Flight 256Flight 256

Skeletal SystemSkeletal System

Child’s first steps

SkeletonSkeleton

What would you look like What would you look like without bones?without bones?

Without bones Without bones inside you inside you

to give you shape, to give you shape, you would be a you would be a

BLOB!BLOB!

Interesting factsInteresting facts The longest bone in your body is the The longest bone in your body is the

bone above your knee, the thighbone.bone above your knee, the thighbone. Your funny bone isn’t a bone at all.Your funny bone isn’t a bone at all. When you were born, you had more When you were born, you had more

than 300 bones. By the time you stop than 300 bones. By the time you stop growing, you’ll have 206.growing, you’ll have 206.

Your bones are living. They grow as you Your bones are living. They grow as you get older.get older.

• Describe how bone is formed.

• Compare the different types of bones.

• Identify the structure and functions of the skeletal system.

Section ObjectivesSection Objectives

SkeletalSkeletal SystemSystem

Total of 206 bones Total of 206 bones framework, hard, rigidframework, hard, rigid

• The adult human skeleton contains about 206 bones.

• Its two main parts are shown.

Skeletal System Structure

Skeletal System Structure

Skeletal System Structure

What can you do to take What can you do to take care of your skeletal care of your skeletal

system?system?

2 2 Divisions of Skeletal Divisions of Skeletal SystemSystem

1. 1. AxialAxial - skull, vertebrae, ribs - skull, vertebrae, ribs2. 2. AppendicularAppendicular - legs, arms, etc. - legs, arms, etc.

5 5 Functions of Skeletal Functions of Skeletal SystemSystem

1. Support1. Support2. Protection2. Protection3. Stores minerals ( 3. Stores minerals ( Calcium and Calcium and

PhosphorousPhosphorous))4. 4. HemopoiesisHemopoiesis - blood cell - blood cell

formationformation5. Movement5. Movement

Sternum

Sphenoid Bone

Bone StructuresBone Structures : :

Skeleton MovementSkeleton Movement

1. 1. PeriosteumPeriosteum

outside layer of the shaft portion of outside layer of the shaft portion of the long bone.the long bone.

2. 2. Spongy boneSpongy bone

spaces in bone, spaces in bone, found at ends. Air found at ends. Air spaces help reduce spaces help reduce the mass of the the mass of the bone.bone. Above: Note the relationship btwn

the compact and spongy bone.

Below: Close up of spongy bone.

3. 3. Compact boneCompact bone

dense, help give bones strength.dense, help give bones strength.

4. 4. Red bone marrowRed bone marrow

help in red blood cell formation. help in red blood cell formation. Found in the Found in the humerus, femur, humerus, femur, sternum, ribs, vertebrae, and sternum, ribs, vertebrae, and pelvispelvis..

5. 5. Yellow bone marrowYellow bone marrow

mostly made of stored fat cells.mostly made of stored fat cells.

Compare compact and spongy bone as viewed with the light microscope

7. Osteoblasts7. Osteoblasts

Potential bone cells that secrete a Potential bone cells that secrete a protein called protein called collagencollagen that help that help make new bone cells needed for make new bone cells needed for growth and repair of bones. growth and repair of bones.

8. 8. OsteocytesOsteocytes

Living bone cells. Living bone cells.

What does the skull What does the skull protect?protect?

your brain.your brain.

Got Milk?Got Milk?

posterior viewp. 135

Bone GrowthBone Growth

Bone cells do reproduce throughout Bone cells do reproduce throughout life.life.

• Your bones grow in both length and diameter.

• Growth in length occurs at the ends of bones in cartilage plates.

• Growth in diameter occurs on the outer surface of the bone.

• After growth stops, bone-forming cells are involved in repair and maintenance of bone.

Bone growthBone growth

CartilageCartilage

tough flexible connective tissue. tough flexible connective tissue. Cartilage is replaced as a child gets Cartilage is replaced as a child gets older until the age of about 25.older until the age of about 25.

Located: Located: ears, nose, between ears, nose, between vertebraevertebrae. .

