Download A) Skeletal PPT

The Skeletal System
The Skeletal System
 Parts of the skeletal system
 Bones (skeleton) – 20% of your body mass
 Joints – junction of 2 or more bones
 Cartilages - connective tissue
 Ligaments – fasten bone to bone
 Divided into two divisions
 Axial skeleton – skull, spine and thorax
 Appendicular skeleton – limbs & girdles
5 Functions of Bones
 Support of the body
 Protection of soft organs
 Movement due to attached skeletal
muscles
 Storage – Ca & P also K, Na, S, Mg,
and Cu as well as adipose tissue
 Blood cell formation - hematopoiesis
Bones of the Human Body
 The skeleton has 206 bones
 Two basic types of bone tissue
 Compact bone
 Dense
 Homogeneous
 Spongy bone
 Small needle-like
pieces of bone
 Many open spaces
Figure 5.2b
4 Classifications of Bones
 Long bones
 Typically longer than wide
 Have a shaft with heads at
both ends
 Contain mostly compact
bone
• Examples: Femur,
humerus, bones of
fingers
Classification of Bones
 Short bones
 Generally cube-shape
 Contain mostly spongy bone
 Examples: Carpals, tarsals
Classification of Bones
 Flat bones
 Thin and flattened
 Usually curved
 Thin layers of compact bone around a layer
of spongy bone
 Examples: Skull, ribs, sternum
Classification of Bones
 Irregular bones
 Irregular shape
 Do not fit into other bone classification
categories
 Example: Vertebrae and hip
Gross Anatomy of a Long Bone
 Diaphysis
 Shaft – surrounds the
medullary cavity
 Composed of compact
bone
 Epiphysis
 Ends of the bone
 Composed mostly of
spongy bone
 Bulbous shape provides
space for muscle
attachment.
Figure 5.2a
Gross Anatomy of a Long Bone
 Medullary cavity
 Center of long bones
 Contains yellow
marrow (mostly fat) in
adults
 Contains red marrow
(for blood cell
formation) in infants
Figure 5.2a
Gross Anatomy of a Long Bone
• Epiphysis Line
• Found in adult bones
• Thin line of bony tissue
spanning the epiphysis
• Epiphyseal plate
• Cartilage in young bone
between the diaphysis and the
epiphysis for long bone
lengthening
• AKA : Growth Plate
Gross Anatomy of a Long Bone
 Periosteum
 Outside covering of
the diaphysis
 Contains nerves,
blood vessels,
lymph vessels
 Fibrous connective
tissue membrane
contains osteoblasts
 Sharpey’s fibers
 Secure periosteum
to underlying bone
Figure 5.2c
• Arteries
- Supply bone
cells with nutrients
Gross Anatomy of a Long Bone
 Endosteum
 Membrane in
medullary cavity
 Contains
osteoclasts and
osteoblasts
Figure 5.2c
• Arteries
- Supply bone
cells with nutrients
Gross Anatomy of a Long Bone
 Articular cartilage
 Covers the external surface
of the epiphyses
 Made of hyaline cartilage
 Decreases friction at joint
surfaces
Figure 5.2a
Slide 5.8a
Gross Anatomy of a Long Bone
• Hematopoiesis – blood cell formation
• Occurs in red marrow cavities of spongy bone
• Red Marrow Cavities
• Newborn
• Medullary cavity and all cavities of spongy
bone contain red bone marrow.
• Most Adults
• Confined to the cavities of spongy bone of
flat bones and medullary cavity of some long
bones
Bone Markings
Table 5.1
 Surface features of bones
 Sites of attachments for muscles, tendons,
and ligaments
 Passages for nerves and blood vessels
 Categories of bone markings
 Projections and processes – grow out from the
bone surface
 Depressions or cavities – indentations
Bone Markings
Table 5.1
• On a separate sheet of paper and with a
group, examine a collection of bones and
determine their type (long, short, flat,
irregular), their location, and name any bone
markings.
• Make a data table and describe each bone.
Bone
Type
Location
Markings
Microscopic Anatomy of Bone
• What do you remember about this picture?
• What makes it a connective tissue?
