Health Occupations
Skeletal System – Unit 2
Spinal Column

Made up of 26 bones, divided into 5 parts
 Function
– Protect spinal cord
– Provide support for head & neck

Curvature gives strength & flexibility
 Each bone is called vertebrae
 Intervertebral discs
– Pads of cartilage separating the vertebrae
– Act as shock absorbers
– Allow bending & twisting
Vertebrae
Bone is called the vertebral body
 5 parts

– Cervical – neck, 7
– Thoracic – chest, 12
– Lumbar – waist, 5
– Sacrum – back of pelvic girdle, 1
– Coccyx – tailbone, 1
Cervical Vertebrae
Thoracic Vertebrae
C1 - Atlas
C2 - Axis
Vertebral Body
Intervertebral Disk
Lumbar Vertebrae
Sacrum
Coccyx
Thorax

Ribs, Sternum, Vertebral bones
– Protect heart & lungs

Ribs
– 12 pair, called COSTAE
– Attach to thoracic vertebrae on DORSAL surface
of body
– Types of ribs
• True ribs – first 7, attach directly to sternum
• False ribs – next 3, attach to cartilage of rib above
• Floating ribs – last 2, do not attach to front of body
– INTERCOSTAL space –
• Area between ribs containing muscles, blood vessels, &
nerves
Thorax (cont)

Sternum
– Breast bone
– 3 parts
• Manubrium – upper part, where clavicles attach
• Gladiolous – body, where hands are placed during CPR
• Xiphoid process – small piece of cartilage at bottom,
DANGER during CPR
– Ribs attach to sternum with costal cartilage &
provide a cage protecting the heart & lungs
Sternum - Gladiolus
True Ribs
Xiphoid process
False Ribs
Floating Ribs
Vertebral column
Pectoral Girdle
Shoulder – made up of clavicles & scapulas
 Clavicle –

– 2 bones
– Collar bones
– Attach to manubrium of sternum with ligaments

Scapula
– 2 shoulder blades
– Provide for attachment of upper arm bones
Bones of the Arm
Humerus – upper arm
 Radius – lower arm, thumb side
 Ulna – larger bone of lower arm, little finger
side

– Olecranon process – projection on upper end of
ulna, forms elbow
Carpals – 8 bones of wrist
 Metacarpals – 5 bones in palm of hand
 Phlanges – 14 bones of fingers

Pelvic girdle

Made up of 2 os coxae (coxal or hip bones)
 Joins with sacrum on dorsal side of body at
the SACROILIAC joint
 Join together on ventral side of body at the
SYMPHYSIS PUBIS
 3 parts, fused together
– Ilium
– Ischium
– Pubis
Acetabula – 2 recessed areas (sockets) for
leg bone attachment
 Obturator foramen – opening between ishium
& pelvis allowing passage of nerves & blood
vessels to & from legs

Sacrum
Sacroiliac
joint
Coccyx
Ilium
Ischial spine
Acetabulum
Obturator foramen
Symphysis pubis
Ischium
Pubis
Legs
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Femur – thigh
Patella – kneecap
Tibia – lower leg, large bone, big toe side
Fibula – lower leg, small bone, little toe side
Tarsals – 7 bones in ankle
Metatarsals – 5 bones in instep of foot
Phalanges – 14 bones in toes
Calcaneous – heel that is formed by the large
tarsal bone
Parietal
Zygomatic
Occipital
Mandible
Scapula
Xiphoid process
Verbebrae
Olecranon
process
Ilium
Sacrum
Maxilla
Clavicle
Sternum
Ribs
Humerus
Ulna
Radius
Carpals
Pubis
Ischium
Coccyx
Symphysis
pubis
Metacarpals
Phlanges
Femur
Obturator foramen
Patella
Tibia
Fibula
Tarsals
Metatarsals
Phlanges
Calcaneous