Lecture 7 - Exocrine Glands Flashcards
use the three question method to classify and identify the exocrine glands within the body
- Tubular (tube) or acinar (grapes)
- Simple (one group) or compound (small sections converge to a common duct)
- 5 also branched or unbranched
- serous (watery fluid with enzymes and good for lubrication) or mucous (secrete mucus, full of mucins)
simple tubular - colon simple branched tubular simple acinar - urethra simple coiled acinar simple branched acinar - cardiac stomach
compound tumbular
compound acinar - pancreas
compound tubuloacinar - submandibular salivary gland
explain unicellular glands ? what are they ?
goblet cells (in the trachea and intestine for example)
they are a mucus secreting epithelial cell
mucus is important for lubrication, trapping pathogens and dust (the muco-cilliary escalator), protection
structure - neucleus and mitochondria at the bottom of the cell
followed by rough ER and golgi apparatus for protein production and post transnational modification and packaging
at the top full of secretory vesicles containing mucin release via exocytosis
microvilli on the surface
what are the glands in the mouth ?
look at the glands hitsologically lec 7
parotid salivary gland - next to the ear
submandibular salivary gland - underneath jaw
sublingual gland underneath tongue
explain the role of the parotid salivary glands
parotid salivary gland - next to the ear
purley serous acini - secrete serous containing enzymes for digestion and lubricate for swallowing and chewing
made of striated ducts, looks stripey with nucleus pushed close to cell surface
explain the role of the submandibular salivary gland - underneath jaw
and sublingual ?
contains serous, mucous and mixed glands
full of ducts - interlobular ducts, intralobular ducts, excretory ducts
made of serous and mucous acini and some demilunes
sublingual glands are almost completely mucus
saliva production is the only digestive enzymes that are controlled only by neurons
what is the role of myoepithelial cells
sit on surface of acini producing stuff
contain actin and can contract to squeeze the secretory product along the duct
what is the structre of the liver ?
a liver is split into lobules
lobules are hexagonal in shape, and further divide into triangles - a liver acinus with a portal triad and the central vein
we have the central vein in the middle
and the portal triad on the exterior - portal triad is made of the hepatic artery , portal vein, and bile duct
they are connected by the liver acinus
bile is produced by the bile caniculus cells and is transported to the bile duct for secretion
the hepatic artery carries oxygenated blood to the liver cells
the portal vein carries deoxygenated blood to the central vein from the stomach and spleen and intestine
the blood will travel from the vein and artery along SINUSOIDS - special blood vessel with lots of gaps for diffusion - an incomplete basement membrane
other strucutes :
we have kupfer cells - macrophages of the liver and sinusoids- detroys pathogens and old RBC’s
hepatoctyes
setllates - contain Vit Aand dendritic cells (immune cell)
endothelial cells
what are the functions of the liver ?
largest exocrine gland in the body - bile secretion
largest endocrine gland in the body - secretes albumin
store
iron, vits A, vit B12, Vit D and vit K
glycogen
produce majority of bodies proteins, enzymes, amino acid synthesis
main site of anabolism
heamopoeisis in the fetus (blood production)
metabolism of drugs, hormones, haemoglobin - passes bilirubin to gall bladder for excretion
toxins - alcohol
produces bile
filters blood
hormone modification
what is the role of hepatocytes ?
hepatoctyes (main liver function cell) - protein synthesis and storage charbohydrate and lipid metabolism cholesterol synthesis detoxification bile secretion via bile caniculus stores vits and mins hepatocytes have alarge amount of microvillli, to provide a space of disse (large SA for diffusion)
