2. “Your brain’s storage capacity is
considered virtually unlimited. Research
suggests the human brain consists of
about 86 billion neurons. Each neuron
forms connections to other neurons,
which could add up to 1 quadrillion
(1,000 trillion) connections.”
5. Head
and
Neck
Muscles of the Anterior Cervical Region
Suprahyoid
muscles:
• mylohyoid,
geniohyoid,
stylohyoid,
digastric,
Infrahyoid
muscles:
• sternohyoid,
omohyoid,
sternothyroid,
thyrohyoid.
6. Head
and
Neck
Muscles of the Prevertebral Area
• longus colli,
• longus capitis,
• rectus capitis
anterior,
• anterior scalene,
• rectus capitis
lateralis,
• splenius capitis,
• levator scapulae,
• middle scalene,
• posterior scalene.
7. Head
and
Neck
Muscles of the Pharynx
• superior constrictor,
• middle constrictor,
• inferior constrictor,
• palatopharyngeus,
• salpingopharyngeus,
• stylopharyngeus.
8. Head
and
Neck
Cervical Triangles of the Neck
Anterior triangle:
• carotid triangle,
• submandibular
triangle,
• submental
triangle,
• muscular
triangle.
Posterior triangle:
• occipital triangle
• subclavian
triangle.
10. Head
and
Neck
Larynx
• The larynx consists of the
cricoid (1), thyroid (1),
epiglottis (1), arytenoid (2),
cuneiform (2), and
corniculate (2) cartilages.
13. Head
and
Neck
Tracheotomy
• A tracheotomy is a
procedure in which a tube
is inserted between the
second and third tracheal
cartilage rings when long-
term ventilation support is
necessary since it reduces
the incidence of vocal cord
paralysis or subglottic
stenosis.
25. Head
and
Neck
Skull
The skull can be divided into two parts: The neurocranium and
viscerocranium.
• Neurocranium. The neurocranium consists of the flat bones of the
skull (i.e., cranial vault) and the base of the skull, which include the
following eight bones: Frontal bone, occipital bone, ethmoid bone,
sphenoid bone, paired parietal bones, and paired temporal bones.
• Viscerocranium. The viscerocranium consists of the bones of the
face that develop from the pharyngeal arches in embryologic
development, which include the following 14 bones: Mandible,
vomer, paired lacrimal bones, paired nasal bones, paired palatine
bones, paired inferior turbinate bones, paired maxillary bones, and
paired zygomatic bones.
34. Head
and
Neck
Dura Mater
• The cranial dura mater is a
two-layered membrane
consisting of the external
periosteal layer (i.e., the
endosteum of the
neurocranium) and the
internal meningeal layer,
which is continuous with
the dura of the vertebral
canal and forms dural
infoldings or reflections that
divide the cranial cavity
into compartments.
35. Head
and
Neck
Dural Infolding or Reflections
• Falx cerebri extends between the cerebral hemispheres
and contains the inferior sagittal sinus and superior
sagittal sinus.
• Falx cerebelli extends between the cerebellar
hemispheres.
• Tentorium cerebelli supports the occipital lobes of the
cerebral hemispheres and covers the cerebellum. It
encloses the transverse sinus and the superior petrosal
sinus.
• Diaphragma sellae forms the roof of the sella turcica
covering the hypophysis.
37. Head
and
Neck
Vasculature of the Dura
• The arterial supply of
the dura mater is by
the middle meningeal
artery (a branch of the
maxillary artery), which
branches into an
anterior branch and a
posterior branch.
44. Head
and
Neck
Cavernous sinus syndrome
• presents with variable
ophthalmoplegia (e.g., CN III
and CN VI), corneal
sensation, Horner syndrome
and occasional decreased
maxillary sensation. 2° to
pituitary tumor mass
effect, carotid-cavernous
fistula, or cavernous sinus
thrombosis related to
infection (spread due to lack
of valves in dural venous
sinuses).
45. Head
and
Neck
Cavernous Sinus Thrombosis
• Infection can spread from the superficial
and deep face into the cavernous sinus,
producing a thrombosis that may result in
swelling of sinus and damage the cranial
nerves that are related to the cavernous
sinus.
46. Head
and
Neck
Cavernous Sinus Thrombosis
• CN III and IV and the ophthalmic and maxillary
divisions of CN V will be compressed in the
lateral wall of the sinus.
• CN VI and the internal carotid artery with its
periarterial plexus of postganglionic
sympathetic fibers will be compressed in the
central part of the cavernous sinus. CN VI is
typically affected first in a cavernous sinus
thrombosis with the other nerves being
affected later. Initially, patients have an internal
strabismus (medially deviated eyeball) (CN VI
lesion). Later, all eye movements are affected,
along with altered sensation in the skin of the
upper face and scalp.
