Class #3 - Bones & Muscles

Question 1

What are the three basic muscle types?

Answer 1

• skeletal muscle
• cardiac muscle
• smooth muscle

Question 2

Muscles are responsible for…?

Answer 2

all types of body movement

Question 3

Where is skeletal muscle found in the body?

Answer 3

attached to bone or skin (for some facial movements)

Question 4

Where is cardiac muscle found?

Answer 4

in the walls of the heart

Question 5

Where is smooth muscle found?

Answer 5

mostly in the walls of visceral organs, primarily in the digestive system

Question 6

What is the cell shape and appearance of skeletal muscle?

Answer 6

• Single cell
• very long
• cylindrical in appearance
• multinucleate
• cells with very obvious striations

Question 7

What is the cell shape and appearance of cardiac muscle?

Answer 7

• branching chains of cells
• uninucleate
• striations
• intercalated discs

Question 8

What is the cell shape and appearance of smooth muscle?

Answer 8

• single cell
• fusiform
• uninucleate
• no striations

Question 9

What are the connective tissue components of skeletal muscle?

Answer 9

• endomysium
• perimysium
• epimysium

Question 10

What are the connective tissue components of cardiac muscle?

Answer 10

• endomysium

Question 11

What are the characteristics of slow twitch fibres?

Answer 11

• aerobic (needs oxygen to produce mitochondria)
• contain lots of mitochondria
  
  • -> mitochondria are responsible for the red colour
• slower, stronger contractions, longer contraction duration
• commonly found in legs, back and endurance athletes

Question 12

What are the characteristics of fast twitch fibres?

Answer 12

• anaeorbic ( don’t need oxygen)
• use glucose for ATP
• white appearance due to lack of mitochondria
• fatigue quicker
• common in arms, chests and sprinters

Question 13

Skeletal muscle cells are surrounded and bundled…?

Answer 13

by connective tissue for strength and support

Question 14

Increasingly tough connective tissue sheets that surround skeletal muscle…?

Answer 14

• enclose single muscle fibers (cells)
• wrap around bundles of muscle fibers
• cover the entire skeletal muscle as fascia - blends with tendons

Question 15

Skeletal Muscle Functions

Answer 15

• produce movement
• maintain posture and stabilize us against pull of gravity
• stabilize joints - esp shallow joints
• generate heat -> 3/4 of energy produced by ATP in muscle contraction is lost as heat

Question 16

What is excitability?

Answer 16

ability to received and respond to stimulus

Question 17

What is contractility?

Answer 17

ability to shorten when adequate stimulus is received

Question 18

What is Extensibility?

Answer 18

Ability to be stretched

Question 19

What is Elasticity?

Answer 19

Ability to recoil and resume resting length after stretching

Question 20

What is a motor unit?

Answer 20

A motor neuron cell that stimulates the contraction of most of the muscle cells

Question 21

Skeletal muscle is…?

Answer 21

• made of several fibers
• at the smallest level, these fibers are made of:
  
  • actin
  • myosin