Muscular System

Question 1

Skeletal muscle

Answer 1

• Moves skeleton
• voluntary control
• Striated
• Multinucleated
• Long, cylindrical fibers

Question 2

Cardiac muscle

Answer 2

• Heart wall
• Involuntary
• Striated
• Uninucleated
• Short, branched fibers

Question 3

Smooth muscle

Answer 3

• Walls of hollow organs
• Involuntary
• NO striations
• Uninucleated
• Small, spindle shaped cells

Question 4

Structure of muscle smallest to largest

Answer 4

sarcomere, myofibril, muscle fiber, fascicle, skeletal muscle

Question 5

What CT surrounds the whole muscle?

Answer 5

• Epimysium
• Dense irregular CT

Question 6

What CT surrounds the fascicles?

Answer 6

• Perimysium
• Fibrous CT

Question 7

CT surrounding individual muscle fibers?

Answer 7

• Endomysium
• Loose CT

Question 8

Identify the levels of organization of a skeletal muscle from whole muscle to myofilament.

Answer 8

-muscle
-bundles of fibers (fascicles)
-individual muscle fibers (cells)
-myofibrils
-myofilaments (actin & myosin)

Question 9

What protein makes up the thick filament?

Answer 9

myosin

Question 10

what proteins are in thin filaments?

Answer 10

actin

Question 11

What are the correct terms for the following found in muscle fibers?
- Smooth endoplasmic reticulum
- Plasma membrane
- Cytoplasm

Answer 11

• Sarcoplasmic reticulum
• Sarcolema
• Sarcoplasm

Question 12

What is a primary function of the T-tubules?

Answer 12

Carries electrical stimulus for myofibrils

Question 13

Define “motor unit”

Answer 13

A motor neuron and all of the muscle fibers it innervates

Question 14

What is the neuromuscular junction? What occurs here and how is it related to muscle contraction?

Answer 14

Junction where neurons connects to fibers; neuron tells fiber to contract

Question 15

List, in order from strongest to weakest, the following shapes of muscles:
- Convergent
- Parallel
- Pennate

Answer 15

Pennate, convergent, parallel

Question 16

List, in order from the most able to shorten to the least able to shorten, the following muscles:
- Convergent
- Parallel
- Pennate

Answer 16

Parallel, convergent, pennate

Question 17

Parallel muscle

Answer 17

parallel to axis

Question 18

Unipennate muscle

Answer 18

connected at angle to one side to ligament

Question 19

Bipennate muscle

Answer 19

connected at angel to both sides

Question 20

Multipennate muscle

Answer 20

connected to many sides at an angle

Question 21

Differentiate between direct and indirect muscle attachments

Answer 21

Direct short, indirect long

Question 22

Differentiate between tendon and aponeurosis. Can you give an example for each?

Answer 22

• tendon is ropelike (arms)
• aponeurosis is like a flat sheet (abs)

Question 23

What is the significance of the bumps, ridges, and raised markings on bones?

Answer 23

Attachment marks for tendons/muscle

Question 24

Origin of a muscle

Answer 24

• Moves less
• Has more mass
• Proximal end of attachment

Question 25

Insertion of a muscle

Answer 25

- Moves more - Has less mass - Distal end of attachment - Moves closer to origin during contraction

Question 26

What does it mean that cardiac muscle cells have autorhythmicity? Do they function completely without nervous input?

Answer 26

- Does not need nervous input to contract - No, they need the brain to contain homeostasis to still act

Question 27

What anchors actin and myosin in smooth muscle cells?

Answer 27

Intermediate filaments

Question 28

Smooth muscle is often found in layers with cells oriented at angles to each other. What is the significance of this?

Answer 28

To make it stronger

Question 29

Elbow flexion and extension requires the coordinated action of a number of muscles. Please give an example of a muscle for the following functional types of muscles involved in elbow flexion and extension: • Synergist • Antagonist • Prime mover • Fixator

Answer 29

- Synergist: Brachial and brachialis - Antagonist: Triceps - Prime mover: Brachialis - Fixator: Scapula

Question 30

What is the neurotransmitter released at the neuromuscular junction?

Answer 30

Acetylcholine