Musculoskeletal System - Gross Anatomy of Muscle

Question 1

What is the difference between the axial and appendicular skeleton?

Answer 1

Bones of appendicular skeleton facilitate movement
Bones of axial skeleton protect vital organs

Question 1

What are fibrous joints?

Answer 1

Bones concerned are bound by tough fibrous tissue
Further classified into sutures, gomphoses and syndesmoses
Sutures - immovable joints found in the skull, help protect the brain and maintain the shape of the skull.
Syndesmoses - slightly movable, interosseous membrane, provide strength along length of long bones preventing them from separating e.g middle tibiofibular
Gomphoses - immovable joints, found where teeth articulate with their sockets in the maxillae, periodontal ligament.

Question 2

What are cartilaginous joints?

Answer 2

Bones are attached by fibrocartilage or hyaline cartilage
Synchondroses - only involve hyaline cartilage, allow for growth in length
Symphyses - bones are connected by fibrocartilage, allows for slight movement and acts as a shock absorber
Amphiarthroses - joints provide limited movement and are stabilized by either hyaline cartilage or fibrocartilage

Question 3

What are synovial joints?

Answer 3

The ends of the 2 bones are coated in hyaline articular cartilage
Separated by a synovial cavityand bound together by a fibrous capsule
lined on the inside by synovial membrane.
The synovial cavity/joint is filled with synovial fluid.

Question 4

What are the 6 types of synovial joints?

Answer 4

Plane - permit gliding movement e.g acromioclavicular
Hinge - permits flexion and extension e.g elbow
Pivot - allows rotation e.g atlantoxial (neck)
Condyloid - permits flexion, extension adduction, abduction and circumduction e.g metacarpophalangeal
Saddle - concave and convex surfaces e.g toes
Ball and socket - permits movement in several axis e.g shoulder.

Question 5

Describe the directional terms.

Answer 5

Anterior (ventral): Toward the front of the body.
Posterior (dorsal): Toward the back of the body.
Superior (cranial): Toward the head or upper part of the body.
Inferior (caudal): Toward the feet or lower part of the body.
Medial: Toward the midline of the body.
Lateral: Away from the midline of the body.
Proximal: Closer to the point of origin or attachment.
Distal: Farther from the point of origin or attachment.
Superficial: Toward or at the body surface.
Deep: Away from the body surface; more internal..

Question 6

Describe the movement terms.

Answer 6

Flexion: Decreasing the angle between two body parts.
Extension: Increasing the angle between two body parts.
Abduction: Moving a body part away from the midline of the body.
Adduction: Moving a body part toward the midline of the body.
Rotation: Turning a body part around its own axis.
Circumduction: Moving a body part in a circular motion.
Elevation: Raising a body part.
Depression: Lowering a body part.
Pronation: Rotating the forearm and hand from a palm-facing-up to a palm-facing-down position.
Supination: Rotating the forearm and hand from a palm-facing-down to a palm-facing-up position.
Dorsiflexion: Flexing the foot upward toward the shin.
Plantarflexion: Pointing the foot downward away from the shin.
Inversion: Turning the sole of the foot inward.
Eversion: Turning the sole of the foot outward.
Opposition: Moving the thumb to touch the tips of other fingers.

Question 7

Describe a strap, fusiform and convergent muscle.

Answer 7

Strap - fibres run parallel to each other along length of muscle, broad attachments, generating sustained contractions and providing stability
Fusiform - spindle shaped appearance, with a central belly that tapers towards both ends, efficient at generating force over a wide range of motion
Convergent - broad origin that converges to a single tendon of insertion. The muscle fibres fan out in different directions from their origin towards the tendon. Can generate force in multiple directions

Question 8

Describe a unipennate, bipennate, multipenatte and sphincter muscle.

Answer 8

Unipennate - if all fascicles are on the same side of the tendon pennate muscle = unipennate, fibres run obliquely from tendon, high force but low range of motion
Bipennate - tendon runs in the centre of the muscle and fibres run obliquely to it from both sides, greater force than unipennate b
Multipennate - multiple rows of diagonal fibres with a central tendon which branches into 2 or more tendons
Sphincter - circular muscle that surrounds an opening, fibres arranged in a concentric fashion.

Question 9

Describe the nomenclature of skeletal muscle.

Answer 9

Size
Shape
Orientation of muscle fibres
Number of origins of a muscle
Points of origin and insertion
Name of muscle function
muscle’s location
Mechanical function/ action of the muscle.

Question 10

Describe the classification of bones and give examples.

Answer 10

Long - humerus, tibia, fibula
Short - carpals, tarsals
Flat - scapula, parietal
Irregular - facial, vertebrae
Sesamoid - patella
Pneumatic - bones that contain air filled spaces

Question 11

Describe the classification of joints

Answer 11

Fibrous
Cartilaginous
Synovial
Synarthrosis - no movement
Amphiarthrosis - little movement
Diarthrosis - freely moving.