Muscle

Question 1

what are myofilaments composed of?

Answer 1

actin and myosin arranged parallel to the direction of cellular contraction

Question 2

what are the types of muscle?

Answer 2

1. skeletal
2. smooth
3. cardiac

Question 3

what part of the nervous system stimulates smooth muscle?

Answer 3

autonomic nervous system

Question 4

is smooth muscle striated?

Answer 4

no

Question 5

can smooth muscle cells remains contracted for long periods?

Answer 5

yes

Question 6

is smooth muscle contraction fast or slow?

Answer 6

slow

Question 7

what are the types of smooth muscle?

Answer 7

1. multiunit

2. visceral

Question 8

what is a multiunit smooth muscle

Answer 8

functionally independent smooth muscle cells which are often innervated by a single nerve terminal and which never contract spontaneously e.g. walls of blood vessels

Question 9

what is a visceral smooth muscle?

Answer 9

bundles of smooth muscle cells connected by GAP junctions, which contract spontaneously if stretched beyond a certain limit e.g. walls of the intestines

Question 10

what innervates skeletal muscle?

Answer 10

somatic nervous system

Question 11

is skeletal muscle striated?

Answer 11

yes

Question 12

what transfers the force generated by the muscle fibres to the tendons?

Answer 12

connective tissue between the fasicles

Question 13

what regenerates damaged skeletal muscle fibers?

Answer 13

satellite cells

Question 14

what are the smallest contractile units of skeletal muscle?

Answer 14

sarcomeres

Question 15

what is the H band in a sarcomere

Answer 15

zone of myosin filaments only

Question 16

where do the myosin filaments overlap with actin filaments?

Answer 16

the A band

Question 17

what is titin responsible for?

Answer 17

aligning the filaments and allowing stretch of the muscle fibres

Question 18

what is the motor end plate?

Answer 18

The area of contact between the end of a motor nerve and a skeletal muscle cell

Question 19

what is the space between the boutons and the muscle fiber called?

Answer 19

primary synaptic cleft

Question 20

what mediates the spread of excitation over the sarcolemma?

Answer 20

voltage gated ion channels

Question 21

what type of fibers control postural muscles?

Answer 21

type I red fibers

Question 22

what do type IIA muscle fibers contain?

Answer 22

many mitochondria and are available for both sustained activity and short-lasting, intense contractions

Question 23

what do type IIB muscle fibers contain?

Answer 23

only few mitochondria, they are recruited in the case of rapid accelerations and short lasting maximal contraction

Question 24

are skeletal muscle fibers connected by a GAP junction?

Answer 24

no

Question 25

what cells regenerate cardiac muscle cells?

Answer 25

none, cardiac muscle is not regenerative