeletal

Sarcplasm

Cytoplasm of the muscle cell

Sarcoplasmic reticulum

Endoplasmic reticulum of the muscle cell

What are myofibrils made of

Contractile proteins ‘myofilaments’