Chapter 3 Medical
Terminology and
Chapter 6 Body
Structures
THE SKELETAL SYSTEM
Structures of the Skeletal
System
 INCLUDES:
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Bones
Cartilage
Ligaments
Joints
Bursa
Functions of the Skeletal System
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Bones – act as framework of body, support
and protect the internal organs – stores
calcium required for normal nerve and
muscle function
Joints/Muscles/Ligaments, and tendons –
make variety of body movements possible
Red Bone Marrow – located in spongy
bone, has important function in the formation
of blood
The Structure of Bones
 Bone is a form of
connective tissue and
is almost the hardest
tissue in the human
body (dental enamel is
harder)
 Tissues of Bone:
 Although it is very hard
and dense, bone is a
living structure that
changes and is
capable of healing
itself
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Located w/in spongy bone,
is hematopoietic and
manufactures red blood
cells, hemoglobin, white
blood cells, thrombocytes
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CAUTION: the word part
myel/o means either bone
marrow or spinal cord
Hematopoietic/hemopoietic:
pertaining to formation of
blood cells
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Hemato/Hemo = blood
Poietic = pertaining to
formation
Yellow Bone Marrow:
found in medullary cavity,
composed chiefly of fat cells
and functions as a fat
storage area
Bone Marrow
Joints - aka articulations
 – connections btwn. Bones
 Articulate: to join or to come together in a
manner that allows motion between parts
 Types of Joints
 Sutures
 Symphyses
 Synovial Joints
Sutures
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The jagged line where
bones join and form an
immovable joint
Fontanel/fontanell:
AKA soft spot – where
the sutures btwn. the
frontal/parietal bones
have not yet closed
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on a baby’s head
disappears as the child
grows and the sutures
close
Symphyses
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Symphysis: where
2 bones join and are
held firmly together
so they function as
one bone
(ie: pubic symphysis)
Synovial Joints
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Movable joints of body
Ball and Socket Joints: synovial joints that allow a
wide range of movement in many directions (ie: hips
and shoulders)
Hinge Joints: synovial joints that allow movement
primarily in one direction or plane (ie: knees and
elbows)
The Skeleton
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206 bones total in adult human body
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divided into 2 systems
 Axial: (80 bones) protects the major organs of the
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nervous, respiratory, and circulatory systems – axial refers
to an imaginary line or axis thru the center of the body –
includes skull, spinal column, ribs, and sternum
Appendicular: (126 bones) makes body mvmt. Possible,
also protects the organs of digestion, excretion, and
reproduction – appendicular refers to an appendage, which
is anything attached to a major part of the body
Organized into:
 Upper extremities: shoulders, arms, forearms, wrists
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and hands
Lower Extremities: hips, thighs, legs, ankles, and feet
Cranium - portion of the skull that
encloses the brain
CONSISTS OF:
 Frontal bone: forms the forehead
 Parietal bones: form most of the roof and upper sides
of the Cranium
 Occipital bone: forms the posterior floor and walls of
the cranium
 foramen magnum: opening in occipital bone thru which
spinal cord passes
 Temporal bones: form the sides and base of the
cranium
 Sphenoid bone: forms part of the base of the skull and
parts of the floor and sides of the bony socket
surrounding and protecting the eyeball
 Ethmoid bone: forms part of the nose, the orbit, and
the floor of the cranium
Auditory Ossicles
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bones of the middle ear
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EAM: external auditory meatus – external opening of
the ear, is located in the temporal bone
Thoracic Cavity, Ribs, and
Sternum
 Thoracic Cavity: AKA rib cage –
made up of the ribs, sternum, and
thoracic vertebrae
 Ribs: 12 pair (costals) attach to
thoracic vertebrae posteriorly
 First 7 pair – true ribs – attach
anteriorly to the sternum (FIG
3.11)
 Next 3 pair – false ribs – attach
anteriorly to cartilage that joins
with the sternum
 Last 2 pair – floating ribs – are not
attached anteriorly
 Sternum: forms middle of the
front of the rib cage – divided into
3 parts
 Manubrium: bone, upper portion
of the sternum
 Body: bone, middle portion
 Xiphoid process: cartilage, lower
portion
Shoulders
 Pectoral girdle: AKA
shoulder girdle –
supports arms and hands
 Clavicle: slender bone
that connects the sternum
to scapula
 Scapula: shoulder blade
 Acromion: an extension
of the scapula that form
highest point of the
shoulder
Arms
 humerus: bone of upper arm
 radius: smaller bone in the
forearm, runs up the thumb
(lateral) side of arm
 ulna: larger bone of the
forearm, articulates with the
humerus to form the elbow
joint
 olecranon process: large
projection on the proximal end
of the ulna that forms the point
of the elbow
Wrists and Hands
 carpals: bones of the
wrist
 metacarpals: form
the palm of the hand
 phalanges: bones of
the fingers (and toes)
 each finger has 3
bones: distal, middle,
proximal phalanges
 thumb: only distal and
proximal phalanges
Spinal Column
 consists of 26 vertebrae
– functions to support
head and body and
protect spinal cord
Types of Vertebrae
 Cervical: first set of 7 –
 form neck C1 – C7
 Thoracic vertebrae: second
set of 12 vertebrae –
 form outward curvature of spine T1
– T12
 Lumbar vertebrae: third set of
vertebrae
 L1 – L5 – largest and strongest of
the vertebrae – form the inward
curvature of spine
Intervertebral Disks
