Lacrimal apparatus

Lacrimal apparatus

1. LacrimalApparatus
DR.ChandraPhilip.

2. Lacrimal
apparatus-It is
concerned with
production and
drainage of
lacrimalfluid

3. Components
1)Lacrimal
gland
2)Conjunctival
sac
3) Lacrimalpuncta
with
canaliculi
4) Lacrimalsac
5) Nasolacrimal
duct

4. Lacrimalgland
Parts-
1)Upper part or
orbital part
2)Lower part or
palpebralpart

6. •Situation
Orbital part-
Lateral part
of roof of
the orbit
Palpebralpart-
lateral part
of the upper
eyelid

7. Ducts-
Gland has about one
dozen ducts which
open into the
superior
conjunctivalfornix
Accessory lacrimal
glands-are present
in the conjunctival
fornicesof both
the eyelids

8. •Histology
Compound tubuloalveolartype
of gland
1)Alveoli are lined by simple
columnar epithelium
showing two types of cells
a)G cells-mainly secrete
serous fluid
b)K cells –secrete mucus
fluid
2) Gland produces 1ml of
secretion per day
3) Secretion is alkaline in nature
rich in various salts and
lysozymeenzyme which is
bactericiidalin nature.

9. Functions of tears
1)Flush the conjuctivalsac and keep the cornea
moist and transparent
2)It provides nourishment to the cornea
3)Bactericidal
4)One can express emotions with out break of
tears

10. Nerve supply
Sensory –
Lacrimal
nerve
Secretomotor-
from
parasympathe
tic nerves via
pterygopalati
neganglion.

11. Arterial supply-
Lacrimalartery
branch of
ophthalmic
artery.

12. •Conjunctivalsac
Potential space
between eyelids
and eyeball is
known as
conjunctivalsac
Conjuctival
fornices-
Line of reflexion
between bulbar
and palpebral
conjunctiva

14. Lacrimalcanaliculi-
measures 10
mm in length.
1) Superior
canaliculi-
begins from the
lacrimalpuncta,
passes upward
and then
downwards and
medially and
open into the
lacrimalsac

15. Inferior canaliculi
begins from
the puncta,
passes
downward
and then
horizontally
medialward
to reach the
lacrimalsac
At the bending
each
canaliculi
presents a
dilatation
known as
ampulla.

16. Lacrimalsac-
It is the upper blind end of
the nasolacrimalduct
situated in the lacrimal
fossa, formed by the
frontal process of the
maxilla and lacrimal
bone.
Boundaries-
Infront-Medial palpebral
ligament
Behind-Lacrimalpart of
orbicularisoculi.
Laterally –lacrimalfascia
Medially-sac is separated
from bony fossa by an
arterial plexus derived
from terminal branches
of facial artery.

17. Nasolacrimalduct-
1)It is a
membranous
canal
measuring
about 18mm
in length
2)It begins from
the lower
end of
lacrimalsac
runs
downward
and opens
into the
inferior
meatusof
the nose

19. 3) The duct is
narrow in the
middle and
wide at both
the ends.
4) Lower opening
is guarded by
valve of Hasner
which prevents
air being
blown up the
duct into the
eye.

20. •Inflammation of
the lacrimalsac
due to
obstruction of the
nasolacrimalduct,
leading to
retention of
mucus and tears
in the sac .