The Skeletal System
http://www.octc.kctcs.edu/gcaplan/anat/Notes/API Notes H Skeletal System.htm
Terminology
•
•
•
•
1Condyle
– Rounded prominence
2Facet – Smooth articular surface
3Fissure – Narrow opening
4Foramen – Opening or hole through
bone
• 5Fossa – Depression or groove
http://faculty.pnc.edu/rhengst/articsurf/condyle.GIF
http://www.downingchiropractic.com/clipart/facet.gif
FISSURE
FISSURE
http://www.octc.kctcs.edu/gcaplan/anat/images/Image180.gif
http://faculty.washington.edu/chudler/gif/foramen.gif
FOSSA
http://www.mut.ac.th/~vet/Anat-html/bone/bone_html_m5461230e.jpg
• 6Process – Any bone projection
• 7Spine – A narrow or pointed
projection
• 8Trochanter – A large, blunt
process
http://www.octc.kctcs.edu/gcaplan/anat/Notes/API Notes H Skeletal Features.htm
PROCESS
http://ect.downstate.edu/courseware/haonline/figimgs/22_1.gif
SPINE
http://ect.downstate.edu/courseware/haonline/imgs/00000/1000/700/1753.jpg
TROCHANTER
http://www.amberdragon.ca/book/images/0503/0301pelvis.gif
• 9).Tubercle – A small, rounded
process
• 10).Tuberosity – A rounded,
elevated area of a bone that is
usually roughened
http://www.gla.ac.uk/ibls/fab/images/anatomy/glegadtu.gif
http://www.eorthopod.com/images/ContentImages/knee/child_knee_osgood/child_knee_osgood_anatomy01.jpg
Types of bones
• 4 types of bones.
• Long bones - longer than they are
wide.
• Short bones - equal in length and
width.
• Flat bones - thin and flat.
• Irregular bones do not fit into any
of these categories.
http://upload.wikimedia.org/wikipedia/commons/9/94/Illu_long_bone.jpg
http://www.personal.psu.edu/users/j/m/jmh595/
http://www.personal.psu.edu/users/j/m/jmh595/graphics/flatbone.jpg
IRREGULAR BONES
http://www.personal.psu.edu/users/j/m/jmh595/Irregular%20bones.htm
Bone Structure
• The shaft of the long bone is called
the diaphysis.
• The extreme ends of the bones are
known as the epiphyses.
• The diaphysis is between the two
epiphyses.
http://www.octc.kctcs.edu/gcaplan/anat/images/Image267.gif
• Epiphysis of one bone meets the
epiphysis of another bone is called
a joint.
• Cartilage in joint known as the
articular cartilage.
http://www.the-health-pages.com/images/artic0.jpg
• Bone - covered by a layer of
connective tissue (periosteum).
• Provides nourishment attaches
ligaments and tendons.
http://faculty.southwest.tn.edu/rburkett/AP1_b12.jpg
• Two types of bone tissue in the
diaphysis.
• Compact bone is tightly packed and
forms the walls of the diaphysis.
• Spongy bone is less compact and is
found in the diaphysis.
http://training.seer.cancer.gov/module_anatomy/images/illu_compact_spongy_bone.jpg
• Within the spongy bone is red
marrow.
• Within the diaphysis is a chamber
called the medullary cavity.
• This cavity has yellow marrow which
is used for energy storage.
http://www.sirinet.net/~jgjohnso/skeletonorg.html
Leukemia
• Red marrow - makes red blood cells
(hematopoiesis), white blood cells,
and platelets.
• When white blood cells can’t fight
off infection, leukemia develops.
• Treatment for leukemia - injecting
new bone marrow into the patient.
http://www.montana.edu/wwwai/imsd/cancer/van1/vwtreatments_files/image009.jpg
*Bone cells
• There are three types of bone
cells.
• 1Osteoblasts - come from
embryonic cells and found on
surface of bone tissue.
• They lay bone down around
themselves - become surrounded
by bone matrix.
• Then they are called 2osteocytes.
http://academic.kellogg.edu/herbrandsonc/bio201_McKinley/f6-6a_types_of_cells_in_c.jpg
• 3Osteoclasts are found in the bone
tissue and are involved with
secretion of a substance that
breaks down the bones.
• Osteoclasts help to break down the
bone so that osteoblasts can lay
new bone.
