exam 2 AP pg 5-10

What is the difference between a 1st, 2nd, and 3rd class lever?

• 1st class lever: load between effort and fulcrum; 2nd class lever: effort between load and fulcrum; 3rd class lever: fulcrum at one end.
• 1st class lever: effort and load on the same side of the fulcrum; 2nd class lever: fulcrum at the end; 3rd class lever: load at the end.
• 1st class lever: fulcrum at the load; 2nd class lever: effort at the load; 3rd class lever: fulcrum at the effort.
• 1st class lever: fulcrum between effort and load; 2nd class lever: load between fulcrum and effort; 3rd class lever: effort between fulcrum and load.

How do they 1st, 2nd, 3rd lever affect range of motion

and speed of movement? Which operate at a mechanical advantage/disadvantage?

• 1st lever: mechanical advantage, small range of motion
• 1st lever: mechanical disadvantage, large range of motion; 2nd lever: mechanical advantage, smaller range of motion; 3rd lever: mechanical disadvantage, greater speed.
• 2nd lever: mechanical disadvantage, large range of motion
• 3rd lever: mechanical advantage, slower speed

What is the difference between single-unit and multi-unit smooth muscle?

• Single-unit smooth muscle contracts independently, while multi-unit smooth muscle contracts as a single unit.
• Both single-unit and multi-unit smooth muscle contract as a single unit.
• Single-unit smooth muscle

  More common

  Occurs in visceral muscle and multi-unit occurs in some large arteris and air passages.

• Single-unit smooth muscle is found only in the heart, while multi-unit smooth muscle is found in the digestive tract.

Where does most calcium come from in smooth muscle activation? What does calcium bind to

in smooth muscle?

• Calcium is comes from extracellular fluids and the calcum binds to calmodulin

• Calcium is released from the nucleus and binds to actin in smooth muscle.
• Calcium comes from the mitochondria and binds to myosin in smooth muscle.
• Calcium is primarily sourced from the sarcoplasmic reticulum and binds to troponin.

Where is dystrophin normally found?

• In muscle cells, specifically skeletal and cardiac muscle fibers.
• In red blood cells
• In skin cells
• In nerve cells

What happens in muscular dystrophy?

• Muscular dystrophy only affects the heart and has no impact on skeletal muscles.
• Muscular dystrophy actin does not link to sarcolemma

• Muscular dystrophy improves muscle strength and coordination.
• Muscular dystrophy is a condition that enhances muscle growth.

What is myasthenia gravis?

• Myasthenia gravis is a genetic disorder that causes heart problems.
• Myasthenia gravis is a viral infection that targets the lungs.
• Myasthenia gravis is a type of cancer affecting the blood.
• Myasthenia gravis is an autoimmune disorder characterized by weakness in the skeletal muscles.

What are the symptoms of myaasthenia gravis?

• Severe headaches and migraines
• Persistent cough and fever
• drooping eyelids and double vision, difficulty swallowing, and weakness of the

  limbs; strabismus: inability to fixate on the same point with both eyes

• Numbness in the fingers and toes

how is myasthenia gravis treated?

• Cholinesterase inhibitors, immunosuppresive agents, Thymus removal, Plasmapheresis

• Dietary changes and supplements
• Physical therapy and exercise
• Antibiotics and pain relievers

What are the major subdivisions of the nervous system?

• Autonomic Nervous System (ANS) and Somatic Nervous System (SNS)
• Cerebral Nervous System and Spinal Nervous System
• Sympathetic Nervous System and Parasympathetic Nervous System
• Central Nervous System (CNS) and Peripheral Nervous System (PNS)