Lacrimal sac

{{short description|Upper, dilated end of the nasolacrimal duct}}

{{Infobox anatomy

| Name = Lacrimal sac

| Latin = saccus lacrimalis

| Image = Sobo 1909 764.png

| Caption = The lacrimal apparatusis shown through dissection on the left side.

| Image2 = Sobo 1909 765.png

| Caption2 = The lacrimal sac has been opened showing internal organization as well as the naso-lacrymal duct.

| Precursor =

| System =

| Artery = Angular artery

| Vein =

| Nerve =

| Lymph =

}}

The lacrimal sac or lachrymal sac{{cite book | title=Sobotta's Atlas and Textbook of Human Anatomy | author=Dr. Johannes Sobotta | year=1909 | location=Philadelphia}} is the upper dilated end of the nasolacrimal duct,{{cite book | title=Endoscopic Dacryocystorhinostomy | date=2019-01-01 | doi=10.1016/B978-0-323-47664-5.00017-1 | url=https://www.sciencedirect.com/science/article/pii/B9780323476645000171 | access-date=2020-05-08 | pages=143–148.e1 | quote=Anatomy: The lacrimal sac extends approximately 10 mm above the axilla of the middle turbinate.| last1=Sacks | first1=Raymond | last2=Naidoo | first2=Yuresh | isbn=9780323476645 }} and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from the eye's surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity.{{cite book | last=Remington | first=Lee Ann | title=Clinical Anatomy and Physiology of the Visual System | chapter=Ocular Adnexa and Lacrimal System | publisher=Elsevier | year=2012 | isbn=978-1-4377-1926-0 | doi=10.1016/b978-1-4377-1926-0.10009-8 | pages=159–181 | quote=The lacrimal sac lies within a fossa in the anterior portion of the medial orbital wall. This fossa is formed by the frontal process of the maxillary bone and the lacrimal bone. The sac is surrounded by fascia, continuous with the periorbita, which runs from the anterior to the posterior lacrimal crests. }} Lacrimal sac occlusion leads to dacryocystitis.

{{cite book | last1=Beare | first1=Nicholas A.V. | last2=Bastawrous | first2=Andrew | title=Manson's Tropical Infectious Diseases | chapter=Ophthalmology in the Tropics and Sub-tropics | publisher=Elsevier | year=2014 | isbn=978-0-7020-5101-2 | doi=10.1016/b978-0-7020-5101-2.00068-6 | pages=952–994.e1 | quote=Tears drain through the canaliculi, lacrimal sac and naso-lacrimal duct into the nose. Blockage of the naso-lacrimal duct prevents drainage of the lacrimal sac, which may lead to infection, causing a painful swelling at the side of the nose below the medial canthus. This may present as a chronically watery, discharging eye, or as an acutely inflamed abscess. This should be treated with oral broad-spectrum antibiotics. The problem may recur unless drainage into the nose is re-established.}}