Microscopic Anatomy of Bone
 Bone consists of a few different types of cells
 Osteoblasts – bone building
 Osteocytes – mature bone cells
 Osteoclasts – bone destroying
Microscopic Anatomy of Bone
 Osteoblasts – bone building
 Found in periosteum and endosteum
 Secrete matrix
Microscopic Anatomy of Bone
 Osteocytes – mature bone cells
 Osteoblasts that have become trapped in lacunae
 Maintain the bone tissue
Microscopic Anatomy of Bone
 Osteoclasts – bone destroying
 Giant cells that participate in bone resorption
 Mainly found in endosteum
Microscopic Anatomy of Bone
 Bone also is made up of a hard matrix
 Organic Component: collagen fibers and other organic
materials
 Inorganic component: 2 salts: calcium phosphate and
calcium hydroxide form hydroxyapatite.
Microscopic Anatomy of Bone
 The tissue consists of many units working together
 Osteon (Haversian System)
 A unit of microscopic bone; concentric circle &
matrix rings
Microscopic Anatomy of Bone
 Osteon (Haversian System)
 Cells = osteocytes
 Matrix = lamellae
Microscopic Anatomy of Bone
 Each Osteon contains:
 Central (Haversian) canal
 Opening in the center of the osteon
 Carries blood vessels and nerves
Microscopic Anatomy of Bone
 Each Osteon contains:
 Lacunae
 Cavities containing
bone cells
(osteocytes)
 Arranged in
concentric rings
 Lamellae
 Rings around the
central canal
 All collagen fibers
run in the same
direction
Figure 5.3
Microscopic Anatomy of Bone
 Each Osteon contains:
 Canaliculi
 Tiny canals
 Radiate from the central
canal to lacunae
 Form a transport system
Microscopic Anatomy of Bone
 Each Osteon contains:
 Volkmann’s canal
 Canal perpendicular to the central canal
 Connect blood vessels and nerves of periosteum to
Haversian canal
Microscopic Anatomy of Bone
• Make a concept map of the microscopic structure
and anatomy of a long bone. Each section should
be connected with a phrase. For example, osteon
= contains osteocytes and lacunae
Osteon
Contains cells and matrix
Osteocytes
Lamellae
Changes in the Human Skeleton
 In embryos, the skeleton is primarily hyaline
cartilage
 During development, much of this cartilage
is replaced by bone
 Cartilage remains in isolated areas
 Bridge of the nose
 Parts of ribs
 Joints
Bone Growth
 Epiphyseal plates allow
for growth of long bone
during childhood
 New cartilage is
continuously formed
 Older cartilage
becomes ossified
 Cartilage is broken
down
 Bone replaces
cartilage
Hormonal Effects
on Bone
• Growth hormone, produced
by the pituitary gland, and
thyroxine, produced by the
thyroid gland, stimulate bone
growth.
• GH stimulates protein synthesis
and cell growth throughout the
body.
• Thyroxine stimulates cell
metabolism and increases the
rate of osteoblast activity.
Hormonal Effects on Bone
• At puberty, the rising levels of sex hormones (estrogens in
females and androgens in males) cause osteoblasts to
produce bone faster than the epiphyseal cartilage can
divide. This causes the characteristic growth spurt as well
as the ultimate closure of the epiphyseal plate.
• Estrogens cause faster closure of the epiphyseal growth
plate than do androgens.
• Estrogen also acts to stimulate osteoblast activity.
Hormonal Effects on Bone
• Parathyroid hormone and calcitonin are 2
hormones that antagonistically maintain blood
[Ca2+] at homeostatic levels.
• Since the skeleton is the body’s major calcium
reservoir, the activity of these 2 hormones affects bone
resorption and deposition.
Growth in Bone
Length
• Epiphyseal cartilage
(close to the epiphysis)
of the epiphyseal plate
divides to create more
cartilage, while the
diaphyseal cartilage
(close to the diaphysis)
of the epiphyseal plate is
transformed into bone.
This increases the length
of the shaft.
At puberty, growth in bone length
is increased dramatically by the
combined activities of growth
hormone, thyroid hormone, and
the sex hormones.
•As a result osteoblasts begin
producing bone faster than the rate
of epiphyseal cartilage expansion.
Thus the bone grows while the
epiphyseal plate gets narrower and
narrower and ultimately
disappears. A remnant
(epiphyseal line) is visible on Xrays (do you see them in the
adjacent femur, tibia, and fibula?)
