Skeletal System Flashcards
Two divisions of skeletal system
Axial skeleton
Appendicular skeleton
Parts of the skeletal system
Bones
Joints
Cartilages
Ligaments
Functions of the bones
Support the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formation
Skeleton comprises how many bones?
206 bones
Two basic types of bone tissue
Compact bone - homogeneous
Spongy bone
- small needle-like pieces of bone
- many open spaces
Classified as he “short bone”
Calcaneus
Classification of bones according to SHAPE
Long bones
- typically longer than wide
- have a shaft with heads at both ends
- contain mostly compact bone
Short bones
- generally cube-shape
- contain mostly spongy bone
Flat bones
- thin and flattened
- usually curved
- thin layers of compact bone around a layer of spongy bone
Irregular bones
- irregular shape
- do not fit into other bone classification categories
Gross anatomy of long bones:
Shaft
Composed of compact bone
Diaphysis
Gross anatomy of long bones:
Ends of the bone
Composed mostly of spongy bone
Epiphysis
Junction between DIAPHYSIS AND EPIPHYSIS
Metaphysis
Covers the external surface of the epiphysis
Made of hyaline cartilage
Decreases friction at joint surfaces
Articular cartilage
Cavity of the shaft
Contains yellow marrow (mostly fat) in adults
Contains red marrow ( for blood cell formation) in infants
Medullary cavity
Forms the longitudinal part of the body
Divided into three parts: skull, vertebral column, bony thorax
Axial skeleton
Evzones of endochondral ossifications would cells accumulate Glycogen?
Zone of hypertrophy
Bone formation
Intramembranous - DIRECT
Intracartilagenous/ENDOCHONDRAL - INDIRECT
Zones of osteogenesis
Resting zone - site at which chondrocytes divide
Zone of proliferation - lengthens the cartilage model
Zone of hypertrophy - mature chondrocytes undergo hypertrophy, contain vacuoles and accumulate glycogen
Zone of calcification - degenerating chondrocytes, matrix between cells becomes filled with hydroxyapatite
Zone of ossification - contains differentiating osteoblasts
Immovable joints
Synarthroses
Functional classification if joints
Synarthroses - immovable joints
Amphiarthroses - slightly moveable joints
Diarthroses - freely moveable joints
Structural classification of joints
Fibrous joints - generally immovable
Cartilaginous joints - immovable or slightly moveable
Synovial joints - freely moveable
Bones united by FIBROUS TISSUE
SUTURES, SYNDESMOSES (allows more movement than sutures)
Fibrous joints
Bones connected by CARTILAGE
Pubic symphysis, intervertebral joints
Cartilaginous joints
Articulating bones are separated by a JOINT CAVITY
SYNOVIAL FLUID is found in the joint cavity
Synovial joints
Features of SYNOVIAL JOINTS
Articular cartilage (HYALINE CARTILAGE) covers the ends of bones
Joint surfaces are enclosed by a FIBROUS ARTICULAR CAPSULE
have a joint cavity filled with synovial fluid
Ligaments reinforce the joint
Pyramidal in shape
Axilla
Boundaries of the axilla
ANTERIORLY
Anterior (pectoral):
Pectoralis major
Pectoralis minor
Subclavius
Boudaries of the axilla
POSTERIORLY
Posterior (scapular):
Subscapular
Latissimus dorsi
Teres major
Boundaries of the axilla
MEDIALLY
Medial (costal):
2nd and 6th rib, and intercostal muscles
Serratus anterior muscle
Boundaries of the axilla
LATERALLY
Lateral (humeral): Humerus Long head of biceps brachii Short head of biceps brachii Coracobrachialis
Boundaries of axilla
APEX
Apex: Bounded by 3 bones Clavicle (anterior) Scapula (posterior) 1st rib (medially)
Boundaries of the axilla
BASE
Base:
Skin, subcutaneous fascia and axillary fascia
Contents of axilla
Axillary vein
Axillary artery
Brachial plexus
Distal part of the sheath is closed with finger pressure
Syringe needle is inserted into the proximal part of the sheath - anesthetic solution is injected
Position verified by feeling the pulsations of the THIRD part of the axillary artery
Brachial Plexus Nerve Block
Tendons may become torn or inflamed
Inflammation of the rotator cuff
Most commonly affected tendon
Tendon of SUPRASPINATUS MUSCLE
Dorsal scapular spaces
Quadrangular space
Triangular space
Quadrangular space
Above - teres minor
Below - teres major
Medial - long head of triceps brachii
Lateral - surgical neck of humerus
Contents : axillary nerve (circumflex nerve), posterior circumflex humeral vessels
Triangular space
Above - teres minor
Below - teres major
Laterally - long head of biceps brachii
Contents: circumflex scapular vessels
Deep fascia of the arm
Bicipital apeneurosis
Muscles of the arm
ANTERIORLY
Flexor
Contents: Musculocutaneous nerve Coracobrachialis - adducts/flexes arm Brachialis - main flexor of forearm Biceps brachii - flexes and main supinator of forearm
Muscles of arm
POSTERIORLY
Extensor
Contents:
Radial nerve
Triceps brachii - main extensor of forearm
