generalities n anatomical positions
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Generalities
History of Anatomy
History of Anatomy
• Anatomy = the study of the structure and function of the body.
• Egypt (500 B.C.) = first formal study in anatomy• Earliest descriptions of anatomy in papyrus = 3000 B.C.• Hippocrates
first taught anatomy Greece (460 – 377 B.C.
founder of the science of anatomy
made the Hippocratic oath
Wrote a book “The nature of the human body is the beginning of Science”.
• Aristotle = ( 384-322 BC), first used the word “Anatome” Greek for cutting up or taking apart “Dissecare”
• Vesalius “ De Humani Corpori Fabrica” 1543. ( masterpiece)
• Hieronymus Fabricus (1537-1619) constructed the anatomical theater at in 1594 is a teacher of William Harvey, discovered the veinous valve.
• William Harvey (1628) “Exercitacio Anatomica De Motu Cordis et Sanguinis in Animalibus”. Discovered the blood circulation.
• 17th century, human dissection became an important feature in European medical schools.
• 18th and 19th centuries anatomist published impressive treatises and atlas with illustration
• Anatomy act of Britain was passed in Parliament 1832 legalizing the donation and receiving of human bodies for scientific studies.
Approaches to the study in Anatomy
• Regional anatomy – topographical anatomy• Systemic anatomy – study by systems, circulatory etc.• Clinical anatomy – emphasizes structures and functions
as they relate to the practice of medicine and other health sciences.
Regional anatomy
• Surface anatomy – study anatomy of the living body at rest and in action. The aim is to visualize structures that lie underneath the skin and are palpable.
• Physical examination – the clinical application of surface anatomy.
• Palpation – the clinical technique for examining living anatomy.
System
• Skeletal system
• Muscular system
• Integumentary system
• Nervous system
• Blood vascular system
• Lymphatics system
Anatomical Position
Normal anatomical position
• Normal anatomical position = the person is erect ( or lying supine as in erect) with the arms by the sides, palms facing forward, the legs together, and the feet directed forward.
Anatomical planes
• The midsagittal median plane is vertical between the anterior midline & the posterior midline dividing the body into left and right halves.
• Parasagittal ( paramedian) planes are parallel to the midsagittal plane.
• Coronal planes = are vertical and perpendicular to the midsagittal plane
• Midcoronal plane = (frontal) plane divides the body into anterior and posterior halves.
• Transverse (horizontal) plane = are mutually perpendicular to the midsagittal and coronal planes, dividing the bodyby cross sections.
• Axis = an intersection of any 2 mutually perpendicular planes.– Vertical axis = intersection between midsagittal
midcoronal plane– Anteroposterior axis = intersection between
trtansverse and sagittal planes– Bilateral axis = intersection between coronal and
transverse planes.
Anatomical Planes & References
• Frontal plane• Median plane• Sagittal plane• Parasagittal
plane
Anatomical positions
• Superficial• Superior• Inferior• Posterior • Anterior
(Ventral)• Caudal
(tail)
Anatomical adjectives
• Anterior/posterior – Anterior (ventral), towards the front aspect of the body– Posterior(dorsal), towards the back aspect of the body
• Proximal/distal– Proximal = close to the median or near the origin of a structure– Distal = away from the origin of a structure
• External/internal– External (superficial) = is close to the surface of the body.– Internal (deep) = is close to the center of the body.
• Superior/ inferior- Superior (cephalad, craniad, cephalic, rostral) towards the head– Inferior (caudad, caudal) towards the tail or feet.
• Medial / lateral– Median = in the midsagittal plane– Medial = towards the median.– Lateral = away from the median
• Central / peripheral– Central = toward the center of mass of body– Peripheral = away from the center of mass of the
body• Prone / supine
– Prone = ventral surface down.– Supine = ventral surface up
Anatomic movements• Flexion / extension = usually occurs in the midsagittal or parasagittal
plane.– Flexion = brings primitively ventral surfaces together.
• Plantar flexion = downward flexion of foot at the ankle joint.• Dorsiflexion = upward flexion (extension) of foot at ankle joint.• Radial deviation (flexion), abduction of the hand at the wrist joint.• Ulnar deviation (flexion), adduction of hand at the wrist joint.
– Extension = away from the ventral surface ( straightening the leg at the knee joint).
• Abduction / adduction = occurs in the midcoronal plane– Abduction (lateral flexion), movement away from the median plane.– Adduction , movement towards the median, towards the middle finger, or toward
the second toe.
• Medial rotation / lateral rotation =occurs about a line by the intersection of the coronal and or parasagittal plane sagittal)
– Medial rotation = movement of a ventral surface towards the median plane.– Lateral rotation = movement of a ventral surface away from the median plane
• Elevation / depression– Elevation, raises or moves a structure cephalad (shoulder shrug)– Depression, lowers or moves a structure caudally (directing the
eye downward)
• Protraction / retraction – Protraction = Moves a structure anterior (jutting out of the jaw)– Retraction = moves a structure towards the median (withdrawing a
protracted tongue into the oral cavity)
• Pronation/supination, refers to rotation of a specific region.– Pronation of the arm, a medial rotation so the palm face posteriorly.
– Supination of the arm = a lateral rotation so that the palm faces posteriorly.
Anatomical position
• Adduction• Abduction• Flexion• Extension• Rotation , medial
and lateral• Circumduction
• Inversion / eversion– Inversion of the foot, rotates the plantar surface inwards.– Eversion of the foot rotates the plantar surface laterally.
• Other terms– Intorsion / extorsion of the eye, rotation about an axis thru the
pupil.– Opposition / reposition of the thumb, a uniquely human
characteristics, refers to a rotation about a complex axis.– Circumduction = a combined movement, involving flexion/
extension with abduction/adduction.
