IDENTIFICATION OF BONES
CRANIUM
The cranium is formed by a number of flat and irregular bones that provides bony protection for the brain. It has a base upon which the brain rests and a vault that surrounds and covers it. The bones of the cranium are:
- Frontal bones
- Parietal bones
- Temporal bones
FRONTAL BONES
This is the bone of the forehead. It forms part of the orbital cavities and the prominent ridges above the eyes the supraorbital margins. Just above the supraorbital margins within the bone, there are two air-filled cavities or sinuses lined with ciliated mucous membrane which have openings into the nasal cavity.
The coronal suture joins the frontal and parietal bones and other fibrous joints are formed with sphenoid, zygomatic, lacrimal, nasal, ethmoid bones. The bones originate in two parts joined in the midline by the frontal suture.
PARIETAL BONES
These bones form the side and root of the skull. They articulate with each other at the sagittal suture with the occipital bone at the lambdoidal suture and with the temporal bones at the squamous sutures. The inner surface is concave and is grooved by the brain and blood vessel.
TEMPORAL BONES
These bones lie one on each side of the head and form immovable joints with the parietal, occipital, sphenoid, zygomatic bones. Each temporal bone has several important features.
The squamous part is the thin and fan-shaped part that articulates with the parietal bones. The zygomatic process articulates with the zygomatic bone to form the zygomatic arch.
The mastoid part contains the mastoid process a thickened region behind the ear. It contains a large number of very small air sinuses which communicate with the middle ear and are lined with squamous epithelium.
The petrous portion forms part of the base of the skull and contains the organ of hearing and balance.
The temporal bone articulates with the mandible at the temporomandibular joint, the only movable joint of the skull. Immediately behind this articulating surface is the external auditory meatus which passes inwards towards the petrous portion of the bone.
OCCIPITAL BONE
This bone forms the back of the head and parts of the base of the skull. It has immovable joints with the parietal, temporal, sphenoid bones. Its inner surface is deeply concave and the concavity is occupied by the occipital lobes of the cerebrum by cerebellum. The occipital has two articular condoyles that form a hinge joint with the first bone of the vertebral column, the atlas. Between the condyles there is a foreman magnum through which the spinal cord passes into the cranial cavity.
SPHENOID BONE
This bone occupies the middle portion of the base of the skull and articulates with the occipital, temporal, parietal, and frontal bones. On the superior surface in the middle of the bone, there is a little saddle-shaped depression, the hypophyseal fossa in which the pituitary gland rest. The body of the bone contains some fairly large air sinuses lined by a ciliated mucous membrane with openings into the nasal cavity.
ETHMOID BONE
The ethmoid bone occupies the anterior part of the base of the skull and it helps to form the orbital cavity, nasal septum and lateral walls of the nasal cavity. On each side are two projections into the nasal cavity, the upper and middle conchae or turbinated processes. It is a very delicate bone containing many air sinuses lined with ciliated epithelium and with openings into the nasal cavity. The horizontal flattened part, the cribriform plate, forms the roof of the nasal cavity and has numerous small foramina through which nerve fibres of the olfactory nerve pass upwards from the nasal cavity to the brain.
There is also a very fine perpendicular plate of bone that forms the upper part of the nasal septum.
FACIAL BONES
The bones of the face expand as we grow i.e their size keeps on increasing. Our facial bones include the following bones:-
- LACRIMAL BONES: These are the smallest bones of the face , are thin and resemble in fingernail in size and shape. Each lacrimal bone contains a LACRIMAL FOSSA that houses the LACRIMAL SAC which is a structure that gathers tears and passes them to nasal cavity. These bones are posterior and lateral to the nasal bomnes and form a part of the medial wall of each orbit.
- NASAL BONES:- The paired nasal bones meet at the midline and form part of bridge of the nose and rest of the supporting tissues of the nose consists of cartilage.
- ZYGOMATIC BONES:- Also called the cheek bones are part of the lateral wall and floor of each orbit.They articulate with the maxilla , frontal, sphenoid and temporal bones.
- MAXILLAE:- The paired maxillae unite to form the upper jawbone. They articulate with every bone of the face except the mandible or low jaw bone. The maxillae form part of the floor of the orbits, part of the lateral wall and floor of the nasal cavity and most of the hard palate.Each maxillae contains a large MAXILLARY SINUS that empties into the nasal cavity. The ALVEOLAR PROCESS of the maxilla is an arch that contains the alveoli for the maxillary teeth. The PALANTINE PROCESS is a horizontal projection of the maxilla that forms the anterior three-quarters of the hard palate. The union and fusiom of the maxillary bone normally is completed before birth. The INFRAORBITAL FORAMEN is an opening in the maxilla below orbit.
