Lecture 7- Exocrine glands Flashcards
exocrine glands produces and secrete
serous and mucous substances via a duct onto an epithelial surface
which surfaces do exocrine glands secrete onto
- Surface of the body (e.g. sweat glands, sebaceous glands)
- The lumen of the digestive tract (e.g. digestive glands)
Structure of the exocrine gland
Composed of a cluster of secretory cell which collectively form an acinus.
acini cells are surrounded by
basement membrane and held together by tight junctions between secretory cells
secretory cells possess a highly developed
ER and golgi network for material secretion and are rich in mitochondria
exocrine products are released via
secretory vesicles into a duct - which connects to an epithelial surface
ducts may arise to an epithelial surface- these may arise from convergence of
smaller ductules (all connected to acinus) in order to enhance secretion
example of exocrine glands
- Pancreas
- Parotid
- Salivary
- Submandibular
- Liver
exocrine function found within
acinar cells
what does the acinar cells produce
- Trypsinogen (converted to trypsin)
- Chrymotrysingoen (chymotrypsin)
- Lipase
- Amylase
endocrine gland
cells that release hormones directly into the blood stream
name the 3 salivary glands
parotid
submandibular
sublingual glands
parotid glands secrete
almost totally serous secretions
submandibular gland secretes
mostly serous and some mucous
sublingual gland secretes
almost completely mucous
mucous secreting cells are in small numbers in
parotid glands
where are parotid glands found
in the cheeks
how much saliva do parotid glands produce
1.6l - 20%
which enzymes do parotid glands secrete
amylase enzymes
submandibular glands are. located
beneath the lower jaw, outside oral cavity
how much saliva do submandibulr glands produce
70%
saliva produced by the submandibular gland is more ……. than the parotid
viscous (more mucous)
sublingual gland located
under the tongue
how much saliva produced by the sublingual gland
5%
sublingual saliva
most viscous due to mucous
structure of parotid gland
- Striated ducts within the parotid gland have large lumen
- Serous acinus drains substances into striated duct
- Basal lamina is invaginated which forms the striations, therefore the nucelli aren’t on the basal lamina- means serous material can get into ducts quickly
parotitis
gland can be blocked e.g. if the secretion dries up the electrolytes like calcium can produce stones (colliculi).
Swelling and pain
Treatment- you have to get rid of the stones of treat the cause of the pain
as you get olde the amount of ….. in the parotid increases, decreasing the amount of …. produced
- adipose
- saliva
submandibular tissue
mostly serous, more mucous than parotid
structure of submandibular gland
- In two parts: superficial and deep (separated by mylohyoid muscle)
o Superficial- mucus acini/cells
o Deep- serous acini. - This gland has its own duct which passes up and joins with the sublingual gland and has its outlet under the tongue.
- The duct is the Wharton’s duct.
salivary gland stimulus
Both parasympathetic and sympathetic ANS supply salivary glands and increase salivary secretions.
- NOT controlled by hormones
- other parts of the digestive system are controlled by both
Parasympathetic
large volumes of watery saliva rich in enzymes
Sympathetic
produces a small, thick secretion of saliva, rich in mucus
what is the largest exocrine organ
the liver
where is the liver fgound
right side of the body
gross structure of the liver
- 2 anterior lobes- right and left
left lobe of the liver fact
can take 2/3 away and donate- liver has regenerative quality (within a year)
function of the liver
Catabolism anabolism storage of nutrients detoxification Bile production
which vessels supply the liver with blood
hepatic portal vein
hepatic artery
hepatic portal vein
from the intestinal tract
- Supplies the liver with nutrient rich blood from the food absorbed in the intestines
- Low oxygen content
- 70% of blood entering the liver
hepatic artery
- Supplies oxygen rich blood
- Nutrient poor
- 25% of blood entering the liver
which vessel carries the blood away from the liver
The hepatic vein
the hepatic vein
- Takes nutrient and oxygen poor blood
- Circulates back to the heart and intestines to receive oxygen and nutrients
