6. The Skull
The skull is a part of axial skeleton. It consists of 22 bones in total and is
composed of two sets of bones (1) CRANIAL and (2) FACIAL.
7. CRANIALBONES
Cranial bones are EIGHT in number.
FUNCTION OF CRANIAL BONES
They form the hard protective outer covering, cranium for the brain.
The temporal
bones are situated at
the sides and base of
the skull, where they
protect the temporal
lobe of the brain and
surround the ear canal.
The parietal bones
are two bones in
the skull which, when
joined at a fibrous
joint, form the sides
and roof of
the cranium.
The occipital bone is
an unpaired bone
which covers the
back of the head
(occiput).
The sphenoid bone is
an unpaired bone. It is
situated in the middle
of the skull towards
the front.
The Ethmoid bone
is an unpaired
cranial bone that is
a significant
component of the
upper nasal cavity
The frontal bone
is an unpaired bone
that is a part of the
boney structure that
forms the anterior
and superior
portions of the
skull.
8. There are total 14 facial bones.
FUNCTION OF FACIAL BONES
They provide a frame on which the soft tissues of the face can act to facilitate eating, facial expression,
breathing, and speech.
The maxilla in
vertebrates is the upper
fixed bone of
the jaw formed from the
fusion of two maxillary
bones.
The nasal bone is a
small, flat bone of the
skull. It makes up the
facial skeleton.
The zygomatic bone is a
paired, irregular bone that
defines the anterior and
lateral portions of the face.
The mandible is the
largest bone in the human
skull. It holds the lower
teeth in place, it assists in
mastication and forms the
lower jawline.
The lacrimal bone is a
paired facial bone It is a small
and fragile bone of the facial
skeleton that is roughly the
size of the little fingernail. It
is situated at the front part of
the medial wall of the orbit.
FACIALBONES
MAXILLA NASAL BONE ZYGOMATIC BONE MANDIBLE LACRIMAL BONE
10. RIBCAGE
The ribcage, also known as the thoracic
cage, is a bony and cartilaginous
structure which surrounds the thoracic
cavity and supports the pectoral girdle
(shoulder girdle), forming a core portion
of the human skeleton.
A typical human rib cage consists of 24
ribs, the sternum (with xiphoid process),
costal cartilages, and the 12 thoracic
vertebrae. Together with the skin and
associated fascia and muscles, the rib
cage makes up the thoracic wall and
provides attachments for the muscles of
the neck, thorax, upper abdomen, and
back.
12. FORELIMBS
● A forelimb or front limb is one of the paired
articulated appendages (limbs) attached
on the cranial (anterior) end of a terrestrial
tetrapod vertebrate’s torso .
● All vertebrate forelimbs are homologous,
meaning that they all evolved from the
same structures. For example,
the flipper of a turtle or of a dolphin, the
arm of a human, the foreleg of a horse,
and the wings of both bats and birds are
ultimately homologous, despite the large
differences between them.
