Introduction to anatomy

4TH... LECTURE

Introduction to anatomy

4TH... LECTURE

Bone:

- It is living tissue – highly specialized connective

tissue.

- Storage for salt (calcium).

- has blood vessels, lymph vessels, nerves.

- Exists in two forms :

1- Compact bone : solid mass

2- Canacellus bone : branching network

:Classification of bones

1- according to region:-

- Axial skeletal : include skull

vertebra

sternum

- Upper extremities :include Hummers, radius

ulna, carpal, metacarpal, phalanges.

- Lower extremities : include femur, patella,

fibula, tibia, tarsal, metatarsal, phalanges

2- according to general shape:-

A- Long bone : femur They have shaft

called diaphysis and

at each ends have epiphysis.

B- Short bone :found in the hand and foot

C- Flat bone : in skull

D- Irregular bone : vertebra, pelvic bone

E- Sesamoid bone : bones found in tendon

like patella

-Surface Marking of bones: Are various marking or irregularity where band of fascia ,

ligament, tendom or aponeursis are attached to bone. The

surface is raised or roughened . (see table 1-3 in Snell)

Bone development:

By two process:-

1- membranous development from connective

tissue membrane .(in skull)

2- endochondral development cartilaginous model

(in long bones)

Cartilage:

Is form of connection tissue , they are 3 types of

cartilage

1- Hayaline cartilage: epiphyseal plate

2- Fibro cartilage: temporomandibular

3- Elastric cartilage: auricle of ear

Joints

A site where two or more bones come

together, occurs between them, is Joints

are classified according to the tissues

that lie between the bones:

1- fibrous joints

2- cartilaginous joints

3 -synovial joint

Fibrous Joints

The articulating surfaces of the bones are joined by fibrous tissue and thus very

little movement is possible.

The sutures of the vault of the skull and the inferior tibiofibular joints are

Cartilaginous Joints

Divided into :

: bones unite by plate or bar of hyalin Primary cartilage .

Example : between epiphysis and diaphysis , no movement .

: bones are unite by plate of the Secondary fibrocatilage.

Example: joint between vertebral bodies and symphysis pubis ,small amount of movement is possible.

Synovial Joints

The articular surfaces of the bones are covered by:

1- a thin layer of hyaline cartilage

2- separated by a joint cavity. 3- permits a great degree of freedom of movement.

4- The synovial membrane is protected on outside by capsule.

5- articular surfaces are lubricated by synovial fluid .

Synovial joints can be classified according

to:

A- the arrangement of the articular

surfaces.

B-types of movement that are possible.

1-Plane joint :

- Flat

- Sternoclavicular , acromio

clavicular joint.

2- hing joint :

- Resemble hing on door

- Elbow , knee , ankle joint.

3-Pivot joints:

Central bony pivot is surronding

by bony ligmentous ring.

Example: atlanto axial joint.

Rotation is the only possible

movement.

3-Pivot joints:

Central bony pivot is surronding

by bony ligmentous ring.

Example: atlanto axial joint.

Rotation is the only possible

movement.

4-Saddle joints:

- These concave and convex surface.

- Movement is flexion, extension, abduction,addection, with small amount of rotation.

Example: metacarpo phalangal joint.

5-Ellipsoid joints:

- Elliptal convex fit into elliptal concave surface.

- Movement is flexion, extension, abduction,addection, but rotation is immpossible.

Example: wrist joint.

6- Saddle joint:

- Resemble saddle on horse back .

- Flexion, extension, adduction ,

abduction and rotation.

Example: carpometacarble joint of the

thumb.

7- ball and socket joint:

-permit three movement.

Example.: shoulder , hip joint.

Stability of Joints

The stability of a joint depends on three

main factors:

1-the shape, size, and arrangement of

the articular surfaces.

2- the ligaments

3- the tone of the muscles around the

joint.

Nerve Supply of Joints

The capsule and ligaments receive an

abundant sensory nerve supply.

1-A sensory nerve supplying a joint also

supplies the muscles moving the joint 2-

skin overlying the insertions of these

muscles, a fact that has been called

Hilton's law.