• This is how a bone grows.
http://ae.medseek.com/bguide/reftext/images/osteoclast.jpg
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/bonediagr.gif
Under the microscope
• Osteocytes are found in spaces
called lacunae, which are found
between lamellae.
• These lamellae are layered in
circles around canals known as
Haversian canals.
http://w3.ouhsc.edu/histology/Glass%20slides/69_04.jpg
http://www.cytochemistry.net/microanatomy/bone/cpbone.jpg
Bone Growth
• 2 forms of development.
• 1Intramembranous bones - cells
develop between sheetlike layers of
connective tissue.
• 2Endochondral bones - masses of
cartilage are later replaced by bone
tissue.
• Intramembraneous bones - bones
of the skull.
• Connective tissue appears where
the bones will eventually be.
• Some of that connective tissue
differentiates into the osteoblasts,
which lay down bone.
http://www.mhhe.com/biosci/esp/2001_saladin/folder_structure/su/m2/s4/assets/images/sum2s4_1.jpg
• In endochondral bone (most other
bones) - masses of cartilage have
same basic shape as future bones.
• The cartilage cells die - osteoblasts
replace them.
• Happens in two stages - primary and
secondary ossification centers.
• When bone nears end of early
development, a narrow band of
cartilage remains between
epiphyses and the diaphysis
(epiphyseal plate)
• These are growth plates - located
at each end of the bone.
• Determines how long your bones will
be.
http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/18022.jpg
http://www.curehandpain.com/images/bone/bone_growth.gif
• Growth plate injuries can happen.
• This is when the growth plate area
is broken.
• In severe cases (only in children), it
can stunt growth of the bone.
• When these growth plates close,
you are done growing.
http://www.vetsurgerycentral.com/images/growth_plate.gif
• Osteoblasts and osteoclasts - lay
down bone and breaking down bone.
• Once the epiphyseal plate is gone done growing.
• The osteoblasts and osteoclasts are
important in broken bones.
http://www.hughston.com/hha/b_15_3_1c.jpg
Broken bones
• Complete fractures - bone is
completely broken.
• Greenstick fracture - fracture is
not completely through.
• Comminuted fracture - bone is
shattered.
http://www.medterms.com/images/ABBONE.GIF
Organization of Skeletal System
• Skeleton is divided into two parts.
• 1Axial skeleton - bones that are
located medially.
• 2Appendicular skeleton - bones that
are responsible for appendages.
http://ae.medseek.com/bguide/reftext/images/Axial_AppendicularSkel.jpg
• Axial skeleton - skull, the hyoid
bone, vertebral column, and
thoracic cage.
• Appendicular skeleton - the
pectoral girdle, upper limbs, pelvic
girdle, and lower limbs.
http://nsca.hkeducationcenter.com/courses/OEC_Previews/hf-ft101ue_preview/images/Fig_06.png
Axial Skeleton *
• ASkull - Consists of 22 bones that
are joined by sutures.
• Sutures are rigid, narrow joints.
• The “soft spot” in infants is an area
where the sutures have not fully
closed yet.
http://www.chsd.org/images/craniofacial/3a.gif
• Sinuses - chambers in the skull that
are lined with mucous membranes.
• Drain fluids, reduce the weight of
the skull, and resonate sound from
the voice.
• Sinuses can become infected (sinus
infection).
http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1108.jpg
Bones of the skull
• The cranium encloses and protects
the brain. It is made of 8 bones.
• 1Frontal bone – large bone that
forms the anterior part of the skull
above the eyes. Contains the eye
sockets (orbits).
Frontal bone
http://www.ams.org.za/CME-Topics/images/cme1-1.jpg
• Located above each orbit is the
supraorbital foramen which is a
hole through which blood vessels
and nerves travel.
• The frontal bone also has the
frontal sinuses.
Supraorbital foramen
http://www.upstate.edu/cdb/grossanat/imgs/skullantmax3.jpg
• 2The parietal bones (2)
• Two parietal bones - one left and
one right. Form the lateral part of
the cranium.
• Meet at the top (the sagittal
suture); meet the frontal bone at
the coronal suture.
Parietal bones
http://www.thecraniofacialcenter.org/images/cranio_sksag.jpg
http://www.thecraniofacialcenter.org/images/cranio_skcor.jpg
• 3Occipital bone - forms the
posterior wall of the cranium.
• Meets the parietal bones at the
lambdoidal suture.
