Exam 3

Question 1

Cardiac muscle tissue

Answer 1

• involuntary
• responsible for pumping action of the heart
• makes up most of the wall of the heart

Question 2

skeletal muscle tissue

Answer 2

• attached to bones of skeleton
• voluntary

Question 3

smooth muscle

Answer 3

• found in wall of internal organs (digestive tract)
  -involuntary

Question 4

Fascia

Answer 4

-Thin covering of connective tissue around a muscle

Question 5

Tendon

Answer 5

-cord-like mass of connective tissue
- connects muscle to bone

Question 6

Aponeurosis

Answer 6

-sheet-like mass of connective tissue
- connects muscle to bone, skin, or another muscle

Question 7

Parts of a muscle fiber

Answer 7

Sarcoplasmic Reticulum, T-tubules, Triad

Question 8

Sarcoplasmic reticulum function

Answer 8

• endoplasmic reticulum of muscle
• stores calcium

Question 9

T-tubules function

Answer 9

Relays electrical impulses to the SR

Question 10

Triad function

Answer 10

• consisting of 1 T tubule and 2 SR cisternae
• translate the action potential from the plasma membrane to the sarcoplasmic reticulum

Question 11

What neurotransmitter plays a big role in muscular contraction

Answer 11

• acetylcholine
• binds to receptors on the outside of the muscle fiber. That starts a chemical reaction within the muscle

Question 12

What are cross-bridges

Answer 12

The attachment of myosin (thick) with actin (thin) within the muscle cell

Question 13

What are the parts of a sarcomere

Answer 13

-actin, myosin, troponin, tropomyosin

Question 13

myosin function

Answer 13

• converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement

Question 13

Actin function

Answer 13

• allows movement of cell surface
• cell division
• determines shape of cell
• muscle contraction

Question 13

troponin function

Answer 13

• slide past myosin to cause muscle shortening

Question 14

Anaerobic

Answer 14

• glycolysis
• occurs in cytoplasm
• produces little ATP

Question 14

tropomyosin

Answer 14

• prevents the muscle from contracting at the wrong time by making sure actin and myosin doesn’t touch each other

Question 15

Aerobic

Answer 15

• requires more oxygen
• occurs in mitochondria
• Citric acid cycle and electron transport system
• Myoglobin stores extra oxygen in muscles

Question 16

importance of oxygen debt

Answer 16

• The amount of oxygen required to remove the lactic acid, and replace the body’s reserves of oxygen
  -restores oxygen balance in our body

Question 17

importance of myoglobin

Answer 17

• facilitates oxygen diffusion
• stores extra oxygen in muscles

Question 18

Twitch

Answer 18

• response of a single muscle fiber to a single
  impulse

Question 19

Complete tetany

Answer 19

-Occurs at very high frequencies of stimulation
- Does not occur in body, only in laboratory
- Forceful sustained contraction has no relaxation between twitches

Question 19

Partial tetany

Answer 19

• Occurs at higher frequencies of stimulation
• Time spent in relaxation between twitches becomes very brief

Question 20

Summation

Answer 20

• Process by which the force of individual muscle fiber twitches combine,
  when frequency of stimulation increases
• Produces sustained contractions
• Can lead to partial or complete tetanic contractions

Question 21

Recruitment

Answer 21

• Increase in the number of motor units activated, to produce more force
• Certain motor units are activated first, and others are activated only
  when the intensity of stimulus increases
• As intensity of stimulation increases, recruitment of motor units
  continues until all motor units are activated

Question 22

Motor Unit

Answer 22

• A motor neuron plus all of the muscle fibers it controls
• They are activated to produce a given level and type of muscle contraction

Question 23

Type of muscle contractions

Answer 23

• Concentric, eccentric, isometric

Question 24

Concentric

Answer 24

• shortening contraction; occurs when lifting an object

Question 25

Eccentric

Answer 25

• lightening contraction; occurs when force is not sufficient to lift an object

Question 26

Isometric

Answer 26

• -muscle contracts, but doesn’t change length
  -means “equal length”
  -tension develops, but parts attached to muscles don’t move