chapter 20 AnP 2

for each of the following organs, provide two clues that would help identify it under a microscope

• tongue

• salivary gland

• pancreas

• liver

tongue → papilae with taste buds

salivary glands → roundish lobules with connective tissue septa

pancreas → island of pink within sea of purple

liver → hexagonal plates with central veins

why would you expect to find blood vessels associated with islets of langerhans

to carry hormones (insulin and glucagon) to their target tissues

after eating a candy bar and drinking soda, what pancreatic hormone would be released into the blood

insulin

the space between the lingual papillae can narrow as we age. Why would that affect our sensation of taste

there will be less interaction with food molecules as we age

this is a picture of the

esophagus

label

A. esophagus

B. stomach

C. small intestine

D. large intestine

what is this

the esophagus

what is this?

the stomach

what is this

stomach

what is this?

the stomach

what is this

the stomach

what is this

the small intestine

what is this

the small intestine

what is this

the colon of the large intestine

what is this

the colon of the large intestine

what is this

taste bud on the tongue

what is this

the tongue

what is this

the tongue

label

this is the pancreas

1. acinus

2. Islets of Langerhans

3. duct

what is this

the liver

what do accessory organs do?

Play a role in digestion even though food does not actually pass through them

what is this a picture of?

a tongue

the tongue has notable projections on its superior surface is the blue box? What is it and what. isits function

this is the papillae. They provide a source of friction for the tongue, which is helpful when eating soft foods

the papillae contain

taste buds

what is the pink circle on the side? What is its function

these are taste buds. They are involved in a sense of gustation (being able to taste something)

the epithelium of the papillae is ______. What does this do

non-keratinized stratified squamous. This provides protection against chemical, thermal and abrasive injuries that foodstuffs can occasionally cause

what is the pink star? what does it do

these are the skeletal muscle fibers inferior to the papilar. These are responsible for changing the shape and position of the tongue. They also project in many different directions. This gives the tongue great flexibility and the capacity to move in multiple directions

interspeed among the muscle cells are numerous

lingual salivary glands

what is the green and its function

this is the lingual salivary glands. they constantly secrete saliva in order to keep the oral epithelium moist

multilayered circular structures found on the lateral surfaces of the papillae.

taste buds

each taste buds contain furty slim receptors known as

gustatory cells that are involved in chemical detections and initiating the sensation of taste.

what is this?

a taste bud

what is this

parotid gland

what are septa on the parotid gland

inward extensions of connective tissue capsule that divide the gland into lobules. Supports and compartmentalizes it

The cells of each serous acinus are

pyramidal in shape and often have granules of material to be secreted

what is the blue?

secretory cells called the serous acini

The acini are surrounded by myoepithelial cells. This layer of epithelium does what

contracts to help move serous fluid out of the lumen of the serous acini and into the attached ducts

what is the black arrow pointing at

myoepithelial cells

fluid from serous acini flows into neighboring

intercalated ducts

what is purple and what is it lined by

intercalated ducts which are lined by simple squamous or cubodial epithelium

intercalated ducts join together to form larger

stratiated ducts

what is red? What are some characteristics

this is a stratified duct. These ducts are lined by simple colmnar epithelial cells which exhibit significant folding on their basal surface and thats why they have their name.

Striated ducts merge to form _____ + function

larger ducts which continue merging and eventually form the parotid excretory duct that carries saliva to the oral cavity

The epithelium of excretory ducts can increase from

simple columnar to pseudostratified columnar or even stratified columnar.

what is it?

this is the pancreas

in the pancreas, the partitions of connective tissue separate the pancreas into

lobules

Each lobules will primarily consist of circular collections of cells stained a deep purple. These cells are _____ cells and each small collection of them is a ______

acinar cells; pancreatic acinus

what is blue

pancreatic acini

function of blue

this is the pancreactic acini. They produce a multitude of digestive enzymes and secrete the digestive enzymes into small ducts. including proteases, lipases, amylases, and nucleases

The acini secrete the digestive enzymes into small ducts that converge to form

large ducts that merge into the main pancreatic duct, which empties into the duodenum

Together the alkaline fluid from the duct cells and the enzymes from the acinar cells constitute

pancreatic juice

what is the red star? describe it

it is a pancreatic duct. They are lined by cuboidal epithelium which secretes an alkaline fluid.

exocrine function of pancreas

secretion of pancreatic juice

Scattered amidst the acini and making up 1% of the pancreas is the

islets of Langerhans which control blood glucose levels

what is outlined in red

islets of langerhans. These are found clusters of cells that are light pink in color and have prominent nuclei. While they can’t be distinguished with the microscope, several discrete cell types can be found in these.