Bone Fractures
 A break in a bone
 Types of bone fractures
 Closed (simple) fracture – break that does not
penetrate the skin
 Open (compound) fracture – broken bone
penetrates through the skin
 Bone fractures are treated by reduction
and immobilization
 Realignment of the bone
Common Types of Fractures
Repair of Bone Fractures
 Hematoma (blood-filled swelling) is
formed
 Break is splinted by fibrocartilage to
form a callus
 Fibrocartilage callus is replaced by a
bony callus
 Bony callus is remodeled to form a
permanent patch
Stages in the Healing of a Bone
Fracture
Figure 5.5
Fracture
Repair
•
Step 1:
A.
B.
Immediately after
the fracture,
extensive
bleeding occurs.
Over a period of
several hours, a
large blood clot,
or fracture
•
hematoma,
develops.
Bone cells at the
site become
deprived of
nutrients and die.
The site becomes
swollen, painful,
and inflamed.
Step 2:
A.
B.
C.
D.
Granulation tissue is formed as the hematoma is
infiltrated by capillaries and macrophages, which begin
to clean up the debris.
Some fibroblasts produce collagen fibers that span the
break , while others differentiate into chondroblasts and
begin secreting cartilage matrix.
Osteoblasts begin forming spongy bone.
This entire structure is known as a fibrocartilaginous
callus and it splints the broken bone.
Fracture
Repair
•
Step 3:
A.
•
Bone trabeculae
increase in number
and convert the
fibrocartilaginous
callus into a bony
callus of spongy
bone. Typically
takes about 6-8
weeks for this to
occur.
Step 4:
A.
B.
During the next several months, the bony callus is continually
remodeled.
Osteoclasts work to remove the temporary supportive structures
while osteoblasts rebuild the compact bone and reconstruct the
bone so it returns to its original shape/structure.
What kind of fracture is this?
It’s kind of tough to tell, but
this is a _ _ _ _ _ _ fracture.
AXIAL SKELETON
•
Forms the longitudinal part of the body
•
80 bones; Divided into three regions
1. Skull
2. Vertebral column
3. Bony thorax
•
Protect brain, spinal cord, and organs within the
thorax
The Axial Skeleton
The Skull
THE SKULL
• 22 bones
• Divided into Cranial & Facial bones:
• Cranial- Attachment for head muscles and protect brain
• Facial- form framework for the face
• 1. hold eyes forward
• 2. provide cavities for special sense organs (taste and smell)
• 3. secure teeth
• 4. anchor the facial muscles
Bones of the Cranium
The Skull – Cranium Bones
• Frontal bone
• Parietal bones
• Meet in the midline of the skull at the sagittal suture
• Occipital Bone
• Foramen magnum “large hole”
• Occipital condyle on either side of foramen articulates with
1st vertebrae- lets nod !
Frontal View
Frontal
Frontal View
Parietal
Frontal View
Temporal
Frontal View
Nasal
Frontal View
Vomer
Frontal View
Zygomatic
Frontal View
Maxilla
Frontal View
Mandible
Frontal View
Frontal
Parietal
Temporal
Nasal
Vomer
Zygomatic
Maxilla
Mandible
Frontal View
The Skull - Cranium Bones
• Temporal bones = “time”
• External Auditory Meatus – canal that lead to the eardrums and
middle ear.
• Mastoid process- anchoring site for neck muscles, lump behind
ear, less prominent in females than males
• Styloid process- attachment for muscles in neck and ligaments
• Zygomatic Process- attachment site for some muscles of the
neck
• Jugular Foramen – allows jugular vein to pass through; which
drains the brain
• Carotid Canal – through which internal carotid artery runs,
supply blood to the brain.
The Skull - Cranium Bones
• Sphenoid• looks like a bat, butterfly; inside of the skull
• Foramen Ovale – allows fibers of cranial nerve V to
pass to the chewing muscles of the lower mandible.
