Lab 4Bone and Axial Skeleton

J.R. Schiller, PhD., G.R. Pitts, PhD., & Amy L. Thompson, Ph.D.

Lab 4 Activities1. Describe functions of skeleton2. Learn histology of bone and

cartilage using microslides, figures, and osteon models

3. Learn general anatomy of a long bone

4. Classify bones by shape/origin5. Define each of the various bone

markings6. identify all bones and their bone

markings of the axial skeleton individually or in articulated skeletons (see list, pp. 4-9 to 4-13)

Functions of Bones

• Support - framework for body• Protection of:

– many internal organs including the brain, spinal cord, thoracic (heart and lungs) organs, and pelvic (reproductive) organs

• Movement - muscle attachments to bones

• Mineral homeostasis – storage resevoir of Ca++, PO-4

• Hemopoiesis: Site of blood cell production in red bone marrow

Bone Tissue• CompactCompact

– appears very dense

• SpongySpongy– small struts of

bone = trabeculae are generally oriented with the directions of stress

Spongy Bone

Histology of Compact Bone

• Structural unit = osteon

The Osteon

osteoosteonn

Central Central canalcanal

Slide 19

Ground Bone

( = central canals)

lamellaelamellae

Slide 19

Hyaline Cartilage

Slide Slide 1717

Slide Slide 1717

Lacunae Lacunae w/chondrocytesw/chondrocytes

Elastic Cartilage Slide 16Slide 16

Fibrocartilage

Slide Slide 1818

Classification of Bones

• Long, short, flat, and irregular (shape)

• Wormian (Sutural): extra flat bones of cranium

• Sesamoid: bones that form in tendon – Normal: patellae– Pathological: bone

spurs

Structure of a Long Bone• Diaphysis (shaft)

– medullary (marrow) cavity • red (hematopoietic) marrow in

infancy• yellow (fat) marrow later

– Compact bone (mostly)– nutrient foramina

• Epiphyseal Plate (line)• Connects diaphysis to epiphyses• epiphyseal plate - growth plate in

childhood• Epiphyseal line when growth ends

• Epiphysis (“end”)– nutrient foramina– articular cartilage - hyaline

cartilage– Spongy bone w/red marrow

The Axial Skeleton (blue)

Lateral Aspect of the Skull

Medial Aspects of the Skull

Inferior Aspect of the Skull

Inferior Aspect of Cranium

The Vertebral Column

Note the Double Curvature of the Spine.

It is an Adaptation for Upright Posture.

Examine the Vertebrae from All Angles

Posterolateral View of Articulated Vertebrae

Much of the Rotation of the Head Occurs at the Joint Between the Atlas (C1) and Dens of the Axis (C2).

Regional Characteristics of Cervical, Thoracic, and Lumbar Vertebrae

ForBloodVessels

Facets for Rib to Attach.

No Facets for Rib to Attach

Key Differences Among Vertebral Types:Key Differences Among Vertebral Types:

SizeOfBody

The Bony Thorax

End Lab 4 Presentation.