Life 48- Musculoskeletal Systems

Question 1

T tubules

Answer 1

A system of tubules that runs throughout the cytoplasm of a muscle fibre, through which action potentials spread

Question 2

Cancellous bone

Answer 2

A type of bone with numerous internal cavities that make it appear spongy, although it is rigid

Question 3

Actin

Answer 3

A protein that makes up the cytoskeletal microfilaments in eukaryotic cells and is one of the two contractile proteins in muscle

Question 4

Extensor

Answer 4

A muscle that extends an appendage

Question 5

Ligament

Answer 5

A band of connective tissue linking two bones in a joint

Question 6

Tropomyosin

Answer 6

One of the three protein components of an actin filament; controls the interactions of actin and myosin necessary for muscle contraction

Question 7

Muscle fibre

Answer 7

A single muscle cell. In the case of skeletal muscle, a syncytial multinucleate cell.

Question 8

Sliding filament theory

Answer 8

Mechanism of muscle contraction based on the formation and breaking cross ridges between actin and myosin filaments, causing the filaments to slide together.

Question 9

Endoskeleton

Answer 9

An internal skeleton covered by other, soft body tissues.

Question 10

Skeletal systems

Answer 10

Organ systems that provide rigid supports against which muscles can pull to create directed movements.

Question 11

Tetanus

Answer 11

A state of sustained maximal muscular contraction caused by rapidly repeated stimulation.

Question 12

Cartilage bone

Answer 12

A type of bone that begins its development as a cartilaginous structure resembling the future mature bone, then gradually hardens into mature bone.

Question 13

Membranous bone

Answer 13

A type of bone that develops by forming on a scaffold of connective tissue

Question 14

Bone

Answer 14

A rigid component of vertebrate skeletal systems that contains an extracellular matrix of insoluble calcium phosphate crystals as well as collagen fibres

Question 15

Osteoclast

Answer 15

A cell that dissolves bone

Question 16

Joint

Answer 16

In skeletal systems, a junction between two or more bones

Question 17

Osteoblast

Answer 17

A cell that lays down the protein matrix of bone.

Question 18

Motor unit

Answer 18

A motor neuron and the muscle fibres it controls

Question 19

Osteocyte

Answer 19

An osteoclast that has become enclosed in lacunae within the bone it has built

Question 20

Fast-twitch fibres

Answer 20

Skeletal muscle fibres that can generate high tension rapidly, but fatigue rapidly (“sprinter” fibres). Characterised by an abundance of enzymes of glycolysis

Question 21

Tendon

Answer 21

A collagen-containing band of tissue that connects a muscle with a bone.

Question 22

Myofibril

Answer 22

A polymeric unit of actin or myosin in a muscle

Question 23

Myoglobin

Answer 23

An oxygen-binding molecule found in muscle. Consists of a heme unit and a single globin chain; carries less oxygen than hemoglobin

Question 24

Sarcomere

Answer 24

The contractile unit of a skeletal muscle

Question 25

Hydrostatic skeleton

Answer 25

A fluid-filled body cavity that transfers forces from one part of the body to another when acted on by surrounding muscles

Question 26

Smooth muscle

Answer 26

Muscle tissue consisting of sheets of mononucleated cells innervated by the autonomic nervous system

Question 27

Myosin

Answer 27

One of the two contractile proteins of muscle

Question 28

Cartilage

Answer 28

In vertebrates, a though connective tissue found in joints, the outer ear, and elsewhere. Forms the entire skeleton in som animal groups.

Question 29

Skeletal muscle

Answer 29

A type of muscle tissue characterised by multinucleated cells containing highly ordered arrangements of actin and myosin microfilaments

Question 30

Compact bone

Answer 30

A type of bone with a solid, hard structure

Question 31

Troponin

Answer 31

One of the three components of an actin filament; binds to actin, tropomyosin, and Ca2+

Question 32

Titin

Answer 32

A protein that holds bundles of myosin filaments in a centred position within the sarcomeres of muscle cells. The largest protein in the human body.

Question 33

Sarcoplasmic reticulum

Answer 33

The endoplasmic reticulum of a muscle cell

Question 34

Flexor

Answer 34

A muscle that flexes an appendage

Question 35

Sarcoplasm

Answer 35

The cytoplasm of a muscle cell

Question 36

Cardiac muscle

Answer 36

A type of muscle tissue that makes up, and is responsible for the beating of, the heart. Characterised by branching cells with single nuclei and a striated (striped) appearance.

Question 37

Slow-twitch fibres

Answer 37

Skeletal muscle fibres that generate tension slowly, but are resistant to fatigue ("marathon" fibres). They have abundant mitochondria, enzymes of aerobic metabolism, myoglobin, and blood supply.

Question 38

Twitch

Answer 38

A single unit of muscle contraction

Question 39

Haversian systems

Answer 39

Units of organisation in compact bone that reflect the action of intercommunicating osteoblasts.