Due in Lab

1. Skeletal System 33-34

2. Skeletal System 26

3. PreLab 6

Due next week in lab - Scientific America Article

Select one article to read and complete article summary

Cell Defenses and the Sunshine Vitamin (Summary in Case Study

19-20)

Skin Deep (Summary in Case Study 21-22)

Sex and the Secret Nerve (Instructor website)

The Naked Truth (Instructor website)

Introduction

The Skeletal System

Skull

Thoracic cage

(ribs and sternum)

(a) Anterior view

Facial bones Cranium

Sacrum

Vertebral

column

Clavicle Scapula Sternum Rib Humerus Vertebra Radius Ulna Carpals

Phalanges Metacarpals Femur Patella

Tibia Fibula

Tarsals Metatarsals Phalanges

Functions

1. Support

For the body and soft organs

2. Protection

For brain, spinal cord and vital organs

3. Movement

Levers for muscle action

4. Mineral reservoir

Calcium and phosphorus

5. Hematopoiesis

Marrow cavities

Bone

Osseous tissue

Hydroxyapatite (85%)

Calcium carbonate (10%)

Inorganic minerals

Magnesium, sodium, fluoride

Organic material

Collagen

Chondroitin sulfate

Figure 6.3c

(c)

Yellow

bone marrow

Endosteum

Compact bone

Periosteum

Perforating

(Sharpey’s) fibers

Nutrient

arteries

Bone consists of multiple tissues

A single bone may be considered an organ

Figure 6.3a-b

Proximal

epiphysis

(b)

(a)

Epiphyseal

line

Articular

cartilage

Periosteum

Spongy bone

Compact bone

Medullary

cavity (lined

by endosteum)

Compact bone

Diaphysis

Distal

epiphysis

Bones are organs comprised of more than just osseous tissue

Figure 6.2

Bone Classification

General Bone Features

Long bone anatomy (Humerus)

Diaphysis

Epiphysis

Metaphysis

Epiphyseal growth plate or line

Articular cartilage

Periosteum

Medullary cavity

Endosteum

Figure 6.3a-b

Proximal

epiphysis

(b)

(a)

Epiphyseal

line

Articular

cartilage

Periosteum

Spongy bone

Compact bone

Medullary

cavity (lined

by endosteum)

Compact bone

Diaphysis

Distal

epiphysis

Anatomy of a long bone

Figure 6.3c

(c)

Yellow

bone marrow

Endosteum

Compact bone

Periosteum

Perforating

(Sharpey’s) fibers

Nutrient

arteries

Outer layer of periosteum = dense irregular fibrous sheath

Proximal

epiphysis

(b)

(a)

Epiphyseal

line

Articular

cartilage

Periosteum

Spongy bone

Compact bone

Medullary

cavity (lined

by endosteum)

Compact bone

Diaphysis

Distal

epiphysis

Epiphyseal line is a remnant of the epiphyseal plate

Bone Histology

Components

Cells

Fibers

Ground substance

Bone Histology

Cells

Osteogenic (osteoprogenitor) cells

Stem cells in periosteum and endosteum → osteoblasts

Osteoblasts

Bone forming cells

Figure 6.4a-b

(a) Osteogenic cell (b) Osteoblast

Stem cell Matrix-synthesizing

cell responsible

for bone growth

Bone Histology

Cells

Osteocytes

Mature bone cells

Maintain bone matrix

Osteoclasts

Break down (resorb) bone matrix

Related to macrophages

Figure 6.4c-d

(c) Osteocyte

Mature bone cell

that maintains the

bone matrix

(d) Osteoclast

Bone-resorbing cell

Figure 6.5

Compact

bone

Trabeculae

Spongy bone

(diploë)

Compact bone

covers all spongy

bone and the shafts

of long bones

Bone Histology

Primary bone types

Compact

Spongy

Figure 6.3a-b

Proximal

epiphysis

(b)

(a)

Epiphyseal

line

Articular

cartilage

Periosteum

Spongy bone

Compact bone

Medullary

cavity (lined

by endosteum)

Compact bone

Diaphysis

Distal

epiphysis

Figure 6.7a-c

Endosteum lining bony canals

and covering trabeculae

Perforating

(Volkmann’s) canal

Perforating (Sharpey’s) fibers

Periosteal blood vessel Periosteum

Lacuna (with

osteocyte)

(a)

(b) (c)

Lacunae

Lamellae

Nerve

Vein

Artery

Canaliculi

Osteocyte

in a lacuna

Circumferential

lamellae

Osteon

(Haversian system)

Central

(Haversian) canal

Central

canal

Interstitial lamellae

Lamellae

Compact

bone

Spongy bone

Figure 6.6

Structures

in the

central

canal

Artery with

capillaries

Vein

Nerve fiber

Lamellae

Collagen

fibers

run in

different

directions

Twisting

force

Figure 6.3b

(b)

Lacunae

Lamellae

Nerve

Vein

Artery

Canaliculus

Osteocyte

in a lacuna

Central

canal

Figure 6.5

Compact

bone

Trabeculae

Spongy bone

(diploë)

Bone Histology

Bone marrow

Location

Medullary cavity and spaces between trabeculae

Bone Histology

Bone marrow

Types

Red

Red blood cells

Hematopoiesis

Yellow

Replaces red with age

Fat storage

Gelatinous

Mostly water and protein

Skeletal System 17

Proximal epiphysis

Distal epiphysis

Epiphyseal line

Articular cartilage

Spongy bone

Compact bone

Medullary canal

Periosteum

Endosteum

Diaphysis

Nutrient artery

Marrow

Perforating (Sharpey’s)

fibers

Label the following

Turn in

Table 6.1

Skeletal System 19

Table 6.1

Skeletal System 19

Table 6.1