Ch.7 Anatomy of Bones and Joints

General Considerations of Bones

• 206 bones in adult skeleton

• 270 at birth, bones fuse over time

• Terminology– Articulate-bones joined or

connected together

– Paired bones

• Of the same type located on the R/L side of the body (arm and legs)

– Unpaired bones

• Located on the midline of the body (vertebrae)

Bone Markings• Surface features of bones: bulges, depressions, and holes that

serve as:

– Joint surfaces

– Sites of attachment for muscles, ligaments, tendons

– Passages for blood vessels and nerves

Muscle attachment Joint surfacesVessel passage

Bone Markings (Surface Features)

Markings for articulations:

� head

� condyle

� facet

General elevations & projections:

� process

� ramus

Table 5-1


Processes for attachment:� trochanter (femur only)� tuberosity� tubercle� epicondyle� crest� line� spinous process (vertebrae

only)� transverse process (vertebrae

only)

Spinousprocess

Transverse process


Spinous

process

Transverse

process

Depressions:

�fossa

�sulcus

Openings:

�foramen (canal)

�meatus

�fissure

�sinus

Bone Markings

• Two types of bone markings:

– Projections (aka processes) that grow out

from the bone

– Depressions or cavities that indent the bone

Joint Projections

• 1) Condyle: Rounded articular projection

Condyle

Joint Projections

• 2) Head: bony

expansion on a

narrow neck

• 3) Facet: smooth,

nearly flat articular

surface

Head

Condyle

Joint Projections

• 4) Ramus: Armlike bar of bone

Ligament/Tendon Projections

1) Crest: Narrow ridge

of bone (Line: smaller

than a crest)

2) Epicondyle: Raised

area on or above a

condyle

ULNA

3) Tubercle: Small

rounded projection

4) Tuberosity: large

rounded or

roughened projection

5) Trochanter: very

large, blunt projection

(only on femur)

Proximal Tibia

Ligament/Tendon Projections

6) Spine: Sharp, pointed

projection

Thoracic Vertebrae

Depressions• Allow blood vessels or nerves to pass

through.

1) Meatus: Canal or tube

Depressions

2) Fossa: shallow basin

3) Fissure: narrow, slit-

like opening

Depressions

4) Sinus: Cavity within a

bone; filled with air

and lined with

mucous membranes

5) Foramen: Round or

oval opening

Foramen Magnum

Depressions

6) Sulcus, Groove or Furrow: a shallow depression

Foramen

Spinous process

Transverse process

Crest

Tuberosity

Divisions of the Skeleton• Axial Skeleton

– Skull

– Vertebral column

– Thorax (chest)

– Auditory ossicles

– Hyoid bone

• Appendicular Skeleton

– Limbs

– Girdles (pectoral and pelvic)

Skull

• Composed of 22 bones– Bones are joined by sutures (fixed, non-movable joints)

– Only the mandible is attached by a freely movable joint

• Cranium: protects the brain– 8 bones in contact with brain and/or meninges

• Frontal, parietal (2), occipital, temporal (2), sphenoid, ethmoid

• Facial bones protect the sensory organs and serve as muscle attachment sites – The 14 facial bones, no contact with brain or meninges

• Auditory ossicles that function in hearing, are located inside the temporal bones

• Hyoid Bone

Cranial Bones

8 Cranial Bones

1 x Frontal

2 x Parietal

1 x Occipital

2 x Temporal

1 x Sphenoid

1 x Ethmoid

Frontal Bone

• Forms forehead, roof

of the cranium and

orbits of eyes

• Supraorbital foramen

• Supraorbital margin

• Coronal suture

Parietal Bone

• Roof of the cranium

• Bordered by 4 sutures

– Coronal

– Sagittal

– Lambdoid

– Squamous

Occipital Bone

• Back of the skull

• Foramen magnum

– Spinal cord, verves, and blood vessels

• Occipital condyle

– Articulation with atlas

• External occipital

protuberance

– Attachment of ligamentumnuchae (keeps head erected)

• Nuchal line

– Points of attachment for neck muscles

Temporal Bone• Right & left; forms

temple, cheek, ear openings

• Houses middle and inner ear– Zygomatic process

– Mastoid process

– Styloid process

– External Auditory meatus

– Mandibular fossa

– Squamous suture

Temporal Bone

• Zygomatic process• Forms bridge with zygomatic

bone across the skul

• Mandibular fossa

– Mandible articulate with skull

• Styloid process

– Attachment site for 3 muscles: tongue, pharynx, and hyoid bone

• External auditory meatus

– Transmits sound waves toward eardrum

• Mastoid process

– Attachment for muscle that move the head

Sphenoid Bone

• Bat shaped

• All skull bones

connected to it

– Sella turcica: depression for

pituitary gland (hypophyseal fossa)

