The Skeleton• Comes from the Greek word meaning

“dried-up body” or “mummy”

• Accounts for about 20% of body weight

• Made up of bones, cartilages & ligaments

Horse skeleton found along Stewart’s Pocket Loop, Payson, AZ 9-2014

2 Skeletal Systems for the Price of One!• There are 206 bones in human body divided

into 2 systems

• Axial skeletal system• Skull (cranium), vertebral column, rib cage

(bony thorax)

• Appendicular skeletal system• Comprises rest of the bones

The Axial Skeleton• Have out the “Skeletal Skeleton”

handout & 3 different colored pencils

• Name (identify) & color-code the 3 sets of bones (80 total bones) that make up the Axial Skeletal System

Cranium/SkullVertebral columnRib cage/Bony thorax

Ossicles – inner ear (6)Hyoid bone (1)

Per. 3 start, Fri

Bones of the Human SkeletonAxial Skeleton – 80 bones • Skull/Cranium

• Cranial bones – 8: • Frontal (1), parietal (2), occipital (1), temporal (2),

ethmoid (1), sphenoid (1)

• Facial Bones – 14:• Maxillary (2), mandible (1), inferior nasal conchae (2),

lacrimal (2), nasal (2), palatine (2), vomer (1), zygomatic (2)

• Vertebra – 26: • Cervical (7), thoracic (12), lumbar (5), sacrum

(1), coccyx (fusion of 3)

• Ribs & Sternum (bony thorax) – 25:Ribs (24 – 1 pair/thoracic vertebra), sternum (1)

• Ossicles (inner ear bones) – 6:• Incus – 2, Malleus -2, Stapes - 2

• Hyoid bone (attachment for tongue) - 1

Week #10 (9/22-9/26)Warm Up – Tues, 9/23:

Have out:Human Skull diagramAxial Skeletal Sys. notes

Agenda:1. Finish Axial Skeleton notes – Skull 2. Human Skull identification activity

Homework:1. Skull Quiz – Wed,

9/24 & Thurs, 9/25

2. Axial Index Card check - Wed, 9/24 & Thurs, 9/25

3. Axial Practical Exam – Tues, 10/21 (MOVED due to Guest Speaker)

Anatomy Fun Fact:Enamel is hardest substance in the human body. What mineral do you think is found in tooth enamel?

Bones of the Human Skeleton

Appendicular Skeleton – 126 bones • Girdles:

• Pectoral: clavicle (2) & scapula (2)• Pelvic: ossa coxae/coxal bone (2),

consisting of ilium, pubis & ischium

• Arm – 30 bones (per arm): • Humerus, radius & ulna, carpals (8),

metacarpals (5), phalanges (14)

• Leg – 30 bones (per leg): • Femur, tibia & fibula, patella, tarsals (7),

metatarsals (5) & phalanges (14)

The Skull (Cranium)

• Formed by 22 bones divided into 2 sets:• Cranial bones• Facial bones

• The skull can be divided into 2 regions: • Vault (skullcap)• Base

Human Skull animation

The Skull (Cranium)• Cranial Bones - 8

bones • 2 Parietal• 2 Temporal• Frontal• Occipital• Sphenoid• Ethmoid

The Skull (Cranium)• Facial Bones - 14 bones

• Maxillary (2)• Inferior nasal conchae (2)• Lacrimal (2)• Nasal (2)

• Palatine (2)• Zygomatic (2) • Mandible & vomer are unpaired

• Males: more elongated than females

• Females: rounder & less angular

• Mandible (jaw): largest & strongest bone of the face

The Skull (Cranium)• All bones of adult skull are firmly

connected by interlocking joints called sutures• Coronal

• Connects frontal & parietal bones• Squamous

• Connects parietal & temporal bones

• Sagittal• Connects 2 parietal bones

• Lambdoid• Connects occipital &

parietal bones