Topic 14: Animal Skeletal and Muscular Systems

Question 1

attach bones to bones (joints)

Answer 1

Ligaments

Question 2

attach bones to muscle

dense connective tissue

Answer 2

Tendons

Question 3

(torso) bones such as skull, backbone, ribcage, breastbone, vertebral column

Answer 3

Axial skeleton

Question 4

attached to axial at pectoral girdle or pelvic girdle [hips and shoulders]

Answer 4

Appendicular skeleton

Question 5

Bone function is

Answer 5

calcium and phosphate reservoir

Question 6

not modeled in cartilage first

Answer 6

Flat bones

Question 7

modeled in cartilage first

blood cells made in the bone marrow of this type of bone

Answer 7

Long bones

Question 8

located in spaces of spongy bone

Answer 8

Bone marrow

Question 9

Structure of bone

Answer 9

collagen fibers coated in hydroxyapatite crystals (calcium phosphate)

Question 10

weak and flexible part of bone; redistributes stress to help hydroxyapatite crystals from fracturing

Answer 10

Collagen matrix

Question 11

secrete collagen fibers

Answer 11

Osteoblast (cells)

Question 12

calcified collagen fibers

Answer 12

Osteocytes

Question 13

encase osteocytes

Answer 13

Lacunae

Question 14

narrow channels that run parallel to length of the bone

interconnect and carry blood vessels and nerve fibers

surrounded by lamellae bone layers

Answer 14

Halversian canals

Question 15

thin, concentric layers of bone surrounding Halversian canals

Answer 15

Lamellae

Question 16

openings in bone between osteocytes and the canals

Answer 16

Canaliculi

Question 17

cartilage at ends of bones, involved in joints

Answer 17

Articular cartilage

Question 18

can dissolve bone, allowing remodeling

Answer 18

Osteoclasts

Question 19

nearly immovable joints, joined by connective tissue (fontanels in infants) (ex. cranial bones)

Answer 19

Sutures

Question 20

sutures in human infants

Answer 20

fontanels

Question 21

freely movable joints

Answer 21

Synvovial joints

Question 22

fibrous structure containing ends of bones, strengthened by ligaments

Answer 22

Synvovial capsule

Question 23

degeneration of connective tissue in synvovial joint

Answer 23

Rheumatoid arthritis

Question 24

part of tendon that attaches to stationary base

Answer 24

Muscle origin

Question 25

part of tendon that attaches to movable bone

Answer 25

Muscle insertion

Question 26

tendons that decrease joint angle, move bones closer

Answer 26

Flexors

Question 27

tendons that increase joint angle, move bones further apart

Answer 27

Extensors

Question 28

muscle type with long, spindle-shaped, mononuclear cells

Answer 28

Smooth muscle

Question 29

muscle type with slow, maintained contraction with minimal energy use

Answer 29

Smooth muscle

Question 30

muscle type with very long, parallel multinucleate cells (muscle fibers)

Answer 30

Skeletal muscle

Question 31

muscle type with rapid contraction with large force

Answer 31

Skeletal muscle

Question 32

muscle type with striated, mononuclear branching cells

Answer 32

Cardiac muscle

Question 33

separate cardiac muscle cells

Answer 33

Intercalated disc

Question 34

Myofilament structure

Answer 34

long chains of actin and myosin proteins (also troponin and tropomyosin)

Question 35

(muscle) polymer in thin filaments (2 strings wound in loose double helix)

Answer 35

Actin

Question 36

(muscle) spontaneous polymerization in thicker filaments 10x longer than actin twisted pair of polypeptides

Answer 36

Myosin

Question 37

dark bands of stacked thick (myosin) filaments

Answer 37

A bands

Question 38

light bands of stacked thin (actin) filaments

Answer 38

I bands

Question 39

dark lines of dense material in the center of I bands; form anchors for thin filaments

Answer 39

Z lines

Question 40

lighter region in center of A band, where thin filaments are not present

Answer 40

H bands

Question 41

mechanism of contraction

Answer 41

Sliding filament

Question 42

Mechanism of contraction: myosin "pulls" ______ in, reducing size of ____ and _____

