Module 10

Question 1

Skeletal Muscle

Answer 1

• voluntary muscle
• moves body at joints
• MULTIPLE CELLS FUSE TO FORM long muscles fibers , so it has MULTIPLE ECCENTRIC NUCLEI see pic pg 430
• fusion of multiple embryonic cells (syncytium) FUNCTIONAL UNIT= SARCOMERE

Question 2

Cardiac Muscle

Answer 2

• Only found in the Heart
  *NOT under voluntary control
  *Striated appearance like skeletal
  *BRANCHED structure
  see pic pg 430
• connected at intercalated discs
  *single nucleus along outside of branched muscle cells

Question 3

Smooth Muscle:

Answer 3

• Single Cells, CENTRAL NUCLEUS
• Not under voluntary control
• ARTERIES, GUT TUBE
  see pic pg 430
• Spindle shaped, SINGLE NUCLEUS in th center of cell.

Question 4

Contractile Proteins are what?

Answer 4

actin and myosin

Question 5

Regulatory Proteins:

Answer 5

control how actin and myosin deal with each other

Question 6

Structural Proteins:

Answer 6

keep the actin filaments and myosin filaments in the correct orientation so they can interact when needed.

Question 7

Actin:
Myosin:

Answer 7

muscle cells use actin

Myosin: protein that intereacts with actin to cause contraction.

Question 8

Syncytium:

Answer 8

The resulting multinucleate incredibly long cell in skeletal muscle. All the small skeletal muscles together

Question 9

Sarcomere:

Answer 9

When actin and myosin occur in a regular array. the basic unit of muscle contraction

Question 10

When the muscle is relaxed a sarcomere is:

When sarcomere collapse:

Answer 10

At its maximum width

it becomes shorter and entire muscle is shorter

Question 11

What is SKELETAL Muscle controlled by?

What is the CARDIAC MUSCLE controlled by?

Answer 11

Skeletal -The Nervous system.

Cardiac Muscle: Controlled by a nerve cell that makes synaptic (cell to cell) contact with the muscle fiber.

Question 12

Cardiac Pacemaker:

Answer 12

The Cardiac Muscles own electrical signaling system. send electrical spike every 0.8 seconds to cause the heart to contract. (the PULSE or HEART RATE)

Question 13

Sarcolemma:

Answer 13

The Cardiac Muscles own surrounding membrane

Question 14

Gap Junctions in Cardiac Muscle:

Desmosomes:

Answer 14

are used to transmit electrical impulses between cells to ensure coordinated firing of muscle contraction. ALL parts of the heart contracts all the way all at once.
DESMOSOMES: are used to hold muscles together at intercalated discs. So it doesnt rip itself apart.

Question 15

Where is smooth muscle found?

Answer 15

Lining the blood vessels, lining airways, lining the gut tube throughout the digestive system and in other places.

Question 16

Nerves in Smooth Muscle

Answer 16

are there to regulate smooth muscle contractions rather than control it. They release chemicals that increase or decrease the overall activity level of smooth muscle, but they dont control individual muscle cells as in Skeletal muscle. They DO NOT HAVE Ca++ managment

Question 17

If cell is infected, it can shut down by way of what?

Answer 17

Calcium

Question 18

What is a Myofibril:

Answer 18

a long strand of sarcomeres arranged end-to-end

Question 19

What is in a Muscle cell or Muscle FIber

Answer 19

a MYOFIBRIL. What Is a myofibril made up of? a SARCOMERE. What is Sarcomere made up of? ACTIN and MYOSIN. One muscle fiber is the product of many embryonic muscle cells fusing into one long tube.. (syncytium) with multiple nuclei Each muscle fiber runs the entire length of a muscle. it is surrounded by plasma memrane of the cell.