different bone, structure of bone

  A. Scapula(Shoulder Blade):-

Scapula is flat bone places on the posterolateral aspect of the thoracic cage.

It has 2 surface , 3 borders , 3 angels , and 3 processes.

2 SURFACE:-

 1. costal surface or subscapular fossa:- It is concave. It is marked by three longitudinal ridges. there is another rod like thick ridges adjoins lateral border.

 2. dorsal surface :- it gives attachment to spine of scapula that divides surface into supraspinous fossa and infraspinous fossa

3 BORDER:-

 1. superior border:- it presents the suprascapular notch.

 2. lateral border: - it presents the infraglenoid tubercle

 3. medial border: - extends from the superior angle to the inferior angle.

3 ANGLES :-

 1. superior angle

 2. inferior angle

 3. lateral or glenoid angle

3 PROCESSSES:-

 1. spine or spinons process

 2. acromion prosess

 3. coracoid process

ATTACHMENTS :-

 • muscles that arises from scapula are subscapularis , supraspinatus ,infraspinatuss , deltoid , long head of the biceps , coracobrachialis, long head of triceps brachii , teres minor and teres major.

 • muscles that insert to scapula are trapezius, serratus anterior , pectoralis minor and levator scapulae.

 B. Humerus:-

The humerus is the bone of the arm. It is the longest bone of the upper limb. It has an upper end, a lower end and a shaft.

UPPER END :-

 1. The head - It articulates with the glenoid cavity of the scapula to form the shoulder joint.

 2. The line separating the head from the rest of the upper end is called the anatomical neck.

 3. bicipital groove separates the lesser tubercle from greater tubercle.

LOWER END:-

 1. The lower end of the humerus forms the condyle which has articular and nonarticular parts.

 2. articular part includes capitulum and trochlea.

 3. nonarticular part includes the following:-

 • medial and lateral epicondyle

 • coronoid fossa , It accommodates the coronoid process of the ulna

 • Olecranon fossa ,It accommodates the olecranon process of the ulna .

 • radial fossa, It accommodates the head of the radius.

SHAFT:-

The shaft is rounded in the upper half and triangular in the lower half. It has three borders (anterior, lateral , and medial border) and three surfaces(anterolateral, anteromedial, and posterior surface ).

ATTACHMENT:-

 • these muscle are inserted in humerus subscapularis, supraspinatus, infraspinatus, teres minor , pectoralis major , latissimus dorsi, teres major deltoid etc.

 • these muscle are originated from humerus brachialis, brachioradialis, pronator teres , superficial flexor muscles, superficial extensor muscles , triceps brachii etc.

CLINICAL ANATOMY:-

The common sites of fracture of humerus are the surgical neck, shaft, and supracondylar region.

 C. Tibia:-

 • it is the weight bearing vertiacl bone of the leg .

 • it has tibial tuberosity into which the patellar ligament inserts.

 • it has medial and lateral condyles that articulate with the condyles of the femur.

 • it has a projection called medial malleolus with a malleolar groove for the tendons of the tibialis posterior and flexor digitorum longus muscles

 • it has another groove (posterolateral to the malleolus groove) for the tendon of the flexor hallucis longus muscle.

 • It also provides attachment for the deltoid ligament.

 D. HIP(COXAL) BONE

It Is formed by the fusion of the ilium, pubis, and ischium .

Articulates with the sacrum at the sacroiliac joint to form the pelvic girdle.

Acetabulum Is an incomplete cup-shaped cavity on the lateral side of the hip bone in which the head of the femur fits.

 1. ILIUM :-

 • it Forms the lateral part of the hip bone.

 • it has two parts

 a. body- which joins the pubis and ischium to form the acetabulum,

 b. ala or wing - which forms the iliac crest.

 • it also Comprises the

 anterior–superior iliac spine,

 anterior–inferior iliac spine,

 posterior iliac spine,

 greater sciatic notch,

 iliac fossa, and

  gluteal lines.

 2. PUBIS:-

 • It forms anteromedial part of the hip bone.

 • It has

 a. the body, which articulates at the symphysis pubis;

 b. the superior ramus, which enters the formation of the acetabulum; and

 c. the inferior ramus, which joins the ramus of the ischium

 3. ISCHIUM:-

 • it forms lower posterior part of the hip bone.

 • It has

 a. the body, which joins the ilium and superior ramus of the pubis to form the acetabulum, and

 b. the ramus, which joins the inferior pubic ramus to form the ischiopubic ramus.

 • it Has the ischial spine, ischial tuberosity, and lesser sciatic notch.

 E. NAME THE BONES OF CRANIUM

The bones of cranium are

 • Frontal Bone

 • Parietal Bone

 • Temporal Bone

 • Occipital Bone

 • Sphenoid Bone

 • Ethmoid Bone

 F. CLAVICLE:-

 • Clavicle is a long bone . It is also known as beauty bone. It supports the shoulder so that the arm swing freely away the trunk.

 • It is curved and divided into 2 parts, medial 2/3 and lateral 1/3.

 • It has shaft , medial end and lateral end.

lateral end- attached with acromian process of scapulaa and forms acromioclavicular joint.

Medial end- attached eith clavicular notch of manubrium sterni and forms sternoclavicular joints.

 • calvicle is lighter , smaller ,smoother and less curved in females.

 • most commonly fractured bone of the body.

common site of fractured junction of its medial 2/3 and lateral 1/3.

 • it Is the first bone to begin ossification , but it is the last one to complete ossification aprox at the age of 21 years.

 G. STRUCTURE OF BONE:-

A bone is a rigid organ that consititutes part of the vertebrate skeleton in animals.

Bone is a modified form of connective tissue. Strucuture of bone can be studied under two headings :-

structure of COMPACT BONE:

 1. Its outer and inner surface is covered by periosteum(external surface of bone) and endosteum respectively.

 2. It is made up of lamellar bones.

 3. Lamellae are of three different patterns

 a. Haversian system of lamellae.

 • it is also known as osteon. it consists multiple concentric lamellae arranged around a central canal.

 • the central canal is called as haversian canal.

 • between the lamella there are lacunae containg osteocytes.

 • Through volkman's canal blood vessels and nerve enter in compact bone and also communicate with haversian canal.

 • Volkman's canals are horizontally or obliquely oriented in relation to long axis of bone. They are not surrounded by lamellae.

 b. Interstitial lamellae

 c. circumferential lamellae.

Structute of SPONGY BONES:-

 • made up of meshwork of trabeculae or spicules.

 • Between boon tissues there are numeroua spaces .

 • these sapces are filled with bone marrow.

DIFFERNT CELLS PRESENT IN BONE ARE:-

 • Osteocytes

 • Osteoblasts-produce and deposit collagenous bone matrix.

 • Osteoclasts-multinucleated cells that are responsible for reabsorption of bone.