It is skeletal system of human body in detail description. In this ppt gives axial skeleton of body cranium thoracic cage and Vertibral coloumn . i gave structure and function of the bone , parts of axial skeleton with diagram

1. Osseous System
Part - I
Swati G. Patil
M. Pharmacy
K.Y. D.S.C.Ts College of Pharmacy, Sakegaon.

2. Skeleton Constitute the bony framework of the body.
The framework of the body not only consist of bone , but it is made
up bone and other related tissue which actually hold the organs of
the body in place and thus make their possible called skeleton.
1) They form the supporting framework of the body
2) The form boundaries for the cranial , thoracic and pelvic cavities.
3) The give protection to delicate organs
4) They form joints which are essential for the movement of the body
5) They provide attachment for the voluntary muscles . This helps in the movement of joints
6) The form blood cells in the red bone marrow in cancellous bone
7) They act as store house of calcium salts

3. The bone making of skeleton are various type:
e.g. 1) long bone ( femur)
2) Short bone ( carpel in the wrist )
3) Flat bone ( skull)
4) Irregular bone ( vertebrae )
5) Sesamoid bone ( patella)
The bone skeleton are divided into two groupe:
(1) The axial skeleton : It consist of bone which
form scull, the vertebral column and thoracic age.
(2) The appendicular skeleton : It consist of shoulder
girdle , upper limb, pelvic girdle, lower limb
The total number of bone in adult skeleton about about 206

4. • It is also called gristle. It is modified connective tissue ,
• Cartilage is strong , it’s not as rigid as the bone
• It is like a flexible plastic and is found in those parts of the
where support is needed , but have to adapt themselves to
changes in position from time to time.
• It support and give shape to some parts of the body like nose ,
external ear, larynx , trachea.
• Cushions of cartilage are found between the bone of some of
the joints . Due to presence of cartilage in between the bearing
surface is increased and therefore the joint become stronger
and more efficient . Such cartilage cushion can be seen
between the bone of vertebral column.
• Cartilage is vascular , and consist of cells and fibers like that of
other tissues. In cartilage the fiber are surrounded by a firm
material which binds them together and also permit their slight
movement . The cells of cartilage are scattered through out the
cartilage substance , and the fibers of cartilage are produced by
these cells.
Cartilage

5. Bone
• A bone is a rigid tissue that constitutes part of the vertebrate skeleton in animals. Bones protect the various organs of the
body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility.
Bones come in a variety of shapes and sizes and have a complex internal and external structure. They are lightweight yet
strong and hard, and serve multiple functions.
• Bones posses several ridges and elevation on its surface . These serves as the point of attachment for muscles and tendons
(a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone)
• All bone are externally covered by periosteum , which is a layer of tough tissue . Periostenum helps the bone grow , in
childhood , just as that of the bark of the tree
• Bone is firm and more or less brittle, it is a living tissue containing million of living cells. Each cell is located in a tiny
space and receive nourishment through minute canals which run through substance of bone
• The bone being living tissue require supply of blood . Some blood vessel enters the interior of the bone through the small
holies or canals called as foramen.
• The hard substance of bone is made up of organic and inorganic matter. Organic matter occurs in the form of fibers,
which are similar ligaments and tendons . These fibers are enclosed in mineral substance consisting principal of the salt of
calcium , phosphorus and magnesium

6. • The skull (also known as cranium) consists of
22 bones ,
 8 cranial bones
 14 facial bones .
The scull rests on superior end of the vertebral
column.
• The skull is a bony structure that supports the
face and forms a protective cavity for the brain.
• It is comprised of many bones, which are
formed by intramembranous ossification, and
joined by sutures (fibrous joints).
• The bones of the skull can be considered as two
groups:
 cranium (which consist of the cranial roof
and cranial base)
 face.
Axial skeletal

