useful

befor analyzing the various elemnts of hand we must remeber the importence of anatomical nomenclature . terms of aterior,posterior,medial and lateral can only be applied when the specimen is in proper anatomical position.
it is useful to supplement the directional terms when possible, using these terms:


anterior= palmar
posterior= dorsal
medial=ulnar= little finger side
lateral= radial=tumbside

hand phalanges

The phalange are all shorter than MC ,lack rounded heads and are antreposteriorly flattedned in shafts. The thunb phalanges are shorter and squatter than the others, and the thumb lacks intermediate phalanx. The expanded proximal end of each phalanx is the base. the distal end is head ( proximal or intermediate phalanges) or the distal tip (distal phalanges only). the non articulate tubercles adjacent to the MC heads and the phalangeal joints are attachement points for the collateral ligament.
dorsal surface ofthe hand phalanges are smooth and rounded. The palmar surfaces, incontrast, are flat and more roughened,especially along either site of the shaft, where raised ridge mark attachment sites for the fibrous flexor shealts, tissues that prevent the flexor tendos from " bow stringing" away from the bones as the fingers are felxed.

hand phanalges each ossify from 2 centers:

1- for shaft plus distal end

2- for the base

hand phalanges have shafts whose palmar surface are flattened, forming a half-circle in cross section. Foot phalanx shafts are circular in cross section.

MC

The metacarpus is the intermediate part of the hand skeleton that is located between the fingers distally and the carpus which forms the connection to the forearm.
they are all tubular bones,with round distal articulate surfaces (heads) and more squarish proximal ends (base).
all of the four carpals in the distal row articulate with one or more metacarpal bases:
Trapezium =MC1 + MC2
Trapezoid = MC2
Capitate= MC2+MC3+MC4
Hamate= MC4+MC5
{first MC= Thumb}

each MC except MC1 ossifies from 2 centers : 1- shaft (body) + base
: 2- distal extremity (head)
MC1 (thumb) :seprate center for it base (not distal extremity)

MC2-5 could easily be confuse with MT 2-5 :
metatarsal shafts are larger in diameter relative to lenght
metacarpal heads are more rounded than the mediolaterally compressed metatarsal heads.

carpal bones

BONES OF HAND

Proximal: A=Scaphoid, B=Lunate, C=Triquetral, D=Pisiform

Distal: E=Trapezium, F=Trapezoid, G=Capitate, H=Hamate

The eight bones of the adult wrist are often described as cubical in shape with six surface.eachccarpal projections. the hook of the hamate and the pisiform underlie the medial edge of the palm at the base of metacarpal 5.

The scaphoid tubercle and trapzium crest underlie the laterla edge of the plam, at the base of the thumb metacarpal.

Carpel Tunnel : fibrous band stretched transversley between carpal elevation.

Proximal row incorporation ( from Radial to Ulnar) :

scaphoid-> articulate with radius

lunate-> // // //

triquetral

pisiform

Distal row of carplas (from Radius to Ulnar):

trapezium ( greater multangular)

trapezoid ( lesser multangular)

capitate

hamate

carpal bones each ossify from single center.

Many skeleton , especially those from archaeological sites, have incoplete hand because of the postmortem disturbance of the skeleton before excavation for exp, rodant

these animals often move smaller skeletal elements during their burrowing activities

seamoids, pisiform, terminal phalanges are often lose in excavation

confusion of carpale bone with tarsal bones.

hand

The hand is a complex structure that represents the distal tetrapod limb segment.It is the modified end of the ancestral dish fin, a structure based on jointed bony rays. In the generalized reptilian hand, a set of small wrist bones (carpals) forms the foundation for five digits. Each digit is composed of one large proximal segment (a metacarpal) and a chain of additional bones (the phalanges). digital reduction and modification have occured in a great variety of mammals, from the wings of bats to the single tors of the modern horses. Humans have retained the generalized pattern of five digits. there are a total of 27 bones in each human hand, 8 carpal bones arranged in 2 rows, followed distaly by a single row of 5 proximal phalanges, a single row of 4 intermediate phalanges, and a dingle row of five distal/terminal phalanges.

In addition to the 27 major hand bones, there are small bones called SESAMOID bones(small ossified nodes) that lie with in tendors of the hand. In the hand, a pair of sesamoid is usally found in at the palmar surface of the first metacarpal head.

hand skeleton :

Carpals

Metacarpals

Hand phalanges

the term of RAY= often used to each finger/toe/ including the digit's phalanges and metacarpal

Thumb ray= Pollex= ray 1

Index finger= ray 2

Middle finser= ray 3

Ring finger= ray 4

Littel finger= ray 5