Page 7 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

205
(A) RIGHT LATERAL WALL OF NASAL CAVITY AS HN 203 (C)
BUT WITH CONCHAE CUT AWAY
HN 205

ETHMOID
(CRIBRIFORM PLATE)
SPHENOID (BODY)
(1) SPHENO-
ETHMOIDAL
(2) RECESS (MEATUS means
“a hole”.)
ETHMOIDAL
BULLA ("bubble")
SEMILUNAR
HIATUS
("gaping") (3)
INFERIOR

MEATUS.
(1) SUPERIOR PTERYGO PALATINE
(2) MIDDLE CONCHA FORAMEN.
(3) INFERIOR
BONY PALATE THREE CONCHAE
MEANS FOUR
PTERYGOID SPACES.
HAMULUS

(B) DRAINAGE OF THE PARANASAL AIR SINUSES The MAXILLARY, FRONTAL, ETHMOIDAL,
and SPHENOIDAL air sinuses are cavities in the associated bones, filled with air,
and connected to the nasal cavity. They are all PAIRED, except the ethmoidal,
which are multiple on each side. Like the nasal cavity, they are lived with
FRONTAL respiratory epithelium on a vascular muncosa equipped with MUCOUS
AIR GLANDS (parasympathetic secretomoth from FACIAL nerve). The slime
SINUS has to go somewhere, & infact joins that of the

nasal cavity itself. NOTICE that with
the exception of the
SPHENOIDAL air sinus, ALL
SPHENOIDAL discharge into The MIDDLE
ALR SINUS
SEMI- meatus. The exit from
LUNAR the sphenoidal
HIATUS air sinus is

NASO- non-too-cleverly
LACRIMAL placed (would
DUCT you put a spigot in
(SHEET 121)
the top of a beer barrel?) – although
the cilia help.
The arrangement for
the MAXILLARY air sinus
is even worse ( ). TEARS are
K.E.W.
(Z) discharged into the INFERIOR meatus -
(Y)
OPENING FROM the largest, but with only a single inlet...
MAXILLARY
AIR SINUS
NB. THE SEMILAR HIATUS IS A CRESCENTIC
CLEFT BETWEEN THE BULLA OF THE
ETHMOID ABOVE & THE MAXILLA BELOW ( ).