PHYL 141 - Muscle Tissue (Quiz 9)

hypocalcemia

condition characterized by abnormally low levels of calcium

sarcoplasm

cytoplasm of a muscle cell

What causes the myosin head to release its attachment to actin?

A new ATP molecule binds to the myosin head, releasing it from actin.

________ is required to detach cross-bridges and reactivate the myosin head in a myofibril.

ATP

Enzyme that hydrolyzes ATP to ADP

ATPase

Which of these structures is continuous with the sarcolemma and carries action potentials into the deeper centers of muscle cells?

T-tubules

What happens during the power stroke?

The thin filaments slide toward the M line.

The thin filaments of a myofibril consist mostly of ________.

a pair of actin molecules twisted together

Movement in the coronal plane that moves a limb laterally away from the body; spreading of the fingers

abduction

Neurotransmitter that binds to receptor ion channels at neuromuscular junctions to trigger depolarization of muscle cells

acetylcholine

Protein that makes up most of the thin myofilaments in a sarcomere muscle fiber

actin

what happens during the contraction phase of a single twitch?

actin and myosin molecules are sliding against eachother

Movement in the coronal plane that moves a limb medially toward or across the midline of the body; bringing fingers together

adduction

sarcopenia

age-related muscle atrophy

fast oxidative (FO) fiber

also called intermediate fibers, a muscle fiber that can switch between oxidative aerobic respiration and glycolysis and are more resistant to fatigue than fast twitch fibers

Formation of blood capillary networks

angiogenesis

A(n) ________ is a broad sheet of fused connective tissues at the end of a muscle.

aponeurosis

Broad, tendon-like sheet of connective tissue that attaches a skeletal muscle to another skeletal muscle or to a bone

aponeurosis

Region of the upper limb located between the shoulder and elbow joints; contains the humerus bone

arm

Refers to the heart's ability to control its own contractions

autorhythmicity

Second cervical (C2) vertebra

axis

The first step in the contraction cycle in skeletal or cardiac muscles is when ________ binds to ________.

calcium; troponin

Striated muscle tissue found in the heart; joined to one another at intercalated discs and under the regulation of pacemaker cells

cardiac muscle

Anatomical synonym for the skull

cranium

Movement at the ankle that brings the top of the foot toward the anterior leg

dorsiflexion

Muscle contraction that lengthens the muscle as the tension is diminished

eccentric contraction

Loose, and well-hydrated connective tissue covering each single muscle fiber in a skeletal muscle

endomysium

Outer layer of connective tissue around an entire skeletal muscle

epimysium

Which connective tissue layer wraps around an entire muscle organ?

epimysium

Wide section at each end of a long bone; filled with spongy bone and red marrow

epiphysis

Vertebrochondral ribs 8-12 whose costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all

false ribs

A ________ is a bundle of muscle fibers grouped within a perimysium.

fascicle

Replacement of muscle fibers by scar tissue

fibrosis

What structure is responsible for the spread of action potentials between the cytoplasm of visceral smooth muscle cells?

gap junctions

Lip of fibrocartilage located around the outside margin of the glenoid cavity of the scapula

glenoid labrum

Anaerobic cytosolic breakdown of glucose into pyruvate and ATP

glycolysis

Which of the following processes can produce ATP from glucose without needing oxygen?

glycolysis

Addition of structural proteins to muscle fibers or an increase in size without additional cell division

hypertrophy

synarthrosis

immobile or fixed joint

Middle of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the medial cuneiform bone, laterally with the lateral cuneiform bone, and anteriorly with the second metatarsal bone

intermediate cuneiform

Wide sheet of fibrous connective tissue that fills the gap between two parallel bones, forming a syndesmosis; found between the radius and ulna of the forearm and between the tibia and fibula of the leg

interosseous membrane

Structure located between the bodies of adjacent vertebrae that strongly joins the vertebrae; provides padding, weight bearing ability, and enables vertebral column movements

intervertebral disc

You're trying to hold a yoga pose and contract your muscles while remaining upright with as little movement as possible. This type of contraction is best described as a ________ contraction.

isometric

Muscle contraction that involves changes in muscle length

isotonic contraction

Site at which two or more bones or bone and cartilage come together (articulate)

joint

Chemical product of glycolysis and anaerobic metabolism of pyruvate for the process of ATP production without oxygen

lactic acid

foramen magnum

large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium

Most lateral of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the intermediate cuneiform bone, laterally with the cuboid bone, and anteriorly with the third metatarsal bone

lateral cuneiform

Strong band of dense connective tissue spanning between bones

ligament

C-shaped fibrocartilage articular disc located at the knee, between the lateral condyle of the femur and the lateral condyle of the tibia

meniscus

Nasal concha formed by the ethmoid bone that is located between the superior and inferior conchae

middle nasal concha

All the muscle fibers and the single motor neuron that innervates and stimulates them are called a ________.