7. 1. Cranial cavity protects the delicate tissues of cerebrum, cerebellum and brain stem and
orbits of the eyes.
2. To provide protection and structure to meninges.
3. Paranasal air sinuses make the skull lighter.
4. Orbital cavity protects the eye ball and gives attachment to the muscles that move the eye
ball.
5. It has maxillae and mandible which have alveolar processes that bear sockets for teeth.
6. Delicate middle and internal ear are protected in petrous part of temporal bone.
7. Bones of the skull form the boundary walls of nasal cavities which keeps the inlet of
respiratory passage open.
8. Structurally it provides an anchor for tendinous and muscular attachments of the muscles of
the scalp and face
9. The skull also protects various nerves and vessels that feed and innervate the brain, facial
muscles, and skin.
Function of skull

8. Anatomically, the cranium can be subdivided into a roof and a base.
Cranial roof – comprised of the frontal, occipital and two parietal bones. It is also known as the
calvarium.
Cranial base – comprised of six bones: frontal, sphenoid, ethamoid, occipital, parietal and temporal.
These bones articulate with the 1st cervical vertebra (atlas), the facial bones, and the mandible (jaw).
1) The Cranial Bone : Which
forms cranium and is made up of
eight bones
The cranium (also known as the
neurocranium)
• Is formed by the superior aspect
of the skull. It encloses and
protects the brain, meninges, and
cerebral vasculature.

9. 1)One Frontal bone
2)Two parietal bone
3)One Occipital bone
4)Two Temporal bone
5) One Ethmoid bone
6)One Sphenoid bone

10. There are eight cranial bones, each with a unique shape
1) Frontal bone : This is the flat bone that makes up forehead.
It also forms the upper portion of your eye sockets.
.
2) Parietal bones :This a pair of flat bones
located on either side of your head, behind
the frontal bone.

11. 3) Temporal bones : This is a pair of irregular
bones located under each of the parietal bones.
4) Occipital bone. This is a flat bone located in
the very back of your skull. It has an opening
allows your spinal cord to connect to your brain.

12. 5) Sphenoid bone. This is an irregular bone
that sites below the frontal bone. It spans the
width of your skull and forms a large part of the
base of your skull.
6) Ethamoid bone. This is an irregular bone
located in front of the sphenoid bone. It makes
up part of your nasal cavity.

13. • Cranial bones are held together by unique joints called sutures ,
which are made of thick connective tissue.
• They’re irregularly shaped, allowing them to tightly join all the
uniquely shaped cranial bones.
• The sutures don’t fuse until adulthood, which allows your brain to
continue growing during childhood and adolescence.
• They are immovable fibrous in type .
Suture
1. Coronal suture : In between frontal and two parital bones
2. Sagittal suture : The suture between two parital bones
3. Lamboid suture : The suture between two parital and one
occipital bone
4. Squamous suture : The suture in between parital and temporal
bone with lining attaches to lamboid suture
of left and right side of the scull

14. Face bone
14 Facial bone that form the face .
• Nasal bone (2) : that form the lateral wall of the nose
• Inferior nasal concha (2) : Forming lateral wall of the nose
• Vomer bone (1) : Which form the septum of the nose
• Lacrimal bone (2): Which form the medial wall of the orbit
• Zygomatic bone (2): These are also referred as the cheek bone
• Maxillae (2): Which unit to form the upper jaw bone.
• Mandible (1) :Which is known as lower jaw bone . It is largest and strongest facial bone , and the
only moving scull bone
• Palatine bone (2) :Are l –shaped and they form the posterior parts of the hard palate , parts of
floor , small portion of the floor of orbit and lateral wall of the nasal cavity .

15. Neck Bone
• 8 Bone are located in neck
region , which include one
hyoid bone and seven
cervical vertebrae .
• Hyoid bone is an unique
bone of the axial skeleton .
It dose not articulate with
any other bone. It is located
in the anterior parts of the
neck , below the mandible
and above thyroid
cartilage.

