Gastro 1- Mar. 21/12 - Teppermen
Gut is the largest endocrine organ in the body. It contains within its wall a nervous
system that functions independently of the central nervous system. Gut receives over 1/3
of total cardiac output so it influences cardiovascular system. And effect on electrolytes
thus influences respiratory and renal system.
GI tract: Secretes, moves, digests and absorbs. Look at first function = secretion – look at
most of all secretory organs.
1) Salivary glands – 3 pairs of salivary glands (parotid, submandibular, sublingual-
major). Salivary output is large – 1L to 1.5L – most during daytime. Why? If you
had to classify the salivary glands? Why do we need them? They are primarily
digestive glands and since we eat during daylight hours. What we learn is in most
mammals (humans). Salivary output in human and the composition is different
than a rodent or a cat or dog, etc. Because it depends upon the diet. They adapt to
a. Each juice coming from eat kind of salivary gland is different.
b. Converging duct system. What it means is that you start with in the gland,
thousands and millions of them that drain into many ducts. They fuse to
form a smaller number but larger diameter duct, and then to one main
secretory duct. Large number of primary ducts, to one main large one.
Exocrine: out of the body into a duct. It means into a duct. Out of. Endocrine means into
the body/ blood. Inside of the duct is actually outside the body.
c. Salivon is the functional unit. It functions a lot like the nephron. At the
closed end of the system, they have acinar cells. They form a space called
the acinus. It’s in the acinus that primary saliva is formed. You have
intercalated duct and on the basolateral side (luminal side = lumen is a
space = space inside the duct. On the basolateral side, you have these
stripes and so it’s called the striated duct. Those microvilli has a lot of
mitochondria which makes ATP, which is for