Lecture 4

Question 1

What are the 2 types of contraction?

Answer 1

Isometric and isotonic

Question 2

A type of contraction that the length of the muscle does not change?

Answer 2

Isometric

Question 3

A type of contraction that the length of the muscle does change?

Answer 3

Isotonic

Question 4

When a muscle gets shorter it is called?

Answer 4

concentric

Question 5

When a muscle gets longer it is called?

Answer 5

eccentric

Question 6

What are the basis for names of muscles?

Answer 6

Shape, origin-insertion, function, relative size, fiber arrangement, location

Question 7

What are the types of fiber arrangements?

Answer 7

Straight, fusiform, unipennate, bipennate, multipennate

Question 8

A muscle doing the desired action is called what?

Answer 8

agonist

Question 9

A muscle that opposes the agonist is called what?

Answer 9

antagonist

Question 10

A muscle that eliminates unwanted action by the agonist?

Answer 10

synergist

Question 11

A muscle that stabilizes base of attachment of agonist is called what?

Answer 11

fixator

Question 12

A muscle that crosses only one joint is called what?

Answer 12

unijoint

Question 13

A muscle that crosses more than one joint is called what?

Answer 13

multijoint

Question 14

What is the inability of multijoint muscle to contract maximally over all joints crossed simultaneously?

Answer 14

insufficiency

Question 15

Which type of insufficiency refers to the agonist?

Answer 15

active insufficiency

Question 16

Which type of insufficiency refers to the antagonist?

Answer 16

passive insufficiency

Question 17

What is it called when a muscle whose primary function is to cause the particular movement and one which makes a strong contribution to that movement?

Answer 17

prime mover

Question 18

When it has the ability to assist in the movement but is only of secondary importance to the movement what is it called?

Answer 18

assistant mover

Question 19

When a muscle acts as a stabilizer it usually contracts how?

Answer 19

isometrically

Question 20

What are the 3 types of muscle tissue?

Answer 20

Skeletal, smooth, cardiac

Question 21

What are the characteristics of skeletal, smooth and cardiac tissue?

Answer 21

1. Striated, voluntary, multinucleated
2. Non-striated, involuntary, mononucleated
3. Striated, involuntary, mononucleated

Question 22

What are the major characteristics of cardiac muscles?

Answer 22

Intercellular junctions called intercalated discs

Question 23

What are the characteristics of skeletal muscle?

Answer 23

striated, peripheral nuclei, multinucleated, conducts action potentials

Question 24

What is the gross structure of tendons?

Answer 24

Attachments between muscle fibers and bone, dense collagenous connective tissue, surrounded by peritendineum, bundles of collagen fibers, poorly vascularized

Question 25

What are the gross structures of aponeuroses?

Answer 25

Flat, fan-shaped tendons typically giving rise to other tendons

Question 26

What is the hierarchical structure of skeletal muscle?

Answer 26

myofilament, myofibril, myofiber, fascicle, muscle

Question 27

What are the types of myofilaments and how are they organized?

Answer 27

Types: myosin and actin | Organized by: sarcomeres

Question 28

Myofibrils are what?

Answer 28

chain of sarcomeres

Question 29

What is often referred to as a muscle cell, and are a bundle of myofibrils?

Answer 29

myofiber

Question 30

What is a bundle of myofibers?

Answer 30

fascicle

Question 31

what does connective tissue provide?

Answer 31

Physical support and a pathway for nerves and vessels

Question 32

What surrounds each muscle fiber and lies outside sarcolemma?

Answer 32

endomysium

Question 33

What surrounds each fascicle?

Answer 33

perimysium

Question 34

What surrounds each muscle, becomes continuous with tendons and attached to periosteum?

Answer 34

epimysium

Question 35

What are some characteristics of dark fibers?

Answer 35

* Do not fatigue * Contract slow * Oxidative phosphorylation * large # of mitochondria * high concentration of myoglobin * low concentration of ATPase

Question 36

What are some characteristics of light fibers?

Answer 36

* fatigue fast * contract fast * glycolysis * small # of mitochondria * low concentration of myoglobin * high concentration of ATPase

Question 37

A motor unit consists of a __ and all the myofibers it innervates.

Answer 37

motor neuron

Question 38

What is in the middle of the A band, composed entirely of myosin, band width changes during contraction?

Answer 38

H-band

Question 39

What is on either side of A band and split by Z-lines and is composed entirely of actin?

Answer 39

I bands

Question 40

What is between two I bands in the middle of the sarcomere, composed of both myosin and actin, represents length of myosin chains, does not change width during contraction?

Answer 40

A-band

Question 41

What are the tubular extensions of the muscle fiber membrane (sarcolemma) that extend down into the cytoplasm (sarcoplasm) and conduct action potential from cell membrane surface to interior?

Answer 41

T-tubules

Question 42

What are saccular extensions of the sarcoplasmic reticulum that release calcium ions in response to action potential, calcium ions trigger sliding myosin and actin filaments resulting in a contraction?

Answer 42

Cisternae