Muscle Anatomy

Question 1

What is the main function of muscles?

Answer 1

• Contraction
• Stabilising joints
• Maintaining continence of bladder and bowel
• Generating heat

Question 2

What are the three classifications of muscle?

Answer 2

Skeletal, cardiac and visceral

Question 3

What are the characteristics of skeletal muscle?

Answer 3

• Striated
• Voluntary contraction
• Somatic nervous system

Question 4

What are the characteristics of cardiac muscle?

Answer 4

• Striated
• Involuntary contraction
• Autonomic nervous system

Question 5

What are the characteristics of visceral muscle?

Answer 5

• Smooth
• Involuntary contraction
• Autonomic nervous system

Question 6

What is muscle fiber called?

Answer 6

Myocytes

Question 7

What are myofibers made up of?

Answer 7

Long cylindrical cells which are multi nucleated

Question 8

What is in myofibrils?

Answer 8

Myofilaments

Question 9

What are myofilaments?

Answer 9

Parallel protein chains of actin and myosin

Question 10

What is the sarcomere?

Answer 10

Basic unit of muscle that contracts

Question 11

What does thick myofilaments look like and what are they made up of?

Answer 11

They appear dark and contain mostly myosin

Question 12

What does thin myofilaments look like and what are they made up of?

Answer 12

They appear light and contain actin

Question 13

What gives the striated appearance of some muscle?

Answer 13

The actin and myosin myofilaments

Question 14

What holds muscle fibres together?

Answer 14

They are held together by connective tissue

Question 15

What is the belly of the muscle?

Answer 15

Area in the centre of the muscle rich in muscle fibres, blood vessels, and nerves

Question 16

How are tendons formed?

Answer 16

Connective tissue sheets merge (bands of collagen) at each end and attach to bone

Question 17

What are the 3 regions of the muscle?

Answer 17

Origin, belly and insertion

Question 18

What is the origin of the muscle?

Answer 18

Portion of muscle attached to either the least moveable bone or most proximal bone

Question 19

What is the insertion of the muscle?

Answer 19

Distal or most moveable attachment

Question 20

What colour are tendons and why?

Answer 20

White as they only have few vessels

Question 21

How fast do tendons heal?

Answer 21

Slowly

Question 22

What is aponeuroses?

Answer 22

Sheet-like elastic tendon structures that cover a portion of the muscle belly

Question 23

What protects tendons?

Answer 23

Sesamoid bones, fluid filled cushions or sheaths

Question 24

What is the principle of muscle shortening?

Answer 24

Is a function of the length of fibres the longer the fibres the greater the shortening capacity

Question 25

What is the principal of muscle power?

Answer 25

Is a function of cross-sectional area muscles which join tendons at an angle are stronger

Question 26

What is a strap muscle?

Answer 26

Fibres that run longitudinally to the contraction direction

Question 27

What is fusiform muscle?

Answer 27

Have a spindle-like shape, with parallel fibers that run the length of the muscle

Question 28

What is pennate muscle?

Answer 28

The muscle fibres are arranged at an angle to the tendon, much like the bristles on a feather

Question 29

What is bipennate muscle?

Answer 29

Feather-like architecture with muscle fibres that converge from two sides onto a central tendon

Question 30

What is multipennate muscle?

Answer 30

Fibers are oriented at multiple angles along the force-generating axis.

Question 31

What is the order of muscles from lowest to highest power?

Answer 31

Strap, fusiform, pennate, bipennate and multipennate

Question 32

What is the order of muscles from longest to shortest shortening capacity?

Answer 32

Strap, fusiform, pennate, bipennate and multipennate

Question 33

What are extrinsic muscles?

Answer 33

Muscles with attach the limb to the trunk

Question 34

What are intrinsic muscles?

Answer 34

Muscles that are contained entirely within the limb

Question 35

What are extensors?

Answer 35

Muscles that straighten bone alignment or open joint

Question 36

What are flexors?

Answer 36

Muscles that angulate bones or bend joints

Question 37

What is an agonist vs antagonist muscles?

Answer 37

A muscle that is an agonist for one movement will be an antagonist for the opposite

Question 38

What are epaxial muscles?

Answer 38

Muscles dorsal to the line of the transverse process of vertebrea

Question 39

What are hypaxial muscles?.

Answer 39

Ventral to transvere processes