Muscular System

Step 1

The brain decides to contract a skeletal muscle

Step 2

Motor neurons carry the action potential down the spinal cord to the skeletal muscle

Step 3

The action potential arrives at the neuromuscular junction

Step 4

The action potentail cause the axon terminal to release ACh (Acetylcholine)

Step 5

ACh binds to receptors on the sarcolemma

Step 6

The binding causes the action potential to travel down the sarcolemma

Step 7

The action potential travels down the T-tubules

Step 8

The sarcoplasmic reticulum is stimulated by the action potential and releases calcium ions

Step 9

Calcium ions triggers the muscle fiber to contract

Z-Line

The boundary between sacromeres

Myosin

The thick myofilament

Has “hands” to bind to the actin

M-Line

The “middle line”

Holds together the myosin myofilaments

Actin

The thin myofilament

“2 strands of pearls”

I-Band

The light color band

Contains only the actin myofilament

A-Band

The dark color band

Contains the entire length of the myosin filament

H-Zone

Contains only the myosin filament

2 Bands That Change Size When Contracting a Muscle

I-Band and A-Band

Skeletal, Cardiac, or Smooth: Cells branch and interconnect

Cardiac

Skeletal, Cardiac, or Smooth: Central nuclei

Cardiac

Skeletal, Cardiac, or Smooth: Multinucleated

Skeletal

Skeletal, Cardiac, or Smooth: One nucleus

Smooth

Skeletal, Cardiac, or Smooth: Peripheral nuclei

Skeletal

Skeletal, Cardiac, or Smooth: Striated

Skeletal and Cardiac

Skeletal, Cardiac, or Smooth: Completely involuntary control

Skeletal, Cardiac, or Smooth: Completely voluntary control

Skeletal

Skeletal, Cardiac, or Smooth: Example is biceps brachii

Skeletal

Skeletal, Cardiac, or Smooth: Found attached to bones and sometimes skin

Skeletal

Skeletal, Cardiac, or Smooth: Found in urinary bladder

Smooth

Skeletal, Cardiac, or Smooth: Found in eye and blood vessels

Smooth

Skeletal, Cardiac, or Smooth: Found in heart

Cardiac

Skeletal, Cardiac, or Smooth: Found in intestines and stomach

Smooth

Skeletal, Cardiac, or Smooth: Found in uterus and vas deferens

Smooth

Skeletal, Cardiac, or Smooth: Job-Causes blushes

Cardiac

Skeletal, Cardiac, or Smooth Job: Causes movements such as kicking, running, or walking

Skeletal

Skeletal, Cardiac, or Smooth: Job-Contractions during birth

Smooth

Skeletal, Cardiac, or Smooth: Job-Creating body heat

Skeletal

Skeletal, Cardiac, or Smooth: Job-Digestion

Smooth

Skeletal, Cardiac, or Smooth: Job-Maintains our posture when sitting and walking

Smooth

Skeletal, Cardiac, or Smooth: Job-Pumping blood through blood vessels

Cardiac

Mainly involuntary control

Skeletal, Cardiac, or Smooth: Slow contractions (called peristalsis)

Smooth