- PALANTINE BONES:- These two are L shaped and form the posterior part of the hard palate and lateral wall of the nasal cavity. The horizontal plates separates the nasal cavity from the oral cavity.
- MANDIBLE:- Mandible also known as LOWER JAW. This is the largest and strongest facial bone. This bone helps us in movement while chewing or talking. This is only movable and flexible bone of our face.
ATLAS AND AXIS VERTENRAE
In anatomy, the atlas (C1) is the most superior (first) cervical vertebrae. They are responsible for the nodding and rotation movements of the head the atlas atlanto-occipital joint allows the head to nod up and down on the vertebral column. The dens act as a pivot that allows the atlas and attached head to rotate on the axis, side to side. The atlas’s chief peculiarity is that it has no body. It is ring-like and consists of an anterior and a posterior arch and two lateral masses. The atlas and axis are important neurologically because the brain stem extends down to the axis.
Lumbar vertebra
In human anatomy, the LUMBAR VERTEBRA are the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process (as it is only found in the cervical region|) and by the absence of facets on the side of the body. They are designated L1 to L5 starting at the top. The lumbar vertebrae help support the weight of the body and permit movement. A typical lumbar vertebra has the following characteristics:
- The body is large and kidney shaped.
- The pedicles are strong and directed backward.
- The laminar are short in a vertical dimension (important when performing a spinal tap).
- The vertebral foramina are triangular.
- The transverse processes are long and slender.
- The spinous processes are short, flat and quadrangular and project posteriorly. These processes are well adapted for the attachment of the large bones.
- The articular surfaces of the superior articular processes face medially and those of the nferior articular processes face laterally.
CERVICAL VERTEBRAE
The bodies of the cervical vertebrae (C1-C7) are smaller than all other vertebrae except those that form the coccyx. All cervical vertebrae have three foramina : one vertebral foramen and two transverse foramina. The vertebral foramina of cervical vertebrae are the largest in the spinal column because they house the cervical enlargement of the spinal cord. The first two cervical vertebrae differ considerably from others. The atlas (C1) named after the mythological atlas who supported the world on his shoulder is the first cervical vertebra inferior to the skull.
The atlas is a ring of bone with anterior and posterior arches and large lateral masses. It lacks a body and a spinous process paired atlanto-occipital joints. These articulations permit you to move your head to signify yes. The inferior surfaces of the lateral masses the inferior articulate facets articulate with the second cervical vertebra. The transverse processes and transverse foramina of the atlas are quite large.
The second cervical vertebra (C2) , the axis does have a body. A peg-like process called dens (tooth) or odontoid process projects superiorly through the anterior portion of the vertebral foramen of the atlas.
The third through sixth cervical vertebrae (C3-C6) represented by the vertebra corresponds to the structural pattern of the typical vertebra previously described.
THORACIC VERTEBRAE
There are 12 thoracic vertebrae (chest) are posterior to the thoracic cavity. Thoracic vertebrae (T1-T2) are considerably larger and stronger than cervical vertebrae. In addition, the spinous processes on T1-T2 are long, laterally flattened and directed inferiorly. In contrast, the spinous processes on T11 and T 12 are shorter, broader, and directed more posteriorly. Compared to cervical vertebrae, thoracic vertebrae also have longer and larger transverse processes. The feature of the thoracic vertebrae that distinguishes them from other vertebrae is that they articulate with the ribs. Except for T11 and T12 , the transverse processes have facets for articulating with the tubercles of the ribs.
The bodies of thoracic vertebrae also have either facets or demifacets ( half facets) for articulation with the heads of the ribs. The articulations between the thoracic vertebrae and ribs, called vertebrocostal joints, occur on both sides of the vertebral body. T1 has a superior facet and an inferior demifacet. T2-T8 have superior and inferior demifacets. T9 has a superior demifacet. T10- T11 have a facet. Movements of the thoracic region are limited by the attachment of the ribs to the sternum.
SACRUM
The sacrum is a large wedge-shaped vertebra at the inferior end of the spine. It forms the solid base of the spinal column where it intersects with the hip bones to form the pelvis. The sacrum is very strong that supports the weight of the upper body as it is spread across the pelvis and into the legs. Developmentally, the sacrum forms from five individual vertebrae that start to join during late adolescence and early adulthood to form a single bone by around the age of thirty. A ridge of tubercles along the posterior surface of the sacrum represents the spinous processes of these fused bones.
