Muscle tissue and muscles

Question 1

What is a contraction

Answer 1

a response to a stimulus

Question 2

types of contractions

Answer 2

isometric and isotonic

Question 3

what is an isometric contraction

Answer 3

length of muscle does not change

-Force that you exert= force exerted on you

Question 4

what is an isotonic contraction

Answer 4

length of muscle does change

Question 5

What is it called when a muscle gets shorter during an isotonic contraction

Answer 5

concentric

Question 6

What is it called when a muscle gets longer during an isotonic contraction

Answer 6

Eccentric

Question 7

What is an agonist

Answer 7

• muscle doing the desired action

- prime movers and assistant movers

Question 8

What is a antagonist

Answer 8

-muscle that opposes the agonist

Question 9

what is a synergist

Answer 9

muscle that eliminates unwanted action by the agonist

Question 10

what is a fixator (stabilizer)

Answer 10

Muscle that stabilizes base of attachment of agonist

-when a muscle acts as a stabilizer, it usually contracts isometrically

Question 11

what are the types of muscle tissue

Answer 11

skeletal
cardiac
smooth

Question 12

Characteristics of skeletal muscle

Answer 12

• known as striated or voluntary
• typically attached directly or indirectly t the skeletal system
• peripheral nuclei
• multi-nucleated
• conducts action potential

Question 13

Characteristics of smooth muscle

Answer 13

• known as visceral or involuntary
• not striated
• consists of groups of spindle shaped mono nucleated cells with centrally located nuclei
• most commonly known with viscera= gut tube and other hollow organs

Question 14

Characteristics of cardiac muscle

Answer 14

• both skeletal and smooth
• striated
• involuntary
• specialized intercellular junctions called intercalated discs

Question 15

name the types of attachments

Answer 15

origin and insertion

Question 16

characteristics of origin attachment

Answer 16

• proximal

- may be fixed with regard to movement

Question 17

characteristics of insertion attachment

Answer 17

• distal

- more moveable

Question 18

what is the hierarchical structure of a skeletal muscle (from smallest to largest)

Answer 18

Myofilament
myofibril 
myofiber
fascicle
muscle

Question 19

Myofilament

Answer 19

-types:
myosin (thick)
actin (thin)
-they are organized into sarcomeres

Question 20

Microfibril

Answer 20

chain of sarcomeres

Question 21

myofiber

Answer 21

• bundle of myofibrils

- known as muscle cell

Question 22

Fascicle

Answer 22

bundle of myofibers

Question 23

muscle

Answer 23

composed of varying numbers of fascicles

Question 24

Parts of the connective tissue framework of skeletal muscle to nerve and vascular supply

Answer 24

Endomysium
Perimysium
Epimysium

Question 25

Endomysium

Answer 25

surrounds each muscle fiber | lies outside sarcolemma (cell membrane)

Question 26

Perimysium

Answer 26

surrounds each fascicle

Question 27

Epimysium

Answer 27

surrounds each muscle becomes continuous with tendons attached to periosteum

Question 28

True or false: connective tissue provides physical support and a pathway for nerves and vessels

Answer 28

True

Question 29

True or false: number of myofibers cannot be increased after birth

Answer 29

true

Question 30

True or false: the number of myofibrils cannot be increased

Answer 30

false

Question 31

What occurs during the sliding filament theory

Answer 31

I bands and H bands shorten and A band remains the same. Sliding occurs when ATPase heads of myosin attach to actin via troponin and swivel

Question 32

What is a motor unit

Answer 32

a motor unit consists of a motor neuron and all the myofibers it innervates

Question 33

how many fibers does a unit for fine control have

Answer 33

fewer fibers

Question 34

how many fibers does a unit for gross control have

Answer 34

many fibers

Question 35

When a neuron fires what happens to al of the myofibers in the motor unit

Answer 35

they all contract

Question 36

what is all or none related to

Answer 36

refers to a motor unit contracting fully or not at all

Question 37

how are muscle fibers classified

Answer 37

based on endurance and speed of contraction

Question 38

what are the types of muscle fibers

Answer 38

dark, slow fibers (red) | light, fast fibers (white)

Question 39

Muscle predominantly composed of dark fibers

Answer 39

soleus - Ducks have sark breast meat because they have to fly south for the winter so they can't get tired easy - pretty good blood supply

Question 40

muscle predominantly composed of light fibers

Answer 40

gastrocnemius | -When chickens get scared they run fast but eventually get tired

Question 41

Characteristics of dark, slow fibers

Answer 41

- Fatigue resistant - contract slowly (slow twitch) - Need oxygen - having large number of mitochondria - having a high concentration of myoglobin - low concentration of ATPase

Question 42

Characteristics of light, fast fibers

Answer 42

- Fatigue easily - Contract rapidly (fast twitch) - rely on glycolysis - have a small number of mitochondria - have a low concentration of myoglobin - have a high concentration of ATPase