Exam 3 Chapter 9

Question 1

Like nervous tissue, muscles are excitable or “irritable”, what does this mean?

Answer 1

They have the ability to respond to a stimulus

Question 2

Unlike nerves, muscles have three distinct characteristics, what are they?

Answer 2

1. Contractible (they can shorten in length)
2. Extensible (they can extend or stretch)
3. Elastic (they can return to their original shape)

Question 3

What are the five main function of muscle?

Answer 3

1. Create motion – (with nerves, bones, and joints)
2. Stabilize body positions and maintain posture
3. Store substances within the body using sphincters
4. Move substances by peristaltic contractions
5. Generate heat through thermogenesis

Question 4

What sphincters are important to our muscle tissue network?

Answer 4

anal, urethral, cardiac, pyloric, ileocecal

Question 5

How do muscles create heat?

Answer 5

movement needs ATP; we lose energy as heat when we use ATP; that heat warms our water

Question 6

Describe the organization of whole muscles.

Answer 6

Whole muscles are attached to bone by tendons; each muscle is organized into bundles called fascicles; each fascicle is a collection of muscle fibers (or muscle cells); each muscle fiber (or muscle cell) is broken down into myofibrils.

Muscle > Fascicle > Muscle Fiber > Myofibril

*Muscle fiber and muscle cell can be used interchangeably

Question 7

Many large muscle groups are encased in both a _____ and a _____ fascia.

Answer 7

superficial; deep

Question 8

What are some areas of the body covered in deep fascia?

Answer 8

abs; traps; forearms; tibialis anterior

Question 9

______, _____, and _____ are located in the deep fascia between muscles of the thigh.

Answer 9

Veins, Arteries, Nerves

Veins, arteries, and nerves are located in the deep fascia between muscles of the thigh.

Question 10

What are the seven primary components of skeletal muscle fiber?

Answer 10

1. Triad
2. Sarcoplasmic reticulum
3. Sarcomere
4. Sarcolemma
5. Sarcoplasm
6. Myofibril
7. T-tubules

Question 11

What is the sarcolemma of muscle fiber?

Answer 11

plasma membrane

Question 12

What is the sarcoplasm of muscle fiber?

Answer 12

Sarcoplasm is the cytoplasm of skeletal muscle fibers; it is full of contractile proteins arranged in myofibrils

Question 13

What kind of muscular tissue can be subconciously controlled to some extent?

Answer 13

skeletal

Question 14

What kind of muscular tissue is striated with multi-nucleated (eccentric) fibers parallel?

Answer 14

skeletal

Question 15

What kind of muscular tissue has no striations and one central nucleus?

Answer 15

visceral (smooth)

Question 16

What kind of muscular tissue is striated with one central nucleus?

Answer 16

cardiac

Question 17

Which two muscular tissues have involuntary control?

Answer 17

visceral (smooth), cardiac

Question 18

What is the general location of skeletal muscle tissue?

Answer 18

skeleton

Question 19

What is the general location of cardiac muscle tissue?

Answer 19

heart

Question 20

What is the general location of visceral (smooth) muscle tissue?

Answer 20

G.I. tract, uterus, eye, blood vessels

Question 21

What is a sarcomere?

Answer 21

Basic functional unit of skeletal muscle;

An arrangement of thick and thin filaments sandwiched between two Z discs

Question 22

Myofibrils are built from three groups of proteins; what are they?

Answer 22

Contractile proteins
Regulatory proteins
Structural proteins

Question 23

What do regulatory proteins do?

Answer 23

help switch the contraction process on and off

Question 24

What do structural proteins do?

Answer 24

keep the thick and thin filaments in proper alignment and link the myofibrils to the sarcolemma and extracellular matrix

Question 25

What do contractile proteins do?

Answer 25

generate force during contraction

Question 26

The thin filaments found within muscle are made of what contractile protein?

Answer 26

actin

Question 27

The thick filaments found within muscle are made of what contractile protein?

Answer 27

myosin

Question 28

What is the largest known protein?

Answer 28

Titin (titan); provides elasticity of sarcomere (structural protein)

Question 29

In the thin filaments actin proteins are strung together like a ______

Answer 29

band of pearls

Question 30

In the thick filaments myosin proteins are strung together like ______

Answer 30

golf clubs

Question 31

What are four characteristics of red muscle fibers (as compared to white)?

Answer 31

1. high myoglobin content 2. more mitochondria 3. more energy stores 4. greater blood supply

Question 32

What are three characteristics of white muscle fibers (as compared to red)?

Answer 32

1. less myoglobin 2. less mitochondria 3. less blood supply

Question 33

What is the function of skeletal muscle tissue?

Answer 33

movement, heat, posture

Question 34

What is the function of cardiac muscle tissue?

Answer 34

pump blood continuously

Question 35

What is the function of visceral (smooth) muscle tissue?

Answer 35

Peristalsis, blood pressure, pupil size, erects hairs

Question 36

Skeletal muscles are some of the longest cells in the body, which muscle has the longest single fibers?

Answer 36

Sartorius (~30 cm)

Question 37

Outer connective tissue sometimes becomes thicker, forming ____

Answer 37

fascia

Question 38

What are characteristics of exercise induced muscle damage?

Answer 38

- Torn sarcolemmas, damaged myofibrils, disrupted Z-discs - Increased myoglobin and creatine kinase in blood - DOMS: delayed onset muscle soreness

Question 39

What is plantar fasciitis?

Answer 39

- Inflammation of plantar fascia - Improper shoes, excess weight, poor biomechanics - Ice, heat, stretching, shoe inserts, steroid injections

Question 40

What are the characteristics of intramuscular injections?

Answer 40

- Prompt absorption (good blood supply) - Given when larger doses are needed or med is irritating subcutaneously. - Faster than oral meds; slower than IV

Question 41

Why does rigor mortis occur?

Answer 41

- Ca2+ leaks from SR causing myosin to bind actin - ATP production stops; myosin can’t unbind - Lasts until enzymes in lysosomes digest the proteins.

Question 42

About half the fibers in a typical skeletal muscle are slow oxidative (SO) fibers. True or False?

Answer 42

True

Question 43

Most skeletal muscles are a mixture of all three types of skeletal muscle fibers. True or False?

Answer 43

True

Question 44

The different motor units in a muscle are recruited in a specific order depending on the task being performed. True or False?

Answer 44

True

Question 45

In one motor unit all the skeletal muscle fibers are the same type. True or False?

Answer 45

True

Question 46

What is the triad made up of?

Answer 46

2x terminal cisterns and T-tubule together

Question 47

what is the functional unit of the muscle cell?

Answer 47

sarcomere

Question 48

where does muscle contraction actually occur?

Answer 48

sarcomere

Question 49

What are the three types of skeletal muscle fibers?

Answer 49

- slow oxidative fiber - fast glycolytic fiber - fast oxidative-glycolytic fiber

Question 50

How much ATP produced for each molecule of glucose?

Answer 50

36

Question 51

Which mechanism end neural transmission at the neuromuscular junction?

Answer 51

1. ACh diffuses away from the synaptic cleft. | 2. ACh is broken down into acetic acid and choline by the enzyme acetylcholinesterase (AChE).

Question 52

What must happen for the movement of the thin filament toward the M line (the center of the sarcomere)?

Answer 52

The myosin head binds to the active site on actin and pivots toward the M line.

Question 53

What powers the contraction of a muscle cell?

Answer 53

ATP