EXPERIMENT 11 Objective. To study and identification of human bones and joints.

EXPERIMENT 11

Objective. To study and identification of human bones and joints.

 INTRODUCTION

1.Study and identification of bones and joints is one of the important part of biological practical's. Human bones and joints are generally used for this purpose.

2.Observe the bone joint carefully and draw its labelled diagram.

3.Write down special features of the bone and features of identification.

IDENTIFICATION OF HUMAN SKELETONBONES

AND THE TYPES OF JOINTS

1.IDENTIFICATION OF HUMAN SKELETONBONES

COMMENTS

1. Human endoskeleton is composed of 206 bones (300 above in children)

2. its differentiated into axile  and appendicular.

3. The axial include the bone of skull, vertebral column and chest cage .

4. Appendicular include the bone of limbs and girdle .

2.IDENTIFICATION OF HUMAN SKULL

COMMENTS

(i) It is a strong and firm bony box.

(ii) It has a cavity called cranial cavity.

(iii) In all, eight bones are articulated to form the cranium.

(iv) At about middle of the floor of cranium, there is a large opening called foramen magnum through which brain is connected to the spiral cord.

(v) The front or anterior part of the skull is made up of 14 bones.

3. IDENTIFICATION-VERTEBRAL COLUMN OF MAN 

COMMENTS

(i) It is backbone of man which extends in the mid-axis of the back part of the trunk from head to the lower extremity of trunk.

(ii) It is composed of 26 small bones called vertebrae.

(iii) The vertebrae are five types namely cervical, thoracic, lumbar, sacral and coccygeal or coccyx.

(iv) It has four curves to enhance balancing power and firmness for upright posture of the body.

.STRUCTURE OF TYPICAL VERTEBRA

(i) The basic structure of all the vertebrae is same, each having a ring like structure. 

(ii) The hole is called vertebral or neural canal.

 (iii) The ventral side (front side) of each vertebra consists of body or centrum which is very thick. 

(iv) Lateral walls of vertebral canal are formed by the neural arch. 

(v) Seven spine like processes arise from neural arch which project backwards. 

(vi) These include a pair of superior articular processes projecting up warts and inwards : in pair of inferior articular processes projected downwards and outwards : 

4.IDENTIFICATION OF ATLAS VERTEBRA 

COMMENTS:- 

1. It is the first cervical vertebra .

2. its body is formed by centrum vertebral arch.

3. its support the skull.

4. its has reduced spine .

5. its transverse processes are long.

5.IDENTIFICATION OF AXIAL VERTEBRA

COMMENTS :

1. its is second cervical vertebra.

2. its has acoelum centrum. 

(iii) It has odontoid process which acts as pivot for the rotation of atlas.

(iv) Its transverse processes are small.

6. IDENTIFICATION-TYPICAL CERVICAL VERTEBRA 

COMMENTS

(i) The third, fourth, fifth, sixth and seventh neck vertebrae are called typical cervical vertebrae.

(ii) A typical cervical vertebra has a long bifurcated spine.

(iii) It has acoelus centrum and long transverse processes.

(iv) It has cervical ribs.

7. IDENTIFICATION-THORACIC VERTEBRA 

COMMENTS

(i) Thoracic vertebrae twelve in number and occur in chest region of vertebral column.

(ii) A thoracic vertebra has club shaped transverse processes and a well developed neural spine.

(iii) Its centrum is acoelus which has a demifacet for articulation with ribs.

8. IDENTIFICATION-LUMBAR VERTEBRA (Fig. 11.8)

COMMENTS

(i) Lumbar vertebra are five in number and occur in abdomen region of vertebral  column.

(ii) A lumbar vertebra has acoelus centrum and well defined neural spine.

(iii) Its transverse processes are thin and long, each with a small accessary process near its roof.

9. IDENTIFICATION-SACRAL VERTEBRAE OR SACRUM 

COMMENTS

(i) Sacral vertebrae are five in number and are found in thigh region of vertebral column.