Sphenoid Bone

Sphenoid Bone

• Greater wing

• Lesser wing

• Optic foramen

– Passage of the optic nerve

• Foramen rotundum

and ovale

– Trigeminal nerve

Ethmoid Bone• Anterior to shenoid

• Bony area between nasal cavity and orbits– Crista galli

• Attachment for dura matter

– Cribriform plate with olfactory foramina

•Perpendicular plateforms nasal septum

•Nasal conchae: Turbunates in the lateral

wall of nasal caviy

Sutures• Coronal Suture: between

the frontal and parietal bones

• Sagittal Suture: between right and left parietal bones

• Lambdoidal Suture: between the parietal and occipital bones

• Squamous Suture: between temporal and parietal bones

Fontanels• Fusion of the cranial bones

is not complete at birth• Space between the bones

remains• Anterior “soft spot” closes at

18 months

• Posterior (Occipital):triangular, closes at 2 – 3 months

• Anteriolateral (Sphenoidal):at 2 temples, closes at 2 – 3 months

• Posterolateral (Mastoidal): 2 behind ears, closes at 1 year

Baby Skulls

Baby Skull

Facial Bones

• 14 Facial Bones– Nasal Bones (2)

– Inferior nasal canchae (2)

– Lacrimal (2)

– Vomer (1)

– Zygomatic (2)

– Maxillae (2) (pl.)• Maxilla (sing.)

– Palatine (2)

– Mandible (1)

Nasal Bones

• Small rectangular

bones

• Form bridge of the

nose

Inferior Nasal Conchae

• Thin, curved bones

attached to lateral

wall of nasal cavity

• Different from

superior and middle

conchae

Lacrimal Bones

• Form medial wall of

each eye socket

• Lacrimal groove

(canal) drains tears

into nasal cavity

Vomer• Inferior half of the nasal cavity

• Joints with the perpendicular plate of

ethmoid to form nasal septum

Zygomatic Bones

• Forms the cheekbone

and part of lateral

orbital wall

• Zygomatic Arch =

zygomatic bone +

zygomatic process of

temporal bone

Palatine Bones

• Forms back roof of

mouth and floor of

nose

• Horizontal plates form

posterior portion of

hard palate

• Vertical portion form

the lateral wall of

nasal cavity

Maxillae• Paired bones that

form the upper jaw and face – Alveolar processes

• Contain teeth

– Palatine processes• Part of hard palate

– Infraorbital foramen• Infraorbital nerve

– Maxillary sinuses• Paranasal sinuses

Mandible• Lower jaw bone; largest

bone of face• Only moveable

– Body - forms the chin– Ramus- projects upward– Mandibular condyle,

mandibular notch and coronoid process

• Joint with temporal bone

– Mental foramen• Mental nerve

– Mandibular foramen• Nerve to mandibular teeth

– Alveolar margin and process

• Contain teeth

Angle

Mandibular

notch

Hyoid Bone

• U-shaped bone

• In neck

• At base of tongue

• Only bone in body that

does NOT articulate

with another bone

• Suspended from styloid

process by muscles

and ligaments

Cranial Sinuses

• 4 sets of cavities

within the cranium

• Resonance chambers

for voice

• Decrease weight of

skull

• Lined with mucous

membrane

Cranial Sinuses• Frontal sinuses (2): above

eyebrows, open into nasal cavity

• Ethmoid sinuses (2): between the eyes

• Spenoidal sinus (1): posterior to ethmoidalsinus, opens into nasopharynx

• Maxillary sinus (2): on either side of the nose, opens into the lateral wall of the nasal cavity

Auditory Ossicles

• 3 tiny bones form a

chain in each middle

ear cavity

• Transmit sound

waves from eardrum

to the receptors of the

inner ear

Vertebral Column

• Supports trunk and

neck

• Protects spinal cord

• Multiple joint spaces

allow for bending and

twisting

• 33 vertebrae,

fibrocartilage disks

between them

Spinal Curvatures

• Allow for resilience and spring for walking

• Thoracic: present at birth

• Sacral: bow back

• Cervical: begins at 3 months when infant first begins to lift head

• Lumbar: begins when child first walks

Spinal Curvatures

Abnormal Spinal Curvatures

• Result from diseases, posture, paralysis, or congenital defects

• Scoliosis (lateral) from lack of proper development of one vertebrae

• Kyphosis (exaggerated thoracic curve) from osteoporosis

• Lordosis (exaggerated lumber curve) from weak abdominal muscles

Scoliosis

Kyphosis

Lordosis

The woman on the right exhibits lordosis

Vertebral Sections• Five types

– 7 cervical in the neck

– 12 thoracic in the

chest

– 5 lumbar in lower back

– 5 sacral fused into

sacrum

– 4 coccygeal fused into

coccyx

Intervertebral Disc

• Outer fibrocartilage disk

• Gelatinous center

• Has high water content

• Normal disc is so strong

that it can be damaged only be extreme forces

• A normal, healthy disc is

one of the strongest parts of the spine

General Structure of Vertebra

• Body

• Vertebral foramen

• Vertebral (neural)

arch

• Processes

– Spinous

– Transverse

– Articular (superior and inferior)