• Foramen magnum - large opening
that allows spinal cord to pass
between the cranium and the spinal
cavity.
Occipital Bone
http://www.upstate.edu/cdb/grossanat/hnsklatob1.shtml
• 4Temporal bones (2) - on either side
of the cranium (think temples!!)
• External auditory meatus located
here and is the opening to the inner
ear.
• Zygomatic arch (your cheekbone)
joins the temporal bone to the
zygomatic bone.
Temporal Bone
http://www.upstate.edu/cdb/grossanat/hnsklatob1.shtml
Zygomatic Arch
• The mastoid process is located
posterior and is the location of the
attachment of neck muscles.
• The styloid process is the location
of the attachment of the muscles
of the tongue.
Mastoid process
Styloid process
http://ect.downstate.edu/courseware/haonline/figimgs/22_3.gif
External auditory meatus
• 5Sphenoid bone- wedged between
other bones in the skull.
• Home of the optic foramen, where
the optic nerve passes to go to the
brain.
• Pituitary gland is housed in the sella
turcica in the sphenoid bone.
• Sphenoidal sinuses here.
Sphenoid Bone
http://www.upstate.edu/cdb/grossanat/hnsklatob1.shtml
Sella Turcica (means “Turkish saddle”)
http://ect.downstate.edu/courseware/haonline/simgs/00000/3000/600/3615.jpg
Optic
foramen
http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1276.jpg
• 6Ethmoid bone - anterior to the
sphenoid.
• Mostly internal and forms part of
nasal cavity.
• Ethmoid forms into the superior
and middle nasal conchae (into the
nostrils)
• Ethmoidal sinuses here.
http://www.tpub.com/content/medical/14274/css/14274_43.htm
Nasal conchae
*
• BFacial bones - 13 immovable bones
in the face and a movable lower jaw.
• Support the face and provide
attachments for the muscles that
control facial expressions.
• 1Maxillary bones - two bones
located on side of the face that
form the upper jaw.
• Maxillary sinuses (the largest ones)
are located here.
• The roof of the mouth (including
both palates) are formed by these
bones.
http://www.octc.kctcs.edu/gcaplan/anat/images/Image179.gif
• 2Palatine bones - 2 L-shaped bones
that are located posterior to the
maxillary bones.
• Form the posterior roof of the
mouth.
http://www.octc.kctcs.edu/gcaplan/anat/Notes/Image524.gif
• 3Zygomatic bones – 2 bones that
are found on the side of the face
and form the cheekbones.
• Forms the zygomatic arch with the
temporal bones.
Zygomatic
bones
http://mywebpages.comcast.net/wnor/latskulllabelled.jpg
• 4Nasal bone - the two bones meet
at the midline to form the bridge
of the nose.
• The rest of the nose is formed
from cartilage.
Nasal Bones
http://www.upstate.edu/cdb/grossanat/hnskullantzb.shtml
• 5Lacrimal bones – 2 bones that are
posterior and lateral to the nasal
bones.
• Lacrimal means tears, so they are
located in approximately the same
area as your tear ducts.
Lacrimal Bone
http://www.upstate.edu/cdb/grossanat/hnskullantzb.shtml
• 6Vomer (1) - Located along the
midline of the nasal cavity.
• The nasal septum divides the cavity
into the left and right sides.
• A deviated septum is when the
cavity is not divided into equal
halves.
Vomer
http://www.mnsu.edu/emuseum/biology/humananatomy/skeletal/skull/vomer/done4.jpg
• 7Inferior nasal conchae (2) - Found
below the superior and middle
conchae of the ethmoid bone.
Inferior nasal conchae
http://anatomy.uams.edu/anatomyhtml/graphics/rsa1p9.gif
• 8Mandible - lower jaw bone that
articulates with the temporal
bones.
• The only movable bone of the skull.
http://www.probertencyclopaedia.com/ED.HTM
The hyoid bone
• This bone does not articulate with
any other bone in the entire body.
• It supports the tongue and provides
attachment for some of the
muscles of the tongue.
http://www.octc.kctcs.edu/gcaplan/anat/images/Image186.gif
• CVertebral column - support for the
trunk of the body.
• It runs from the skull to the pelvis.
