Human Anatomy and Physiology 1 Exam 2

Which of the following best describes the term sarcomere?

repeating unit of striated myofibrils

The lining of the medullary cavity is called the

endosteum

A condition in which bone becomes riddled with holes is called

osteoporosis

The names of the muscles can indicate all of the following, except

collagen content of the muscle

The dense layer of connective tissue that surrounds an entire skeletal muscle is the

epinmysium

Contracting the gastrocnemius muscles to elevate the body on the toes involves a ____ lever.

second-class

How would an elevated level of thyroid hormone in the body affected skeletal muscles?

it would stimulate energy use and heat production

Interactions between acting and myosin filaments of the sarcomere are responsible for

muscle contraction

Put the following structures in order from superficial to deep:
1. muscle fiber
2.perimysium
3.myofibril
4.fascicle
5.endomysium
6. epimysium

6. epimysium
2.perimysium
4.fascicle
5.endomysium
1. muscle fiber
3.myofibril

Nerves and blood vessels that service a muscle fiber are located in the connective tissues of its

endomysium

The interconnecting tiny arches of bone tissues found in spongy bone are called

trabeculae

Elevated levels of calcium ion in the blood stimulate the secretion of the hormone

calcitonin

Which of the following best describes the term Z line?

thin filaments are anchored here

Creatine phosphate

acts as an energy reserve in muscle tissue

Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for

contraction

At each end of the muscle, the collagen fibers of the epimysium, and each perimysium and endomysium, come togethre to form a

tendon

Which of the following is not a function of smooth muscle tissue?

forcing blood from the heart into the major arteries

The advantage of having many nulcei in a skeletal muscle fiber is

the ability to produce large amounts of the muscle proteins needed for growth and repair.

The region of the sarcomere containing the thick filaments is the

A band

Which of these phrases most aptly decribes "muscle insertion"?

tendon attachment that moves

___ are squamous stem cells that develop into osteoblasts

osteoprogenitor cells

The type of muscle fiber that is most resistant to fatigue is the ____ fiber.

slow

The repeating unit of a skeletal muscle fiber is the

sacromere

At rest, active sites on the actin are blocked by

tropomyosin molecules

A shallow depression on a bone is termed a

fossa

Cells that secrete the organic components of the bone matrix are called

osteoblasts

The series of membranous channels that surround each myofibril is the

sarcoplasmic reticulum

Each thin filament consists of

two actin protein strands coiled helically around each other

Which of the following is not one of the forms of fascicle organization?

perpendicular

Which of the following bones is classified as "irregular" in shape?

vertebra

The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the

endomysium

Which of the following is a recognized function of skeletal muscle?

guard body entrances and exits
maintain posture
produce movement
maintain body temperature

A lever consists of

a bone, a muscle, and a nerve

Which of following is a function of the skeletal system?

protection of internal organs
calcium homeostasis
blood cell production
body support

An antagonist to the gatrocnemius is the

tibialis anterior

How is vitamin D(vitamin D3) related to calcium homeostasis in bone?

vitamin D is involved in calcium absorption by the digestive tract so calcium is available for ossification and remodeling

Which type of muscle fibers are best adapted for prolonged contraction such as standing all day?

slow fibers

A fascicle is

a group of muscle fibers that are encased in the perimysium

The central canal of an osteon contains

blood vessels

Cross-bridges are poertions of

myosin molecules

The condition known as osteopenia

causes a gradual reduction in bone mass

In a sacromere, thick filaments are linked laterally by proteinds of the

M line

A muscle that assists the muscle that is primarily responsible for a given action is a(n)

synergist

Each skeletal muscle fiber contains ____ myofibrils.

hundreds to thousands

Which of the following best describes the term sarcoplasmic reticulum?

storage and release site for calcium ions

The region of the sarcomer that always contains thin filaments is the

I band

Muscle fibers differ from "typical cells" in that muscle fibers

have many nuclei

At rest, the tropomyosin molecule is held in place by

troponin molecules

During the Cori cycle, in the liver

glucose is produced from lactic acid

The most common lever systems in the body are those that have the applied force between the fulcrum and the load. These are called ____ levers.

third-class

In a ____ muscle, the fascicles are concentrically arranged around an opening.

circular

Which of the following best describes the term titin?

protein that accounts for elasticity of resting muscles

Skeletal muscle fibers are formed from embryonic cells called

myoblasts

A hole through a bone is termed a

foramen

Put the following steps of bone repair in correct sequence:
1. cartilage in the external callus is replace by bone
2. a hematoma occurs
3. an internal callus forms at the site of injury
4.osteoclasts remodel the bone at the site of repair

2. a hematoma occurs
3. an internal callus forms at the site of injury
1. cartilage in the external callus is replace by bone
4.osteoclasts remodel the bone at the site of repair

The area in the center of the A band that contains no thin filaments is the

H band

Fast fibers

have low resistance to fatigue and have quick twitches

The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n)

tendon

The plasma membrane of a skeletal muscle fiber is called the

sarcolemma

The narrow passageways that contain cytoplasmic extensions of osteosytes are called

canaliculi

The skeletal muscle complex known as the triad consists of

a transverse tubule and two terminal cisternae

The space occupied by an osteocyte is called a

lacuna

The following are important steps in the process of endochondral ossification.
1. enlarged chondrosytes die
2. osteoblasts replace calcified cartilage with spongy bone
3. chondrosytes enlarge and the surrounding matrix begins to calcify
4. blood vessels invade the perichondrium
5. perichondrial cells become osteoblasts and produce a thin shell of bone

3. chondrosytes enlarge and the surrounding matrix begins to calcify
1. enlarged chondrosytes die
4. blood vessels invade the perichondrium
5. perichondrial cells become osteoblasts and produce a thin shell of bone
2. osteoblasts replace calcified cartilage with spongy bone

Which of the following is formed by intramembranous ossification?

the roof of the skull and the clavicle

Each of the following terms is a descriptive term for a muscle's action, except:

sartorius

During physical exercise, when our bodies are involved in intense, powerful contraction and utilizing fast twitch muscle tissue, the power comes from the fact that the process allows 38 ATP's of energy to be utilized from the breakdown of glucose in the aerobic respiration cycle.

False

The "H" band in the sacrcomere of a muscle cell is the lighter region on either side of the "M" line.

True

One important feature of muscle fiber is that they contract in both directions allowing for fluid movement of our bodies.

False

One of the ways to recognize cardiac muscle tissue is to look for striations. The fact that this tissue is striated indicates that it is heart muscle tissue.

False

One way to remember where the "A" bands are in a sarcomere is the they appear dArk.

True

Immature bone cell that secretes osteoid, the organic component of bone matrix.

osteoblast

Mature bone cell that maintains bone matrix.

osteocyte

Most of the bone cell population is comprised of this cell type.

osteocyte

This cell type allows calcium and phosphate concentrations in the blood to be maintained through their activity.

osteoclast

This cell type does not divide.

osteosyte

This cell type occupies a space called a lacuna, sandwithced between layers of matrix.

osteosyte

This squamous cell type differentiates to produce osteoblasts.

osteoprogenitor

This cell type makes and releases proteins and other organic components of the matrix.

osteoblast

Multinucleate cell that secretes acids and enzymes to dissolve bone matrix.

osteoclast

Stem cells whose divisions produce osteoblasts.

osteoprogenitor