RT 204: RADIOGRAPHIC ANATOMY AND PHYSIOLOGY
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
FUNCTIONS OF THE BONES
• Support of the body
• Protection of soft organs
• Movement due to attached skeletal muscles
• Storage of minerals (calcium and phosphorus)
and fats
• Blood cell formation (red bone marrow for the
RBCs and yellow marrow for the fats)
THE SKELETAL SYSTEM BREAKDOWN OF THE 206 BONES
Parts of the Skeletal System • 8 Bones
22 bones in skull
• Bones • 14 Facial bones
• Joints • Malleus (2)
• Cartilages 6 in middle ears • Incus (2)
• Ligaments (an example of a fibrous connective • Stapes (2)
tissue that connect to a bone to bone) • Serves as the base of the
• Tendon (bone to muscle) 1 hyoid bone tongue and doesn’t
articulate with other bones
Divided into two divisions • C1 – C7 (C1: Atlas, C2: Axis)
• Axial Skeleton (skeleton that is located in our trunk • T1 – T12
and also intersects the axis. It is composed of: skull, 26 vertebral column • L1 – L5
vertebral column, thoracic cage) • Sacrum
• Appendicular Skeleton (composed of our limbs • Coccyx
[upper and lower limbs] and girdles [pectoral and • 24 Ribs (12 pairs)
pelvic]) 25 in thoracic cage
• Sternum
• Scapula (2)
4 pectoral girdle
• Clavicle (2)
• Humerus (2)
• Radius (2)
• Ulna (2)
60 in upper limbs
• Carpals (16)
• Metacarpals (10)
• Phalanges (28)
• Femur (2)
• Tibia (2)
• Fibulla (2)
60 in lower limbs • Tarsals (14)
• Metatarsals (10)
• Phalanges (28)
• Sesamoids (2)
• Ishium
BONES OF THE HUMAN BODY
2 in pelvic girdle • Illium
• Pubis
An adult human skeleton has 206 bones. 84 for the axial
skeleton and 126 for the appendicular skeleton. It has two 206 BONES IN TOTAL
(2) basic types of bone tissue:
CLASSIFICATION OF BONES
Compact
Homogeneous
Bone
Also known as the cancellous bone.
Spongy
It is small needle-like pieces of bones and
bone
has many open spaces
, RT 204: RADIOGRAPHIC ANATOMY AND PHYSIOLOGY
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
CLASSIFICATION OF BONES
NAME DESCRIPTION EXAMPLES
Typically, longer then
wide. It has a shaft with • Femur
Long
heads at both ends. • Humerus
Bones
Contain mostly of • Clavicle
compact bone.
Generally, they are
Short cube-shape. It contains • Carpals
Bones mostly on spongy • Tarsals
bones.
• Parietal
• Frontal
• Occipital
Thin and flattened and
• Scapula
usually curved. Thin
• Lacrimal
Flat Bones layers of compact
• Nasal
bone around a layer of
• Vomer
spongy bone.
• Hip
• Ribs
• Sternum
• Ethmoid
• Palatine
• Sphenoid
• Zygomatic
• Inferior
Irregular shape and
Nasal
Irregular they do not fit into other
concha
bones bone classification
• Maxilla
categories.
Mandible
• Vertebrae
• Hip
• Sacrum
Coccyx
BONE GROWTH
Ossification is the process of bone formation by osteoblasts
The two (2) distinct mechanisms in ossification:
• Intramembraneous Ossification
o Intra – inside the membrane. This is the • Endochondral Ossification
process of bone development from o Endo mean inside while chondral means
fibrous membranes. It is invloved in the cartilage. This is the process of bone
formation of the flat bones of the skull, the development inside the hyaline cartilage.
mandible, and the clavicles. It occurs in a It occurs in all bones except flat bones.
12-week old fetus at ossification centers.
During the embryonic stage, the skeletal system is mostly
composed of hyaline cartilage. Mesenchymal stem cells
that will differentiate into osteoblasts. The osteobalsts will
continuouslly secrete bone matrix, it will then rugate
outwards. Because of those osteoblasts there will be a
, RT 204: RADIOGRAPHIC ANATOMY AND PHYSIOLOGY
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
After birth, there will be an occurrence where the
appearance of the secondary ossification center which is
located at the epiphysis. Osteoblasts will produce bone
matrixes until they will close the epiphyseal plate and will
turn into an epiphyseal line.
