Skeletal System

What parts make up the skeletal system?

Bones, joints, cartilages, ligaments

How many bones are in the body?

206

2 Subdivisions of the Skeleton

Axial, appendicular

Skull, vertebral column, thoracic cage

Axial skeleton

Pectoral girdle, upper limbs, pelvic girdle, lower limbs

Appendicular skeleton

Two sets of bones in the skull

Cranium, facial

What are bones joined by?

Sutures

Attached by a freely movable joint

Mandible

Fibrous membranes separating cranial bones

Fontanelles/soft spots

Replace fontanelles

Bones, become sutures

Hollow portions of bones surround the nasal cavity

Sinuses

Functions of paranasal sinuses

Lighten skull, give resonance + amplification to voice

Doesn’t articulate with another bone

Hyoid

Serves as a moveable base for the tongue

Hyoid

Aids in swallowing and speech

Hyoid

Extends from the skull to the pelvis

Vertebral column

Composed of vertebrae (24)

Vertebral column

Supports the head and trunk of body

Vertebral column

Protects the spinal cord

Vertebral column

Types of vertebrae

Cervical, thoracic, lumbar, sacrum, coccyx

7 vertebrae

Cervical vertebral

12 vertebrae

Thoracic vertebral

5 vertebrae

Lumbar vertebral

Both have one vertebrae

Sacrum, coccyx

Supports the shoulder girdle and arms

Thoracic cage

Protects the visceral organs in the chest and upper abdomen

Thoracic cage

Made of ribs and sternum

Thoracic cage

12 pairs - 2 floating

Ribs

1 long bone with 3 divisions

Sternum

Supports arms

Pectoral girdle

Made of clavicle, scapula, humerus, radius, ulna, olecranon process, hand

Pectoral girdle

Amount of clavicle

2

Amount of scapula

2

Upper arm

Humerus

Lower arm

Radius

Lower arm, elbow

Ulna

On ulna

Olecranon process

Hand parts

Carpals, metacarpals, phalanges

Wrist

Carpals

Hand

Metacarpals

Fingers

Phalanges

2 coxal bones that come together to form the pelvis

Pelvic girdle

Strong, stable support for the vertebral column

Pelvic girdle

Attaches lower limbs to axial skeleton

Pelvic girdle

Pelvic girdle parts

Ilium, ischium, pubis

Lower Limbs

Femur, patella, tibia, fibula, foot

Thigh

Femur

Kneecap

Patella

Lower leg-shin

Tibia

Lower leg-lateral

Fibula

Foot Parts

Tarsals, metatarsals, phalanges, talus, calcaneus

Connects lower leg to foot

Talus

Heel bone

Calcaneus

Ankle

Tarsals

Foot

Metatarsals

Toes

Phalanges

Types of bones

Long, short, flat, irregular

Parts of Long Bones

Epiphysis, epiphyseal disk, articular cartilage, diaphysis, medullary cavity, periosteum, compact, spongy

The end of the bone that forms a joint with another bone

Epiphysis

Growth plate - dark line at epiphysis where growth takes place

Epiphyseal disk

Cartilage that covers the ends of bones - serves to cushion + decrease friction

Articular cartilage

Main shaft of the bone

Diaphysis

Contains bone marrow, a specialized soft connective tissue

Medullary cavity

Lined by endosteum

Medullary cavity

Makes RBCs, WBCs, platelets

Red bone marrow

Stores fat

Yellow bone marrow

Tough vascular covering of the bone that functions to form and repair bone tissue

Periosteum

Tightly tied packed tissue that makes up the diaphysis; very strong

Compact bone

Spongy inner portion of the bone that makes up the epiphysis; helps reduce the weight of the bone; provides strength at the ends of bones

Spongy bone

Proximal epiphysis

Diaphysis

Distal diaphysis

Articular cartilage

Spongy bone

Epiphyseal disk

Periosteum

Compact bone

Medullary cavity