16. Typical vertebra
Typical vertebra
It consist of two basic parts
1. A body 2. The neural arch
The neural arch of typical vertebra
possesses following parts
a) 2 pedicles
b) 2 laminae
c) 2 transverse processes
d) 1 spine or spinous process
e) 4 articulate processes
It is solid box shape structure situated anteriorly and possess slightly concave
upper and lower surface . The intervertebral disc of fibrocartilage separate the body
of the vertebra from the upper and lower one

17. • The pedicles :
these are two short and stout bars of the bone that project
backward from either side of posterior aspect
• The laminae :
These start from posterior ends of the pedicles that back word
direction and meet in the midline behind.
• The transverse processes :
these project outward from the junction of pedicle with the laminae
on the either side .
• The spine and spinous process :
It is formed at union of laminae and project backwards ; but in few
parts , downwards
• The articular process :
These are two in number and are situated on the upper and lower surface on each vertebrae at junction of pedicle and
laminae , near the origin of transverse processes
• The neural Canal :
It is Roughly circular opening enclosed by body in front and the pedicles on either side and laminae behind , spinal
cord is enclosed with in .
Parts of vertebra

18. It consist of Twenty four separate , movable, irregular
bone called vertebrae .
which are classified as follows:
• Cervical: 7
• Thoracic: 12
• Lumbar: 5
In addition , consisting fused bone i.e.
• Sacral: 5 (fused into one bone, the sacrum)
• Coccygeal: 4 (fused into one or two bones, the
coccyx)
Functions
The vertebral column has four main functions:
• Protection – encloses and protects the spinal cord within
the spinal canal.
• Support – carries the weight of the body above the pelvis.
• Axis – forms the central axis of the body.
• Movement – has roles in both posture and movement.
By TeachMeS2021)
Vertebral Column

19. There are seven cervical vertebrae in the human body. They have three
main distinguishing features:
• Bifid spinous process – the spinous process bifurcates at its distal end.
• Exceptions to this are C1 (no spinous process) and C7 (spinous
process is longer than that of C2-C6 and may not bifurcate).
• Transverse foramina – an opening in each transverse process, through
which the vertebral arteries travel to the brain.
• Triangular vertebral foramen Two cervical vertebrae that are unique.
C1 and C2 (called the atlas and axis respectively), are specialized to
allow for the movement of the head.
Cervical Vertebrae
Cervical Vertebrae Function
• The cervical vertebrae are responsible for movements of the head and neck.
• They are relatively mobile and allow flexion and extension of the joints between the vertebrae, which helps
to produce movement.
• The atlanto-occipital joint has also been dubbed the “yes” joint because the joint allows you to nod your
head. The atlanto-axial joint is the “no” joint, allowing you to shake your head.
• The rest of the cervical vertebrae contribute to this movement through rotation, flexion, and extension.

20. • The first cervical vertebra ( C1 ) known as
atlas .
• It is large ring with anterior and posterior
arch and large lateral mass does not possess
body or spine .
• The superior articular facets articulate with
occipital , comdyles of the occipital bone .
• This articulation provides the “yes” saying
movement of scull .
• The inferior articular facets articulate with
axis .
Atlas

21. It is second cervical vertebrae . In the axis , a body is absent , it contains an up
projecting process called dens, which articulates with the atlas to form pivot joint,
which helps us rotating our head side- to- side.
( Dens)
The remaining four vertebrae ( C3 to C7 ) are typical cervical vertebrae . C3 to C7
posses bifid spinous processes where as seventh cervical vertebra ( c7 ) processes a
large , non-bifid spinous process , which may be left at base of the neck , therefore it
serves as an important anatomical landmark
Axis

22. These are larger and stronger as compared to cervical vertebrae . There
are12 thoracic vertebrae . The thoracic vertebrae articulate with rib , at
surface called facets .
The characteristics feature of the vertebra include :
a) Heart-shaped bodies, intermediate in size between the cervical vertebra
and lumber vertebra
b) The pointed spinous process are pointed downward
c) The possess two type of articulate facets for the rib
i) Two facets , one above and one below on each side of the bodies
ii) A small facets ate the tip of the transverse process articulating with
the tubercle of the rib
Thoracic Vertebrae Function
• To support the back.
• To provide a protective cage around the delicate organs of the thorax, including the heart and lungs.
• There is limited mobility in this section of the spine due to these joint articulations and their design.
• Cervical vertebrae that allow nodding and shaking of the head .
• The thoracic vertebrae allow some twisting and bending motions, but little beyond that.
Thoracic vertebra