(ii) All the five vertebrae are fused in the form of a triangular structure called synsacrum.

(iii) They have extra articular surface area for articulation with ilium of pelvic girdle.

(iv) Their transverse processes are modified into broad sloping mass projected laterally from the body.

10. IDENTIFICATION-CAUDAL VERTEBRAE OR COCCYX 

COMMENTS

(i) Caudal vertebrae are four in number which are fused to form coccyx.

(ii) Their transverse processes are rudimentary.

(iii) There are present two coccygeal cornna to articulate with sacral cornna.

11. IDENTIFICATION-THORACIC CAGE OR CHEST CAGE 

COMMENTS

(i) It is a cage like structure meant for the protection of lungs and heart.

(ii) It is made up of thoracic vertebrae, sternum and ribs.

(iii) Twelve pairs of ribs form the sides of the chest cage.

(iv) The upper seven pairs are true ribs and remaining five pairs are called false ribs.

(v) The ribs of 11th and 12th pair are free and are called floating ribs.

12. IDENTIFICATION-SCAPULA BONE OF PECTORAL GIRDLE 

COMMENTS

(i) It is a large, flat and triangular bone which overlaps the transverse processes of second to seventh thoracic vertebrae on its side.

(ii) Its posterior (back) surface has a prominant edge or spine which project as a triangular acromian process.

(iii) It has another process called coracoid process, which projects upwards from the broad end of the scapula near acromian process.

(iv) Below acromian process, there is cup like cavity called glenoid cavity into which head of humerus is articulated.

13. IDENTIFICATION-HUMERUS (BONE OF UPPER ARM) 

COMMENTS

(i) It is a long bone with a rounded upper end called head, which articulates into glenoid cavity of scapula.

(ii) It has two tuberosities a greater and a lesser tubercles near the head.

(iii) The main bone called shaft have a V-shaped deltoid ridge.

(iv) Lower end is flattened with two projections called lateral and medial epicondyles.

(v) A rounded knob like structure is present below lateral condyle called capitulum.

(vi) Between capitulum and medial condyle is a pulley like structure called trochlea, which articulates with ulna of lower arm.

14. IDENTIFICATION-ULNA AND RADIUS (BONES OF LOWER ARM OR FOREARM)

COMMENTS

(i) Ulna is medial and longer than radius.

(ii) Its upper end has a larger olecranon process and a smaller coronoid process with a semilunar trochlear notch in between where trochlea of humerus articulates.

(iii) There is another notch called radial notch on lateral side which articulates with radius.

(iv) Radius is lateral and shorter than ulna.

(v) Its upper end has a head, a neck and a tuberosity. The head articulates with capitulum of humerus.

(vi) The lower end of radius has two articular surfaces, one for ulna and the other for wrist bones.

15. IDENTIFICATION-BONES OF WRIST AND HAND

COMMENTS

(i) The wrist consists of two rows of 8 small bones called carpals. Scaploid, lunate, triquetrum and pisiform form proximal row, and trapazium, trapizoid, capitate and hamate form the distal row.

(ii) The bones of hand consists of 5 metacarpels and finger bones called phalanges. There are 2 phalanges in thumb and 3 in each of the four fingers.

16. IDENTIFICATION-PELVIC GIRDLE OR HIP GIRDLE 

COMMENTS

(i) Two irregular, broad and massive semicircular hip bones called coxae form the arch like pelvic girdle by articulating with each other in front by a highly flexible pubic symphysis. The arch is completed behind by the sacrum and coccyx forming a complete ring called pelvis.

(ii) Each hip bone is formed of three bones called ileum, ischium and pubis. A small area, where the three bones meet is in the form of a deep socket called acetabulum. The head of thigh bone (femur) articulates into this socket.

(iii) The main part of ischium and pubis are separated by a large space called obturator foramen.