Epiphyseal Plate or Epiphyseal Plate or growth plategrowth plate

growth line of long bones.growth line of long bones.

Body MovementBody Movement – –

occurs when limbs or other body occurs when limbs or other body parts move. The interaction of bones parts move. The interaction of bones and muscles. and muscles.

Skeletal OrganizationSkeletal Organization

Skull – protects the brainSkull – protects the brain

Rat skull

Fontanels Fontanels ––

soft spots of a baby’s head which soft spots of a baby’s head which helps the skull compress during child helps the skull compress during child birth. Later they close and harden. birth. Later they close and harden.

Sutures Allows forgrowth

Hyoid BoneHyoid Bone

Located in the neck Located in the neck between the lower jaw between the lower jaw and larynx.and larynx.

Supports the tongue and Supports the tongue and helps with movement.helps with movement.

U ShapedU Shaped

Vertebral ColumnVertebral Column

Consists of the vertebrae.Consists of the vertebrae.

They are separated by They are separated by cartilaginous discs.cartilaginous discs.

They help with support, They help with support, movement and movement and hemopoiesis.hemopoiesis.

JointJoint

articulations between bones. Allow articulations between bones. Allow fexibilty. fexibilty.

There are 230 joints in the body.There are 230 joints in the body.

3 3 Joint TypesJoint Types::

JointsJoints

4 4 Kinds of Joints:Kinds of Joints:

1. Ball and socket (hip or shoulder)1. Ball and socket (hip or shoulder)2. Pivot (head and forearm at elbow.) 2. Pivot (head and forearm at elbow.)

Kinds of Joints: ContKinds of Joints: Cont

3. Hinge (knee or elbow)3. Hinge (knee or elbow)4. Gliding (wrist)4. Gliding (wrist)

JointsJoints

Fixed – unmoveable joint. Ex: joints Fixed – unmoveable joint. Ex: joints (suture) in the skull.(suture) in the skull.

Joint StructuresJoint Structures::

1. 1. BursaeBursae - fluid filled sacs found in - fluid filled sacs found in joints that help cushion.joints that help cushion.

2. 2. LigamentsLigaments - connective tissue - connective tissue that connects bone to bone.that connects bone to bone.

Joint StructuresJoint Structures::

3. 3. TendonsTendons - connective tissue that - connective tissue that attaches muscle to bone.attaches muscle to bone.

4. Menisci – flattened, shock 4. Menisci – flattened, shock absorbing pad between two absorbing pad between two articulating surfaces of the bone.articulating surfaces of the bone.

Diseases and Conditions of the Diseases and Conditions of the skeletal systemskeletal system

7 7 Injuries and Diseases of Injuries and Diseases of Bones:Bones:

1. 1. BursitisBursitis - bursae produces - bursae produces too much fluid making the joint too much fluid making the joint swollen and tender.swollen and tender.

2. 2. ArthritisArthritis - joint becomes - joint becomes inflamed and painful.inflamed and painful.

3. 3. FractureFracture - heal with - heal with cartilaginous tissue cartilaginous tissue calluscallus. As a . As a fracture heals cartilage is fracture heals cartilage is replaced by bone.replaced by bone.

Clinical Clinical ConditionsConditions

4. Osteomalacia4. Osteomalacia ““soft bones.” Adult form of soft bones.” Adult form of

RicketsRickets Causes can include insufficient Causes can include insufficient

dietary calciumdietary calcium Insufficient vitamin D Insufficient vitamin D

fortification or insufficient fortification or insufficient exposure to sun light.exposure to sun light.

5. Rickets5. Rickets Children's form of osteomalaciaChildren's form of osteomalacia

What about the above x-ray is indicative of rickets?

Clinical Clinical ConditionsConditions

6. Osteomyelitis6. Osteomyelitis Osteo=bone + Osteo=bone +

myelo=marrow + myelo=marrow + itis=inflammation.itis=inflammation.

