Muscle Tissue I

Question 0

The involuntary control of skeletal muscle

Answer 0

Diaphragm for breathing

Muscles for posture

Question 1

Primary function of muscle

Answer 1

Change chemical to mechanical energy to produce movement

Question 2

Intercalated discs connect – heart muscles

Answer 2

Cardiac muscle

Question 3

• • muscle is located in walls of hollow organs, blood vessels, hair follicles
• non striated, involuntary, SOME autorhythmicity

Answer 3

Smooth muscle

Question 4

4 functions of muscles

Answer 4

1. Produce body movement
2. Stabilize body positions
3. Move substances within body
4. Generate heat

Question 5

Properties of muscle (4)

Answer 5

Electrical excitability
Contractility
Extensibility
Elasticity

Question 6

Individual skeletal m tissue cells are called – –

Answer 6

Muscle fibers

Question 7

What surrounds and protects skeletal muscle tissue

Answer 7

Connective tissue

Question 8

Connective tissue organization from large to small

Answer 8

Epimysium –> perimysium –> endomysium

Question 9

Epimysium

Answer 9

Outermost layer of dense connective tissue, encircling skeletal m

Question 10

Perimysium

Answer 10

Dense connective tissue that separates a muscle into groups of muscle fibers (fascicles)

Question 11

Endomysium

Answer 11

Sheath of connective tissue that separates individual muscle fibers (cells)

Question 12

Tendon

Answer 12

All 3 layers of connective tissue form a rope like structure to connect muscle to periosteum of bone

Question 13

– – are precursors to skeletal m cells and can re enter cell cycle to proliferate and differentiate into myoblasts

Answer 13

Satellite cells

Question 14

What is increase in size of muscle fibers and how does this occur

Answer 14

Hypertrophy

• occurs by increased production of myofibrils (component of muscle fiber/cell)
• more myofibrils = more forceful contraction

Question 15

Sarcolemma

Answer 15

Plasma membrane of a muscle fiber where muscle action potentials travel

Question 16

Transverse tubules

Answer 16

Extensions of sarcolemma where action potentials travel to reach fibers quickly

Question 17

Components of sarcoplasm

Answer 17

Organelles
Glycogen
Myoglobin

Question 18

– – encircle each myofibril (many in a muscle fiber), fluid filled membranous sacks that RELEASE Ca to trigger contraction (need Ca for muscles to work)

Answer 18

Sarcoplasmic reticulum

Question 19

– are Basic Functional Unit of myofibril, extend from z disc to z disc and contain thin & thick filaments

Answer 19

Sarcomere

Question 20

The myosin-binding site on actin is typically covered by –

Answer 20

Tropomyosin

Question 21

Regulatory muscle proteins on actin, thin filament

Answer 21

Tropomyosin & troponin

Question 22

What the structural protein Titin (think tightening) does

Answer 22

Connect z disc to m line

Responsible for elasticity and extensibility of myofibrils

Question 23

– protein links thin filaments of sarco mere to sarcolemma

Answer 23

Dystrophin

Question 24

Synapse bw motor neuron and muscle fiber & site of action potential initiation

Answer 24

Neuromuscular junction

Question 25

Synaptic end bulb (axon terminal) + motor end plate (muscle fiber, NOT another neuron) =

Answer 25

NMJ or neuromuscular junction

Question 26

Space bw axon terminal and motor end plate of muscle cell

Answer 26

Synaptic cleft

Question 27

Motor end plate of NMJ

Answer 27

Folded region of sarcolemma w abundant acetylcholine receptors

Question 28

First step of nerve impulse/action potential

Answer 28

Release of ACh: Gated channels in axon terminal open, allowing Ca to enter --> stimulate synaptic vesicles containing ACh to fuse with plasma membrane and into synaptic cleft

Question 29

Second step of action potential/nerve impulse

Answer 29

2 molecules of ACh activate receptors on motor end plate of muscle fibers --> opens ion channels to allow Na+ to flow in

Question 30

3rd step of action potential

Answer 30

Generation of muscle action potential: | Na+ move into muscle fiber --> positive change in membrane potential -->muscle contraction

Question 31

4th n last step of action potential

Answer 31

Termination of ACh activity and break down by acetylcholinesterase

Question 32

The NMJ is located at -- of SKELETAL muscle fiber to allow simultaneous activation of all parts of fiber

Answer 32

Midpoint