Support › Allows us to stand erect. Protection › Ribs protect the heart and lungs. Movement › Serve as attachment for skeletal muscles Storage

Bones and the SkeletonOsseus tissues

Function Support

› Allows us to stand erect. Protection

› Ribs protect the heart and lungs. Movement

› Serve as attachment for skeletal muscles Storage

› Mineral, including calcium Blood Cell Formation

› hematopoiesis

Tissue Types

Compact (dense) bone› Looks smooth and homogeneous

Spongy (cancellous) bone› Composed of small needlelike or flat pieces

called trabeculae.› Has a lot of open space.

Structure, microscopic Compact

bone:› Filled with

canals and passages for nerves and vessels.

› Structural unit is the osteon or Haversian system.

Structure, microscopic

Spongy Bone› Consists of

trabeculae.› No osteons are

present.

Structure

Structure, Cont.

Diaphysis- shaft of the long bone. Consists of a collar of compact bone surrounding a medullary cavity.

Epiphyses- ends Epiphyseal Line- remainder of the

growth plate. (cartilage) Endosteum- thin membrane lining the

medullary cavity. Contains osteoblasts and osteoclasts.

HEM

ATO

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IESIS

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Red marrow is found in long bones and flat bones. This is the area where blood cell production takes place.

Bone Marrow Donation

Some illnesses can only be cured with a bone marrow transplant.

What do you think you know about this process?

Bone Homeostasis

Remodeling› Coordinated by packets of osteoblasts and

osteoclasts called remodeling units.› In healthy adults, bone mass remains

constant.› Controled by 2 loops

1. mechanical and gravitational forces 2. negative feedback hormonal mechanism.

blood calcium release of PTH release of Ca from bone by osteoclasts.

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Bone Developement

Osteogenesis and ossification› Fetal skeleton is mostly hyaline cartilage.› Gradually replaced by bone and hardened.› Flat and irregular bones are formed by

intramembranous ossification.› Long and short bones are formed by

endochondral ossification.

Bone Growth

Longitudinal› Growth at the epiphyseal plate by mitosis.› Grow in length.

Appositional› Increases bone thickness.

*Growth hormone released during infancy and childhood

Homeostatic Imbalances Osteoporosis

› Reduced by mass due to increased bone reabsorption.

Osteomalacia/ Rickets› Bones do not have enough calcium,

making them soft.› Caused by Vit. D deficiency.

Paget’s Disease› Excessive and abnormal bone formation.

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Bone Markings: every bump and grove has a name and purpose.

Two types of bone markings:› Projections (aka processes) that grow out

from the bone

› Depressions (cavities) that indent the bone

Joint Projections

Condyle: Rounded articular projection

Head: bony expansion on a narrow neck

Facet: smooth, nearly flat articular surface

head

Facet

Joint Projections

Ramus: Armlike bar of bone

Projections for ligament/ tendon attachment.Crest: Narrow ridge

of bone (Line: smaller than a crest)

Epicondyle: Raised area on or above a condyle

Tubercle: Small rounded projection

Tuberosity: large rounded or roughened projection

Trochanter: very large, blunt projection

(only on femur)

Spine: Sharp, pointed projectionEx: sharp points on the throacic vertebrae.

Depressions

Allow blood vessels or nerves to pass through.› Meatus: (me - A-

tus) Canal or tube› Sulcus, Groove or

Furrow: a shallow depression

Depressions

Sinus: Cavity within a bone; filled with air and lined with mucous membranes

Foramen: Round or oval opening

Foramen Magnum

Depressions

Fossa: shallow basin

Fissure: narrow, slit-like opening

Review of markings:

Projections1) Condyle2) Head3) Facet4) Ramus5) Crest6) Epicondyle7) Tubercle8) Tuberosity9) Trochanter10) Spine

Depressions1) Meatus2) Fossa3) Fissure4) Sinus5) Sulcus or Groove

or Furrow

The Skeleton Axial: skull,

vertebral column and bony thorax.

Appendicular: hang from 2 yokelike, bony girdles anchored to axial skeleton.

The Skull

· Two sets of bones

· Cranium

· Facial bones

· Bones are joined by sutures

· Only the mandible is attached by a freely movable joint

The Skull

Bones of the Skull

Figure 5.11

Human Skull, Superior View

Figure 5.8

Human Skull, Inferior View

Figure 5.9

Slide 5.27a

The Fetal Skull

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

· The fetal skull is large compared to the infants total body length

Figure 5.13

Slide 5.27b

The Fetal Skull


· Fontanelles – fibrous membranes connecting the cranial bones

· Allow the brain to grow

· Convert to bone within 24 months after birth

Figure 5.13

Slide 5.26

The Hyoid Bone


· The only bone that does not articulate with another bone

· Serves as a moveable base for the tongue

Figure 5.12

Slide 5.28

The Vertebral Column


· Vertebrae separated by intervertebral discs

· The spine has a normal curvature

· Each vertebrae is given a name according to its location

Figure 5.14

Slide 5.29

Structure of a Typical Vertebrae


Figure 5.16

The spinal column contains 33 bones termed vertebrae. The spine has five regions.

