The document describes the bones found in the skull, pectoral girdle, pelvic girdle, forelimb, and hindlimb of mammals. In the skull, dorsal, ventral and lateral views describe the various bones visible from each perspective, such as the frontal, parietal, maxilla, and zygomatic bones. The pectoral girdle consists of the scapula, coracoid process, and clavicle. The pelvic girdle is formed from the fusion of the ilium, ischium, and pubis bones into an innominate bone on each side. Descriptions are also provided of bones in the forelimb like the humerus, radius,
4. Dorsal view :- Skull/bones seen in dorsal view are anterior nares, pre-maxilla, nasal,
maxilla, frontal, jugal, parietal, squamosal, tympanic bulla, interparietal,
supraoccipital, external auditory meatus, zygomatic process of squamosal, supra-
orbital process of frontal, zygomatic arch, zygomatic process of maxilla, maxillary
process of frontal, nasal or frontal process of premaxilla and I incisor tooth.
Ventral view :-
Skull bones seen in ventral view are incisor tooth, palatine process of pre-maxilla,
anterior palatine foramen, palatine process of maxilla, premolar teeth, zygomatic
process of frontal,
zygomatic process of squamosal, eustachian canal, external auditory meatus, para-
occipital process of exoccipital, supraoccipital, foramen magnum periotic, occipital
condyle, exoccipital, mastoid process,
tympanic bulla, basioccipital, alisphenoid, basisphenoid, pterygoid, pituitary foramen,
presphenoid, palatine, vomer, maxilla, pre-maxilla, nasal and II incisor tooth.
5. Lateral view :- Skull bones seen in lateral view
consists of premaxilla, I-incisor, II-incisor,
zygomatic process of maxilla, premolars,
molars, jugal, palatine, pterygoid,
basisphenoid, basioccipital, tympanic
bulla, paraoccipital process of exoccipital,
occipital condyle, stylomastoid foramen for
facial nerve, external auditory meatus,
periotic, supraoccipital, interparietal, post
tympanic process of squamosal, squamosal,
zygomatic process of squamosal, parietal,
alisphenoid, sphenoid fissure, supraoccipital
process of frontal, frontal, optic foramen,
orbitosphenoid, lacrymal, maxillary process of
frontal, nasal or frontal process of premaxilla.
maxillary process of premaxilla, palatine
process of premaxilla and nasal process of
premaxilla.
6. Ventral view :- Various skull bones seen are
nasal process of premaxilla, palatine process of
premaxilla, maxillary process of premaxilla,
frontal zygomatic process of frontal, zygomatic
process of temporal basitemporal,
basioccipital, occipital condyle, exoccipital,
paramastoid process, tympanic cavities,
pterygoid, common eustachian opening,
parasphenoid rostrum, palatine vomer and
internal naris.
7. Lateral view :- Various skull bones seen in
lateral view consists of maxillopalatine process
of maxilla, nasal chamber nasal lacrymal, inter-
orbital septum, frontal, olfactory frontal, optic
foramen, zygomatic process of frontal parietal
lamboidal crest, supraoccipital foramen of V
nerve, occipital condyle, fenestra ovalis,
tympanic cavity, fenestra rotundum,
paramastoid process, eustachian opening,
quadratojugal, quadrate, zygomatic process of
temporal, pterygoid, jugal, palatine, maxilla,
vomer and premaxilla.
8.
9. Pectoral Girdle:
It consists of two separate halves placed dorsal to the anterior thoracic ribs in
between the forelimbs, it supports forelimbs and protects the soft parts of the
body from the ventral side. Each half of the pectoral girdle is known as
innominate. Thus one half of the pectoral girdle is formed of a broad, more or
less triangular bony plate, called scapulo-coracoid and a small clavicle bone.
Scapulo-Coraciod:
It is mainly formed of scapula which is a thin, flat, and more or less triangular
bony structure. Its outer surface bears a prominent ridge, called the spine which
divides its surface into antero-dorsal and postero-dorsal portions to which are
attached muscles. The spine terminates ventrally into an expanded knob-like
structure, the acromion process which posteriorly bears backwardly directed
metacromion process.