alpha cells in the islets of langerhans release

glucagon

beta cells in the islets of langerhans release

insulin

together, alpha and beta cells release hormones that

act in an antagonistic and negative feedback fashion to control plasma glucose levels

When plasma glucose levels rise → the beta cells release ____ and then

insulin. Insulin increases uptake of glucose by most body cells and lowers the levels of plasma glucose

When plasma glucose levels fall → alpha cells release glucagon and then

Glucagon increases glycogen breakdown and glucose release by the liver, raising the level of plasma glucose

what is this? what is in blue

this is the liver. The blue is a liver lobule

liver lobules are composed primarily of

hepatocytes

functions of liver lobules

• nutrient metabolism

• vitamin and mineral storage

• drug inactivation

Lobules also play a role in modifying the blood by

synthesizing plasma proteins and removing circulating pathogens, debris, aged RBCs, hormones, antibodies, and toxins.

The digestive functions of liver lobules

is the synthesis and secretion of bile

Adjacent lobules are separated from one another by connective tissue known as

interlobular septa

In the center of each lobule is a blood vessel known as the

central vein

pink arrow with function

the central vein drain liver lobules taking blood onward towards hepatic vein

at each of the 6 corners of the lobule, there is a portal triad composed of

2 blood vessels and a bile duct

The bile duct in each triad collects bile

from the hepatocytes within the lobule and ultimately delivers it to the large left and right hepatic ducts that take bile away from the liver (duodenum or gallbladder)

what is each part of the portal triad

1. branch of hepatic portal vein (portal venule)

2. arteriole: branch of hepatic artery

3. bile duct

the two blood vessels of the portal triad are

portal arteriole: a branch of the hepatic artery

portal venule (a branch of the hepatic portal vein)

the portal arteriole and portal venule bring blood

to the sinusoidal capillaries that run inbetween the hepatocytes and empty into the central vein.

The portal arteriole brings oxygen rich blood

to feed hepatocytes

The portal venule brings blood

from the hepatic portal system (draining the intestines, stomach, and spleen) which may be rich in nutrients, toxins, and pathogens. The hepatocytes can then eliminate any dangerous substances and gather any nutrients

label everything

this is the tongue

blue box → stratified squamous epithelium papilae

pink circle → taste buds

green circle → seromucous salivary glands

red star → salivary glands

• these make saliva

pink star → skeletal muscle

bands of ______ make up the bulk of the tongue

skeletal muscle

label the tongue

A. taste buds

B. papilae

C. stratified Squamous epitheium

D. lingual salivary glands

E. Skeletal muscle

label

A. taste buds

B. papilae

C. stratified squamous epithelium

D. skeletal muscle tissue

in taste buds, there can sometimes be an opening called

the taste pour which lets chemicals in food interact with the cells and create the sensation of taste.

label the parotid gland

red arrow → stratified epithelium duct

blue → serocus acini

purple → connective tissue suptum

pink→ salivary duct of simple epithelium

a whole circle is a lobule

serous acini function

secrete saliva into intercalated ducts

stratified ducts merge to form larger ducts with stratified epithelium which eventually all merge to

exit the gland

Label

blue shape → serous acini

purple arrow → intercalated duct with simple epithelium

red arrow → stratified duct

blue arrow → stratified duct

99% of the pancreas is composed of clusters of cells attached to small ducts. These clusters are known as

pancreatic acini

label

blue → pancreatic acini

red → islet of langerhans/pancreatic islets

label

Blue → pancreatic acini

Red → pancreatic duct

function of pancreatic duct

The duct carries the acinar enzymes and secretes an alkaline fluid as well. The high pH of pancreatic juice helps nutralize the acidity of gastric chyme

label

Red star → pancreatic duct

Blue star → pancreatic acini

label

pancreas

Black circle → pancreatic islet

Red circles → acini

Purple arrow -> pancreatic duct

The liver is composed of thousands of roughly hexagonal structures called ______. Each liver lobule contains a lumen of a______surrounded by _______

liver lobules; central vein; hepatocytes and sinusoidal capillaries

Blood flows through the triad vessels

through the sinusoids to the central vein and is filtered along the way

the bile duct collects bile produced by

hepatocytes

label the liver

blue → liver lobule

green star → hepatocytes and sinusoidal capillaries

red → portal triad

label liver

A. portal triad

B. Liver lobule

C. central vein

green → pink is hepatocyte while white is sinusoidal capillaries

label the middle of the liver lobule

circle → central vein

pink → hepatocytes

white parts → sinusoidal capillaries

label portal triad

A. interlobular connective tissue

B. hepatocytes

C. portal vein

D. branch of hepatic artery

E. branch of bile duct

F. branch of hepatic artery

G. branch of bile duct

H. PV