• The bones that make up this column
are known as vertebrae and are
separated from each other by
intervertebral discs.
http://hippocrates.ouhsc.edu/showcase/Gross/Lab3/Fig2-6.jpg
• A herniated
disk happens
when the disk
breaks and puts
pressure on the
spinal nerve.
http://www.diagnostico.com/trejos/herniate.stm
• The 33 vertebrae are divided into
regions.
• Cervical vertebrae (7) are in the
neck.
• Thoracic vertebrae (12) in the
thorax.
• Lumbar vertebrae (5) in the lower
trunk
• Sacral vertebrae (5) are fused
(sacrum)
• The coccygeal (3-5) are fused
(coccyx).
• Each region has a curve associated
with it.
http://sinoemedicalassociation.org/orthopedicsurgery/vert-column.gif
• A vertebrae made up mostly of the
body.
• Middle - vertebral foramen that
the spinal cord passes through.
• Spiny part of the vertebrae called
the spinous process.
• Connected to the body by pedicle.
• Transverse process are lateral
projections.
http://www.hunterian.gla.ac.uk/collections/anatomy/students_projects/spinalcord/images/vertebrae-top.jpg
• The cervical vertebrae have two
unique members.
• The atlas is the first vertebrae and
it articulates with the skull.
• The second vertebrae is the axis
and allows the nodding of the head
by articulating with the atlas.
http://www.spineuniverse.com/displaygraphic.php/127/atlasaxis3-BB.jpg
• The thoracic vertebrae are larger
than the cervical vertebrae.
• The lumbar vertebrae are thicker
than the thoracic.
• The sacrum is triangular as a result
of the fusion.
• The coccyx is your tailbone.
http://www.nlm.nih.gov/medlineplus/directories.html
• DThoracic cage - formed from the
sternum and ribs.
• Sternum is the breastbone and
located in the middle of the chest.
• It is made of three parts; the
superior manubrium, the body, and
the inferior xiphoid process.
http://academic.kellogg.edu/herbrandsonc/bio201_McKinley/f7-32b_thoracic_cage.jpg
• Ribs (12 pairs) attaches to
individual thoracic vertebra
sternum (by costal cartilage)
• First seven pairs of ribs are true
ribs - attached at both points.
• Five pairs are false ribs have very
little connection.
• Last two - floating ribs (no
cartilage)
http://www.accd.edu/pac/biology/a_plabs/LabEx10Week6/LabEx10images/ribcagelabel.jpg
Appendicular Skeleton
• AThe Pectoral Girdle - shoulder
girdle is made up of two clavicles
(collarbones) and two scapulae
(shoulder blades)
• Scapulae have two processes (the
coracoid process and the acromion
process) allows for attachment of
muscles.
http://www.pinkmonkey.com/studyguides/subjects/biology-edited/chap20/fig20_15.jpg
http://www.sci.utah.edu/~simpson/documentation/projects/annotation/webdocs/image_gal_files/miscellaneous/clavicle.jpg
*
• BThe upper limb - humerus extends
from scapula to elbow.
• The head of the humerus fits into
the glenoid cavity of the scapula.
• The two tubercles (the greater and
lesser) provide attachments for
muscles.
http://academic.wsc.edu/faculty/jatodd1/351/humerus.jpg
• Lower end of the humerous - two
condyles that articulate with radius
and ulna.
• Two fossas (the coronoid on the
anterior side and the olecranon on
the posterior side) allow for elbow
movements.
http://medicalclipart.tripod.com/skelbw/HUMERUS.gif
• Radius - bone located on thumb side
of forearm; extends from elbow to
wrist.
• Head of radius articulates with
humerus and a notch of the ulna.
• Radial tuberosity allows for muscle
attachment and styloid process
allows for wrist ligament
attachment.
Radius
• Ulna is longer than radius and
overlaps the end of the humerus.
• Proximal end - the ulna has a
trochlear notch that articulates
with the humerus.
• Two processes on either end of the
notch; the olecranon process and
the coronoid process.
http://www.pdh-odp.co.uk/images/RadiusUlna.JPG
• Distal end of ulna is the head that
articulates with the radius.
• Ulna also has a styloid process that
allows for attachment of the wrist
ligaments.
• Hand is composed of wrist, palm,
and five fingers.
• Wrist is made up of eight carpal
bones.
• The eight bones of the wrist are
the lunate, hamate, triquetrum,
pisiform, scaphoid, capitate,
trapezoid, and trapezium.
http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/T051169A.gif
• Palm consists of five metacarpal
bones.
