Shapes of bones1. Long bones.

e.g. Humerus

2. Short bones.

e.g. Wrist bones

3. Flat bones.

e.g. Scapula

4. Irregular bones.eg. Vertebra

5. Sesamoid bones.eg. Patella

Dr. Maher T. Hadidi, Univ. of Jordan 1

Divisions

Two parts:

1. Axial skeleton

(80 bones).

2. Appendicular skeleton

(126 bones).

– Upper:

• Shoulder girdle

• Bones of upper limb

– Lower:

• Pelvic girdle

• Bones of lower limb

2

Bones of the

axial skeleton

1- SKULL

2- VERTEBRAL

COLUMN

3-THORIC CAGE

The Skull➢The skull is composed of several separate bones (22

bones) united at immobile joints called sutures.

➢Only one moveable bone, the mandible which

is united to the skull by the mobile

Temporomandibular Joint

1- Bones of the cranium (contain the brain)

2- Bones of the face

➢The bones of the skull can be divided into:

➢The upper part of the cranium is The vault

➢ The base of the skull is the lowest part of the

cranium

5

Skull- Superior View

Four bones united

by four sutures.

• 4 bones:

– Frontal

– Occipital

– 2 Partials

• 3 Sutures:

– Coronal

– Sagittal

– Lambdoid

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

Pterion: is an area located on the lateral side of the skull

Where 4 bones meet at an H-shaped structure

Epidural bleeding

FONTANELLES

Clinical Features of the Neonatal Skull

Palpation of the fontanelles enables the

physician to determine :

1-The progress of growth in the

surrounding bones

2-the degree of hydration of the baby ;

A-if the fontanelles are depressed below

the surface THE BABY IS

DEHYDRATED

B- a bulging fontanelle indicates

RAISED INTRACRANIAL PRESSURE

Samples of cerebrospinal fluid can be

obtained by passing a long needle obliquely

through the anterior fontanelle into the

subarachnoid space

When they close

The anterior fontanelles after 18 months,

Posterior Fontanelle: Close by the end of

the 2nd month

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

RibsThere are 12 pairs of ribs, all of which are

attached posteriorly to the thoracic vertebrae.

The ribs are divided into three categories:

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.

True ribs: The upper seven pairs are attached

anteriorly to the sternum by their costal

cartilages

Floating ribs: The 11th and 12th

pairs have no anterior attachment

In the subcostal groove the structures of the neurovascular bundle Are arranged as follow:A-INTERCOSTAL VEINB-INTERCOSTA L ARTERY VANC-INTERCOSTA L NERVE

The ribs have subcostal groove which

contains

A-INTERCOSTAL VEIN

B-INTERCOSTA L ARTERY

C-INTERCOSTA L NERVE

Therefore, the needle should be inserted above the superior border of the

ribهام

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.

These foramina, in an

articulated skeleton, serve to

transmit the spinal nerves

and blood vessels.

On each side

the superior notch of one

vertebra and the inferior

notch of an adjacent

vertebra together form an

intervertebral foramen.

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

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 in the Sagittal Plane

In the fetus,

the vertebral column has one continuous anterior

concavity

Curves of the Vertebral Column

Toward the end of the first year,

when the child begins

to stand uprightthe lumbar part of the vertebral column

becomes concave posteriorly.

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

1

2

3

4

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.

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