The apex of scapulo-coracoid is directed downwards and forwards terminating
below into a concave glenoid cavity for the head of humerus. Above this cavity
is present a small hook-like coracoid process, the rudimentary coracoid. The
suprascapula is in the form of a thin strip of cartilage situated along the dorsal
or vertebral border of the scapula.
Clavicle is a thin, slightly curved bone extending between the acromion
processes and manubrium of the sternum.
10.
11.
12. Pelvic Girdle:
The pelvic girdle is also formed of two equal
halves or os-innominate. Both the halves are
joined together mid-ventrally by pubic
symphysis to form a stout and strong girdle
situated in the pelvic region between the two
hindlimbs. Each half or os-innominatum is
formed of three bones, the ilium, ischium, and
pubis. All these bones are fused together to
form a single hip bone.
The ilium is the antero-dorsal longest bone,
which bears a rough flat articular surface
roughly at about the middle of its length for
sacrum. The anterior and dorsal edge of the
ilium is raised into iliac-crest. The ilium extends
posteriorly up to the acetabulum. The postero-
dorsal part of the os-innominate is formed by
the ischium.
13. The posteriormost part of ischium is broad and projects
outwards into a prominent ischial tuberosity. The pubis is
a narrow bone and forms the ventro- median portion of
innominate. Both the pubes unite with each other on the
mid-ventral line to form a pubic-symphysis.
The pubis does not take part directly in the formation of
acetabulum, because a cotyloid bone is present in
between the acetabulum and pubis. A big obturator
foramen is present between the ischium and pubis which
is always covered by the obturator membrane and
muscles in the lifetime. Acetabulum is only formed by the
ilium and ischiam on both sides of the girdle and into it
articulates the head of humerus.
16. Comments :
Humerus :-
It is a rod-shaped bone.
Head articulates with glenoid cavity.
Close to head are outer greater and inner lesser tuberosities and bicipital
fossa.
Deltoid ridge present.
Distally humerus contains a pulley-like trochlea to articulate with ulna.
Just above trochlea are coronoid and olecranon fossae.
Humerus in posterior view shows bicipital fossa, lesser tuberosities, greater
tuberosity, shaft, supratrochlear lumen head and trochlea.
Radius and ulna (Side view).
Radius and ulna are separate but united firmly at both ends.
Radius is smaller and curved.
At the proximal end of ulna is an olecranon process which articulates with
olecranon fossa of humerus.
At the base of olecranon process is a sigmoid notch which fits into trochlea of
humerus.
17. Bones of forefoot or hand :-
Wrist contains nine small bones in two rows,
namely radiale, intermedium and ulnare in
proximal row and single centrale, trapezium,
trapeziod, magnum, and unciform in distal
row.
A sesamoid bone or pisciform is found on
ventral side of carpus.
Manus has five digits with 2, 3, 3, 3 and 3
phalanges, respectively.
Terminal phalanx bears a horny claw.
18.
19. Hind limb is formed by femur, tibio-fibula and bones of hindfoot.
Comments :
Right femur (Back view) :- (i) It is thigh bone. (ii) Proximal head articulates with
acetabulum. (iii) Lesser, greater and third trochanters present for muscle
attachment. (iv) Distally it has pulley-shaped structure, having two lateral
condyles which enclose an intercondylar groove.
Right femur (Front view) :- It shows head, greater trochanter, lesser trochanter,
shaft, patellar groove and condyles.
Bones of hind foot :- (i) It contains tarsal bones in two rows. (ii) Tibiale and
intermedium of the proximal row are fused to form astragalus on pre-axial side,
while fibulare or calcaneum is the largest tarsal bone produced into a spur on
post-axial side. (iii) Distal row contains three bonesmesocuneiform,
ectocuneiform and cuboid. (iv) Only four toes each having three phalanges, the
terminal one bearing a claw.
