Chapter 1

Question 1

How mobile are fibrous joints?

Answer 1

Immobile

Question 2

How mobile are cartilaginous joints?

Answer 2

Limtied

Question 3

How mobile are synovial joints?

Answer 3

Considerably mobile

Question 4

What type of cartilage is found at joint articulations?

Answer 4

Hyaline

Question 5

What are fasciculi?

Answer 5

Bundles of ~150 muscle fibers, covered by perimysium

Question 6

What connective tissue covers invidual muscle fibers?

Answer 6

Endomysium

Question 7

What is a sarcolemma?

Answer 7

Muscle fiber membrane, contiguous with muscle fiber itself.

Question 8

What is a motor unit?`

Answer 8

A motor neuron and all of the muscle fibers that it innervates.

Question 9

What is the M Bridge?

Answer 9

Center of sarcomere. Where Myosin is anchored.

Question 10

What are the Z lines?

Answer 10

Ends of sarcomere, where the actin anchors.

Question 11

What is the arrangement of actin and myosin?

Answer 11

Each actin has 3 myosin around it, each myosin has 6 actins around it.

Question 12

What is the A band?

Answer 12

Area with myosin, goes from M bridge to I zone

Question 13

What is the H zone?

Answer 13

Center of the sarcomere where only myosin exists, no overlap with actin

Question 14

What is the I zone?

Answer 14

Periphery of sarcomere where only actin is, no overlap with myosin.

Question 15

Which parts of the sarcomere shrink when contraction occurs?

Answer 15

H and I zones.

Question 16

What is the sarcoplasmic reticulum?

Answer 16

Series of tubules that release calcium from vessicles at Z lines to stimulate a contraction.

Question 17

What are T tubules?

Answer 17

tubules that run perpendicular to sarcoplasmic reticulum and terminate near Z lines, carry action potentials into muscle fibers in a coordinated manner.

Question 18

What happens when calcium is released into the sarcoplasm?

Answer 18

Calcium binds to troponin which shifts tropomyosin, allowing for myosin to form cross bridges with actin.

Question 19

What determines force production by a muscle?

Answer 19

The number of cross bridges that are formed.

Question 20

What must occur for power strokes to occur?

Answer 20

ATP hydrolyzes to ADP via the action of myosin ATPase, which allows the pulling action of the myosin head to occur.

Once this occurs, another ATP is needed to reset the initial globular myosin head position.

Question 21

What does calcium regulate in muscle tissue?

Answer 21

Contraction, glycolytic and oxidative energy metabolism.

Question 22

What is needed for contraction to occur?

Answer 22

Adequate calcium, ATP, myosin ATPase, and some initial overlap of myosin and actin.

Question 23

What type of motor unit allows for precision?

Answer 23

Motor units with small numbers of fibers.

Question 24

What is the all or nothing principle?

Answer 24

If a sufficient amount of acetylcholine is released from vesicles at nerve terminal in response to an action potential, action potential is propogated into the muscle.

A motor neuron being stimulated causes a contraction in all fibers.

Question 25

What are the two ways of increasing the force generated by muscle contractions?

Answer 25

Temporal summation of action potentials, altering the number of motor units activated at a given time.

Question 26

Describe Type I muscle fibers

Answer 26

Slow twitch. Efficient, fatigue resistant. High oxidative capacity, low anaerobic capacity and limited potential for rapid force development.

Question 27

Describe Type II muscle fibers

Answer 27

Fast twitch. Inefficient, fatiguable. Low oxidative capacity, high aerobic capacity and high potential for rapid force development.

Question 28

Contrast Type IIa and Type IIx muscle fibers

Answer 28

Type IIa has a higher aerobic capacity than IIx, surrounded by more capillaries.

Question 29

What do muscle spindles do?

Answer 29

Monitor muscle length/stretch, use amount of stretch on muscle to determine appropriate force required to overcome resistance. Facilitate muscle activation.

Question 30

What do golgi tendon organs do?

Answer 30

Monitor muscle tension. Protective. Inhibit muscle activation if tension is too great.

Question 31

Which node initiates the beating of the heart?

Answer 31

SA node

Question 32

Why is there a delay at the AV node?

Answer 32

Allow filling of the ventricles prior to ejection

Question 33

What is the P wave?

Answer 33

Depolarization of the Atria

Question 34

What is the QRS complex?

Answer 34

Depolarization of the ventricles, repolarization of the atria is masked here.

Question 35

What is the T wave?

Answer 35

Repolarization of the ventricles

Question 36

What are the two roles of hemoglobin?

Answer 36

Carry oxygen, act as an acid base buffer

Question 37

What does carbonic anhydrase do?

Answer 37

Catalyzes reaction between CO2 and water to facilitate CO2 removal.

Question 38

What is pleural pressure?

Answer 38

Pressure between membranes of lungs and chest wall, slightly negative

Question 39

What is alveolar pressure?

Answer 39

Pressure in alveoli when glottis is open and there is no breathing occurring. Equivalent to atmospheric pressure.

Question 40

How much energy goes to respiration at rest? During heavy activity?

Answer 40

3-5%, 8-15%