Topic 7

Question 1

Functions of muscular tissue

Answer 1

Producing body movements
Stabilizing body positions
Moving substances within the body
Generating heat

Question 2

Excitability

Answer 2

Ability to respond to stimuli

Question 3

Contractility

Answer 3

Ability to contract forcefully when stimulated

Question 4

Extensibility

Answer 4

Ability to stretch without being damaged

Question 5

Elasticity

Answer 5

Ability to return to an original length

Question 6

Striated

Answer 6

Alternating light and dark bands

Question 7

Voluntary

Answer 7

Activity is consciously controlled

Question 8

Myocyte

Answer 8

Mature muscle cell AKA muscle fibre (set before birth and last a lifetime)

Question 9

Hypertrophy

Answer 9

An enlargement existing muscle fibres (muscle growth)

Question 10

Satellite cells

Answer 10

Quiescent cells located next to a muscle fibre and become active when regeneration or repair is necessary

Question 11

Inside a myocyte

Answer 11

Surrounded by a cell membrane called sarcolemma and contains sarcoplasm and cell organelles, including myofibrils, nuclei, mitochondria, and T tubules

Question 12

Inside myofibrils

Answer 12

Contractile filaments called actin and myosin

Question 13

CT components

Answer 13

Fascia
Tendon
Aponeurosis

Question 14

Fascia

Answer 14

Dense sheet or broad band of irregular CT that surrounds muscles
Epimysium, perimysium, endomysium

Question 15

Tendon

Answer 15

Cord that attaches a muscle to bone

Question 16

Aponeurosis

Answer 16

Broad, flattened tendon

Question 17

A muscle

Answer 17

Fascicles
Blood vessels
Nerves
Epimysium

Question 18

Fascicle

Answer 18

Muscle fibres
Blood vessels
Nerves
Perimysium

Question 19

Muscle fibre

Answer 19

Myofibrils 
Sarcolemma
Sarcoplasm
Mitochondria
Multi nuclei
Endomysium

Question 20

Myofibril

Answer 20

Thin filaments (actin)
Thick filaments (myosin)
Sarcomeres

Question 21

Somatic motor neurons

Answer 21

Neurons that stimulate skeletal muscle to contract

Question 22

Neuromuscular junction

Answer 22

The synapse between the end of a somatic motor neuron and the muscle fibre

Question 23

Acetylcholine (ACh)

Answer 23

Neurotransmitter released into the synaptic cleft. Binds to receptors on the muscle fibre plasma membrane, causing depolarization of the cell membrane

Question 24

Neuromuscular junction

Answer 24

1) AP travels along pre-synaptic neuron
2) AP stimulates release of ACh from vesicle into synaptic cleft
3) ions travel across muscle cell membrane which changes charge
4) sarcoplasm continues to depolarize and
5) AP spreads throughout T tubule system
6) stimulates release of calcium into sarcoplasm
7) reuptake of calcium to end contraction

Question 25

If a muscle contraction occurs for more than a few seconds this will take place

Answer 25

Cellular respiration

Question 26

Metabolizing

Answer 26

Créatine phosphate - 15 seconds of energy

Question 27

Anaerobic glycolysis

Answer 27

Converts glucose into ATP - 2 minutes of energy

Question 28

Aerobic respiration

Answer 28

Converts glucose into ATP as well as going through a number of reactions that require oxygen to produce a lot ATP - minutes to hours of energy

Question 29

Muscle fatigue

Answer 29

Inability of muscle to maintain force of contraction after prolonged activitiy

Question 30

Factors that contribute to muscle fatigue

Answer 30

Inadequate release of calcium ions from the SR Depletion of creatine phosphate Insufficient oxygen Depletion of glycogen and other nutrients Buildup of lactic acid and ADP Failure of the motor neuron to release enough acetylcholine

Question 31

Red muscle fibres

Answer 31

``` Have a high myoglobin content Appear darker Contain more mitochondria Supplied by more blood capillaries Produce slow and weak contractions ```

Question 32

White muscle fibres

Answer 32

Have a low content of myoglobin Appear lighter Produce fast and strong contractions

Question 33

Muscle tone

Answer 33

A small amount of tension in the muscle due to weak contractions of motor units Small groups of motor units are alternatively active and inactive in a constantly shifting pattern to sustain muscle tone Muscle tone keeps skeletal muscles firm

Question 34

Cardiac muscle tissue

Answer 34

Found only in the walls of the heart Striated like skeletal muscle, mononucleated Cardiac muscle cells do not regenerate quickly, most often scar tissue forms

Question 35

Heart contraction

Answer 35

Involuntary

Question 36

Smooth muscle tissue

Answer 36

Located in the walls of hollow internal organs, blood, vessels, and airways. Also found in the eyes and the arrector pili muscle of the hair follicles. Lacks the striations of skeletal and cardiac muscle tissue Usually involuntary Contraction lasts longer than skeletal muscles and hence able to sustain long-term muscle tone Regenerates most easily of all the muscle tissue types