• Air cavities that fill the sphenoid bone are called
sphenoid sinuses
Lateral View
Frontal
Lateral View
Parietal
Lateral View
Temporal
Lateral View
Nasal
Lateral View
Zygomatic
Lateral View
Maxilla
Lateral View
Mandible
Lateral View
Sphenoid
Lateral View
Occipital
Lateral View
Mastoid Process
Lateral View
External Auditory Meatus
Lateral View
Parietal
Frontal
Sphenoid
Temporal
Occipital
Mastoid Process
Nasal
Zygomatic
Maxilla
Mandible
External Auditory Meatus
Lateral View
The Skull
•
Most bones are flat bones
•
Contain interlocking joints called SUTURES
•
There are 4 types of sutures:
1. Coronal - frontal bone meets parietal
2. Sagittal- parietal bones are paired, separated
3. Squamous-parietal bone meets temporal bone
4. lambdoidal -parietal bones meet occipital bone
Sutures
Sagittal
Sutures
Frontal
(Coronal)
Sutures
Squamous
Sutures
Lambdoid
Sutures
Sagittal
Frontal
(Coronal)
Squamous
Lambdoid
Sutures
FACIAL BONES
•
14 bones form the lower front of the skull and provide
the framework for most of the face.
•
12 of those bones are paired; Mandible & Vomer are single
1. Mandible - strongest, largest bone in the face (lower jaw)
2. Maxillae - upper jaw
3. Palatine bones – form posterior part of the hard palate.
4. Zygomatic bones = cheekbones
FACIAL BONES (Continued)
6. Nasal bones - fused medially, form bridge of nose
•
Lower part of nose is made of cartilage
7. Lacrimal bones
•
very small within orbit (eye-socket)
8. Hyoid
•
Only bone in the entire body that does not articulate to another bone
•
Not really part of the skull, but is closely related to the mandible and
the skull.
•
Serves as movable base for the tongue
•
Attachment point for several muscles in the neck, elevates larynx
during speech and swallowing
•
Anchored by ligaments attached to styloid processes of temporal
bones
Bones of the Skull
Figure 5.11
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 5.22
Human Skull, Superior View
Figure 5.8
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 5.23
Human Skull, Inferior View
Figure 5.9
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 5.24
Pasanasal Sinuses
• Clustered around nasal cavity
• Lighten the skull & Enhance resonance of voice
• Air enters sinuses from nasal cavity; mucous from
sinuses drips to nasal cavity
VERETBRAL COLUMN
• AKA the spine
• 70 cm= 28 inches long in average adult
• 26 irregular bones connected so the flexible,
curved spine is formed
• Extends from the skull to pelvis
• Spinal cord runs through the central canal
• Attachment points for ribs and muscles
• 33 in fetus and infant- 9 fuse to form sacrum
and coccyx
• Remaining 24 act as separate vertebrae with
connective tissue discs in between each
• Ligaments and trunk muscles hold column in
place
• Intervertebral discs- cushion-like pads- shock
Vertebral Column
• 5 major divisions:
• 7 cervical
• 12 thoracic (1 per each pair of ribs)
• 5 lumbar
• sacrum, coccyx (tiny)
• about 5% of otherwise normal people have
variations in numbers of thoracic and lumbar
vertebrae (cervical # is constant)
Abnormal Spinal Curvatures
• Scoliosis- abnormal lateral
curvature
• Result from abnormal
vertebral structure or disease
involving muscle paralysis,
uneven pull of muscles on
spine
• kyfosis- hunchback• dorsally exaggerated
curvature of thoracic
vertebrae- osteomalacia,
rickets
• lordosis- exaggerated lumbar
curvature (temporary in prgnant
or obese- trying to correct center
of gravity
Structure of Vertebrae
•
Body or Centrum – weight
bearing
•
Vertebral arch
•
Vertebral foramen – canal through
which spinal cord passes
•
Spinous process
•
Superior and Inferior Articular
processes – all vertebrae to form
joints
•
Intervertebral foramina- notched
in pedicles of vertebrae to allow
space btw vertebrae (from side
view)- allows nerves from spinal
cord to pass through
APPENDICULAR SKELETON
• Appendages hang
from pectoral and
pelvic girdles
• Upper and lower
limbs differ in their
functions and
mobility, they have
the same structural
plan- 3 major
segments connected
by freely movable
joints
Regional Characteristics of Vertebrae
