INTRODUCTION TO HUMAN BODY By Dr.Sisara Bandara MBBS

EVOLUTION

BODY AS A WHOLE 1.HEAD AND NECK

2. THORAX

3. ABDOMEN AND PELVIS

4. UPPER LIMB

5. LOWER LIMB

HEAD AND NECK

The Frankfurt plane is a plane formed by drawing a straight horizontal line from the top of the ear canal to the bottom border of the eye along either side of the human skull. The line is called a Frankfurt horizontal line (FHL) and is an important reference point in medical imagingstudies. The plane itself is used as a standard reference in anthropometry — the science that studies measurements of human anatomy in order to describe variations in human characteristics. The plane is also called the auriculo-orbital plane because it passes through the auriculus, or ear, and the orbitales, or eye sockets. It was established in 1884 in Frankfurt, Germany, by the World Congress of Anthropology. The Frankfurt plane became the principal standard of skull measurement because it also identifies the normal plane in which the head is positioned parallel to the ground. Because the Frankfurt plane serves as a benchmark for making skull measurements, it is also called a craniometric plane. This is simply a point on the skull, or cranium, from which measurements can be made. Craniometric measurements made on the exterior of the skull have endocranial equivalents, which are points within the skull that correspond to the external measurements.

Human skull  It is a bony structure, the head in the skeleton, which supports the structures of the face and forms a cavity for the brain.  consist of two parts of different embryological origin–the neurocranium and theviscerocranium. The neurocranium (or braincase) is a protective cranial vault that surrounds the brain and brainstem. The viscerocranium (also splanchnocranium or facial skeleton) is formed by the bones supporting the face. Except for the mandible, all of the bones of the skull are joined together by sutures,

The magic of 22 bones Occipital bone Two temporal bones  Eight bones of the neurocranium Occipital bone Two temporal bones Two parietal bones Sphenoid bone Ethmoid bone Frontal bone

Vomar Two Chochae bones Two nasal bones Two maxilla Mandible  Fourteen bones of the viscerocranium Vomar Two Chochae bones Two nasal bones Two maxilla Mandible Two Palatine bones Two Zygomatic bones Two Lacrimal bones

FRONTAL BONE The frontal bone forms the front portion of the skull above the eyes and includes the forehead, the roof of the nasal cavity, and the roofs of the orbits (bony sockets) of the eyes. On the upper margin of each orbit, the frontal bone is marked by a supraforamen (or supraorbital notch in some skulls), through which blood vessels and nerves pass to the tissues of the forehead. Within the frontal bone are two frontal sinuses, one above each eye near the midline.

OCCIPITAL BONE The occipital bone joins the parietal bones along the lambdoidal suture. It forms the back of the skull and the base of the cranium. There is a large opening on its lower surface called the foramen magnum, through which nerve fibers from the brain pass and enter the vertebral canal to become part of the spinal cord. Rounded processes called occipital condyles, which are located on each side of the foramen magnum, unite with the first vertebra of the spinal column.

TEMPORAL BONES The temporal bone is one of two bones that form parts of the sides and base of the cranium. A temporal bone on each side of the skull joins the parietal bone along the squamosal suture. The superior temporal line is the topmost curved line on the parietal bone and lies above the inferior temporal line. This is where the temporal fascia attaches. The inferior temporal line also lies on the parietal bone, and is the site of attachment of the temporal muscle. Located near the lower edge is a gap, the external auditory meatus, which leads inward to parts of the ear. The temporal bones house the internal structures of the ear and have depressions, the mandibular fossae, which join the processes of the mandible. Below each external auditory meatus, there are two projections: a rounded mastoid process and a long, pointed styloid process. The mastoid process provides an attachment for certain muscles of the neck, while the styloid process serves as an anchorage for muscles associated with the tongue and pharynx. The mastoid foramen is a prominent opening in the temporal bone, which is located behind (or posterior) to the mastoid process. Generally, it provides the opening through which a vein and artery pass. A zygomatic process projects from the front of the temporal bone in the region of the external auditory meatus. It joins the zygomatic bone and helps form the prominence of the cheek.

PARIETAL BONES One parietal bone is located on each side of the skull just behind the frontal bone. It is shaped like a curved plate and has four borders. Together, the parietal bones form the bulging sides and roof of the cranium. They are fused in the middle along the sagittal suture, and they meet the frontal bone along the coronal suture. Where the two sutures meet is called the bregma. There is a gap through the parietal bone that serves as a passageway for blood vessels and nerves, called the parietal foramen.

SPHENOID BONE The sphenoid bone is wedged between several other bones in the front of the cranium. It consists of a central part and two wing-like structures that extend sideways toward each side of the skull. This bone helps form the base of the cranium, the sides of the skull, and the floors and sides of the orbits (eye sockets). Along the middle, within the cranial cavity, a portion of the sphenoid bone rises up and forms a saddle-shaped mass called sella turcica (Turk's saddle). The depression of this saddle is occupied by the pituitary gland, which hangs from the base of the brain by a stalk. The sphenoid bone also contains two sphenoidal sinuses, which lie side by side and are separated by a bony septum that projects downward into the nasal cavity.

ETHMOID BONE The ethmoid bone is located in front of the sphenoid bone. It consists of two masses, one on each side of the nasal cavity, which is joined horizontally by thin cribriform plates. These plates form part of the roof of the nasal cavity, and nerves (ethmoidal cells) associated with the sense of smell pass through tiny openings in them. Portions of the ethmoid bone also form sections of the cranial floor, eye sockets, and nasal cavity walls. A perpendicular plate projects downward in the middle from the cribriform plates to form the bulk of the nasal septum. Delicate scroll-shaped plates called superior and middle nasal conchae project inward from the sides of the ethmoid bone toward the perpendicular plate. These bones, which are called the turbinate bones, support mucous membranes that line the nasal cavity

MUSCLES OF THE HEAD

THORAX

Abodomen

Upper limbs

Lower Limbs