17. IDENTIFICATION-FEMUR OR THIGH BONE

COMMENTS

1.ita long and cylindrical bone. its upper end has rounded head , a constricted neck and two eminences called greater and lesser trochanters , head articulate into the acetabulum of hip bone.

2. The lower end is flatted and divided into eminances or condyles with a notch like, intercondylar fossa. 

18. IDENTIFICATION-TIBIA AND FIBULA OR BONES OF SHANK 

COMMENTS

(i) Tibia is long, thick and lies more medially and in front. Fibula is short, thin and located more laterally and deeply.

(ii) The upper end of tibia is concave for articulation with femur and knee cap. The lower of tibia which articulates with talus bone of ankle has a strong and medial process called medial malleolus.

(iii) The upper end or head of fibula articulates with the upper end of tibia, but does not reach the knee joint. Its lower end articulates with the end of tibia as well as with the talus by mean of a lateral malleolus.

19. IDENTIFICATION-BONES OF ANKLE AND FOOT 

COMMENTS

(i) Seven bones called tarsals from the ankles. These are calcaneum, talus, cuboid, navicular and first, second and third cuneiforms. Of these, the calcaneum (heel bone) is largest and strongest.

(ii) The bones of foot include 5 elongated metatarsus (sole bones) and bones of toes called phalanges. There are two phalanges in thumb and three in each of the remaining four toes.

TYPES OF JOINTS

1. IDENTIFICATION-FIBROUS OR IMMOVABLE JOINT BETWEEN THE BONES OF

CRANIUM 

COMMENTS

(i) It is an immovable joint and does not allow the movement of bones.

(i) At the joint, bones are held firmly together by bundles of strong white collagen fibres.

(iii) The place of joint is often called suture.

2. IDENTIFICATION-CARTILAGINOUS OR SLIGHTLY MOVABLE JOINT BETWEEN

THE VERTEBRAE 

COMMENTS

(i) This type of joint allow a limited movement of the bones. Such a joint is often called symphysis.

(ii) there is presen…

(i) This type of joint allow a limited movement of the bones. Such a joint is often called symphysis.

(ii) there is present an elastic pad of fibro-cartilage between the bones of the joint.

(iii) The bones are held together by ligaments extending across the joint.

3. IDENTIFICATION-BALL AND SOCKET JOINT HUMERUS IN GLENOID

CAVITY/FEMUR IN ACETABULUM) 

COMMENTS

(i) It is the most movable joint, because one bone of the joint can move freely in all directions.

(ii) One bone forms a ball like head that fits into a socket formed in the other bone.

(iii) Movements at this joint may stretch, fold and rotate limbs and also draw the limb towards or away from the body.

4. IDENTIFICATION-HINGE JOINT (ELBOW JOINT/KNEE JOINT) 

COMMENTS

(i) It is synovial or freely movable joint.

(it) This joint allows the movement of a bone in one plane only.

(ii) The joint is held intact by ligaments.

5. IDENTIFICATION-GLIDING JOINT OR ANGULAR JOINT BETWEEN

CARPALS/TARSALS

COMMENTS

(i) It is a synovial or freely movable joint.

(ii) An oval condyle of one bone fits into an elliptical concavity of the other.

(iii) The joint allows movement in two directions i.e., side to side and back and forth.

6. IDENTIFICATION-PIVOT JOINT OR ROTARY JOINT AT UPPER END OF RADIUS

AND ULNA 

COMMENTS

(i) This joint permits only a rotary movement of one bone on the other, which remains stationary.

(ii) It enables the head of radius to turn from side to side.

7. IDENTIFICATION-SADDLE JOINT BETWEEN METACARPAL OF THUMB AND

CORRESPONDING CARPAL 

COMMENTS

(z) This joint resembles with ball and socket joint but both the ball and socket are poorly developed.

(ii) It permits the movement of carpel in many directions.