Ch 48: Musculoskeletal Systems Flashcards Preview

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Flashcards in Ch 48: Musculoskeletal Systems Deck (44):
1

Skeletal muscle

Voluntary movements
Striated

2

Cardiac muscle

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

3

Myofibrils

Highly ordered assemblages of myosin and actin filaments
In muscle fibers

4

Actin

Thin filaments
Actin monomers + tropomyosin + troponin

5

Myosin

Thick filaments

6

Motor unit

One motor neuron and all the muscle fibers it synapses with

7

Muscle membrane

Sarcolemma

8

Muscle cytoplasm

Sarcoplasm

9

Troponin

Binds to actin, tropomyosin, and calcium

10

Muscle endoplasmic reticulum

Sarcoplasmic reticulum

11

Neuromuscular junction

Synapse of neuron to muscle

12

Tropomyosin

Covers myosin binding points on the actin filament

13

Hydrolysis of ATP

ATP + H2O --> ADP +Phosphate + Energy

14

Glycolytic system

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

15

Power stroke

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

16

Slow-twitch muscle fibers

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

17

Fast-twitch muscle fibers

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

18

Noreponephrine

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

19

Smooth muscle

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

20

Immediate system

Uses pre-formed ATP and creatine phosphate
Available immediately

21

Osteoblasts

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

22

Osteocytes

Thick extracellular matrix layer

23

Osteoclasts

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

24

Oxidative system

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

25

Acetylcholine

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

26

Hydrostatic skeleton

Liquid inside the body works with the muscles to provide movement

27

Exoskeleton

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

28

Endoskeleton

Provides support
Allows the rest of the body to grow together

29

Osteoporosis

Loss of bone density

30

Joints

Where two or more bones come together

31

Ligaments

Hold bones together at joints

32

Tendons

Join muscles to bone

33

Flexor

The muscle that bends the joint

34

Extensor

The muscle that straightens the joint

35

Gap junctions

Connect the cardiac cells together
Allow the free flow of ions

36

Striated

Stripes
Skeletal muscles
In the sarcomeres

37

Sarcomere

Smallest unit of contraction
Found in skeletal muscles

38

Z line

Beginning to end of sarcomere

39

A band

Length of thick filament + overlap

40

H zone

Length of thick filament without overlap

41

I band

Thin filament only

42

M band

"midline"
Lind down the center

43

DHP receptor

...

44

Ryanodine receptor

...