Topic 14: Animal Skeletal and Muscular Systems Flashcards Preview

BIOL 1030 > Topic 14: Animal Skeletal and Muscular Systems > Flashcards

Flashcards in Topic 14: Animal Skeletal and Muscular Systems Deck (73):
1

attach bones to bones (joints)

Ligaments

2

attach bones to muscle

dense connective tissue

Tendons

3

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

Axial skeleton

4

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

Appendicular skeleton

5

Bone function is

calcium and phosphate reservoir

6

not modeled in cartilage first

Flat bones

7

modeled in cartilage first

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

Long bones

8

located in spaces of spongy bone

Bone marrow

9

Structure of bone

collagen fibers coated in hydroxyapatite crystals (calcium phosphate)

10

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

Collagen matrix

11

secrete collagen fibers

Osteoblast (cells)

12

calcified collagen fibers

Osteocytes

13

encase osteocytes

Lacunae

14

narrow channels that run parallel to length of the bone

interconnect and carry blood vessels and nerve fibers

surrounded by lamellae bone layers

Halversian canals

15

thin, concentric layers of bone surrounding Halversian canals

Lamellae

16

openings in bone between osteocytes and the canals

Canaliculi

17

cartilage at ends of bones, involved in joints

Articular cartilage

18

can dissolve bone, allowing remodeling

Osteoclasts

19

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

Sutures

20

sutures in human infants

fontanels

21

freely movable joints

Synvovial joints

22

fibrous structure containing ends of bones, strengthened by ligaments

Synvovial capsule

23

degeneration of connective tissue in synvovial joint

Rheumatoid arthritis

24

part of tendon that attaches to stationary base

Muscle origin

25

part of tendon that attaches to movable bone

Muscle insertion

26

tendons that decrease joint angle, move bones closer

Flexors

27

tendons that increase joint angle, move bones further apart

Extensors

28

muscle type with long, spindle-shaped, mononuclear cells

Smooth muscle

29

muscle type with slow, maintained contraction with minimal energy use

Smooth muscle

30

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

Skeletal muscle

31

muscle type with rapid contraction with large force

Skeletal muscle

32

muscle type with striated, mononuclear branching cells

Cardiac muscle

33

separate cardiac muscle cells

Intercalated disc

34

Myofilament structure

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

35

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

Actin

36

(muscle) spontaneous polymerization in thicker filaments

10x longer than actin

twisted pair of polypeptides

Myosin

37

dark bands of stacked thick (myosin) filaments

A bands

38

light bands of stacked thin (actin) filaments

I bands

39

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

Z lines

40

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

H bands

41

mechanism of contraction

Sliding filament

42

Mechanism of contraction:

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

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

43

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

Sarcomere

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

Cross-bridge cycle in muscle contraction

45

myosin head changes shape and pulls actin toward sarcomere center

Power stroke

46

formed where nerve fiber embeds in muscle

Neuromuscular junction

47

released by motor neuron at neuromuscular junction

stimulates electrochemical impulse that travels along muscle fiber membrane and opens Ca++ channels

Acetylcholine

48

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

Electrochemical impulse

49

opened by electrochemical impulse caused by acetylcholine

located on muscle membranes; embedded in SR

Ca++ channels

50

have Ca++ channels embedded in it

Sarcoplasmic reticulum (SR

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

Effect of opening Ca++ channels

52

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

Sarcoplasm

53

bound to tropomyosin

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

Troponin

54

When does contraction end?

Ca++ pumped back into SR

55

Ca++ is responsible for this

Excitation-contraction coupling

56

covers myosin binding site on actin in resting muscle

Tropomyosin

57

repetitive firing of motor neuron

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

Summation

58

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

increased [Ca++]

increased total contraction force

smooth, forceful (individual) contractions

59

In summation, ______ must be faster than individual ________

Neuron firing frequency must be faster than individual muscle twitch

60

how fast muscle will contract and relax

Twitch

61

maximum contraction value (smooth, sustained)

Tetanus

62

multiple, larger motor units are activated to increase contraction force

Recruitment

63

innervates many muscle fibers (or motor units)

Motor neuron

64

set of muscle fibers controlled by one neuron

Motor unit

65

initiates impulse in cardiac muscle

Pacemaker

66

Cardiac muscle have no ______ or ______

summation or tetanus

67

2 myocardias in the heart: one for _____ and _____

One for 2 atria (receive blood)

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

68

Characteristics of smooth muscle contraction:

Not organized in sarcomeres

Myosin molecules attached to dense bodies or muscle membrane

No SR

69

Effects of no SR in smooth muscle contraction

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

70

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

Calmodulin

71

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

Myosin light chain kinase (MLCK)

72

slightly movable

bones bridged entirely
by cartilage

Cartilaginous joints

73

Vertebral bones are an example of ____ joints

cartilaginous joints