Answer 42

myosin "pulls" actin in, reducing size of H bands and I bands

Question 43

organizational muscle unit of Z-I-A-H-A-I-Z

Answer 43

Sarcomere

Question 44

myosin heads (ATPases) "cock" heads and bind with actin to form cross-bridges power stroke myosin head binds to new ATP and releases from actin

Answer 44

Cross-bridge cycle in muscle contraction

Question 45

myosin head changes shape and pulls actin toward sarcomere center

Answer 45

Power stroke

Question 46

formed where nerve fiber embeds in muscle

Answer 46

Neuromuscular junction

Question 47

released by motor neuron at neuromuscular junction stimulates electrochemical impulse that travels along muscle fiber membrane and opens Ca++ channels

Answer 47

Acetylcholine

Question 48

stimulated by acetylcholine; travels along muscle fiber membrane, opening Ca++ channels

Answer 48

Electrochemical impulse

Question 49

opened by electrochemical impulse caused by acetylcholine located on muscle membranes; embedded in SR

Answer 49

Ca++ channels

Question 50

have Ca++ channels embedded in it

Answer 50

Sarcoplasmic reticulum (SR

Question 51

SR wraps around myofibril calcium pump actively transports Ca++ into SR, flooding its sarcoplasm Ca++ and troponin move tropomyosin out of the way so myosin binds to actin

Answer 51

Effect of opening Ca++ channels

Question 52

located in SR, flooded with Ca++ when calcium channels open

Answer 52

Sarcoplasm

Question 53

bound to tropomyosin this in addition to Ca++ move tropomyosin out of the way so myosin binds to actin

Answer 53

Troponin

Question 54

When does contraction end?

Answer 54

Ca++ pumped back into SR

Question 55

Ca++ is responsible for this

Answer 55

Excitation-contraction coupling

Question 56

covers myosin binding site on actin in resting muscle

Answer 56

Tropomyosin

Question 57

repetitive firing of motor neuron increased stimulation rate (increased [Ca++], increased total contraction force, and smooth, forceful (individual) contractions)

Answer 57

Summation

Question 58

Summation increases the rate of stimulation, which leads to these effects

Answer 58

increased [Ca++] increased total contraction force smooth, forceful (individual) contractions

Question 59

In summation, ______ must be faster than individual ________

Answer 59

Neuron firing frequency must be faster than individual muscle twitch

Question 60

how fast muscle will contract and relax

Answer 60

Twitch

Question 61

maximum contraction value (smooth, sustained)

Answer 61

Tetanus

Question 62

multiple, larger motor units are activated to increase contraction force

Answer 62

Recruitment

Question 63

innervates many muscle fibers (or motor units)

Answer 63

Motor neuron

Question 64

set of muscle fibers controlled by one neuron

Answer 64

Motor unit

Question 65

initiates impulse in cardiac muscle

Answer 65

Pacemaker

Question 66

Cardiac muscle have no ______ or ______

Answer 66

summation or tetanus

Question 67

2 myocardias in the heart: one for _____ and _____

Answer 67

One for 2 atria (receive blood) One for 2 ventricles (pump blood to lungs and body)

Question 68

Characteristics of smooth muscle contraction:

Answer 68

Not organized in sarcomeres Myosin molecules attached to dense bodies or muscle membrane No SR

Question 69

Effects of no SR in smooth muscle contraction

Answer 69

Ca++ comes from extracellular space Ca++ channels opened by automatic neurotransmitter activation Ca++ binds to calmodulin, which activates MLCK to phosphorylate myosin heads and activate them

Question 70

Ca++ in sarcoplasm binds to this, which then activates MLCK

Answer 70

Calmodulin

Question 71

phosphorylates myosin heads, activating them; activated by Ca++/calmodulin combination

Answer 71

Myosin light chain kinase (MLCK)

Question 72

slightly movable bones bridged entirely by cartilage

Answer 72

Cartilaginous joints

Question 73

Vertebral bones are an example of ____ joints

Answer 73

cartilaginous joints