SKELETAL SYSTEM

SKELETAL SYSTEM

Functions of the Skeletal System●Bones are made of OSSEOUS TISSUE

●Support and Protection●Body movement●Blood cell formation (bone marrow) - hemopoiesis●Storage of inorganic materials 

                   (salt, calcium, potassium….)

ORGANIZATION

●About 206 bones

●2 Main Divisions – Axial & Appendicular

Axial Skeleton

●Head, neck, trunk●Skull●Hyoid Bone●Vertebral Column●Thoracic Cage (ribs, 12 pairs)●Sternum

Hyoid Bone

Appendicular Skeleton

●Limbs & Bones that connect to theoPectoral Girdle (shoulders)oPelvic Girdle (hips)

BONE STRUCTURE - Long Bone

1.Epiphysis2.Diaphysis3.Articular Cartilage4.Periosteum

Inside the Long Bone

Medullary Cavity – hollow chamber filled with bone marrow

Red Marrow (blood)Yellow Marrow (fat)

Endosteum– lining of the medullary

Types of Bone Tissue

Compact (wall of the diaphysis)Spongy (cancellous, epiphysis) - red marrow

Structure of a Long Bone

Figure 6.3a-c

* Assignment – Coloring of a Long Bone 

Review the Structure of a Long Bone

Matching quiz at http://www.mhhe.com/biosci/ap/holehaap/student/olc2/chap07matching01.html

Microscopic Structure

MATRIX - where the bone cells live OSTEOCYTES  - mature bone cells, enclosed in tiny chambers called LACUNAE OSTEOCYTES form rings (LAMELLAE) around a HAVERSIAN CANAL which houses blood vessels Osteocytes are linked by CANALICULI Haversian Canals are linked by VOLKMAN's CANALS 

Osteocytes

Haversian CanalVolkmann’s Canal

Compact Bone

BONE COLORING!

Test Yourself

Find the...

Haversian CanalVolkman's Canal

Lamellae

Spongy BoneCompact Bone

BONE DEVELOPMENT & GROWTH

1.Intramembranous bones – flat, skull2. Endochondral bones – all other

  ALL BONES START AS HYALINE CARTILAGE, areas gradually turn to bone         PRIMARY OSSIFICATION CENTER (shaft)        SECONDARY OSSIFICATION CENTER (ends)

Bone Development & GrowthEPIPHYSEAL DISK  (growth plate) is a band of cartilage between the epiphysis and diaphysis These areas increase bone length as the cells ossify Cartilage becomes OSTEOBLASTS become OSTEOCYTES

RESORPTION

OSTEOCLASTS - dissolve bone tissue to release minerals,  process is called RESORPTION

Bone Growth

Bone Growth

* Assignment - Coloring of the Aging Hand

Types of Joints (articulations)

1.Synarthrotic (not moveable, aka sutures)

2.Amphiarthrotic (slightly moveable, vertebrae)

3.Diarthrotic (moveable joint, aka synovial joints)

Synovial fluid - fluid within the joints that helps to lubricate

Types of Joints

1.  Ball and Socket2.  Hinge3.  Pivot4.  Saddle

BONES OF THE SKULL

1. Frontal -2. Parietal - 3. Occipital -4. Temporal - 5. Sphenoid - 6. Maxilla - 7. Mandible - 8. Zygomatic -

Sutures - connection points

1. Coronal - between frontal and parietal bones2. Lambdoidal - between occipital and parietal bones3. Squamosal - between temporal and parietal bones4. Sagittal - between parietal bones

Suture - refers to any connection between large bones (in fetal skulls, these are called fontanels)

Fissure - any wide gap between bones

Fontanels are “soft spots” on an infant’s skull

TOPOGRAPHY OF THE SKULLForamen - refers to any opening in the skull, nerves and blood vessels leave this opening to supply the face

Mental Foramen

Foramen Magnum

Foramen Magnum

* Assignment: Skull Labeling

Figure 6.10

Figure 6.10

The Rest of the Bones

VertebraeNeck = cervical

 Middle Back = thoracic

   Lower Back = lumbar

Thoracic Cage

Pectoral Girdle

Bones of the Arm

Ulna goes to pinky  (P-U)

Radius goes to thumb

Wrist Bones

For test

Carpels

Metacarpals

Phalanges

*extra credit opportunity

Name the carpals for extra credit on test.

Pelvic Girdle

COXAL BONES - separated

Bones of the Leg

Bones of the Ankle

Assignment – Skeleton Labeling

For Test

Calcaneous

Tarsals

Metatarsals

Phalanges

Broken Bones

Warning: Next slide is graphic!

Upcoming Assignments

●The Skeleton Mystery - read about a “crime scene” and reconstruct skeletons to identify the remains

●Watch a Bones Episode●Identify Bones on a real skeleton • Lab

Practical Test●Medical Imaging – learn how doctors view

bones and diagnose problems

TEST INFORMATION

●Test will cover everything in your notes and on the slides presented in class

●Visit biologycorner.com for study aids●A second test will occur that covers the lab portion

Abnormal Bone Conditions

●BONE SPURS: abnormal growth. Can occur on any bone (e.g. heel).

●OSTEOPOROSIS: Increased activity of osteoclasts cause a break down bone, and the subsequent fewer minerals in the extracellular matrix make it fragile. The spongy bone especially becomes more porous.

●Men get it as well as women. What’s the best way to prevent osteoporosis? Exercise! What does exercise do? Makes bones bigger.

●The most common bone used for a bone graft is the iliac bone of the hip.

Osteoporosis

Figure 6.15

Rheumatoid arthritis is an autoimmune disease which causes joint stiffness and bone deformity

Source: http://www.thetimes.co.uk/tto/public/article3233439.ece 

ABNORMALITIES OF THE SPINE

ABNORMALITIES OF THE SPINE●SCOLIOSIS is a lateral curve in the spine●KYPHOSIS is a hunchback curve●LORDOSIS is a swayback in the lower region.●ANKYLOSIS is severe arthritis in the spine and

the vertebrae fuse.

SCOLIOSIS

LORDOSIS

ANKYLOSIS

FUN FACTS ABOUT BONESBone is made of the same type of minerals as limestone.●Babies are born with 300 bones, but by adulthood

we have only 206 in our bodies. ●The giraffe has the same number of bones in its

neck as a human: seven in total. ●The long horned ram can take a head butt at 25

mph. The human skull will fracture at 5mph.