LESSON 3: DIGESTIVE SYSTEM - ACCESSORY GLANDS

Salivary Glands - Exocrine glands

Produce saliva

Salivary Glands - Exocrine glands

Wet and lubricate the oral cavity and its contents

Salivary Glands - Exocrine glands

Initiates digestion of CHO

• IgA

• lysozymes

• lactoferrin

SALIVARY GLANDS

• Secrete substances such as __________

• Parotid gland

• Submandibular glands

• Sublingual gland

3 MAJOR SALIVARY GLANDS

• Serous

• Seromucous

• Mucous

SALIVARY GLANDS

• Types of Secretion

• Serous cells

• Mucous cells

• Myoepithelial cells

SALIVARY GLANDS

• Epithelial Cells types:

Serous cells

SALIVARY GLANDS

Epithelial Cells types:

• pyramidal shape, forms acinus (note: grape shape)

Mucous cells

SALIVARY GLANDS

Epithelial Cells types:

• columnar shape organized cylindrical tubules

Myoepithelial cells

SALIVARY GLANDS

Epithelial Cells types:

• has smooth muscle (note: highly important for contractile process, can be found in the basal lamina that surrounds your acini)

cells of serous acini

PANCREAS

• Digestive enzymes are produced by _________ in the larger exocrine portion of the pancreas

• Intercalated ducts (simple cuboidal)

• Intralobular ducts (simple columnar)

• Interlobular ducts (simple columnar)

PANCREAS

Intercalated duct cells

PANCREAS

• produces fluids with bicarbonate which alkalinizes and transports hydrolytic enzymes from acinar cells

Hepatic Lobule

LIVER

• structural unit of the liver

• Hepatocytes

• Kupffer cell

• Stellate cell / Ito cell

LIVER

• Cells:

• Hepatic artery

• Hepatic vein

• Bile duct

LIVER

• Portal triad

• Hepatocytes

• Kupffer cell

• Stellate cell / Ito cell

LIVER

• Cells:

Hepatocytes

LIVER

CELLS

• primarily cells in the liver

Kupffer cell

LIVER

CELLS

• macrophages → engulf different foreign materials, toxins, microorganisms → they process that into antigens (because macrophages are APCs [antigen presenting cells]

Senescent erythrocytes

LIVER

CELLS

• Macrophages also engulf old RBCs known as the _________ → They do this in order to free the heme / Iron to reuse later on → they also remove the protein / amino acid part to use for other purposes

storage of vitamin A

LIVER

CELLS

• Stellate cell / Ito cell

Stellate cell / Ito cell

LIVER

CELLS

• Mesenchymal cells → they can transform into other cells when needed

• They can become myofibroblast (after liver injury) (They produce ECM and Cytokines)

Hepatic artery

LIVER

PORTAL TRIAD

• bring oxygenated blood

Hepatic vein

LIVER

PORTAL TRIAD

• carrying nutrients from the smallintestine

bile canaliculi

LIVER

PORTAL TRIAD

• Bile duct starts as _______

bile canals of herring

LIVER

PORTAL TRIAD

• bile canaliculi will become _______

cholangiocytes

LIVER

PORTAL TRIAD

• bile canals of herring is lined by cuboidal epithelial cells called _____

bile ductules

LIVER

PORTAL TRIAD

• bile canals of herring will merge to become _________

bile duct; hepatic duct

LIVER

PORTAL TRIAD

• bile ductules will finally become _____, the left and right _______

Gallbladder

Hollow, pear-shaped organ attached to the lower surface of the liver capable of storing bile.

• Mitochondria

• microvilli

• large intercellular spaces

GALLBLADDER

• compose of:

Cystic duct

GALLBLADDER

• duct where gall bladder release its contents from

Serosa

GALLBLADDER

• the outer covering of gallbladder because it is part of the peritoneal cavity

hepatopancreatic ampulla; hepatopancreatic sphincter

GALLBLADDER

• Pancreas will join its content to the ___________ (of vater) which will then release it content to the opening in the duodenum which has _________

Parotid Gland

3 MAJOR SALIVARY GLANDS

• composed of serous acini

• Produces α-amylase (complete name: salivary α-amylase)(responsible for the hydrolysis of CHO and protein)

• Has Antimicrobial properties

Submandibular glands

3 MAJOR SALIVARY GLANDS

• (Mixed) Branched tubuloacinar gland (there is more serous acini here)

• Crescent shape = serous demilune

• Production of ⅔ total saliva per day

• Contain lysozyme

Sublingual gland

3 MAJOR SALIVARY GLANDS

• Branched tubuloacinar glands (more tubules of mucous cells here)

• Produce mucus

• Produce amylase and lysozyme

Serous

SALIVARY GLANDS
TYPES OF SECRETION

• watery, secreted by parotid gland

Seromucous

SALIVARY GLANDS
TYPES OF SECRETION

• watery mucoid, secreted by SM and SL glands

Mucous

SALIVARY GLANDS
TYPES OF SECRETION

• mucus/mucoid, secreted by Minor salivary glands

• Trypsinogen

• Chemotrypsinogen

PANCREAS

• Two major inactive zymogens

Cholecytoskinin (CCK)

PANCREAS

• resence of fat in the small intestine releases CCK - to release Bile

• secreted by acinar cells

Secretin (water and HCO3-)

PANCREAS

• secreted by duct cells