The skull is composed of 28 bones that can be divided into two main parts: the neurocranium and viscerocranium. The neurocranium includes 14 bones that form the calvaria and enclose the brain. The viscerocranium includes 14 bones that form the facial skeleton. The bones of the skull are joined primarily by sutures, with a few synovial joints including the temporomandibular joint. The skull has several peculiarities, such as fontanelles in infants, air-filled sinuses in some bones, emissary veins connecting intracranial and extracranial veins, and its role in protecting the brain and other structures of the head and

1. AREEB FATIM A
ST U DENT DOCT OR OF PHYSICA L T HERA PY
GOVERNM ENT COLLEGE U NIVERSIT Y
Human Anatomy
Head and Neck

2. Introduction and Osteology
(Part 1)

3. Skull
 The skeleton of head is
called skull/cranium.
 The skull can be divided
into two main parts:
 Neurocranium/
Calvaria/Brain box is the
upper part of cranium
which encloses the brain.
 Viscerocranium/Facial
skeleton constitutes the
rest of the skull and
includes the mandible.

4. Skull (Bones of skull)
 The skull consist of 28 bones.
 The calvaria is composed of 14 bones including 3
paired ossicles.
Paired Unpaired
1. Parietal (2) 1. Frontal (1)
2. Temporal (2) 2. Occipital (1)
3. Malleus (2) 3. Sphenoid (1)
4. Incus (2) 4. Ethmoid (1)
5. Stapes (2)

5. Skull (Bones of skull)
 The facial skeleton is composed of 14 bones.
Paired Unpaired
1. Maxilla (2) 1. Mandible (1)
2. Zygomatic (2) 2. Vomer
3. Nasal (2)
4. Lacrimal (2)
5. Palatine (2)
6. Inferior nasal concha (2)

6. Bones of Calvaria Bones of Facial skeleton
Skull (Bones of skull)

7. Skull (Joints)
 The joints in the skull are mostly
sutures, a few primary
cartilaginous joints, and three pair
of synovial joints.
 Synovial joints in skull:
 Two pairs of synovial joints are present
between the ossicles of middle ear.
 One pair is the largest
temporomandibular joint.
 Sutures:
 Plane : Internasal suture.
 Serrate: Coronal suture.
 Denticulate: Lambdoid suture.
 Squamous: Parietotemporal suture

8. Anatomical Position of Skull
 The skull can be placed
in proper orientation by
any of the two planes:
 Reid’s base line:
Horizontal line obtained
by joining the infraorbital
margin to the centre of
external acoustic meatus.
 The frankfurt’s plane:
Horizontal plane obtained
by joining infraorbital
margin to the upper
margin of external
acoustic meatus.

9. Skull (Peculiarities)
 Base of skull ossifies in
cartilage while the skull
cap ossifies in
membrane.
 At birth, skull
comprises one table
only. By 4 years or so,
two tables are formed.
Between two tables
there are dipoles. Four
dipolic veins drain the
blood cells into
neighbouring veins.

10. Skull (Peculiarities)
 At birth, the 4 angles of parietal bone have
membranous gaps or fontanelles. These allow
overlapping of skull bones during vaginal delivery, if
required. These also allow skull bones to increase in
size after birth, for housing the delicate brain.

11. Skull (Peculiarities)
 Some skull bones have air cells in them and are
called pneumatic bones, e.g. frontal, maxilla,
temporal, sphenoid, ethmoid etc.
 They reduce the weight of skull.
 They maintain humidity of inspired air.
 They give resonance to voice.
 These may get infected resulting n sinusitis.

12. Skull (Peculiarities)
 Skull boes are united mostly by sutures.
 Skull has foramina for “emissary veins” which connect
intracranial venous sinuses with extracranial veins.
These try to relieve raised intracranial pressure .
Infection may reach through the emissary veins into
cranial venous sinuses as these veins are valveless.
 Petrous temporal is the densest bone of the body. It
lodges internal ear, middle ear including three ossicles.
 Skull lodges brain, meninges, CSF, glands like
hypophysis cerebri and peneal, venous sinuses, teeth,
special senses like retina of eyeball, taste buds of tongue,
olfactory epithelium, cochlear and vestibular nerve
endings.