COCCYX
The coccyx is also known as the tailbone is a small bone resembling a tail located at the bottom of the spine. It is composed of three to five coccygeal vertebrae or spine bones. The vertebrae may be fused together to form a single bone.
In some cases, the first coccyxgeal vertebra is separate from the other three. The coccyx is connected to the sacrum by means of an amphiarthrodial joint. The coccyx is a remnant of the vestigial tail; however, unlike most of the other vestigial parts of the body, the coccyx is not completely without function. The coccyx serves as an attachment site for tendons , ligaments and muscles. It also functions as an insertion point of some of the muscles of the pelvic floor. The coccyx also functions to support and stabilize a person while he or she is in a sitting position. The coccyx may be fractured when a person fails abruptly on his or her buttocks. A woman’s coccyx may be broken during childbirth. A qualified medical professional pain medication until the coccyx heals. In extreme cases, the coccyx may need to be surgically removed. This procedure is called a coccygectomy.
THORACIC BONES – STERNUM
The sternum or breast bone is flat, narrow bone located in the center of the anterior thoracic wall. The superior part is the manubrium, the middle and the largest part of the body; and the inferior, smallest part is the xiphoid process. The junction of the manubrium and the body forms the sterna angle. The manubrium has a depression on its superior surface, the suprasternam notch. Lateral to the suprasternal notch are clavicular notches that articulate with the medial ends of the clavicles to form the sternoclavicular joints.
THORACIC BONES- RIBS
Twelve pairs of ribs, numbered 1-12 from superior to inferior, give structural support to the sides of the thoracic cavity. The ribs an increase in length from the first through seventh, and then decrease in length to the twelfth rib. Each rib articulates posteriorly with its corresponding thoracic vertebra. The first through seventh pairs of ribs have a direct anterior attachment to the sternum by a strip of hyaline cartilage called coastal cartilage. The ribs that have coastal cartilage and attach directly to the sternum are called true ribs. The articulates formed between the true ribs and the sternum are called nocostal joints. The remaining five pairs of ribs are termed false because their coastal cartilage either attach indirectly to the sternum or do not attach to the sternum at all. The cartilages of the eighth, ninth, and tenth pairs of ribs attach to one another and then to the cartilages of the seventh pair of ribs. These false ribs are called vertebrachondrial ribs. The eleventh and twelfth pair of ribs are false ribs designated as floating ribs because the costal cartilages at their anterior ends do not attach to their sternum at all. The spaces between the ribs are called intercostal muscles, blood vessels and nerves. The posterior portion of the rib connects to a thoracic vertebra by its head and the articulate part of the tubercle.
FEMUR
The femur or thigh bone is the longest, heaviest, and strongest bone in the body. Its proximal end articulates with the hip bone.
Its distal end articulates with the tibia and patella. The body(shaft) of the femur angles medially and as a result, the knee joints are closer to the midline. The angle (angle of convergence) is greater in females because the female pelvis is broader. The acetabulum of the hip bone forms the hip (coxal) joint. These articulate with the medial and lateral condyles of the tibia. Superior to the condyles are the medial epicondyle and the lateral epicondyle to which ligaments of the knee joint are attached. A depressed area between the condyles on the posterior.
HUMERUS
The humerus or arm bone is the longest and largest bone of the upper limb. It articulates proximally with the scapula and distally at the elbow with two bones, the ulna and the radius. The proximal end of the humerus features a rounded head that articulates with the glenoid cavity of the scapula to form a glenohumeral joint. The distal head is the anatomical neck, which is visible as an oblique groove. The greater tubercle is a lateral projection distal to the anatomical neck. It is the most laterally palpable bony landmark of the shoulder region. The lesser tubercle projects anteriorly between the two tubercles there is a groove named the intertubercular sulcus. The surgical neck is a constriction in the humerus just distal to the tubercles, where the head tapers to the shaft; it is so named because fractures often occur here. The body (shaft) of the humerus is roughly cylindrical atits proximal end, but it gradually becomes triangular umtil it is flattened and broad at its distal end.
Laterally, at the middle portion of the shaft, there is a roughened. The V-shaped area called the DELTOID TUBEROSIS.
ULNA AND RADIUS
The ulna is located on the medial aspect ( the little-finger side) of the forearm and is longer than the radius. One such memonicto help you remember the location of the ulna in relation to the hand is “p.u.”(the pinky is on the ulna side). At the proximal end of the ulna is the olecranon, which forms the prominence of the elbow. With the olecranon, an anterior projection called the coronoid process articulates with the trochlear of the humerus. The trochlearnotch is a large curved area between the olecranon of coronoid process that forms part of the elbow joint. Lateral and inferior to the trochlear notch is a depression, the radial notch which articulates with the biceps brachii muscle attaches. The distal end of the ulna consists of a head that is separated from the wrist by a disc of fibrocartliage. A styloid process is located on the posterior side of the ulna’s distal end. It provides attachment for the ulnar collateral ligament to the wrist.
