HAP 7.6-7.13
Skeletal System
I. The Skull
A. Cranium (8 bones)
1. Frontal bone (1)
a. Anterior portion of skull
b. Supraorbital Foramen
c. Frontal Sinuses
2. Parietal Bones (2)
a. Located to each side of frontal bone
3. Occipital Bone (1)
a. Forms the back of the skull
b. Foramen Magnum – large hole for spinal cord
c. Occipital Condyle – articulate with atlas (1st
vertebra
4. Temporal Bones (2)
a. Form sides of cranium above occipital bone
b. Mastoid Process
c. Styloid Process
d. Mandibular Fossa
e. Zygomatic bone – prominence of cheek
5. Sphenoid Bone (1)
a. Wedged in the middle of cranium
b. Sella Turcica – depression that holds the
pituitary gland
c. Sphenoidal sinuses
6. Ethmoid Bone (1)
a. Located in front of sphenoid bone
b. Ethmoidal sinuses
B. Facial Bones (13 non-moveable + 1 moveable)
1. Maxilla Bones (2) – upper jaw; most anterior
in mouth
a. Forms part of hard palate
b. Maxillary Sinuses
c. Teeth sockets
2. Palatine Bones (2) – behind hard palate (L
shaped)
a. Form part of hard palate
b. Forms wall of nasal cavity
3. Zygomatic Bones (2)
a. Zygomatic arch
4. Lacrimal Bones (2)
a. Scale like bone located in the medial wall
of each orbit b/t ethmoid and maxilla
5. Nasal Bones (2)
a. Long, thin and rectangular
b. Fused at the midline
6. Vomer Bone (1)
a. Anterior of maxilla
7. Inferior Nasal Conchae (2)
a. Nasal cavity bone
b. Supports mucous membranes
8. Mandible (1) – horseshoe shaped
a. Mandibular condyle
b. Coronoid Process – anterior of
mandibular condyle
II. The Vertebral Column
A. Characteristics
1. Location – skull to pelvis
a. Supports head and trunk
b. Protects spinal cord
2. Vertebra Regions
a. Body (1)
-anterior drum shaped portion
-supports weight
-intervertebral discs – cushion pads b/t
b. Pedicles (2)
-projects from body
c. Laminae (2)
-comes off of pedicles
-fuses to form spinous process
-failure causes spina bifida
d. Spinous process (1)
e. Vertebral arch – pedicles, laminae, and
spinous process
f. Vertebral foramen – spinal cord passes
g. Transverse process
-projects laterally and posteriorly
-attachment for ligament and muscles
h. Superior and inferior articular processes
-join vertebrae together
i. Interverteberal foramina
-openings for spinal nerves
1
1
Body
2
2
Pedicle
3
3
Lamina
4
Transverse Process
5
Spinous Process
5
6
Vertebral Foramen
6
7
Rib Facet
7
8
Superior Articular
Facet
8
4
B. Cervical Vertebrae (7)
1. Found in neck
2. Have transverse foramina (blood vessels to
brain)
3. Spinous process is forked (bifid)
4. special cervical vertebrae
a. Atlas
-supports head (up and down movement)
-facets that articulate with occipital
chondyle
b. Axis
-dens (odontoid process)
allows movement from side to side
C. Thoracic Vertebrae (12)
1. Larger than cervical vertebrae
2. long pointed spinous processes
D. Lumbar vertebrae (5)
1. Found in the small of the back
2. larger and more load bearing than thoracic
E. Sacrum (5)
1. Bones are fused together
2. Triangular in shape (pg. 144)
3. spinous processes form a ridge of tubercles
4. post./ant. Saccral foramen
5. vertebral foramen forms the sacral canal
6. sacral hiatus – opening at the inf. end of
sacrum
F. Coccyx (4)
1. inferior most part of vertebral column
2. bones are fused together
3. attachment site.
III. The Thoracic Cage
A. Functions
1. Protection
2. Support and attachment
3. Breathing
B. Bones of the Thoracic Cage
1. Ribs (24 or 12 sets)
a. True Ribs (vertebralsternal ribs) – (7)
-connect vertebrae to sternum
-connected by costal cartilage
b. False Ribs (vertebralcondral ribs) – (5)
-Upper 3 connect by cartilage of true rib #7
-Lower 2 do not connect
floating ribs (vertebral rib)
c. Rib anatomy
-head (posterior end) – articulates with
body of vertebra
-tubercle – close to the head articulates
with transverse process of vertebra
2. Sternum (breastbone)
a. Manubrium – articulates with clavicle
b. Body
c. Xiphoid process
IV. Pectoral Girdle
A. Functions
1. Supports upper limbs
2. attachment for muscles
B. Bones of the Pectoral Girdle
1. Clavicle (2)
a. Runs horizontally between the
manubrium and scapula
b. Braces the scapula
c. Attachment for upper limbs, chest, and
back
d. Sternal and acromial ends
2. Scapula (2)
a. Broad triangular bones
b. Located on the upper posterior back
c. Spine – divides scapula
d. Acromion process – tip of shoulder
-art w/ clavicle
-muscular attachment
e. Coracoid process – curves ant. and inf.
