Skeletal System

Skeletal System

Anatomical Terms Bodily Directions/Orientations • Transverse – Superior – Inferior • Frontal – Anterior – Posterior • Sagittal – (Right - Left) – Medial – Lateral • Proximal (towards) – Distal (away) • Paired – has copy of itself • Articulate - connects

SKELETAL SYSTEM • Living framework of the body • Other Functions: – Serves as anchors to which muscles attach – Protects the internal organs – Make blood cells - Red Bone Marrow – Store minerals like calcium and phosphorus that take part in many biochemical reactions • 20% total mass of the body • Cartilage – bendable “bones”

2 Main Division

. Axial Skeleton – forms long axis – skull, vertebral column, thorax > Skull – 22 bones * Cranial - 8 bones – 2 paired (Parietal, Temporal) - 4 unpaired (Frontal, Occipital, Sphenoid, Ethmoid) * Facial – 14 bones (maxillae, palatine, zygomatic, lacrimal, mandible, nasal, vomer, hyoid- point of attachment of neck, and tongue muscle; no connection to any bone of the body

Axial Skeleton > Vertebral Column Five Divisions 1. Cervical – 7 bones – neck 2. Thoracic – 12 bones – connects with the ribs 3. Lumbar – 5 bones 4. Sacrum – 5 bones – fused 5. Coccyx – 3 bones – fused – tailbone

Vertebral Column Four Curvatures 1. 2. 3. 4.

Cervical – concave Thoracic - convex Lumbar - concave Sacral - convex

form S- shape

Curvature Abnormalities •

Scoliosis – thoracic region – more common to girls – surgery/brace

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Kyphosis – extreme, thoracic region – hunchback

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Lardosis – lumbar region – swayback – pregnant, potbellies

Axial Skeleton > Bony Thorax - Thoracic Ribcage ~Sternum – breast bone ~12 paired ribs – all directly attached to the thoracic vertebrae *1- 7 – true ribs *8- 12 – false ribs *11- 12 – floating ribs

2 Major Divisions

. Appendicular Skeleton upper and lower limbs (arms and legs) > Pectoral Girdle – Shoulder girdle – Clavicle and Scapula > Upper Limb – 30 bones each Humerus - upper arm – largest and longest bone of the upper limb Radius, Ulna - forearm Bones of the Hands - carpals – 8 bones – wrist - metacarpals – 5 bones –palm - phalanges – 14 bones – fingers – pollex = thumb

Appendicular Skeleton > Pelvic Girdle – corner stone of lower limb OS Coxae – Ilium – Pubis – Ischium > Lower Limb – 29 bones * Femur - thigh – longest bone * Tibia, Fibula - leg - * patella = kneecap * Bones of the Feet - tarsals – 7 bones – ankle - metatarsals – 5 bones - sole - phalanges – 14 bones – toes – hallux = big toe

SKELETAL SYSTEM Joints – places where bones meet Kinds: 1. Synarthroses – immovable 2. Amphiarthroses – slightly movable 3. Diarthroses – freely movable Tendons – attach muscles to bones Ligaments – attach bone to another bone

JOINTS Structures: • Fibrous – sutures • Cartilaginous • Synovial (fluids – reduces pressure/impact in between bones) – Gliding – Hinge – elbow, knee – Pivot – atlas and axis – Saddle – thumb – Ball and Socket – Condyloid

Injuries and Disorders • Sprain – the person twists a joint and injures the ligaments and tendons • Dislocation • Fracture / Broken bones – results from accidents • Arthritis – can be any of the following: Osteoarthritis, Rheumatoid or Gout