Atlas – (C1)has no body or spinous process; supports
the head; allows the rocking motion of the occipital
condyles; allows you to say ‘yes’
Regional Characteristics of Vertebrae
Axis- (C2) has a special knoblike feature called the
dens; provides a pivot for rotation of the first cervical
vertebra and the head; allows you to say ‘no’
The Bony Thorax
 “The Chest” forms a
cage to protect major
organs
 Heart and lungs
 Looks like an inverted
cone
 Composed of three parts
 Sternum
 Thoracic vertebrae
 12 ribs
Figure 5.19a
Slide 5.31a
 Sternum (breastbone)
 Manubrium
The Bony Thorax
 Body
 Xiphoid process
 Ribs (12)
 All 12 attach posteriorly
to the thoracic vertebra
 1-7 = true ribs; attach
directly to sternum by
costal cartilages
 8-12 = false ribs
 8-10 attach indirectly to
sternum
Figure 5.19a
Slide 5.31b
The Bony Thorax
 Intercostal spaces are
filled with muscles that
aid in breathing
Figure 5.19a
Slide 5.31a
Pectoral (shoulder girdle)
• 2 Main Bones- clavicle and scapula
• medial ends of each clavicle join
sternum
• distal ends meet scapula
• does not quite make a “belt”- scapula
only attaches to the thorax and
vertebral column by muscles
• pectoral girdle attach upper limbs to
axial skeleton and insertion points for
muscles
• girdles are very light, allow flexibility
and mobility not seen elsewhere in
body
Pectoral (shoulder girdle)
Reasons upper appendages have flexibility and
mobility not seen elsewhere in the body:
1. the only point of attachment of pectoral girdles to axial
skeleton is at sternoclavicular joints
2. looseness of scapular attachments allows scapula to
move rather freely; can be moved side to side, elevated,
depressed
3. socket of shoulder is shallow, small, and poorly
reinforced- good for flexibility, bad for stabilityshoulder dislocations are fairly common
Pectoral (Shoulder) Girdle
 Composed of two bones
 Clavicle (collarbone)
 Scapula (shoulder blade)
 These bones are very light and allow, the
upper limb to have exceptionally free
movement
 Shoulder girdle is very light and unstable
 Clavicle is the only part of the girdle that
attaches to the axial skeleton
 Socket of shoulder is shallow and poorly
reinforced by ligaments
 Good for flexibility; bad for stability
 Shoulder dislocations are common
Scapula- shoulder blades
•
triangular, located btw ribs 2 and 7
•
superior border is the shortest
•
medial border parallels the spinal column
•
lateral border abuts the armpit (axillary border)
•
glenoid cavity- small, shallow cavity- articulates with the humerus of the arm
•
*relatively unstable shoulder joint
•
anterior surface fairly featureless
•
posterior- spine- ends laterally in enlarged projection called acromion
•
acromion articulates with acromial end of clavicle to form acromioclavicular joint
•
projection anterior from superior border is the coracoid process- beaklike, like a bent
little finger- coracoid helps anchor biceps
•
suprascapular notch- a nerve passgeway
Scapula (shoulder blade)
 Connects the clavicle and humerus
 Lie on the dorsal surface of the rib cage over ribs 2-7
 Flat bone, roughly triangular in shape
 Attached to the thorax and vertebral column only by muscles
Scapular Bone Markings
 Glenoid cavity
 Shallow, articular surface that articulates with the head
of the humerus forming the shoulder joint
 Acromion
 Articulates with the clavicle to form the
acromioclavicular joint
 Forms the summit of the shoulder
 Coracoid process
 Small, hook-like structure on the
lateral edge of the superior portion
of the scapula
 Assists in stabilizing shoulder joint
and anchors biceps
 Spine
 Raised region on the posterior
side for attachment of trapezius
Clavicle (collar bone)
 Extend horizontally across the superior thorax
 Functions as an anchor for muscles and ligaments and acts as a brace
 Articulates with the scapula (acromion) at the acromioclavicular joint
 Articulates with the manubrium (sternum) on the medial (sternal) end
Clavicles- collarbones
• rounded on sternal end- attaches to manubrium
• flat on acormial end- attaches to acromion of
scapula
• resist compression poorly- use outstretch arms to