Inflammation of bone and Inflammation of bone and bone marrowbone marrow caused by caused by pus-forming bacteria that pus-forming bacteria that enter the body via a enter the body via a wound (e.g., compound wound (e.g., compound fracture) or migrate from fracture) or migrate from a nearby infection.a nearby infection.

Fatal before the advent Fatal before the advent of antibiotics.of antibiotics.

Clinical Clinical ConditionsConditions

7. Osteoporosis -7. Osteoporosis - loss of loss of bone volume and bone volume and mineral content, this mineral content, this may lead to weaken may lead to weaken bones that break bones that break easily.easily.

Other Clinical Other Clinical ConditionsConditions

GigantismGigantism Childhood hypersecretion of Childhood hypersecretion of

growth hormone by the growth hormone by the pituitary gland causes pituitary gland causes excessive growth.excessive growth.

AcromegalyAcromegaly Adulthood hypersecretion of Adulthood hypersecretion of

GH causes overgrowth of bony GH causes overgrowth of bony areas still responsive to GH areas still responsive to GH such as the bones of the face, such as the bones of the face, feet, and hands.feet, and hands.

PituitaryPituitary dwarfismdwarfism GH deficiency in children GH deficiency in children

resulting in extremely short resulting in extremely short long bones and maximum long bones and maximum stature of 4 feet.stature of 4 feet.

GiantismGiantism

Doctors/MedicineDoctors/Medicine

A. A. CardiologyCardiology - heart - heart B. B. OncologyOncology - cancer - cancer C. C. Pediatrics -Pediatrics - children children

Doctors/MedicineDoctors/Medicine

D. D. GeriatricsGeriatrics - Aging - AgingE. E. DermatologyDermatology - skin - skinF. F. Obstetrics -Obstetrics - childbirth childbirthG. G. OrthopedicsOrthopedics - bone - bone

What type of joint is illustrated in this What type of joint is illustrated in this image? image?

D. gliding

C. pivot

B. hinge

A. ball and socket

Question 1Question 1

The answer is C. Pivot joints allow bones to twist around each other.

Where, on the body, would you find Where, on the body, would you find bursae? bursae?

Question 2Question 2

D. pelvis

C. shoulder

B. hands

A. skull

The answer is C, shoulder. Bursae are fluid-filled sacs located on the outside of the joints. They act to decrease friction.

TriviaTrivia

Humans and giraffes have the Humans and giraffes have the same number of bones in their same number of bones in their necks necks

Important bones of the BodyImportant bones of the Body

Thoracic AreaThoracic Area

Sternum (place ribs attach) Sternum (place ribs attach) Parts of sternum (Manubrium, Body Parts of sternum (Manubrium, Body

and Xiphoid Process)and Xiphoid Process)

Pectoral Girdle –Pectoral Girdle –

Scapula -2 (shoulder blade) and Scapula -2 (shoulder blade) and Clavicle -2 (collar bone)Clavicle -2 (collar bone)

Upper limbs –Upper limbs –

Upper arm is the Humerus -2 Upper arm is the Humerus -2 Lower arm is the Radius -2 and Ulna Lower arm is the Radius -2 and Ulna

– 2 – 2 Hand is the Carpal – 16 and Hand is the Carpal – 16 and

Metacarpals – 10,Metacarpals – 10,Phalanges (fingers) - 28Phalanges (fingers) - 28

Pelvic Girdle –Pelvic Girdle –

Coxae (Hip bone) – 2 Coxae (Hip bone) – 2 sacrum – 1 sacrum – 1 Coccyx (tail bone) -1 Coccyx (tail bone) -1

Lower LimbsLower Limbs

FemurFemur (2) Upper leg (2) Upper legThe strongest bone in the body is the The strongest bone in the body is the

femur. femur. Tibia Tibia (2) and (2) and Fibula (Fibula (2) lower leg2) lower legPatellaPatella (2) knee (2) kneeTarsals Tarsals (14) and (14) and MetatarsalsMetatarsals (5) (5)

FootFootPhlangesPhlanges (28) Toes (28) Toes