with clavicle
-muscular attachment
-glenoid cavity – art. with the humerous
V. Upper Limbs
A. Functions
1. framework of arm
2. act as levers (movement)
3. muscular attachment
B. Bones of the Upper Limbs
1. Humerus
a. Large bone
b. Head fits into the glenoid cavity
c. Greater tubercle
d. Lesser tubercle
e. Intertubecular groove
f. Deltoid tuberosity – attachment for deltoid
g. Lateral and medial condyles
-Capitulum – articulates w/ radius
-Trochlea – articulates w/ ulna
h. Epicondyles – muscular attachment
i. Coronoid fossa – receives the coronoid
process of ulna
j. Olecranon fossa – receives the ulnar
process
2. Radius
a. Thumb side of forearm
b. Head of radius – disclike
-articulates with the ulna and humerus
c. Radial tuberosity – inferior of head
-attaches biceps
d. Styloid process – inferior end
3. Ulna
a. Longer than radius
b. Trochlear notch
c. Olecrenon process
d. Coronoid process
e. Radial notch
f. Styloid process
g. Head articulates with radius and triquetrum
3. The Hand
a. Carpal bones (8)
-articulates with radius and ulna
1
Scaphoid
2
Lunate
3
Triquetrum
4
Pisiform
5
Trapezium
6
Trapezoid
7
Capitate
8
Hamate
b. Metacarpals (5)
-makeup the framework of the palm
-numbered 1-5 (begin with thumb)
-articulate with carpals and phalanges
c. Phalanges (14)
-3 per finger / 2 for thumb
-labeled as “proximal”, “middle”, and
“distal”
VI. Pelvic Girdle
A. Functions
1. Supports the trunk of the body
2. Provides attachment for lower limbs
3. Provides protection of internal organs
B. Bones of the Pelvic Girdle
1. Coxa – Hipbones (2)
a. Ilium – superior portion of coxa
-iliac crest
-iliac fossa
-sacroiliac joint – where ilium and sacrum joint
b. Ischium – lowest posterior part of coxa
-ischial tuberosity – muscular attachment
and supports weight while sitting
c. Pubis – anterior portion of coxa
-pubic symphysis – shock absorber
-pubic arch – wider in females
-obturator foramen – 2nd largest foramen
*all three coxa bones form the acetabulum
-cup shaped cavity that receives the head of
the femur
VII. Lower Limbs
A.
Functions
1. Support body’s weight
2. Acts as levers
3. Muscular attachment
4. Framework of leg
B. Bones of the Lower Limbs
1. Femur
a. Largest bone in the body
b. Similar to the humerus
c. Head of the femur
d. Fovea Capitis – ligament attachment site
e. Greater Trochanter – muscular attachment
f. Lesser Trochanter – muscular attachment
g. Lateral and medial condyles – articulates w/ tibia
h. Patella (bone) – articulates w/ femur
2. Tibia
a. Located medially
b. Also known as the shin
c. Medial/lateral condyles – art. w/ condyles of femur
d. Tibial tuberosity
e. Medial malleolus – inner ankle
-articulates w/ the talus
3. Fibula
a. Lateral to tibia
b. Head of fibula – art. w/ tibia
-non weight bearing bone
c. Lateral malleolus – outer ankle
4. The Foot
a. Tarsal Bones (7)
-Art. with tibia and fibula
1
Talus
2
Calcaneus
3
Navicular
4 Medial Cuneiform
5
Intermediate
Cuneiform
6 Lateral Cuneiform
7
Cuboid
b. Metatarsals (5)
-same as metacarpals
c. Phalanges
-each toe has 3 / great toe 2
VIII. Joints
A. Def – Junction between bones
B. Functions
1. bind skeletal system
2. allow bone growth
3. allow shape change (during childbirth)
4. allow movement
C. Types of Joints
1. Fibrous Joint – no movement
Ex: Skull bones
2. Cartilaginous Joint – limited movement
Ex: Vertebrae, pubic symphysis
3. Synovial Joint – free movement
Ex: Knee, elbow, shoulder…
a. Types of Synovial Joints
-Ball and Socket (hip)
-Condyloid (carpal bones fit into metacarpals)
-Gliding (ribs and carpal bones)
-Hinge (knee and elbow)
-Pivot (proximal end of radius and ulna)
-Saddle (trapezium and thumb)