Salivary Glands

Biologi Oral 2

SALIVARY GLANDSBy : drg. Michael A. Leman

Salivary glands are compound, tubuloacinar, merocrine, exocrine glands whose

ducts open into the oral cavity. The term compounds refers to the fact that a salivary

glands has more than one tubule enetering the main duct; tubuloacinar describes the

morphology of the secreting cells, merecrine indicates that only the secretion of the cell is

released; exocrine describes a gland that secretes fluid onto a free surface.1

Salivary glands consist of multiple secretory units connected to the oral cavity by

a system of ducts." Each secretory unit is a cluster of cells organized in an acinar (round

cluster) or tubular (elongated cluster) conflquration.2

Secretion of saliva is a reflex function emanating from salivary centres that is

dependent on afferent stimulation (e.g. taste and mastication) and involves complex

integration from higher centres. 1

Salivary glands consist of two main elements: the glandular secretory tissue(the

parenchyma) and the supporting connective tissue (the stroma). From the stroma of the

capsule surrounding and proctecting the gland pass septa that subdivided the gland into

major lobes; lobes are futher subdivided into lobules. Each lobe contains numerous

secretory units consisting of clusters of grape like structure (the acini) positioned around

a lumen. Salivary secretory cells may be classified into two broad categories, serous-

secreting and mucous- secreting cells." Serous cells produce a product that is almost

1. Berkovitz BKB, Holland G.R, Moxham BJ. 2002. Oral anatomy, histology and embryology. 3rd edition.. St. Louis. Mosby. p 255-68

2. Garand DMD. Oral cells and tissue. Quintenssencess books. P239-703. Available at : http://www.iob.uio.no/studier/undervisning/histologi/section/003/100_cut_no.php. Download 4 september

20084. Bagian Biologi Oral. 2002. Bahan ajar biologi oral 2. Bagian biologi oral FKG UI.. hal 1-5

http://www.iob.uio.no/studier/undervisning/histologi/section/003/100_cut_no.php.%20Download%204%20september%202008


Biologi Oral 2

entirely protein, while the mucous cells produce a product that contains only a small

amount of protein but a high content of complex carbohydrates. 1,2

The intercalated and striated ducts affect the composition of the secretion passing

through them. Plasma cells(which secrete the immunoglobulins) are found in the stroma

of the gland around the intralobular ducts. The striated ducts empty into the relatively

inert collecting ducts, which carry the saliva to the mucosal surface and which may be

lined near their termination by a layer of stratified squamous epithelial cells. The

connective tissue septa carry the blood and nerve supply into the parenchyma. Apart from

fibroblast and collagen, the connective tissue also contains fat cells. With age, there is a

decrease in the voluyme of the secretory cells and an increase in the connective tissue

components, especially the number of fat cells. Unlike endocrine glands, whose secretion

is controlled by the activity of hormones, the secretion of saliva by the salivary glands is

under the control of the autonomic nervous system. 1

Salivary glands may be classified according to size ( major and minor) and/ or the

types of secretion (mucous, serous or mixed). The three, paired, major salivary glands are

the parotid, the submandibular and the sublingual glands. The numerous minor salivary

glands are scattered throughtout the oral mucosa and include the labial, buccal,

palatoglossal, palatal and lingual glands. Salivary glands are not present in the gingival or

the dorsum of the anterior two-thirds of the tongue. 1

PAROTID GLAND

The parotid gland is the largest of the salivary

glands. The acini of the gland are serous, although

mucous cells have occasionally been reported. 1

It is a strictly serous gland with a well developed

capsule and septa which gives it a lobulated look. There

are serous acini within these lobules which are connected

by connective tissue containing fibroblasts. These serous






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cells look like small pyramids arranged around a lumen. The nuclei are situated basally in

the cells and are quite large and round in shape. Within the connective tissue (in the

interlobular space), there are large excretory ducts, arteries and veins; both last mentioned

structures filled with blood. 1

Saluran keluarnya disebut duktus Parotidea, bermuara pada vestibulumoris

didepan gigi molar dua. Glandula parotis divaskularisasi oleh Transversa fasciei(cabang

A. Temporal Superfacialis) dan diinervasi oleh N. Auriculo magnum, N. Auriculo

temporalis, N.IX. 4

SUBMANDIBULAR GLAND

The second largest of the

salivary glands, the

submandibular gland, produces

a mixed mucous-serous

secretion. Serous acini appear

to outnumber mucous acini by

at least 7:3. much of the

submandibular gland contain

serous acini that appear similar

in those in the parotid gland. 1

As all the other salivary glands, the submandibular gland is a merocrine gland

which means that its cells secretes liquid without themselves being changed or destroyed.

Other secretion techniques are apocrine and holocrine.The submandibular gland is

classified morphologically as a tubuloacinar gland. It is a mixed gland composed

predominantly of serous acini. This is what distinguishes the submandibular gland from

the parotid gland because the parotid gland is purely a serous gland. 3

Saluran keluarnya disebut duktus Whartoni. Kelenjar ini divaskularisasi oleh rami

glandulare arteri facialis, arteri submentalis(cabang A. facialis) dan diinervasi oleh N.

lingualis, Chorda Tymphani (parasimpatis), dan plexus symphaticus. 4






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SUBLINGUAL GLAND

The human sublingual gland is not a single unit like the parotid and

submandibular glands, but is made of one large segment ( the major sublingual glands)

and a group of 8- 30 mixed, minor salivary glands, each having its own duct system

emptying into the sublingual fold. The major sublingual gland is a mixed gland but with a

preponderance of mucosal elements.

Structurally the sublingual gland is a collection of glands that have their own

separate excretory duct terminating in the oral cavity. It is situated below the floor of the

mouth. The sublingual gland is defined as a mixed gland because it contains both serous,

mucous and seromucous acini. The mucous acini dominate, but there are many

seromucous acini too. These are relatively large and consist of pyramid looking cells

close to the lumen. Basally to these cells one can see semilunar serous cells (darker cells).

There are quite few strictly serous acini. There are myoepithelial cells between the acini,

but they are hard to spot and are hard to differentiate from fibroblasts. You won't see as

many intercalated ducts in the glandula sublingualis as in the parotid- and submandibular

gland because these structures are very short in this gland. Within the septa of connective

tissue one can find large excretory ducts, arteries and veins. One can also spot adipose

tissue (large white cells).

Duktus dari kelenjar yang besar (lobus mayor) bermuara dibelakang duktus

kelenjar submandibularis dan disebut duktus Bhartolini, yang juga bermuara di caruncula

sublingualis. Sedangkan kelenjar sublingualis dari lobus minor saluran keluarnya kecil,

disebut dyktus Rivini yang semuanya bermuara di sepanjang Plexus sublingualis.






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Diinervasi oleh a. sublingualis dan a. submentalis (cab. A. facialis) dan diinervasi oleh n.

lingualis dan chorda tymphani.

MINOR SALIVARY GLAND

The minor salivary glands are classified by their

anatomical location: buccal, labial, palatal,

palatoglossal and lingual. They are primarily mucous.

The palatoglossal glands are located in the region of

the pharyngeal isthmus. The palatal glands lie in both

of the soft and hard palate. The anterior lingual glands

are embedded within muscle near the ventral surface

of the tongue, and have short ducts opening near the

lingual frenulum. The posterior glands are located in

the root of the tongue. Both groups are mucous.






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Salivary Glands