break a fall, clavicles break
• sensitive to muscle pull, become larger and
stronger in people who do a lot of manual labor
involving shoulder and arm muscles
Arm
• Upper arm- humerus
• articulates with scapula and radius
and ulna
• Proximal end- smooth head, fits
into glenoid cavityanatomical
neck- slight constriction
• greater and lesser tuberclesmuscle attachment points
• intertubercular groove- serves
as a guide for tendon of biceps
Bones of the Upper Limb
 The Upper Limb
 Pectoral girdle (Shoulder)
 Humerus (Arm)
 Radius and Ulna (Forearm)
 Carpals, metacarpals,
phalanges (Hand)
Arm Bone Markings
•surgical neck- most frequently
fractured portion of the humerus
•medial and lateral epicondyles
•trochlea- medial- articulates with
ulna
•capitulum- lateral, ball likearticulates with radius
ulnar nerve runs behind medial
epicondyle, it’s responsible for
tingling sensation when you hit you
elbow
coranoid fossa- anterior
olecranon fossa- posterior- allow
unla to rotate freely
ForearmUlna & Radius
• Articulate with each
other proximally and
distally at radioulnar
joints
• in anatomical positionradius lateral
• palm faces backpronation- radius and
ulna form an X
Forearm
• ulna- slightly longer, primarily
responsible for forming elbow joint
• coranoid and olecranon processes
fit into fossa of humerus (grip the
trochlea)
• olecranon locks into olecranon
fossa to prevent hyperextension
• radius- styloid process
• major contributor to the wrist
HAND- carpals,
metacarpals, phalanges
•
Carpals- bones of wrist
•
8, marble sized short bones
•
Arranged into 2 irregular rows
•
Metacarpals- bones of palm
•
5- numbered 1-5 from thumb to pinkie
•
heads of metacarpals are knuckles
•
phalanges- bones of fingers
•
each hand has 14 phalanges
•
except for thumb, each finger has 3 bones
•
distal, middle, and proximal phalanges
•
(thumb has no middle)
•
proximal articulate with the heads of metacarpals
The Hand (27 bones)
 Carpals – wrist (8)
 Arranged in two rows of four
 Articulate with the radius to form the
radiocarpal joint
 Articulate with each other and united by ligaments
 Metacarpals – palm (5)
 When you clinch your fist the heads are your “knuckles”
 Articulates between each phalanx called metacarpophalangeal joints
 Phalanges (phalanx bones) – fingers (14)
 Each finger has 3 bones (distal, middle, and proximal) except for the
thumb that has 2 bones
 Articulates between each phalanx called interphalangeal joints
Pelvic Girdle
• attaches lower limbs to axial
skeleton and supports visceral
organs of pelvic cavity
• pelvic girdle secured to axial
skeleton by some of the
strongest ligaments in the body
• sockets are deep and cuplike
• pelvic girdle made up of 2 coxal
(hip) bones
• each unites anteriorly (with each
other) and posteriorly (with
sacrum)
• pelvis= both coxal bones plus
sacrum and coccyx
Pelvic Girdle
•
during childhood, 3 separate bones- ilium, ischium, and pubis
•
these fuse firmly by adulthood
•
point where the three fuse is a deep socket called acetabulum- vinegar cupacetabulum articulates with the head of the femur
•
ilium= hands on hip bone
•
sacroiliac joint
•
ischium- the sitting down bone
•
pubis- bladder rests upon it
•
obturator foramen- blood vessels and nerves pass through
•
pubic symphysis- fibrocartilage
•
pubic arch- sharpness helps us determine male or female
Bony Pelvis
 Both hip (coxal) bones, sacrum and coccyx
Pelvic Girdle (Hip)
 Functions





Connects the vertebral column to the femurs
Bear the full weight of the upper body when
sitting and standing
Transfer the weight from the axial skeleton to
the lower limbs
Provides attachments for powerful muscles,
ligaments and tendons which makes it the
most stable joint but lacks mobility
Protects some of the urinary, reproductive and
digestive organs
Coxal Bones
 Ilium (hands on hip)





Uppermost and largest bone of the pelvis
Large flaring bones that forms the superior region
Anteriorly it joins the pubis
Inferiorly it joins the ischium
Extends upward from the acetabulum
Coxal Bones
 Ischium (sit down bone)
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Lower, back portion of the hip bone
