Kathryn Selman

© 2009 The McGraw-Hill Companies, Inc. All rights reserved

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The Skeletal SystemThe Skeletal SystemPowerPoint® presentation to accompany:

Medical AssistingThird Edition

Booth, Whicker, Wyman, Pugh, Thompson

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Introduction Bones provide the

body with structure and support

206 bones with joints and connective tissue

Divisions Axial – 80 bones

Skull Vertebral column Rib cage

Appendicular – 126 bones

Arms and legs Pectoral girdle Pelvic girdle

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The Skeletal System

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Bone Structure

Bones contain various kinds of tissues, including Osseous tissue Blood vessels Nerves

Osseous tissue can appear compact or spongy

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Bone Structure (cont.) Compact bone looks

solid Structures can be

observed with a microscope

All bones are made up of both compact and spongy bone

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Bone Structure (cont.)

Classification by shape Long bones – located primarily in the arms and legs

Femur (thigh bone) Humerus (upper arm bone)

Short bones – small bones located in the wrists and ankles

Carpals (wrist bones) Tarsals (ankle bones)

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Bone Structure (cont.)

Flat bones – located in the skull and rib cage Ribs Frontal bone

Irregular bones Vertebrae Bones of the pelvic girdle

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Bone Structure: Gender Differences Male Skull

Larger and heavier

Forehead shorter

Face less round

Jaw larger

Mastoid processes more prominent

Male pelvic bones Heavier and thicker Pelvic Basin Narrow

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Male pelvic cavity Narrower and longer Less roomy and more

funnel shaped Male sacrum

Narrower Sacral promontory projects forward

Male coccyx Less movable

Bone Structure: Gender Differences (cont.)

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Apply Your KnowledgeMatch bone to classification.___ Humerus L.

Long bones___ Rib S.

Short bones___ Femur F.

Flat bones___ Pelvic bones I.

Irregular bones___ Carpals___ Frontal bone___ Vertebra___ Tarsals

FL

IS

IF

S

L

ANSWER:

Very Good!

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Functions of Bones Give shape to body parts

Support and protect soft structures Examples – brain, lungs, heart

Allow body movement, because skeletal muscles attach to them Allow for voluntary movement

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Functions of Bones (cont.)

Red bone marrow of bone produces new blood cells – hematopoiesis

Store calcium

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Apply Your Knowledge

ANSWER: Every cell in the body needs calcium, so the body must have a large supply readily available.

Why is it important for the bones to store calcium?

Correct!

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Bone Growth Ossification – process of bone

growth

Intramembranous ossification Bones begin as tough, fibrous

membrane Bone-forming cells called

osteoblasts turn the membrane to bone (located in skull)

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Bony Structures Rigid foundation Projections and processes for muscle and

ligament attachment Depressions and hollows for articulations – the

connection of bones at joints Openings for blood vessels and nerves

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Bony Structures (cont.)

Term Definition

Condyle A rounded process that usually articulates with another bone

Crest A narrow, ridge-like projection

Epicondyle A projection situated above a condyle

Foramen An opening through a bone that is usually a passageway for blood vessels, nerves, or ligaments

Fossa A relatively deep pit or depression

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Bony Structures (cont.)

Term Definition

Head An enlargement on the end of a bone

Process A prominent projection on a bone

Suture An interlocking line of union between bones

Trochanter A relatively large process

Tubercle A small, knoblike process

Tuberosity A knoblike process, usually larger than a tubercle

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The Skull Two bone types:

Cranial – form the top, sides, and back of the skull

Facial – form the face

“Soft spots” felt on an infant's skull are actually fontanels Tough membranes that connect the

incompletely developed bones

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Match the following:

___ Epicondyle A. A relatively deep pit or depression

___ Fontanels B. An interlocking line of union between bones

___ Fossa C. “Soft spots” felt on an infant’s skull

___ Process D. A knoblike process, usually larger than a tubercle

___ Suture E. A projection situated above a condyle

___ Tuberosity F. A prominent projection on a bone

C

A

F

B

D

E

ANSWER:

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The Skull: Cranial Bones

Frontal – anterior

Parietal – top and most of the sides

Occipital – back

Temporal – form the lower sides of the skull

Sphenoid and ethmoid bones – floor

Ear ossicles are the smallest bones of the body Malleus Incus Stapes

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The Skull (cont.)

Mandible – forms the lower jaw bone

Maxillae – form the upper jawbone

Zygomatic – form the prominence of the cheeks

Nasal bones – fuse together to form the bridge of the nose

Click to see Skull

Palatine – form the anterior portion of the palate

Vomer – a thin bone that divides the nasal cavity

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The Spinal Column

7 cervical vertebrae 12 thoracic vertebrae 5 lumbar vertebrae Sacrum Coccyx

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The Spinal Column (cont.)

Cervical vertebrae Smallest and lightest Located in the neck

region First one is atlas Second one is axis

Thoracic vertebrae Join the 12 pairs of ribs

Lumbar vertebrae Have very sturdy

structures

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The Spinal Column (cont.)