• made of cartilage, separate and cushion the
vertebrae from each other, act as shock absorbers
and allow for movement of the spinal column
Sacrum/ Coccyx
 Sacrum
 triangular shaped bone near the base of the
spine (FIG 3.15)
 at birth = 5 separate sacral bones = fuse to
form one in young child
 Coccyx
 tailbone, forms end of spine and is made up
of four small bones fused together
Pelvic Girdle - Protects internal organs and
supports lower extremities
3 BONES FUSED TOGETHER – posteriorly w/
sacrum
 ilium: upper, blade shaped part of hip on each side
of the pelvic girdle
 sacroiliac: slightly moveable articulation btwn. Sacrum and
ilium
 ischium: lower and posterior portion of the pelvic
girdle
 pubis: anterior portion of the pelvic girdle
 2 pubic bones join at anterior midline to form pubic
symphysis – cartilaginous joint that holds the bones firmly
together
 acetabulum: large socket in pelvic bones, forms hip socket
for head of femur
Legs and Knees
Femur
 upper leg bone – largest bone in body
 head: articulated with the acetabulum
 femoral neck: narrow area just below the head of the femur
 trochanter: one of the two large bony projections of the
proximal end of the femur just below the femoral neck
Knees
 patella: bony anterior portion of the kneecap
 popliteal: refers to the posterior surface of the knee – used to
describe the structures in this area
 anterior cruciate ligament (ACL)/posterior cruciate ligament
(PCL): make the movements of the knee possible – shaped like
a cross
Lower Leg
Tibia: larger weight-bearing bone in the anterior of the lower leg
 fibula: smaller of the 2 bones of the lower leg
Medical Specialties Related to
the Skeletal System
 chiropractor
 orthopedic surgeon
 orthotics
 osteopathic physicians
 podiatrist
 rheumatologist
Curvatures of the spine
 kyphosis: abnormal increase in the
outward curvature of thoracic spine
(dowager’s hump)
 lordosis: abnormal increase in forward
curvature of the lumbar spine (swayback)
 scoliosis: lateral curvature of the spine
Scoliosis
Lordosis
Kyphosis
Fractures - broken bone
 greenstick fx: bone is partially bent and only partially
broken
 usually longitudinal and occurs primarily in children
 closed fx: complete fx – bone is broken but there is no
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open wound in the skin
transverse fx: straight across the bone
oblique fx: at an angle
open fx: compound fx – bone is broken and there is an
open wound in the skin
comminuted fx: the bone is splintered or crushed
compression fx: bone is pressed together on itself
spiral fx: bone has been twisted apart – occurs as a
result of a severe twisting motion as in a sports injury
stress fx: small crack in bones that often develop from
chronic, excessive impact – usually due to a sports injury
Diagnostic Procedures of the
Skeletal System
 arthrocentesis: surgical puncture of joint to remove synovial fluid
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for analysis
arthroscopy: visual exam of internal structure of joints, using an
arthroscope
Bone density testing: densitometry, use of radiation tests to
determine bone density
Bone marrow biopsy: insertion of a sharp needle into the hipbone
or sternum and removing bone marrow cells, used to determine why
blood cells are abnormal, also to find a donor match
Bone scan: use of nuclear medicine to detect bone cancer and
osteomyelitis
Dual X-ray absorptiometry
MRI
Radiographs
arthroscopy
arthrocentesis
Bone marrow biopsy and tools
Bone density testing
X-rays
Treatment procedures for Joints
 arthroscopic surgery: use of an arthroscope
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and other instruments to treat the interior of a
joint, ie: removal of torn cartilage
bursectomy: surgical removal of a bursa
chondroplasty: surgical repair of cartilage
synovectomy: surgical removal of a synovial
membrane from a joint, used to repair a joint
damaged by rheumatoid arthritis
arthrodesis: fusion, surgical procedure to
stiffen a joint to join spinal vertebrae
arthrolysis: surgical loosening of an ankylosed
joint
periosteotomy: incision thru the periosteum
chondroplasty
arthroscopy
synovectomy
bursectomy
arthrodesis
Arthroplasty
And
prosthesis
Joint Replacement
 arthroplasty: surgical repair of a
damaged joint – surgical replacement of a
joint
 prosthesis: implant or substitute for
diseased or missing part of the body
 total knee replacement
 partial knee replacement
 total hip replacement
 revision surgery
Spinal Column
 diskectomy: surgical removal of an
intervertebral disk
 percutanious diskectomy: thin tube is inserted
thru skin of the back – suction is used to remove
ruptured disk or vaporize it with a laser
 laminectomy: surgical removal of the lamina
from vertebrae
 spinal fusion: immobilize part of the spine by
fusing 2 or more vertebrae
Bones
 craniectomy: surgical removal of a portion of
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the skull
craniotomy: bone flap – surgical incision or
opening into the skull that is performed to gain
access to part of the brain
cranioplasty: surgical repair of the skull
osteoclasis: surgical fx of bone to correct a
deformity
ostectomy: surgical removal of bone
osteoplasty: surgical repair of bones
osteorrhaphy: suturing or wiring together of
bones
osteotomy: surgical incision or sectioning of a
bone
Treatment of Fractures
 manipulation: attempted realignment of the bone
(closed reduction)
 traction: pulling force exerted on a limb in a distal
direction in an effort to return the bone or joint to normal
alignment
 immobilization: holding or suturing or fastening the
bone in a fixed position (ie casting)
External Fixation
 fx treatment where pins are place thru the soft tissues
and bone for the use of external appliance to hold pieces
of bone firmly in place during healing
 ex fix removed after healing
Internal Fixation
 open reduction – fx in treated with pins or a plate placed
directly into bone to hold broken pieces in place
 not usually removed after healing occurs