motor unit

rotation

movement of a bone around a central axis (antlantoaxial joint) or around its long axis (proximal radioulnar joint; shoulder or hip joint); twisting of the vertebral column resulting from the summation of small motions between adjacent vertebrae

slow oxidative (SO) fiber

muscle fiber that primarily uses aerobic respiration

Low levels of muscle contraction that occur when a muscle is not producing movement

muscle tone

Muscle-forming stem cell

myoblast

Which of the following is NOT found in a thin filament?

myosin

Elongated cell made from the fusion of many myoblast cells

myotube

Signaling chemical released by nerve terminals that bind to and activate receptors on target cells

neurotransmitter

The H band in a sarcomere contains which structures?

only myosin

Primary cell in mature bone; responsible for maintaining the matrix instead of building new matrix

osteocyte

Basic structural unit of compact bone; made of concentric layers of calcified matrix; also called Haversian system

osteon

Ring of bone consisting of the right and left hip bones, the sacrum, and the coccyx

pelvis

Connective tissue that bundles skeletal muscle fibers into fascicles within a skeletal muscle

perimysium

Action of myosin pulling actin inward and toward the M line

power stroke

which of the following is NOT a characteristic of smooth muscle tissue?

presence of striations

T-tubule

projection of the sarcolemma into the interior of the cell

myosin

protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber

Product of glycolysis that can be used in aerobic respiration or converted to lactic acid

pyruvic acid

When you lift a heavy weight, more motor neurons are activated to create greater tension. This phenomenon is known as ________.

recruitment

Period after twitch contraction when tension decreases

relaxation phase

Plasma membrane of a skeletal muscle fiber

sarcolemma

Longitudinally, repeating functional unit of skeletal muscle, with all of the contractile and associated proteins involved in contraction

sarcomere

Myofibrils are formed from repeating functional units called ________.

sarcomeres

Myofibrils have ________ along their length, which are repeating functional units that shorten and contract.

sarcomeres

Cytoplasm of a muscle cell

sarcoplasm

Specialized smooth endoplasmic reticulum, which stores, releases, and retrieves Ca++

sarcoplasmic reticulum

Where is calcium stored in skeletal muscle fibers during muscle relaxation?

sarcoplasmic reticulum

Stem cell that helps to repair muscle cells

satellite cell

iliac fossa

shallow depression found on the anterior and medial surfaces of the upper ilium

What are the three types of muscle tissue?

skeletal, cardiac, and smooth

________ fibers are best suited for endurance-type activities requiring minimal explosive strength.

slow oxidative (SO) fibers

________ fibers have many more mitochondria and the highest myoglobin concentrations compared to other skeletal muscle fibers.

slow oxidative (SO) fibers

what type(s) of muscle tissue do(es) NOT contain sarcomeres?

smooth

Nonstriated, mononucleated muscle tissue that assists in moving materials in the walls of internal organs, blood vessels, hair follicles, and internal passageways

smooth muscle

which type of muscle causes contraction of the urinary bladder, forcing urine out of the body?

smooth muscle tissue

synaptic cleft

space between a nerve (axon) terminal and a motor end-plate

thick filament

structure formed from myosin and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs

thin filament

structure formed from strands of actin and its troponin-tropomyosin complex projecting from the Z-discs toward the center of the sarcomere

Forearm position in which the palm faces anteriorly (anatomical position)

supinated

Thin layer that lines the inner surface of the joint cavity at a diarthrosis and produces lubricating fluid

synovial membrane

Tarsal bone that articulates superiorly with the tibia and fibula at the ankle joint; also articulates inferiorly with the calcaneus bone and anteriorly with the navicular bone

talus

A continuous fused contraction

tetanus

Structure formed from myosin strands and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs

thick filament

________ is a regulatory protein that sits on actin filaments, binds to calcium, and allows myofibril contraction to proceed.

troponin

Single contraction produced by one action potential

twitch

Connective tissue in the interior cavity of a bone where fat is stored

yellow marrow

skeletal muscles generate maximum tension when the maximum number of cross-bridges forms in the ___?

zone of overlap