23. • Lumber vertebrae are the largest vertebrae (five in number).
• Kidney shaped .
• They do not have articulating facets for the rib.
• The spinous processes of the lumber vertebrae are broad , flat and
stout and are directed backwards
• Well adapted for the attachments of the large back muscles
Function of Lumbar Vertebrae
Lumber vertebrae
• Protects the spinal cord and cauda equine (The collection of nerves at the end of the spinal cord is
known as the cauda equine)
• Supports and stabilizes the upper body
• Allows truncal movements
• Controls leg movements
• Contains 5 pairs of spinal nerves, which merge with the lumbosacral plexuses and innervate the lower
body
• to support the great weight of the body and allow certain movements, such as lifting objects

24. • It is a triangular formed by the union of five sacral vertebrae .
• It Articulate above with the fifth lumber vertebrae forming the
lumbo-sacral angle below with coccyx.
• The sacrum possesses anterior and posterior surface and lateral
margins.
The transverse processes project from the body .The neural
canal continued in the sacrum ( sacral canal) and at its lower end ,
open on to the surface of the bone . On the inferior side it articulate
with the coccyx
Function
• The sacrum connects to the hip bones and is important in forming a strong pelvis.
• The sacrum provides support at the base of your spine. (The sacrum is a very strong bone that helps to
support the weight of the upper body. In fact, it's so strong that it is seldom fractured. It takes a severe
injury such as a fall to fracture the sacrum, although someone with osteoporosis is at risk of stress
fractures in the sacrum.)
• There are also several muscles that connect to the sacrum. These muscles pull on the sacrum to allow
the leg to move.
• Without the sacrum, most activity wouldn't be possible, including walking, running, and climbing.
Sacrum

25. • It is referred to as the tail and also triangular .
• It consist of four fused rudimentary vertebrae
• On the upper side coccyx articulate with sacrum
and possesses a series of transverse processes on
the lateral surface
Function :
• When you sit in a chair, your weight is distributed onto your hip bones and your tailbone. This allows you to be
balanced and have stability so you don't topple over easily in your chair. Think of a three legged stool - if there
were only two legs, you could tip it easily.
• Has shock absorber.
Coccyx :

26. The skeletal framework of the thorax is formed by the thoracic vertebrae in the
back side and sternum , costal cartilage and ribs in front
The sternum 1
Pair of ribs 12
Thoracic vertebrae 12
The bone of thorax

27. It also known as breast bone . It is a flat bone and possesses anterior and
posterior surface . The costal cartilage of the rib are attaches to the
sternum .
The sternum can be divided into three parts :
a) The Manubrium
b) The body
c) The xipoid Process
• The manubrium is upper part of the sternum . It articulate with the
clavicle at the stenoclavicular joint .
• The cartilage of the first rib joint the sternum just below the
sternoclavicular joints.
• The body of the sternum is oblong in the shape. The cartilage of the
second rib joint the sternum at level of manubrium and the body . The
cartilage of 3rd , 4th , 5th, and 6th rib also joined to the body of sternum.
• The xipoid is the lower part of the sternum . The cartilage of 7th rib
joint at the union of xipoid and body . Xipoid process is initially
cartilaginous and gets ossified during adulthood. It is small triangular
process .
The sternum

28. The Ribs helps forming the thoracic cage which
protects the delicate lungs and hearts. There are
twelve pairs of ribs .
The ribs are divided into two different groups.
True ribs : The upper seven pairs of rib which
actually articulate with the sternum through the
costal cartilage are referred to as true ribs .
False ribs : The remaining five pairs , i.e. from to
12th are called false ribs , as they do not join the
sternum directly . The costal cartilage of 8th , 9th
and 10th rib fuse with the cartilage immediately
above. The 11th and 12th rib have only a small
costal cartilage and refer to as floating ribs.
The Ribs

29. Each rib is a long bone and is divided into :
a) Head : is slightly enlarge structures at posterior end
which articulate with thoracic vertebrae
b) Neck bone : the neck is the portion between head and
shaft . The neck regions possesses a tubercle and a facet
which articulate with the trancevers process of the
corresponding vertebrae.
c) Shaft :The shaft is flat and curved. Also it is slightly
twisted on itself . The portion of maximum curvature
is called angle of rib . The border of the attaches to
the intercostal mucosa
The Typical Ribs