Cervical Vertebrae (C1-C7)

• Smallest body, larger

foramen

• Transverse processes

with foramen

(vertebral arteries)

• Forked (bifid) spinous

process

• C7 has the longest

spinous proces

Atlas and Axis (C1 and C2)• Atlas (C1)

– Supports the skull

– Has no body, ring shaped

– Large faced (articulation with occipital bone)

– Allows nodding of head “yes”

• Axis (C2)– Dens (odontoid process)

fits in the foramen of the atlas

– Allows rotation of head: “no”

Thoracic Vertebrae (T1-T12)

• Larger body

• Long pointed spinous

process

• Articulate with ribs

• Coastal facets at ends of transverse processes

• Thoracic area is stable

and less susceptible for injuries

Lumbar Vertebrae (L1-L5)

• Large, heavy body for

support

• Short, horizontal

spinous process

• Lumbar area is the

most prone to injuries

Sacrum and Coccyx

http://www.coccyx.org/whatisit/normal.htm

Sacrum• Triangular shape

• 5 sacral vertebrae fuse by age of 26

• Articulate with pelvic girdle (sacroiliac joint)

• Anterior surface– Sacral foramina

• Posterior surface– Superior articulate surface

– Spinal processes fused to form median sacral crest

– Posterior sacral foramina

– Sacral canal ends as sacral hiatus

Spina Bifida

• 3rd week of pregnancy vertebral arches form

around the spinal cord

• Spina bifida-incomplete

closure of the spinal

column during pregnancy

– Creates an opening, or lesion that damages the nerves and causes paralysis

Coccyx

• Tail bone

• Single, small,

triangular bone

• 3-5 small vertebrae

fused by age of 30

Thoracic Cavity

12 Pairs of Ribs, 12 Thoracic Vertebrae and Sternum

Function

• Protect and support

heart and lungs

• Supports bones of

pectoral girdle

• Plays leading role in

respiration

• Ribs and sternum aid

in RBC formation

Ribs

• 12 pairs

• Vertebrosternal (True

ribs #1-7) attach to

sternum with hyaline

cartilage

• Vertebrochondrial

(False ribs #8-10)

• Floating (Vertebral

#11-12)

Sternum

• Breastbone

• Resembles a sword

• 3 parts– Manubrium -handle,

articulates with acromionend of clavicle and 1st rib

• Jugular notch

• Clavical notch

– Body- blade, notched for 1st

7 costal cartilages

– Xiphoid process-: tip, attachment site for diaphragm

Appendicular Skeleton

• Pectoral (Shoulder)

girdle

• Pelvic girdle

• Appendages

– Upper limbs

– Lower limbs

Pectoral Girdle

• Girdle=encircles,

complete ring

– Clavicles (2): collar

bones

– Scapulas (2): shoulder

blades• These bones allow the

upper limb to have

exceptionally free movement

Clavicle

• Collar bone

• S-shaped

• Articulate with

– Proximally manubrium

– Distally- acromium of

scapula

• Sternal end is

rounded-acromial end

is flatten

Clavicle

Scapula

• Spine- bony ridge divides posterior surface

• Acromial process- articulation w/clavicle

• Coracoid proces (hook) -muscle attachment

• Glenoid fossa (cavity) –connects w/ the head of humerus

• Axillary (lateral) border

• Inferior and superior angle

• Vertebral border

• Superior border

Superiorangle

Superior border

Upper Limb

• 30 bones per limb

• Humerus (arm,brahium)

• Forearm (antebrachium)– Radius-thumb side

– Ulna-little finger side

• Carpus=wrist (8)

• Hand (manus) (19)– Metacarpals (palm) (5)

– Phalanges in the fingers(14)

Humerus

• Head –articulate w/ scapula

• Greater, lesser tubercle, and deltoid tuberosity -muscle attachments

• Intertubercular groove-holds biseps

• Capitulum-articulates w/ radius

• Trochlea-articulate w/ ulna

• Anatomical and surgical neck

• Lateral and medial epicondyle -attachment for forearm muscles

• Olecranon fossa -depression where ulna fits with humerus to form hinged joint

Surgical neck

Arm and Forearm

Tennis Elbow

• Inflammation of tissues surrounding the lateral epicondyleof humerus(epycondylitis)

