A & P written test 3 quizzes

The first event in muscle fiber contraction is that

acetylcholine is released from the end of the motor neuron.

Myofibrils are composed primarily of

actin and myosin

Which of the following statements is correct? Tropomyosin molecules move and expose specific sites on myosin filaments. Filaments of troponin and tropomyosin slide past one another. Myosin and actin alternate to form filaments. Cross-bridges form between actin and sarcolemma filaments. Actin filaments slide along myosin filaments.

actin filaments slide along myosin filaments

Functions of muscles are for muscle tone distribution of heat moving bones the heartbeat all of the above

all of the above

Which of the following is a function of the skeletal system? responsible for blood production the storage of inorganic salts the protection of organs, especially in the head and thorax the interaction with muscles for movement all of the above

all of the above

Which of the following movements could occur at the hip joint? Adduction Extension Abduction Flexion all of the above

all of the above

A synchondrosis

allows bone growth

the white material that reduces friction at the ends of bones is called

articular cartilage

joints are also called

articulations

In which of the following is rotational movement possible? Condylar joint Hinge joint All of the above Ball-and-socket joint Pelvic joint

ball-and-socket joint

Osteoblasts are _______, whereas osteocytes are ________.

bone-forming cells; mature bone cells

The outermost layer of connective tissue surrounding a skeletal muscle is the

epimysium

A ball-and-socket joint is also called an ellipsoidal joint.

false

During muscle contraction, calcium ions combine with tropomyosin, and this exposes active sites for cross-bridge formation.

false

If a muscle contracts and its fibers shorten, the contraction is isometric.

false

Motor unit recruitment refers to the fact that some motor neurons can recruit new skeletal muscle fibers with which they connect.

false

White muscles have an increased capacity to carry on aerobic respiration.

false

A gomphosis is a(n) ______ joint

fibrous

a suture is an example of a(n)

fibrous joint

Movements permitted by the elbow joint between the humerus and the ulna are

flexion and extension

The type of cartilage associated with bone function and development is

hyaline cartilage

Cartilagenous joints are connected by

hyaline cartilage or fibrocartilage

The type of calcium phosphate forming most of the inorganic salts in bone extracellular matrix is

hydroxyapatite

The electrical properties of cells are the result of

ion concentration differences across the plasma membrane.

Which of the following four groups of bones, based on shape and with an example of each, is correct? Long bones-wrist and ankle bones Short bones-arm and leg bones Flat bones-facial bones Irregular bones-bones of the backbone short bones-facial bones

irregular bones-bones of the backbone

A fasciculus

is surrounded by perimysium

Greg trips over a toy and experiences a sharp pain. His physician diagnosis a torn meniscus. Greg has injured his

knee joint

A joint capsule is reinforced by

ligaments binding articular ends of bones together

A bone includes

living material and nonliving material

Fibrocartilage discs that divide the joint into two compartments are called

menisci

Threshold stimulus is the

minimal amount of energy required to contract a muscle fiber

Neurotransmitters are stored in vesicles in

motor neuron endings

At a neuromuscular junction

neurotransmitters are released

A bone thickens by activity of osteocytes in the medullary cavity increased secretion of calcium salts by osteoclasts increased activity of the epiphyseal plate adding blood vessels and nerves none of these choices are correct

none of these choices are correct

Skeletal muscle fibers

possess striations

The muscle primarily responsible for an action is the

prime mover

The very brief moment following stimulation when a muscle remains unresponsive to additional stimulation is called the

refractory period

Endochondral ossification ______, whereas intramembranous ossification ______.

replaces hyaline cartilage; replaces undifferentiated connective tissue

Muscles exhibit the property of excitability. This means that the muscle

responds to stimulation by the nervous system

The striated appearance of skeletal muscle results from the

sarcomere organization

Muscle fibers are basically a collection of

sarcomeres

The axial skeleton includes the

skull, hyoid bone, thoracic cage, and vertebral column

creatine phosphate

supplies energy for the synthesis of ATP

Articular cartilage receives oxygen and nutrients from

surrounding synovial fluid

Which of the following is not a synovial joint?

symphysis

The joint that separates two vertebrae is a(n)

symphysis that is amphiarthrotic

Types of fibrous joints include

syndesmosis, suture, and gomphosis joints.

the presence of an epiphyseal plate indicates that:

the bone is lengthening

Classifying joints as synarthrotic, amphiarthrotic, or diarthrotic represents

the degree of movement possible at the joint

At what age are all bones normally ossified?

25 years

Compact bone has _______, whereas spongy bone has ________.

tightly packed tissue that is solid, strong, and resistant to bending; cancellous bone that reduces the weight of bone

Which of the following is not a function of bone? to house the tissue that produces blood cells to store inorganic salts to protect soft tissues to provide a framework for the body to provide nervous communication from bone to muscle

to provide nervous communication from bone to muscle

Transverse tubules

transmit muscle impulses into the cell interior

ATPase is located in myosin cross-bridges

true

Kicking a soccer ball is flexion of the leg at the knee joint as the foot draws back and then extension as it contacts the ball.

true

__________ degrades acetylcholine, keeping it from accumulating in the synapse.

Acetylcholinesterase

The sternum is part of the

Axial skeleton

Which of the following is true about skeletal muscle? There are very few nerve fibers in a muscle. Sensory neurons stimulate muscles to contract. All of these are true. There are very few blood vessels in skeletal muscle. Every muscle fiber receives a branch of an axon from the nerve.

Every muscle fiber receives a branch of an axon from the nerve

Normal bone growth requires adequate amounts of calcium, phosphate, and vitamin E

False

Which of the following is not a step in endochondral bone formation? Hyaline cartilage develops into the shape of the future bone. Periosteum forms from connective tissue outside the developing bone. Hyaline cartilage changes to adipose tissue Osteoblasts deposit osseous tissue in place of disintegrating cartilage. Osteoblasts deposit a thin layer of compact bone beneath the periosteum.

Hyaline cartilage changes to adipose tissue

Which of the following is the form in with calcium is found in the inorganic matrix of the bone? calcium oxalate Hydroxyapatite Hydroxycalcite Haversian crystals Hypochlorite

Hydroxyapatite

Which is true? Osteoblasts are large, multinucleated cells that break down calcified bone matrix. Osteoblasts deposit bone matrix around themselves and become osteocytes when they are isolated in lacunae. Osteoclasts secrete bone matrix and become osteoblasts. Embryos and fetuses have only osteoblasts, children have only osteocytes, and adults have only osteoclasts. Osteocytes secrete bone matrix and become osteoblasts

Osteoblasts deposit bone matrix around themselves and become osteocytes when they are isolated in lacunae.

Which of the following is NOT a property of the myosin head? They bind to ATP They have ATPase activity The bind to troponin They have a hinge region to bend and straighten They form cross-bridges with the active sites of actin

They bind to troponin

Bones of a synovial joint are held together by

a joint capsule

A motor unit is

a motor neuron and the muscle fibers connected to it