• Finger bones are known as the
phalanges.
• Each finger has proximal, middle,
and distal phalanx (the thumb does
not have the middle)
http://www.apta.org/AM/Images/APTAIMAGES/ContentImages/ptandbody/hand/hand-bones.gif
• CPelvic girdle - 2 coxal bones that
articulate with each other
anteriorly and the sacrum
posteriorly.
• Sacrum, coccyx, and pelvic girdle
together form pelvis.
• Pelvis supports trunk of the body,
provides attachments for lower
limbs, and protects organs located
in that area.
http://www.shockfamily.net/skeleton/PELVIC.JPG
* parts.
• Coxal bone has three
• Ilium is part of the bone that you
think of as the hip. Flares outward
and forms the bony prominence of
the hip.
• Top of this is called the iliac crest.
• Ilium joins the sacrum at the
sacroiliac joint and has anterior
superior iliac spine which provides
attachments for muscles.
http://www.coretherapy.com/images/si_joint.jpg
• Ischium forms the lowest portion
of the coxal bone.
• Ischial tuberosity points
posteriorly and downward and
provides attachment for muscles
and ligaments.
• Where the ilium meets the ischium
is a projection called the ischial
spine.
http://emedic.com/images/K_full_anatomy_pelvis.jpg
• Pubis is anterior part of the coxal
bone.
• 2 pubic bones join at midline,
forming a joint called the symphysis
pubis.
• Angle of these bones below the
symphysis pubis is called pubic arch.
• Obturator foramen is found in
pelvic girdle and is the largest in
the body.
http://mywebpages.comcast.net/wnor/xrayhip.jpg
• DLower limbs form thigh, leg, and
foot.
• Femur is longest bone in the body
and extends from hip to the knee.
• Head of the femur fits in the
acetabulum of the coxal bone.
• On head is fovea capitis which
allows attachment of a ligament.
http://www.courses.vcu.edu/DANC291-003/femur%20bone.jpg
• Below the head – 2 processes; the
greater trochanter and the lesser
trochanter.
• Distal end of femur - 2 condyles
(lateral and medial) that articulate
with tibia of the leg.
• Patella (kneecap) articulates with
femur at distal end.
http://www.pawfectchihuahuas.com/patella.gif
• Tibia – shinbone; larger of two
lower leg bones (located medially).
• Proximal end has medial and lateral
condyles that articulate with the
condyles of the femur.
• Below condyles is tibial tuberosity.
• Distal end - medial malleolus.
http://www.allaboutarthritis.com/image/stock_image/MMG_Knee_front_side_view.jpg
• Fibula - smaller lower leg bone.
• Has a head at the proximal end and
a lateral malleolus at the distal end.
• The lateral malleolus is responsible
for the bump you feel on the side
of your ankle.
http://pharyngula.org/archives/A2003111/
• Foot - 7 tarsal bones (calcaneous,
talus, navicular, cuboid, lateral
cuneiform, intermediate cuneiform,
and the medial cuneiform)
• Talus moves freely where it meets
the fibula and tibia.
• Calcaneous - largest (heel bone)
Talus
Calcaneus
http://icbmedical.com/education/anatomy
• Tarsal bones articulate with
metatarsals.
• 5 metatarsals articulate with
phalanges (the toes).
• 3 phalanges for each toe; the
proximal, middle, and distal
phalange.
• Big toe does not have a middle one.
http://www.robbiedeanpress.com/readingroom/rr001.htm
•
http://www.cdc.gov/powerfulbones/images/skeleton2.gif
Diseases
• 1Achondroplasia – form of
dwarfism.
• Due to cartilage converting to bone
during development.
• Normal-size trunk and head; short
extremities.
http://myweb.lsbu.ac.uk/dirt/museum/margaret/48--1521-1680481.jpg
Note the shortened femurs
• 2Osteoporosis – occurs when the
rate of bone formation and bone
resorption changes.
• Results in fragile bones that break
easily.
http://www.connecticutcenterforhealth.com/images/Osteoporosis.jpg
• 3Rheumatoid Arthritis – cartilage
and dense connective tissue
breakdown easily.
• The joint eventually fuses with the
bone.
• Autoimmune disease – person’s
immune system attacks itself.
http://www.med.mun.ca/anatomyts/radioanat/radiology/ken/rheumatoid_arthritis_12.JPG