Exsc 223 Test 2

Front 1

An elaborate network of membranes in skeletal muscle cells that function in calcium storage

Back 1

The Sarcoplasmic Reticulum

Front 2

What is the major factor controlling the manner in which levers work?

Back 2

The difference in the positioning of the effort, load, and fulcrum.

Front 3

Sliding filament model of contraction involves

Back 3

Thin filaments sliding past thick filaments so they overlap to a greater degree.

Front 4

Of the following muscle types, which has gap junctions, caveoli, and no neuromuscular junction?

Back 4

Smooth muscle

Front 5

Growth of bones is controlled by a symphony of hormones, which hormones is important for infancy and childhood?

Back 5

Growth hormone

Front 6

The axial skeleton contains

Back 6

the skull, vertebral columns, and rib cage.

Front 7

7. An individual has just ingested a chemical that binds irreversibly to the ACh receptors in the sarcolemma. By itself it does not alter membrane potential, yet prevents normal neurotransmitter binding ignoring the effects on any other system, the consequence to skeletal muscle would be:

Back 7

No contraction at all by nervous mechanisms

Front 8

Wolff’s Law is concerned with

Back 8

the thickness and shape of bone depending on stress.

Front 9

Wave summation

Back 9

increases muscle tension due to greater intramuscular Ca2+ levels.

Front 10

Which of the following statements best describes the relationship between force production and velocity of skeletal muscles?

Back 10

Force production decreases as velocity of shortening increases

Front 11

With regard to muscle fiber arrangements in a pinnate muscle

Back 11

the fascicles are short and attach obliquely to a central tendon that runs the length of a muscle.

Front 12

Bones are constantly undergoing resportion for various reasons which of the following cells accomplish this process?

Back 12

Osteoclast

Front 13

A sarcomere is

Back 13

the area between two Z-discs.

Front 14

Neural recruitment of motor units involves:

Back 14

Fine motor control due to orderly recruitment of motor units.

Front 15

A hormone signal released from the digestive tract that regulates feeding behaviors is

Back 15

CCK (cholecystokinin).

Front 16

Which statement regarding factors that influence basal metabolic rate is false?

Back 16

As the ratio of surface area to volume decreases, basal metabolic rate increases.

Front 17

The term energy output includes:

Back 17

The energy lost as heat.

Front 18

Glycogen is formed in the liver during

Back 18

The absorptive state

Front 19

Role of Calcium ions in muscle contraction is to

Back 19

Bind to regulatory sites on troponin, changing the configuration

Front 20

the location of blood-forming tissue..

Back 20

Blood forming marrow in epiphysis of most long bones of an adult

Front 21

4 descriptions of peristalsis

Back 21

a. Alternating contractions and relaxations
b. Contractions that mix and squeeze substances through the lumen
c. Unique to smooth muscle
d. Involve longitudinal and circular layers of muscle

Front 22

The 2 major functions of the axial skeleton is to

Back 22

a. Protect the spinal cord
b. Attachment points for muscle

Front 23

Detachment of cross bridges is directly triggered by

Back 23

Attachment of ATP to myosin heads

Front 24

The structural unit of compact bone is

Back 24

The osteon

Front 25

A muscle that provides the major force for producing a specific movement is called

Back 25

An agonist

Front 26

If a muscle were stretched to the point where thick and thin filaments no longer overlapped what would occur?

Back 26

No muscle contraction occurs

Front 27

In some cases the epiphyseal plate of the long bones of children closes too early, what might be the cause?

Back 27

Elevated levels of sex hormones

Front 28

Scissors demonstrate which type of lever?

Back 28

First-Class lever

Front 29

What is not a common trait between skeletal and cardiac muscle?

Back 29

Gap Junctions

Front 30

Bones are covered and lined by a protective tissue called periosteum. The inner (osteogenic) layer consists primarily of

Back 30

Osteoblasts and osteoclasts

Front 31

Normal bone formation and growth are dependent on the adequate intake of

Back 31

Calcium, phosphate, and vitamin D

Front 32

When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?

Back 32

Refractory Period

Front 33

The term metabolism is best defined as

Back 33

The sum of energy produced by all chemical reactions and mechanical work of the body

Front 34

Anabolism includes reactions in which

Back 34

Larger molecules or structures are built from smaller ones

Front 35

As the body progresses from absorptive to the post-absorptive state, only the _____ organ continues to burn glucose while every other organ in the body stops.

Back 35

Brain

Front 36

Several hormones control the remodeling of bones and regulate calcium level homeostasis. What are these two hormones and what is their function?

Back 36

a. Calcitonin - It acts to reduce blood calcium (Ca2+).
b. Parathyroid Hormone (PTH) - It acts to increase the concentration of calcium (Ca2+) in the blood.

Front 37

The peptides called orexins are

Back 37

Powerful appetite enhancers

Front 38

A neuropeptide that makes an individual feel full and satisfied is

Back 38

Serotonin and GLP-1

Front 39

Explain rigor mortis.

Back 39

a. After a muscle contracts, ATP expenditure is required to release the myosin head of a thick filament from its binding site on the thin filament. Since all metabolic processes have come to a halt in a dead body, no ATP is being produced. Therefore, because of a lack of ATP, the myosin head cannot be released from the actin filament, and the sarcomere cannot relax. Because this happens in muscles all over the body, they become "stiff" and "locked" into place.
b. ATP is required to reuptake calcium into the sarcomere's sarcoplasmic reticulum (SR). Additionally, when a muscle is relaxed, the myosin heads are returned to their "high energy" position, ready and waiting for a binding site on the actin filament to become available. Because there is no ATP available, previously released calcium ions cannot return to the SR. These leftover calcium ions move around inside the sarcomere and may eventually find their way to a binding site on the thin filament's regulatory protein. Since the myosin head is already ready to bind, no additional ATP expenditure is required and the sarcomere contracts. When this process occurs on a larger scale, the disturbing twitches and gruesome postures associated with rigor mortis can occur.

Front 40

What are caveoli?

Back 40

Smooth muscle calcium concentrators that are comparable to T-Tubules