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….)

2 Main Divisions – Axial & Appendicular 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 the Pectoral Girdle (shoulders) Pelvic Girdle (hips)

BONE STRUCTURE - Long Bone Epiphysis Diaphysis Articular Cartilage Periosteum

Medullary Cavity – hollow chamber filled with bone marrow Inside the Long Bone Medullary Cavity – hollow chamber filled with bone marrow Red Marrow (blood) Yellow Marrow (fat) Endosteum – lining of the medullary

Compact (wall of the diaphysis) 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 Canal Volkmann’s Canal

Compact Bone BONE COLORING!

Test Yourself Find the... Haversian Canal Volkman's Canal Lamellae Spongy Bone Compact Bone

BONE DEVELOPMENT & GROWTH Intramembranous bones – flat, skull  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 & Growth EPIPHYSEAL 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) Synarthrotic (not moveable, aka sutures) Amphiarthrotic (slightly moveable, vertebrae) Diarthrotic (moveable joint, aka synovial joints)

Synovial fluid - fluid within the joints that helps to lubricate Types of Joints 1.  Ball and Socket 2.  Hinge 3.  Pivot 4.  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 bones 2. Lambdoidal - between occipital and parietal bones 3. Squamosal - between temporal and parietal bones 4. 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 SKULL Foramen - refers to any opening in the skull, nerves and blood vessels leave this opening to supply the face Foramen Magnum Mental Foramen

Foramen Magnum * Assignment: Skull Labeling

Figure 6.10

Figure 6.10

The Rest of the Bones

Vertebrae Neck = 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 For Test Calcaneous Tarsals Metatarsals Phalanges Assignment – Skeleton Labeling

Broken Bones

Warning: Next slide is graphic!

Identify Bones on a real skeleton • Lab Practical Test 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 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.