RADIUS
The radius is the smaller bone of the forearm and is located on the lateral aspect (thumb side) of the forearm. In contrast, the ulna is narrow at its proximal end and widens at its distal end. The proximal end of the radius has a disc-shaped head that articulates with the capitulum
the humerus and the radial notch of the ulna inferior to the head is the constricted neck. A roughened area inferior to the neck on the medial side called the radial tuberosity is a point of attachment for the tendons of the biceps brachii muscle. The shaft of the radius widens distally to form a styloid processor the lateral side which can be felt proximal to the thumb. The styloid process provides attachment for the brachioradialis muscle and for attachment of the radial collateral ligament to the wrist. Fracture of the distal end of the radius is the most common fracture in adults older than 50 years. The ulna and radius articulates with the humerus and the elbow joint. The articulation occurs in two places: where the head of the radius articulates with the capitulum of the humerus and where the trochlear notch of the ulna articulates with the trochlea of the humerus. The ulna and the radius connect with one another at three sites. First, a broad, flat, fibrous connective tissue called the interosseous membrane (in-ter-OS-e-us; inter- between, osse- bone) joins the shaft of the two bones. This membrane also provides a site of attachment for some tendons of deep skeletal muscles of the forearm. The ulna and radius articulate directly at their proximal and distal ends. Proximally the head of the radius articulates with the ulna’s radial notch. This articulation is the proximal radioulnar joint. Distally, the head of the ulna articulates with the ulnar notch of the radius. This articulation is the distal radio ulnar joint. Finally, the distal end of the radius articulates with three bones of the wrist- the lunate. The scaphoid and the triquetrum – top form the radiocarpal (wrist) joint.
TIBIA AND FIBULA
The tibia or skin bone is the larger medial, weight-bearing bone of the leg. The tibia and fibula, like the ulna and radius, are connected by indrosseous membrane.
The proximal end of the tibia is expanded into a lateral condyle and medial condyle. Thus articulate with the condyles of the femur to form the lateral and medial tibiofemural (knee) joint. By upward projection called interocondylar eminence.
The tibia tuberosity on the anterior surface is a point of attachment for the patellar ligament. Inferior to and continuous with the tibial tuberosity.
The fibular notch articulates with the distal end of the fibula to form the distal tibiofibular joint.
The fibia is parallel and lateral to the tibia, but it is considerably smaller unlike the tibia does not articulate with the femur but it does help stabilize the ankle joint. The head of the fibula the proximal end articulates with the inferior surface of the lateral condyle of the tibia below the level of the knee joint to form proximal tibiofibular. The distal end is more arrowhead-shaped has a projection called lateral malleolus that articulates the talus of the ankle. This forms the prominence on the lateral surface of the ankle. As noted previously, the tibia at the fibular notch forms a distal tibiofibular joint at the fibular notch to form a distal tibiofibular joint.
PALM AND WRIST
WRIST:- The carpus (wrist) is the proximal region of the hand and consists of eight small bones, the carpals joined to one another by ligaments. Articulations among carpal bones are called intercarpal joints. The carpals are arranged in two transverse rows of four bones each. The carpals in the proximal row from lateral to medial are the scaphoid (boat-like), lunate (moon-shaped), triquetrum (three-cornered) , and pisiform (pea-shaped).
PALM:- The metacarpus (beyond) or palm is the intermediate region of the hand and consists of five bones called Metacarpals.
Each metacarpal bone consists of a proximal base, an intermediate shaft and a distal head. The metacarpal bones are numbered I to V (or 1-5) starting with the thumb, from lateral to dily visible in a clenc.
SKELETON OF THE FOOT
Tarsals, Metatarsals and phalanges.