Epiphyseal plates allows growth for long bones. For
females their bone growth end at the age of 18, as for the
males it ends at 21.
MACROSCOPIC ANATOMY OF THE BONE
Diaphysis Shaft; composed of compact bone
Ends of the bone; composed of mostly
Epiphysis
spongy bone
2 TYPES OF BONE GROWTH Metaphysis Area containing the epiphyseal plate
• Interstitial Bone Growth Covers the external surfaces of the
Articular
o This a bone growth which results in the epiphyses and reduces friction at joint
Cartilage
lengthening of the bone. surfaces
o Since epiphyseal plates allow growth of Epiphyseal
Growth plate
the long bone during childhood. Plate
Cartilages are continuously formed, older Epiphyseal When the epiphyseal plate is completely
cartilages become ossified (because of Lines closed
ossification). Cartilages are being broken Medullary Cavity of the shaft; contains the red and
down and being replaced by the bones. Cavity yellow bone marrow
o Hyaline cartilage has chondrocytes, Periosteum Outer covering of the diaphysis
which are cartilaginous cells.
Sharpey’s Connective tissue fibers that secures the
Chondroblasts will continuously secrete
Fibers periosteum to the underlying bones
chondrocytes.
Endosteum Inner covering of the diaphysis
• Appositional Bone Growth
o Growth in width or diameter.
o This bone growth happens beneath the
periosteum. Bone matrix will cotinue to
rugate outwards which causes the
increase of bone thickness.
o Osteoclasts will continue to destroy bones
in the medullary cavity to increase the
diameter of the bone.
Epiphyseal plates allow for growth of long bone during
childhood.
Two parts of the long bone
• Diaphysis: the main or midsection of a long bone
• Epiphysis: the end part of a long bone
o New cartilage is continuously formed
o Older cartilage becomes ossified
o Cartilage is broken down
o Bone replaces cartilage
Bones are remodeled and lengthened until growth stops
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
FUNCTIONS OF THE BONES
• Support of the body
• Protection of soft organs
• Movement due to attached skeletal muscles
• Storage of minerals (calcium and phosphorus)
and fats
• Blood cell formation (red bone marrow for the
RBCs and yellow marrow for the fats)
THE SKELETAL SYSTEM BREAKDOWN OF THE 206 BONES
Parts of the Skeletal System • 8 Bones
22 bones in skull
• Bones • 14 Facial bones
• Joints • Malleus (2)
• Cartilages 6 in middle ears • Incus (2)
• Ligaments (an example of a fibrous connective • Stapes (2)
tissue that connect to a bone to bone) • Serves as the base of the
• Tendon (bone to muscle) 1 hyoid bone tongue and doesn’t
articulate with other bones
Divided into two divisions • C1 – C7 (C1: Atlas, C2: Axis)
• Axial Skeleton (skeleton that is located in our trunk • T1 – T12
and also intersects the axis. It is composed of: skull, 26 vertebral column • L1 – L5
vertebral column, thoracic cage) • Sacrum
• Appendicular Skeleton (composed of our limbs • Coccyx
[upper and lower limbs] and girdles [pectoral and • 24 Ribs (12 pairs)
pelvic]) 25 in thoracic cage
• Sternum
• Scapula (2)
4 pectoral girdle
• Clavicle (2)
• Humerus (2)
• Radius (2)
• Ulna (2)
60 in upper limbs
• Carpals (16)
• Metacarpals (10)
• Phalanges (28)
• Femur (2)
• Tibia (2)
• Fibulla (2)
60 in lower limbs • Tarsals (14)
• Metatarsals (10)
• Phalanges (28)
• Sesamoids (2)
• Ishium
BONES OF THE HUMAN BODY
2 in pelvic girdle • Illium
• Pubis
An adult human skeleton has 206 bones. 84 for the axial
skeleton and 126 for the appendicular skeleton. It has two 206 BONES IN TOTAL
(2) basic types of bone tissue:
CLASSIFICATION OF BONES
Compact
Homogeneous
Bone
Also known as the cancellous bone.
Spongy
It is small needle-like pieces of bones and
bone
has many open spaces
, RT 204: RADIOGRAPHIC ANATOMY AND PHYSIOLOGY
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
CLASSIFICATION OF BONES
NAME DESCRIPTION EXAMPLES
Typically, longer then
wide. It has a shaft with • Femur
Long
heads at both ends. • Humerus
Bones
Contain mostly of • Clavicle
compact bone.
Generally, they are
Short cube-shape. It contains • Carpals
Bones mostly on spongy • Tarsals
bones.
• Parietal
• Frontal
• Occipital
Thin and flattened and
• Scapula
usually curved. Thin
• Lacrimal
Flat Bones layers of compact
• Nasal
bone around a layer of
• Vomer
spongy bone.
• Hip
• Ribs
• Sternum
• Ethmoid
• Palatine
• Sphenoid
• Zygomatic
• Inferior
Irregular shape and
Nasal
Irregular they do not fit into other
concha
bones bone classification
• Maxilla
categories.
Mandible
• Vertebrae
• Hip
• Sacrum
Coccyx
BONE GROWTH
Ossification is the process of bone formation by osteoblasts
The two (2) distinct mechanisms in ossification:
• Intramembraneous Ossification
o Intra – inside the membrane. This is the • Endochondral Ossification
process of bone development from o Endo mean inside while chondral means
fibrous membranes. It is invloved in the cartilage. This is the process of bone
formation of the flat bones of the skull, the development inside the hyaline cartilage.
mandible, and the clavicles. It occurs in a It occurs in all bones except flat bones.
12-week old fetus at ossification centers.
During the embryonic stage, the skeletal system is mostly
composed of hyaline cartilage. Mesenchymal stem cells
that will differentiate into osteoblasts. The osteobalsts will
continuouslly secrete bone matrix, it will then rugate
outwards. Because of those osteoblasts there will be a
, RT 204: RADIOGRAPHIC ANATOMY AND PHYSIOLOGY
LECTURE 3: SKELETAL SYSTEM
INSTRUCTOR: LEANDRO DAYAO JR., RRT, MSRT(iP)
FIRST SEMESTER | A.Y. 2022 - 2023 by: Seiton, Heloise L.
After birth, there will be an occurrence where the
appearance of the secondary ossification center which is
located at the epiphysis. Osteoblasts will produce bone
matrixes until they will close the epiphyseal plate and will
turn into an epiphyseal line.
Epiphyseal plates allows growth for long bones. For
females their bone growth end at the age of 18, as for the
males it ends at 21.
MACROSCOPIC ANATOMY OF THE BONE
Diaphysis Shaft; composed of compact bone
Ends of the bone; composed of mostly
Epiphysis
spongy bone
2 TYPES OF BONE GROWTH Metaphysis Area containing the epiphyseal plate
• Interstitial Bone Growth Covers the external surfaces of the
Articular
o This a bone growth which results in the epiphyses and reduces friction at joint
Cartilage
lengthening of the bone. surfaces
o Since epiphyseal plates allow growth of Epiphyseal
Growth plate
the long bone during childhood. Plate
Cartilages are continuously formed, older Epiphyseal When the epiphyseal plate is completely
cartilages become ossified (because of Lines closed
ossification). Cartilages are being broken Medullary Cavity of the shaft; contains the red and
down and being replaced by the bones. Cavity yellow bone marrow
o Hyaline cartilage has chondrocytes, Periosteum Outer covering of the diaphysis
which are cartilaginous cells.
Sharpey’s Connective tissue fibers that secures the
Chondroblasts will continuously secrete
Fibers periosteum to the underlying bones
chondrocytes.
Endosteum Inner covering of the diaphysis
• Appositional Bone Growth
o Growth in width or diameter.
o This bone growth happens beneath the
periosteum. Bone matrix will cotinue to
rugate outwards which causes the
increase of bone thickness.
o Osteoclasts will continue to destroy bones
in the medullary cavity to increase the
diameter of the bone.
Epiphyseal plates allow for growth of long bone during
childhood.
Two parts of the long bone
• Diaphysis: the main or midsection of a long bone
• Epiphysis: the end part of a long bone
o New cartilage is continuously formed
o Older cartilage becomes ossified
o Cartilage is broken down
o Bone replaces cartilage
Bones are remodeled and lengthened until growth stops
