A&p Exam 4 Cards

Front 1

Which connective tissue coat surrounds groups of muscle fibers, separating them into fascicles?

Back 1

Perimysium bundles groups of muscle fibers into fascicles.

Front 2

Which of the following is the smallest: muscle fiber, thick filament, or myofibril? Which is largest?

Back 2

smallest-largest: thick filament, myofibril, muscle fiber

Front 3

How are sarcomeres separated from each other?

Back 3

Sarcomeres are separated from one another by Z discs.

Front 4

Which proteins connect into the Z disc? Which proteins are present in the A band? In the I band?

Back 4

Actin and titin anchor into the Z discs. A bands contain myosin, actin, troponin, tropomyosin, and titin; I bands contain all but myosin.

Front 5

What happens to the I band and H zone as muscle contracts? Do the lengths of the thick and thin filaments change?

Back 5

The I bands and H zones disappear during muscle contraction; the lengths of the thin and thick filaments do not change.

Front 6

What would happen if ATP suddenly were not available after the sarcomere had started to shorten?

Back 6

If ATP were not available, the crossbridges would not be able to detach from actin. The muscles would remain in a state of rigidity, as occurs in rigor mortis.

Front 7

What are the three functions of ATP in muscle contraction?

Back 7

1. Its hydrolysis by an ATPase activates the myosin head so it can bind to actin and rotate; 2. its binding to myosin causes detachment from actin after the power stroke; 3. it powers the pumps that transport Ca2+ from the cytosol back into the sarcoplasmic reticulum (SR)

Front 8

Why is tension maximal at a sarcomere length of 2.2 um?

Back 8

A sarcomere length of 2.2um gives a generous zone of overlap btwn the parts of the thick filaments that have myosin heads and the thin filaments without the overlap being so extensive that sarcomere shortening is limited.

Front 9

What part of the sarcolemma contains acetylcholine receptors?

Back 9

the motor end plate

Front 10

Where inside a skeletal muscle fiber are the events shown here occurring?

Back 10

Glycolysis, exchange of phosphate btwn creatin phosphate and ADP, and glycogen breakdown occur in the cytosol. Oxidation of pyruvic acid, amino acids, and fatty acids (aerobic cellular respiration) occurs in mitochondria.

Front 11

What is the effect of the size of a motor unit on its strength of contraction?

Back 11

Motor units having many muscle fibers are capable of more forceful contractions than those having only a few fibers.

Front 12

What events occur during the latent period?

Back 12

During the latent period, the muscle action potential sweeps over the sarcolemma and calcium ions are released from the sarcoplasmic reticulum (SR)

Front 13

Would the peak force of the second contraction be larger or smaller if the second stimulus were applied a few milliseconds later?

Back 13

If the second stimulus was applied a little later, the second contraction would be smaller than the one illustrated.

Front 14

What type of contraction occurs in your neck muscles while you are walking?

Back 14

mainly isometric contractions

Front 15

Which type of smooth muscle is more like cardiac muscle than skeletal muscle, with respect to both its structure and function?

Back 15

Visceral smooth muscle is more like cardiac muscle; both contain gap junctions, which allow action potentials to spread from each cell to its neighbors.

Front 16

How does the speed of onset and duration of contraction in a smooth muscle fiber compare with that in a skeletal muscle fiber?

Back 16

Contraction in a smooth muscle fiber starts more slowly and lasts much longer than a contraction in a skeletal muscle fiber.

Front 17

Which part of a somite differentiates into skeletal muscle?

Back 17

The myotome of a somite differentiates into skeletal muscle.

Front 18

Where is the belly of the muscle that extends the forearm located?

Back 18

The triceps brachii is located posterior to the humerus

Front 19

How does the inferior oblique muscle move the eyeball superiorly and laterally?

Back 19

b/c it originates at the anteromedial aspect of the floor of the orbit and inserts on the posterolateral aspect of the eyeball.

Front 20

Which is the strongest muscle of mastication?

Back 20

The masseter is the strongest chewing muscle.

Front 21

What are the functions of the tongue?

Back 21

chewing, tasting, swallowing, and speech

Front 22

Which abdominal muscle aids in urination?

Back 22

rectus abdominis muscle aids in urination

Front 23

Which muscle associated with breathing is innervated by the phrenic nerve?

Back 23

The diaphragm is innervated by the phrenic nerve.

Front 24

Which tendons make up the rotator cuff?

Back 24

consists of the flat tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles that form the nearly complete circle around the shoulder joint.

Front 25

Which muscles are the most powerful flexor and the most powerful extensor of the forearm?

Back 25

The brachialis is the most powerful forearm flexor; the triceps brachii is the most powerful extensor.

Front 26

Muscles of the thenar eminence act on which digit?

Back 26

Muscles of the thenar eminence act on the thumb.

Front 27

What is the approximate volume of blood in your body?

Back 27

Blood volume is about 8% of body mass; 5-6L in males, and 4-5L in females

Front 28

Which formed elements of the blood are cell fragments?

Back 28

Platelets are cell fragments

Front 29

From which connective tissue cells do pluripotent stem cells develop?

Back 29

Pluripotent stem cells develop from mesenchyme.

Front 30

How many molecules of O2 can one hemoglobin molecule transport?

Back 30

One hemoglobin molecule can transport a max. of four O2 molecules, one O2 bound to each heme group.

Front 31

What is the function of transferrin?

Back 31

Transferrin is a plasma protein that transports iron in the blood.

Front 32

How might the hematocrit change if you moved from a town at sea level to a high mountain village?

Back 32

Once you moved to high altitude your hematocrit would increase due to increased secretion of erythropoietin.

Front 33

Which WBCs are called granular leukocytes? Why?

Back 33

Neutrophils, eosinophils, and basophils are called granular leukocytes b/c all have cytoplasmic granules that are visible through a light microscope when stained.

Front 34

In what way is the “traffic pattern” of lymphocytes in the body different from that of other WBCs?

Back 34

Lymphocytes recirculate from blood to tissues adn back to blood. After leaving the blood, other WBCs remain in the tissues until they die.

Front 35

Along with platelet plug formation, which to mechanisms contribute to hemostasis?

Back 35

Along with platelet plug formation, vascular spasm and blood clotting contribute to hemostasis.

Front 36

What is serum?

Back 36

Serum is blood plasma minus the clotting proteins.

Front 37

What is the outcome of the first stage of blood clotting?

Back 37

First stage of clotting is the formation of the prothrombinase.

Front 38

Which antibodies are usually present in type O blood?

Back 38

Type O blood usually contains both anti-A and anti-B antibodies.

Front 39

Why is the firstborn baby unlikely to have HDN?

Back 39

B/c the mother is likely to start making anti-Rh antibodies after the first baby is already born, that baby suffers no damage.

Front 40

What is agglutination?

Back 40

the clumping of red blood cells.

Front 41

What are some symptoms of sickle-cell disease?

Back 41

Anemia, mild jaundice, joint pain, shortness of breath, rapid heart rate, abdominal pain, fever, fatigue