• 6 muscles that control movement of the hand attach in this region and repeated contractions irritate the attachments

Radius

• Radius (rotates

around the ulna)

– Head- articulate

w/capitulum

– Redial tuberosity -

attachment for the biseps

– Styloid process -attachment for

ligaments of the wrist

Ulna

• Olecranon process

– fits into olecranon fossa of humerus

• Radial notch-

– Head of the radius fits

• Head and styloid process

– at distal end

– ligament attachments

• Interosseous membrane

– Ligament attaches radius to ulna along the crest

The Wrist and Hand

• Carpals -wrist

– Two rows of 8 bones

• Matacarpals -palm

• Phalanges -fingers

Carpal Tunnel Syndrome

• Bone and ligaments form carpal tunnel on the

anterior site of the wrist

• Median nerve gets

compressed as result of

inflammation associated with overuse or trauma

• Pressure on the nerve causes burning and

numbness of the hand

Pelvic Girdle

• Coxal (Hip) bones– Ilium

– Ischium

– Pubic bone

• Sacrum

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

• Protects several organs– Reproductive organs

– Urinary bladder

– Part of the large intestine

Coxal (Hip) Bone• Acetabulum (hip socket)

• Ilium– Iliac crest -muscle attachment,

forms prominence of hips

• Pubis– Obturator foramen- largest

opening in the body, between pubis and ischium, passage for blood vessels, nerves, and tendons

– Pubic symphysis -midline when two pubic bones meet

– Pubic arch - V-shaped formed by inferior pubic rami

• Ischium– Ischium tuberosity bears the body

weight when sitting, strongest part of coxal bones

Gender Differences of the Pelvis

• Female– Bones lighter, thinner, and

smoother

– Pelvic inlet wider and more oval

– Pubic arch more than 900

– Ischial tuberosities farther appart

– Ilium more flared, giving female broader hips

• Male– Heavier bones, markings more

prominent

– Pelvic inlet heart shaped

– Pelvic cavity narrow, deep, and funnel shaped

– Pelvic arch less than 900

Lower Extremity

• Femoral bone= thigh (femur)

• Patella (knee cap)

• Crural =leg– Tibia-shin bone

– Fibula

• Pedal =foot bones– Tarsals (ankle)

– Metatarsals (sole)

– Phalanges (toes)

Femur• Head

– Fits into acetabulum of coxal bone

• Neck– Offsets thigh from hip joint

for easy In movement

– Muscle attachment

• Lesser and greater trochanter– Muscle attachment (gluteus

and hip m.)

• Medial and lateral condyle– Articulate with tibia

• Gluteal tuberosity– Attachment for gluteal

muscles

• Patellar surface– Articulates with patella

Patella and Tibia

• Tibia: strong weight-bearing, on the medial side– Two flat articulated

surfaces w/ femur: medial and lateral condyle

– Tibial tuberosity• Can be palpated below

the patella (attachment for patellar ligaments)

– Tibial malleosis• Forms medial side of

ankle joint

– Anterior crest• Sharp edge on the shin

Patella

Fibula

• Lateral bone that helps stabilize the ankle, not weight bearing

• Head is proximal– Articulates with tibia

• Lateral malleolus– Forms lateral bulge of

ankle

– Attachment for ligaments

The Ankle and Foot

• Tarsal bone: load-bearing bones of the

ankle

• The bony arches transfer weight from the

heels to the toes and allow the foot to

conform to many different positions

The Ankle and Foot

• Body relies on feet for balance, shock absorption, and support

• Soft yet firm support of all of the bones and arches of each foot is necessary for spine and nervous system function

• Proper weight distribution and support with spinal pelvic stabilizers allows the feet to take extra strain off the pelvis and spine

Arches of the Foot

Tarsals

• Calcaneus (Ca) – Forms the heal

• Talus (T) is most superior tarsal bone– Forms ankle joint with tibia

and fibula

• Navicular (N) boat shaped

• Distal row of cuneiformed(wedged shaped) bones– Cuboid (C)

– Medial (1st) cuneiform (Cm)

– Intermediate (2nd) cuneiform(Ci)

– Lateral (3rd) cuneiform (Cl)

MILC

No

Thanks

Cow

The Foot

• Similar in name and

arrangement to hand

• Metacarpals (5) sole

– 1st is proximal to great toe

• Phalanges (14) toes

– 2 in great toe

• Proximal and distal

– 3 in all other toes

• Proximal, middle, distal

Ch.7 Anatomy of Bones and Joints - South...

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