Lecture 10: Muscular Tissue Part 1

Question 1

What are the 3 types of muscular tissue?

Answer 1

skeletal muscle tissue, cardiac muscle tissue, and smooth muscle tissue

Question 2

Skeletal muscle tissue function

Answer 2

contracts to move bones

Question 3

cardiac muscle tissue function

Answer 3

contracts to move blood through the heart

Question 4

smooth muscle tissue function

Answer 4

contracts to regulate passage of substances through the body

Question 5

What is the scientific study of muscular tissues called?

Answer 5

myology

Question 6

What are the 4 special properties of muscular tissue?

Answer 6

it is electrically excitable, contractile, extensible, and elastic

Question 7

Electrically excitable explained?

Answer 7

• produce electrical signals called muscle action potentials.

Question 8

Contractile explained?

Answer 8

• muscle action potentials stimulate contractions
  -contractions generate tension on bones which cause movement

Question 9

extensible explained?

Answer 9

tissue can be stretched without tearing: smooth muscle around the stomach

Question 10

elastic explained?

Answer 10

resting length is restored after stretching

Question 11

What are the cells of skeletal muscle tissues called?

Answer 11

myocytes or muscle fibres

Question 12

cells contain bunched protein filaments called?

Answer 12

myofibrils

Question 13

what forms a muscle?

Answer 13

muscle fibres + connective tissue + nerve and blood supply

Question 14

muscles are surrounded by connective tissue layers called?

Answer 14

fascia

Question 15

what are the functions of fascia?

Answer 15

1) groups muscles with similar functions and provides passage for vessels

Question 16

what are the 3 layers of the fascia?

Answer 16

1) epimysium: most superficial: wraps muscles
2) perimysium: middle layer: wraps fascicles(bundles of muscle fibres)
3) endomysium: deepest layer: wrap individual muscle fibres

Question 17

what is aponeurosis?

Answer 17

special type of tendons: form broad sheets
ex: epicranial aponeurosis

Question 18

what is voluntary muscle contraction regulated by?

Answer 18

somatic motor neurons

Question 19

what are the immature muscle cells called?

Answer 19

myoblasts

Question 20

myoblasts fuse and form what

Answer 20

large multinucleate cells

Question 21

what is the plasma membrane of myocytes called?

Answer 21

• sarcolemma
• electrical signals run along this
• invaginates inwards to form t tubules

Question 22

what is the cytoplasm of myocytes called?

Answer 22

-sarcoplasm
- densely packed with myofibrils
- rich in glycogen

Question 23

sarcoplasm also contains myoglobin, what is it?

Answer 23

myoglobin is only found in muscle cells.
- binds oxygen at fe containing centre called heme

Question 24

myofibrils are?

Answer 24

long threads of contractile protein filaments.(myofilaments) overlapping filaments gives muscle a striated appearance

Question 25

what does the sarcoplasmic reticulum do?

Answer 25

store and release calcium
- folds around myofibrils

Question 26

membrane folds are called?

Answer 26

cisternae and terminal cisternae release calcium to each t tubule.
- 2 terminal cisternae meet a t tubule = triad

Question 27

muscular hypertrophy

Answer 27

increase in sarcoplasmic volume.

Question 28

what is hypertrophy a response to

Answer 28

• increased mechanical stress
• hormones
• disease

Question 29

myofibrils are made up of myofilaments, what are myofilaments made of?

Answer 29

sarcomeres joined end to end

Question 30

each sarcomere consists of?

Answer 30

overlapping thin and thick filaments

Question 31

thick filaments?

Answer 31

extend from the midline (m line) and are made of myosin

Question 32

thin filaments?

Answer 32

extend from the ends (z discs) and are made of actin

Question 33

the regions where the thick and thin filaments overlap and everything between is called?

Answer 33

a band

Question 34

the regions between the zones of overlap around the m line is called?

Answer 34

h zone

Question 35

the regions between zones of overlap around z discs is called?

Answer 35

I band