Proceeds downward from the acetabulum
below the ilium and behind the pubis
Expands into a large tuberosity and
curves forward and forms the top of the
obturator foramen
Coxal Bones
 Pubis (bladder rests on it)
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Anterior portion of the hip bone
Extends medially and inferiorly from the acetabulum
Articulates with the opposite side at the pubic symphysis
Forms the front of the pelvis and supports the organs
Pelvic Girdle Bone Markings
 Acetabulum
 All three bones fuse together
to form a deep socket
 Located on the lateral surface
of the bone
 Articulates with the head of
the femur for the hip joint
 Iliac crest
 Superior border of the wing
of ilium
 Attachment for many
muscles
 Ischial tuberosity
 Inferior surface of ischium
 Weight is placed on this
Pelvic Girdle Bone Markings
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Pubic symphysis
 Pubis bones
articulate together by
a fibrocartilage disc
Pubic arch
 Inferior to the joint is
an inverted V-arch
 Sharpness
determines male
versus female
True pelvis (lesser
pelvis)
 Inferior region
surrounded by bone
 False pelvis
(greater pelvis)
 Superior, expanded
portion of the cavity
Gender Differences of the Pelvis
 Female pelvis is modified for
childbearing
1. Wider, shallower, lighter and
rounder
2. Tilted forward
3. True pelvis defines the birth
canal
4. True pelvis and false pelvis are
wider in females
5. Pubic arch more than 90
degrees in females
FEMUR
• Femur
• head, fovea capitis
• patella
Femur (Thigh)
 Largest and longest bone in the body
 Length is ¼ of a person’s height
 It can support up to 30 times the weight
of an adult
 Articulates with hip proximally and tibia
distally
 Patella
 Kneecap
 Bone enclosed in the quadriceps
tendon that secures the thigh
muscles to the tibia
Femur Bone Markings
 Head
 Articulates with coxal bone at acetabulum
 Greater and lesser trochanter
 Sites of attachment for thigh and buttocks
muscles
 Gluteal tuberosity
 Lateral ridge that runs vertically upward to the
base of the greater trochanter
 Attachment site for gluteus maximus
 Lateral and Medial condyle
 Distal projections that articulate with the tibia
TIBIA & FIBULA
• Tibia- shin bone
• medial malleolus
• Fibula- little white
bone
• lateral malleolus
Tibia and Fibula (Lower leg)
 Located from the ankle to the knee
 Both ends of the two bones articulate at
tibiofibular joint
 Bones are connected by an
interosseous membrane
Tibia (Shinbone)
 Receives the weight of the body and the
bigger of the two
 Second largest bone in the body
 Articulates with the femur superiorly, the
fibula laterally and with the talus (ankle)
inferiorly
Tibia Bone Markings
 Tibial tuberosity
 Crest to which the patellar ligament
attaches from the patella and the
quadriceps muscle
 Medial malleolus
 Medial surface of the distal tibia
 Articulates with the talus bone to form the
ankle joint
Fibula
 Located on the lateral side of the
tibia
 Stick-like bone with expanded ends
 Articulates with the tibia on both
ends
 Does not articulate with the femur
 Fibula Bone Marking: lateral
malleolus
 Distal end of the fibula that
articulates with talus
 Causes the ankle to bulge
laterally
METATARSALS & TARSALS
• Foot is composed of tarsals, metatarsals and phalanges.
• Supports weight & serves as lever
• Calcaneus and Talus are the two bones that support most of the body’s
weight
• Metatarsals form sole
• 14 phalanges form toes; distal, middle & proximal
Sesmoid bone
The Foot (26 bones)
 Functions
 Supports body weight
 Acts as a level to propel the body
forward in locomotion
 Adapts to uneven ground
Ankle and Foot (26 bones)
 Tarsals (7) – ankle
 Posterior half of the foot
 Forms the arches of the foot which serves as
a shock absorber
 Body weight is carried by two large bones –
talus and calcaneus
 Talus (ankle bone)
 Articulates with tibia and fibula
 Calcaneus (heel bone)
 Attachment site for Achilles tendon
 Metatarsals (5) – sole
 Phalanges – toes (14)
 Each toe has 3 bones (distal, middle, and
proximal) except for the big toe which has 2