Ch 48: Musculoskeletal Systems

Question 1

Skeletal muscle

Answer 1

Voluntary movements

Striated

Question 2

Cardiac muscle

Answer 2

Involuntary beating of the heart - myogenic
Cells are electrically couples
Striated
Resistant to tearing and intense pressure
Action potential spreads fast

Question 3

Myofibrils

Answer 3

Highly ordered assemblages of myosin and actin filaments

In muscle fibers

Question 4

Actin

Answer 4

Thin filaments

Actin monomers + tropomyosin + troponin

Question 5

Myosin

Answer 5

Thick filaments

Question 6

Motor unit

Answer 6

One motor neuron and all the muscle fibers it synapses with

Question 7

Muscle membrane

Answer 7

Sarcolemma

Question 8

Muscle cytoplasm

Answer 8

Sarcoplasm

Question 9

Troponin

Answer 9

Binds to actin, tropomyosin, and calcium

Question 10

Muscle endoplasmic reticulum

Answer 10

Sarcoplasmic reticulum

Question 11

Neuromuscular junction

Answer 11

Synapse of neuron to muscle

Question 12

Tropomyosin

Answer 12

Covers myosin binding points on the actin filament

Question 13

Hydrolysis of ATP

Answer 13

ATP + H2O –> ADP +Phosphate + Energy

Question 14

Glycolytic system

Answer 14

Metabolism of glucose through enzymes
Available through the cytoplasm of the cell
Fast reaction
Harvesting of carbs

Question 15

Power stroke

Answer 15

When the phosphate group falls off the myosin head, causing a large change in myosin conformation
Allows the filaments to slide past each other

Question 16

Slow-twitch muscle fibers

Answer 16

Have a lot of mitochondria
Use the oxidative system
Contain myoglobin and blood vessels
Low maximum tension but high resistance to fatigue
Ex. hamstrings

Question 17

Fast-twitch muscle fibers

Answer 17

Use the glycolytic system
High maximum tension but low resistance to fatigue
Good for short-term work
Ex. biceps

Question 18

Noreponephrine

Answer 18

Accelerates heart rate
Inhibits smooth muscles
Released by the sympathetic nervous system
Neurotransmitter

Question 19

Smooth muscle

Answer 19

Involuntary movement of internal organs
Cells are arranged in sheets
Long, spindle shaped
Provide contractile force for most internal organs
Stretch causes action potential

Question 20

Immediate system

Answer 20

Uses pre-formed ATP and creatine phosphate

Available immediately

Question 21

Osteoblasts

Answer 21

Fresh, new bone cells
Follows the osteoclasts and lays down the new bone material
Build up new bone

Question 22

Osteocytes

Answer 22

Thick extracellular matrix layer

Question 23

Osteoclasts

Answer 23

Dig the bone
Release calcium and minerals from the bone
Break down old bone

Question 24

Oxidative system

Answer 24

Slow metabolism
Depends on mitochondria and oxygen
Takes time
The complete burning system of the muscle

Question 25

Acetylcholine

Answer 25

Inhibits heart rate Stimulates smooth muscle Released by the parasympathetic nervous system

Question 26

Hydrostatic skeleton

Answer 26

Liquid inside the body works with the muscles to provide movement

Question 27

Exoskeleton

Answer 27

Skeleton is outside the body When the body grows, the animal must molt, leaving it vulnerable Provides good protection

Question 28

Endoskeleton

Answer 28

Provides support | Allows the rest of the body to grow together

Question 29

Osteoporosis

Answer 29

Loss of bone density

Question 30

Joints

Answer 30

Where two or more bones come together

Question 31

Ligaments

Answer 31

Hold bones together at joints

Question 32

Tendons

Answer 32

Join muscles to bone

Question 33

Flexor

Answer 33

The muscle that bends the joint

Question 34

Extensor

Answer 34

The muscle that straightens the joint

Question 35

Gap junctions

Answer 35

Connect the cardiac cells together | Allow the free flow of ions

Question 36

Striated

Answer 36

Stripes Skeletal muscles In the sarcomeres

Question 37

Sarcomere

Answer 37

Smallest unit of contraction | Found in skeletal muscles

Question 38

Z line

Answer 38

Beginning to end of sarcomere

Question 39

A band

Answer 39

Length of thick filament + overlap

Question 40

H zone

Answer 40

Length of thick filament without overlap

Question 41

I band

Answer 41

Thin filament only

Question 42

M band

Answer 42

"midline" | Lind down the center

Question 43

DHP receptor

Answer 43

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Question 44

Ryanodine receptor

Answer 44

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