Region # of Vertebrae Body Area Abbreviation Cervical 7 Neck C1 - C7Thoracic 12 Chest T1 - T12Lumbar 5 or 6 Low Back L1 - L5Sacrum 5 (fused) Pelvis S1 - S5Coccyx 3 Tailbone None

TH

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Atlas (C1)› first cervical vertebra, C1. › supports the skull.› It looks different than other

vertebrae. The Atlas is a ring-shaped bone.

Axis (C2)› second cervical vertebra, C2.› It looks like a dull tooth and

sticks upward into the ring of the Atlas. The dens or tooth extends up from the C2 and joins with the inside of the C1 ring.

**The Atlas and Axis allow the head to turn from side to side.

Slide 5.31a

The Bony Thorax


· Forms a cage to protect major organs

Figure 5.19a

Slide 5.31b

The Bony Thorax


· Made-up of three parts

· Sternum

· Ribs

· Thoracic vertebrae

Figure 5.19a

Slide 5.32b

The Appendicular Skeleton


Figure 5.6c

Slide 5.33

The Pectoral (Shoulder) Girdle


· Composed of two bones

· Clavicle – collarbone

· Scapula – shoulder blade

· These bones allow the upper limb to have exceptionally free movement

Slide 5.34a

Bones of the Shoulder Girdle


Figure 5.20a, b

Slide 5.34b

Bones of the Shoulder Girdle


Figure 5.20c, d

Slide 5.35a

Bones of the Upper Limb


· The arm is formed by a single bone

· Humerus

Figure 5.21a, b

Slide 5.35b



• The forearm has two bones

• Ulna

• Radius

Figure 5.21c

Slide 5.36



· The hand

· Carpals – wrist

· Metacarpals – palm

· Phalanges – fingers

Figure 5.22

Slide 5.37

Bones of the Pelvic Girdle


· Hip bones· Composed of three pair of fused bones

· Ilium· Ischium· Pubic bone

· The total weight of the upper body rests on the pelvis

· Protects several organs· Reproductive organs· Urinary bladder· Part of the large intestine

Slide 5.38a

The Pelvis


Figure 5.23a

Slide 5.38b

The Pelvis


Figure 5.23b

Slide 5.39

Gender Differences of the Pelvis


Figure 5.23c

Slide 5.40a

Bones of the Lower Limbs


· The thigh has one bone

· Femur – thigh bone

Figure 5.35a, b

Slide 5.40b



· The leg has two bones

· Tibia

· Fibula

Figure 5.35c

Slide 5.41



· The foot

· Tarsus – ankle

· Metatarsals – sole

· Phalanges – toes

Figure 5.25

Slide 5.42

Arches of the Foot


· Bones of the foot are arranged to form three strong arches

· Two longitudinal

· One transverseFigure 5.26

Joints

Slide 5.43

Joints


· Functions

· Hold bones together

· Allow for mobility

· Ways joints are classified

· Functionally

· Structurally

Slide 5.44

Functional Classification of Joints


· Synarthroses – immovable joints

· Amphiarthroses – slightly moveable joints

· Diarthroses – freely moveable joints

Slide 5.45

Structural Classification of Joints


· Fibrous joints

· Generally immovable

· Cartilaginous joints

· Immovable or slightly moveable

· Synovial joints

· Freely moveable

Slide 5.46

Fibrous Joints


· Bones united by fibrous tissue

· Examples· Sutures

· Syndesmoses· Allows more

movement than sutures

· Example: distal end of tibia and fibula

Figure 5.27d, e

Slide 5.47

Cartilaginous Joints


· Bones connected by cartilage

· Examples

· Pubic symphysis

· Intervertebral joints

Figure 5.27b, c

Slide 5.48

Synovial Joints


· Articulating bones are separated by a joint cavity

· Synovial fluid is found in the joint cavity

Figure 5.27f–h

Slide 5.49

Features of Synovial Joints


· Articular cartilage (hyaline cartilage) covers the ends of bones

· Joint surfaces are enclosed by a fibrous articular capsule

· Have a joint cavity filled with synovial fluid

· Ligaments reinforce the joint

Slide 5.53

Inflammatory Conditions Associated with Joints


· Bursitis – inflammation of a bursa usually caused by a blow or friction

· Tendonitis – inflammation of tendon sheaths

· Arthritis – inflammatory or degenerative diseases of joints· Over 100 different types

· The most widespread crippling disease in the United States

Slide 5.54a

Clinical Forms of Arthritis


· Osteoarthritis· Most common chronic arthritis

· Probably related to normal aging processes

· Rheumatoid arthritis· An autoimmune disease – the immune system

attacks the joints

· Symptoms begin with bilateral inflammation of certain joints

· Often leads to deformities

Slide 5.54b

Clinical Forms of Arthritis


· Gouty Arthritis

· Inflammation of joints is caused by a deposition of urate crystals from the blood

· Can usually be controlled with diet

Documents

Support › Allows us to stand erect. Protection › Ribs protect the heart and lungs. Movement › Serve as attachment for skeletal muscles Storage