Transcript Skull - ISpatula

Bones of the
axial skeleton
1- THE SKULL
2- THE
VERTEBRAL
COLUMN
3-THE THORAX
The Skull
The skull is composed of several separate bones (22
bones) united at immobile joints called sutures.
The connective tissue between the bones is called
a sutural ligament
Only one moveable bone, the mandible which
is united to the skull by the mobile
Temporomandibular Joint
The bones of the skull can be divided into:
1- Bones of the cranium (contain the
brain)
2- Bones of the face
The upper part of the cranium is The vault
 The base of the skull is the lowest part of the
cranium
Skull- Superior View
Four bones united
by four sutures.
• 4 bones:
– Frontal
– Occipital
– 2 Partials
• 3 Sutures:
– Coronal
– Sagittal
– Lambdoid
3
Pterion: is an area located on the lateral side of the skull
Where 4 bones meet at an H-shaped structure
The pterion is the thinnest part of the
lateral wall of the skull. it overlies the
anterior division of
The middle meningeal artery and vein
Trauma to the pterion may result in
Epidural bleeding
Base of the Skull
The interior of the base of the skull is
divided into three cranial fossae:
1-Anterior
2-Middle
3-Posterior
The foramen rotundum
Transmits the maxillary nerve.
THE OPTIC CANAL
Transmits the optic nerve
The foramen ovale
Transmits the mandibular nerve
The small foramen spinosum
The middle meningeal artery
The carotid canal
Transmits: The internal carotid artery
The sella turcica
which CONTAIN
THE PITUITARY GLAND
The sella turcica is bounded posteriorly
by a square plate of bone called
The internal acoustic meatus
A- THE VESTIBULOCOCHLEAR
NERVE
B- THE FACIAL NERVE.
The 9th, 10th, and 11th cranial nerves
5-The foramen magnum
The thorax
THE THORACIC WALL
1-STERNUM
2- Ribs
3-The Vertebral Column
STERNUM
Lies in the midline of the anterior
chest wall
 It is a flat bone
 Divides into three parts:
1-Manubrium sterni
2-Body of the sternum
3- Xiphoid process
The sternal angle
(angle of Louis)
formed by the articulation of the
manubrium with the body of the sternum
Can be recognized by the presence of a
transverse ridge on the anterior aspect of the
sternum
The transverse ridge lies at the level of the
second costal cartilage
The point from which all costal cartilages and
ribs are counted
Ribs
There are 12 pairs of ribs, all of which are
attached posteriorly to the thoracic vertebrae.
The ribs are divided into three categories:
True ribs: The upper seven pairs are attached
anteriorly to the sternum by their costal
cartilages
False ribs: The 8th, 9th, and 10th pairs of ribs
are attached anteriorly to each other and to the
7th rib by means of their costal cartilages and
small synovial joints.
Floating ribs: The 11th and 12th
pairs have no anterior attachment
The ribs have subcostal groove which
contains
A-INTERCOSTAL VEIN
B-INTERCOSTA L ARTERY
C-INTERCOSTA L NERVE
1-
In the subcostal groove the structures of the neurovascular bundle
Are arranged as follow:
A-INTERCOSTAL VEIN
B-INTERCOSTA L ARTERY
VAN
C-INTERCOSTA L NERVE
Therefore, the needle
should be inserted above
the superior border of the
rib
‫هام‬
The vertebral column
The Vertebral Column
is composed of 33
vertebrae
7 cervical
12 thoracic
5 lumbar
5 sacral
(fused to form the sacrum)
4 coccygeal
(the lower 3 are commonly
fused)
A typical vertebra consists of:
1-a rounded body anteriorly
2-a vertebral arch posteriorly.
They enclose a space called
The vertebral foramen
through which run the spinal cord
and its coverings
The vertebral arch gives rise to seven
processes:
a-One spinous
b-Two transverse
c- Four articular
The pedicles
are notched on their
upper and lower borders
Forming
the superior and inferior
vertebral notches.
On each side
the superior notch of one
vertebra and the inferior
notch of an adjacent
vertebra together form an
intervertebral foramen.
These foramina, in an
articulated skeleton, serve to
transmit the spinal nerves
and blood vessels.
Intervertebral Discs
Each disc consists of a
peripheral part,
the anulus fibrosus,
and a central part, the nucleus
pulposus
The anulus fibrosus is composed of
fibrocartilage, in which the
collagen fibers are arranged in
concentric layers or sheets.
The nucleus pulposus in children and
adolescents is an ovoid mass of gelatinous
material containing a large amount of water,
a small number of collagen fibers, and a few
cartilage cells.
The pressure developed in the
nucleus pulposus may be great
enough to rupture the surrounding
fibrocartilage
(annulus fibrosus).
If this occurs, the nucleus pulposus
may herniate (protrude) posteriorly
or into one of the adjacent
vertebral
bodies
This condition is called a herniated
(slipped) disc
The disc usually slips
posteriorly toward the
spinal cord and spinal
nerves.
This movement exerts
pressure on the
spinal nerves, causing
local weakness and acute
pain
Curves of the Vertebral Column
Curves in the Sagittal Plane
In the fetus,
the vertebral column has one continuous anterior
concavity
After birth,
when the child becomes able to raise his or her
head and keep it poised on the vertebral
column,
the cervical part of the vertebral column
becomes concave posteriorly
Toward the end of the first year,
when the child begins
to stand upright
the lumbar part of the vertebral column
becomes concave posteriorly.
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Abnormal Curves of the Vertebral Column
Various conditions may exaggerate the normal curves of the vertebral column, or the
column may acquire a lateral bend, resulting in abnormal curves of the vertebral column.
Scoliosis :
the most common of the
abnormal curves is a lateral
bending of the vertebral
column ,usually in the
thoracic region
Kyphosis :(hump)
Is an increase in the
thoracic curve of the
vertebral column
Lordosis :bent
backward
is an increase in the
lumbar curve of the
vertebral column