• Supination• Pronation• Eversion• Inversion
Anatomical points, Skull
• Pterion – the union of frontal, parietal, sphenoid and temporal bones
• Occiput – from occipital,parietal,mastoid part of temporal
• Inion - Occipital protuberance • Foramen magnum – large opening at the base
of the skull• Lambda – the junction of the sagittal and
lambdoid sutures• Coronal sutures – separates frontal and parietal
bone
• Sagittal sutures – separates parietal bones• Lambdoid sutures – separates the parietal and
temporal bone from occipital bone• Bregma – intersection of sagittal and coronal
sutures.• Vertex – most superior point of the skull• Parietal foramen – found posteriorly near the
sagittal sutures, transmits emissary veins.
The skin
The skin• The largest organ in
the body.• Consist of:
– Epidermis – outer superficial layer, avascular
– Dermis- deeper connective tss.
– Subcutaneous tissue- loose tissue
– Skin ligaments retinacula cutis
– Deep fascia-dense• Functions:
– Protection– Heat regulation– Sensation
Dermis• Vascularized, nourishes the epidermis
• Contains:– Hair follicles– Arrector pili muscles, cause “goose bumps”– Sebaceous glands– Sweat glands– Collagen and elastic fibers- provides skin tone – Has tension lines of Langer
Appendages of the skin
• Hair
• Nail
• Glands (sebaceous & sweat glands)
Cleavage lines of the skin
Skeletal system
Composition of the skeletal system, Classification
• Axial skeleton– Head = Skull bones(hyoid and cervical)– Trunk = ribs, sternum, vertebrae, sacrum
• Appendicular skeleton– Bones of the upper and lower limbs– Pectoral bones (shoulder= clavicle, scapula)– Pelvic girdle (pelvis = ilium, pubis, sacrum,
coccyx)
Function
• Protection for vital structures• Support for the body• Mechanical basis for movements• Storage for salts ( calcium)• A continuous supply of new blood cells.
• Cartilage – resilient, semirigid connective tissue that forms parts of the skeleton where motion occurs. Has no capillary blood supply. Nutrition is thru long range diffusion.
• Bones:* compact bones = provide the strenght for weight bearing and the rigidity for attachment of muscles and ligaments.* spongy or cancellous bones = central mass containing: blood cells, blood platelets
• Axial skeleton
Skull - Cranium 8
- Face 14
- Auditory ossicles 6
Hyoid 1
Vertebrae 26
Sternum 1
Ribs 24
• Appendicular skeleton
Shoulder girdles
Clavicle 2
Scapula 2
Upper extremities
Humerus 2
Radius 2
Ulna 2
Carpals 16
Metacarpals 10
Phalanges 28
• Pelvic girdle
Hip bones 2• Lower extremities
Femur 2
Patella 2
Fibula 2
Tibia 2
Tarsals 14
Metatarsals 10
Phalanges 28
Total 206
Classification of bones (shape)
• Long bone = tubular,i.e., humerus
• Short bone = cuboidal, i.e.,tarsus & carpus
• Flat bones = protective.i.e., skull bones
• Irregular bones = various shapes and length.i.e, fascial bones
• Sesamoid bone = found where tendons cross the ends of long bones.i.e, patella
Accessory bones
• Developed when additional ossification center appears and form extra bones “ are also known as wormian bones or sutural bones”.
• Heterotopic bones = forms in soft tissue when they are not normally present.i.e., scars, riders bones in thighs of horse riders.
Bone markings:• Condyle – rounded articular area, “femur”
• Crest – ridge,i.e., iliac crest
• Epicondyle – eminence superior to a condyle
• Facet – smooth, flat, covered with cartilage, articulate with another bone
• Foramen – passage thru a bone
• Fossa – hollow or depressed area
• Groove – elongated depression or furrow
• Line – linear elevation• Malleolus – rounded process• Notch - indentation at the edge of bones• Protuberance – projection of bones• Spines – thorn like process• Spinous process – projecting spinelike
process• Trochanter – large blunt elevation• Tubercle – small raised eminence• Tuberosity – large rounded elevation
Trauma to bones• Atrophy = reduction in size due to unuse
• Absorbed = mandible in dental extraction
• Hypertrophy = increase in size to support weight for a long period of time.
• Fractures = a break in a normal bone.
• Reduction = to approximate the broken ends of a bone to its normal position.
• Callus formation = during bone healing, a collar of fibroblast surround an injured bone and secretes collagen for its healing.
• Greenstick fracture = incomplete fracture due to bending of a bone.
• Osteoporosis = reduction in the quantity of bone, lose elasticity, becomes brittle, fractures easily.
• Sternal puncture = examination of the bone marrow for hematological diseases.
Bone development
• Derived from mesenchyme thru:– Direct or intramembranous ossification
(membranous bone)= mesenchyme model formed during embryonic period, direct ossification begins in the fetal period.
– Endochondral or indirect ossification (cartilaginous bone) = cartilage models of the bone form from the mesenchyme during fetal period, later bone replaces the cartilage.
• Sutures = joints of two skull bones.
• Joints = an articulation.
• It is the place of union or junction between 2 or more bones or parts of the skeleton.
Classification of joints:
– Synovial = united by an articular capsule, characterized by a joint, covered by a cartilage, filled by fluids.
– Fibrous joints = united by fibrous tissue
– Plane joint = permit sliding or gliding moves in one plane(uniaxial)
– Hinge joint = moves in one plane (sagittal) around one axis. Permit flexion & extension only.
– Saddle joint = biaxial with opposing surface– Condyloid = biaxial and allow movement in 2
planes, sagittal/coronal– Ball & socket = multiaxial – Pivot = uniaxial and allow rotation