Sacrum A triangular-shaped bone that consists of five fused

vertebrae Coccyx

A small, triangular-shaped bone made up of 3 to 5 fused vertebrae

Considered unnecessary More commonly called the tailbone

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Identify the sections of the spinal column and give the number of vertebrae for each.

Thoracic – 12

Lumbar – 5 Sacrum – 5 fused

Coccyx – 3 to 5 fused

Cervical – 7ANSWER:

Right!

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The Rib Cage

Sternum Breastplate Forms the front middle

portion of the rib cage Joins with the clavicles

and most ribs Xyphoid process

Cartilaginous tip

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The Rib Cage (cont.)

12 pairs of ribs All are attached

posteriorly to thoracic vertebrae

True First seven pairs of

ribs Attach to sternum by

costal cartilage

False Rib pairs 8, 9, and 10 Attach to the costal

cartilage of rib pair 7 Floating

Rib pairs 11 and 12 Do not attach anteriorly

to any structure

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True or False:

___ The sternum forms the front middle portion of the rib cage.

___ The xyphoid process is a boney tip of the sternum.

___ The true ribs are the first five pairs of ribs.

___ False ribs attach to the costal cartilage of rib pair seven.

___ Floating ribs attach to the xyphoid process.

T

T

ANSWER:

Fcartilaginous

Fseven

Fdo not attach anteriorly to any structure.

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Bones of the Shoulders, Arms, and Hands

Shoulders – pectoral girdles Clavicles Scapulae

Upper limb or arm bones Humerus Radius Ulna

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Bones of the Shoulders, Arms, and Hands (cont.)

Hand 8 carpals per hand 5 metacarpals per hand 14 phalanges per hand

3 in each finger 2 in each thumb

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Apply Your KnowledgeMatch the following:

___ Clavicle A. Pectoral girdle

___ Radius B. Arm bones

___ Humerus C. Hands

___ Carpals

___ Scapula

___ Ulna

___ Phalanges

___ Metacarpals

A

BB

B

C

CC

AANSWER:

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Bones of the Hips, Legs, and Feet

Hipbones Coxal bones form

the pelvic girdle Ilium Ischium Pubis

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Bones of the Hips, Legs, and Feet (cont.)

Bones of leg Femur Patella Tibia Fibula

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Bones of the Hips, Legs, and Feet (cont.)

Bones of the foot Tarsals Metatarsals Phalanges

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A. Coxal bones B. Leg bones C. Foot bones

___ Tibia ___ Patella

___ Ilium ___ Ischium

___ Femur ___ Metatarsals

___ Pubis ___ Fibula

___ Calcaneus ___ Tarsals

B

B

B

A A

A

C

C

C

B

ANSWER:

Super!

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Joints Junctions between bones Classification based on

structure Fibrous joints

Connected together with short fibers

Between cranial bones and facial bones

Sutures – fibrous joints in the skull

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Joints Cartilaginous

joints Connected

together with a disc of cartilage

Between vertebrae

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Joints Synovial joints

Covered with hyaline cartilage Held together by a fibrous joint

capsule lined with synovial membrane

Secretes synovial fluid so bones move easily against each other

Freely movable Bones are also held together through tough, cord-like

structures called ligaments

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A. Fibrous joints B. Cartilaginous joints C. Synovial joints

____ Between cranial bones and facial bones

____ Covered with hyaline cartilage

____ Between vertebrae

____ Freely movable

____ Sutures in the skullA

BC

C

A

ANSWER:

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Common Diseases and Disorders Arthritis – general term meaning joint

inflammation Osteoarthritis – degenerative joint disease,

primarily of weight-bearing joints

Rheumatoid Arthritis – chronic systemic inflammatory disease of smaller joints and surrounding tissues

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Common Diseases and Disorders (cont.)

Bursitis – inflammation of a bursa (fluid-filled sac that cushions tendons)

Carpal Tunnel Syndrome – overuse of wrist; the median nerve in the wrist becomes compressed

Ewing’s Family of Tumors (EFT) – a group of tumors that affect different tissue types; primarily bone

Gout – a type of arthritis; deposits of uric acid crystals in the joints

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Kyphosis – abnormal curvature of the spine (humpback)

Lordosis – exaggerated inward curvature of the lumbar spine (swayback)

Osteogenesis imperfecta – brittle-bone disease

Osteoporosis – a condition in which bones thin (become porous) over time

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Osteosarcoma – a type of bone cancer that originates from osteoblasts, the cells that make bony tissue

Paget’s disease – causes bones to enlarge and become deformed and weak

Scoliosis – an abnormal S-shaped curvature of the spine

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Osteosarcoma is a type of bone cancer that originates from osteoblasts, the cells that make bony tissue.

The doctor has told your patient that he has an osteosarcoma. What do you know about this disorder?

Nice Work!

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In Summary Skeletal system

Two divisions Bone growth through ossification Functions

Supports the body Protects internal organs Attachment for muscles for movement Stores minerals Produces new blood cells by hematopoiesis

Joined by three types of joints

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End of Chapter

Rigid, the skeleton of habit alone upholds the human frame.

~ Virginia Woolf

Health & Medicine

Kathryn Selman