The tarsus (ankle) is the proximal region of the foot and consists of seven tarsal bones. They include the talus (ankle bone) and calcaneus (heel) located in the posterior part of the foot. The calcaneus is the largest and strongest tarsal bone. The anterior tarsal bones are the navicular (like a little boat) , three cuneiform bones(wedge-shaped) called the third (lateral), second (intermediate) , and first (medial) cuneiforms and the cuboid (cube-shaped). The talus, the most superior tarsal bone, is the only bone of the foot that articulates with the fibia and tibia. It articulates on one side with the medial malleolus of the tibia and on the other side with the lateral malleolus of the fibula. These articulations form the talocrural (ankle) joint. The metatarsus, the intermediate region of the foot consists of five metatarsal bones numbered I to V (or 1-5) from the medial to lateral position. Like the metacarpals of the palm of the hand, each metatarsal consists of a proximal base, an intermediate shaft, and a distal head. The metatarsals articulate proximally with the first, second and third cuneiform bones and with the cuboid to form the tarsometatarsal joints. Distally, the third cuneiform bone forms the tarsometatarsal joints. Distally they articulate with the proximal row of phalanges to form the metatarsophalangeal joints.
The phalanges comprise the distal component of the foot and resemble those of the hand both in number and arrangement. The toes are numbered I to V (or 1-5 ) beginning with the great toe, from medial to lateral. Each phalanx (singular) consists of a proximal base, an intermediate shaft, and a distal head. The great or big toe (hallux) has two large, heavy phalanges called proximal and distal phalanges. The other four toes each have three phalanges – proximal, middle and distal. Joints between phalanges of the foot like those of the hand are called Interphalangeal joints.
PECTORAL GIRDLE
The human body has two pectoral or shoulder girdles that attach the bones of the upper limbs to the axial skeleton. Each of the two pectoral girdles consists of a clavicle and a scapula.
CLAVICLE
Each slender, S-shaped clavicle (key), or collarbone, lies horizontally across the anterior part of the thorax superior to the first rib. The medial end called the sterna end is rounded and articulates with the manubrium of the sternum to form the sternoclavicular joints.
The broad, flat, lateral end, the acromial end articulates with the acromion of the scapula to form the acromioclavicular joint. The conoid tubercle (conelike) on the inferior surface of the lateral end of the bone is a point of attachment for the conoid ligament, which attaches the clavicle and scapula.
SCAPULA
Each scapula or shoulder blade is a large, triangular, flat bone situated in the superior part of the posterior thorax between the levels of the second and seventh ribs. The lateral end of the spine projects as a flattened, expanded process called the acromion, easily felt like the high point of the shoulder. The thin edge of the scapula closer to the vertebral column is called the medial (vertebral) border. The thick edge off the scapula closer to the arm is called the lateral (axillary ) border. The medial and lateral borders join at the inferior angle. The superior edge of the scapula, called the superior border, joins the medial border at the superior angle.
PELVIC GIRDLE
The pelvic (hip) girdle consists of the two hip bones, also called coxal or pelvic bones or oscoxa (hip).
Fortunately, the bony pelvis provides strong and stable support for the vertebral column and pelvic and lower abdominal organs. The pelvic girdle of the bony pelvis also connects the bones of the lower limbs to the axial skeleton.
ILIUM
The ilium (flank), the largest of the three components of the hip bone is composed of a superior ala(wing) and an inferior body. The body helps form the acetabulum, the socket for the head of the femur Bruising of the anterior superior iliac pointer. Below this spine is the anterior inferior iliac spine.
ISCHIUM
The ischium (hip), the inferior, posterior portion of the hip bone is comprised of a superior body and an inferior ramus. The ramus is the portion of the ischium that fuses with the pubis. Features of the ischium include the prominent ischial spine, a lesser sciatic notch below the spine, and a rough and thickened ischial tuberosity. This prominent tuberosity may hurt a person’s thigh when you sit on his or her lap. Together, the ramus and the pubis surround the obturator foramen the largest foramen in the skeleton.
PUBIS
It is the anterior and inferior parts of the hip bone. A superior ramus and inferior ramus and a body between the rami comprise the pubis. The anterior, superior border of the body is the pubic crest, and at its lateral end is a projection called the pubic tubercle. This tubercle is the beginning of a raised line, the pectineal line which extends superior and laterally along the superior ramus to merge with the arcuate line of the ilium. The acetabulum is a deep fossa formed by the ilium, ischium and pubis. It functions as the socket that accepts the rounded head of the femur. Together, the acetabulum and the femoral head from the hip (coxal) joint.
Remedial Biology Practicals
- Introduction to experiments in biology a) Study of Microscope b) Section cutting techniques c) Mounting and staining d) Permanent slide preparation 2. Study of cell and its inclusions 3. Study of Stem, Root, Leaf, seed, fruit, flower and their modifications 4. Detailed study of frog by using computer models 5. Microscopic study and identification of tissues pertinent to Stem, Root Leaf, seed, fruit and flower 6. Identification of bones 7. Determination of blood group 8. Determination of blood pressure 9. Determination of tidal volume
First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise
First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise
