Musculoskeletal System - 6b

Question 1

What are the general functions of muscles?

Answer 1

Stabilize body positions
Produce body movements
Store and move substances within the body
Generate heat (thermogenesis)

Question 2

What properties are unique to muscular tissue?

Answer 2

Electrical excitability
Conductivity
Contractility
Extensibility
Elasticity

Question 3

What are the three types of muscle tissue?

Answer 3

Skeletal muscle – Voluntary, striated, attached to bones
Smooth muscle – Involuntary, non-striated, in walls of organs
Cardiac muscle – Involuntary, striated, found in the heart

Question 4

What is the structural organization of skeletal muscle from largest to smallest?

Answer 4

Skeletal muscle → Fascicles → Muscle fibres (myofibres) → Myofibrils → Sarcomeres → Muscle proteins

Question 5

What connective tissues are associated with skeletal muscle?

Answer 5

Epimysium – Surrounds entire muscle
Perimysium – Surrounds fascicles
Endomysium – Surrounds individual muscle fibres
All layers form tendons

Question 6

What are the basic parts of a skeletal muscle?

Answer 6

Origin: Proximal attachment to stationary bone
Insertion: Distal attachment to moving bone
Belly: Thick central part
Tendon: Connects muscle to bone

Question 7

How do lever systems work in the musculoskeletal system?

Answer 7

Fulcrum: Joint
Effort: Muscle force
Load: Resistance (body part or object)
Types:
* First-class – Fulcrum in the middle
* Second-class – Load in the middle
* Third-class – Effort in the middle

Question 8

What is muscle tone?

Answer 8

A small amount of constant involuntary muscle contraction that keeps muscles firm without producing movement.

Question 9

What are the two main types of muscle contraction?

Answer 9

Isometric: Tension increases, but muscle length stays the same
Isotonic: Muscle changes length:
* Concentric: Shortens
* Eccentric: Lengthens

Question 10

How do muscles work together to create movement?

Answer 10

Prime mover (agonist): Main muscle performing action
Antagonist: Opposes the action
Synergist: Assists the prime mover
Fixator: Stabilizes the origin of the prime mover

Question 11

What muscles are involved in a bench press?

Answer 11

Prime mover: Pectoralis major
Antagonist: Latissimus dorsi
Synergist: Triceps brachii
Fixators: Rotator cuff muscles

Question 12

How are skeletal muscles named?

Answer 12

By shape (e.g., trapezius)
By size (e.g., maximus, minimus)
By direction of fibres (e.g., rectus = straight)
By location (e.g., tibialis anterior)
By number of origins (e.g., biceps = 2 origins)
By action (e.g., extensor, flexor)
By arrangement of fascicles (e.g., pennate, circular)

Question 13

What are the main functions of bones?

Answer 13

Support
Protection
Movement
Mineral storage (Ca²⁺ and P)
Blood cell production
Triglyceride (fat) storage

Question 14

What are the five types of bones?

Answer 14

Long bones – e.g., femur
Short bones – e.g., carpals
Flat bones – e.g., skull
Irregular bones – e.g., vertebrae
Sesamoid bones – e.g., patella

Question 15

What is the anatomy of a long bone?

Answer 15

Diaphysis: Shaft
Epiphysis: Ends
Metaphysis: Region between shaft and end
Articular cartilage: Covers joint surface
Periosteum: Outer covering
Medullary cavity: Hollow space with yellow marrow
Endosteum: Lines the cavity

Question 16

What are the three types of joints?

Answer 16

Synovial: Freely moveable
Fibrous: Immovable or slightly moveable
Cartilaginous: Slightly moveable

Question 17

What types of movement occur at synovial joints?

Answer 17

Gliding
Angular: Flexion, extension, abduction, adduction, hyperextension, circumduction
Rotational: Internal/external rotation
Special movements: Elevation, depression, inversion, eversion, dorsiflexion, plantarflexion, supination, pronation, opposition

Question 18

How is the skeleton divided?

Answer 18

Axial skeleton (80 bones): Skull, thoracic cage, vertebral column
Appendicular skeleton (126 bones): Limbs and girdles

Question 19

What bones are included in the axial skeleton?

Answer 19

Skull: 22 bones
Ear ossicles: 6 bones
Hyoid: 1 bone
Thorax: 25 bones
Vertebral column: 26 bones

Question 20

What bones are part of the appendicular skeleton?

Answer 20

Pectoral girdle: 4 bones
Pelvic girdle: 2 bones
Upper limbs: 60 bones
Lower limbs: 60 bones

Question 21

What is Isometric contraction?

Answer 21

Length of the muscle doesn’t change, holds the body part still without creating movement.

Muscles do not change length, joints do not move.

Question 22

Give an example of Isometric exercises.

Answer 22

Wall sit exercises, holding stable posture against gravity, gripping/holding an object without dropping it.

These exercises maintain muscle tension without movement.

Question 23

What is Isotonic contraction?

Answer 23

Length of the muscle changes.

It can be further divided into concentric and eccentric contractions.

Question 24

What happens during Concentric contraction?

Answer 24

Muscle shortens.

The joint changes angle depending on the location of the muscle.

Question 25

Provide an example of Concentric contraction.

Answer 25

Bicep muscles when lifting a glass of water, gluteus muscles when coming up from a squat. ## Footnote These movements involve shortening of the muscle.

Question 26

What happens during Eccentric contraction?

Answer 26

Muscle lengthens. ## Footnote The joint changes angle depending on the location of the muscle.

Question 27

Provide an example of Eccentric contraction.

Answer 27

Bicep muscles when lowering a glass of water, gluteus muscles when lowering during a squat. ## Footnote These movements involve lengthening of the muscle.