Histology - Cytology Slides

Question 1

Pancreas

Answer 1

Horse

Pancreas:
Mixed exocrine/endocrine gland that produces digestive enzymes and hormones
The enzymes (used for digestion) are stored and released by cells of the exocrine portion arranged in acini

Question 2

Pancreas Identification

Answer 2

Parenchyma
Stroma 
Septa
Zymogen Granules
Mucleus
Basophilic
Acidophilic/Eosinophilic
Vascular Structures

Question 3

Examining Pancreas Slide

Answer 3

1) Low Magnification - Pancreas is separated into lobules separated by septa
2) Find center of lobule and increase magnification

3) High Magnification -
Exocrine pancreatic cells (parenchymal cells) are arranged in clusters called acini with a central lumen into which secretory products are released
Parenchyma are highly polarized with a spherical nucleus (open-faced)
Notice Basophilic (purple - nucleic regions and RER = cell is metabolically active) and Acidophilic/Eosinophilic (pink) regions

4) Lower your condensor = note presence of zygomagen granules within cytoplasm of the pancreatic cells = CELL INCLUSIONS

Ducts and blood vessels also present

Question 4

Lobule of the Pancreas

Answer 4

Parenchyma of pancreas = functional unit of the organ

Made up of pancreatic alcinar cells (arranged into acinii) and pancreatic islet cells (islets of Langerhan; endocrine tissue - secretes product into bloodstream)

Question 5

Septa

Answer 5

Stroma in pancreas

Divides parenchyma

Question 6

Stroma

Answer 6

Nonliving connective tissue that supports organ

Septa (pancreatic version)

Question 7

Acinii

Answer 7

Cellular arrangement of parenchymal cells in a radial formation (lumen in center)

STRUCTURE IN NOTES

Question 8

Purple color of cells = ?

Answer 8

Metabolically activity

Hemotoxylin stain is attracted to basophillic structures = genetic material

Question 9

Zygomagens

Answer 9

CELL INCLUSIONS in Pancreas

Acidophilic = pink

w/ proenzymes needed for digestion

Number of zygomagens is dependent on digestive phase

Question 10

Open- vs closed-face nucleus

Answer 10

Open-Face Nucleus - metabolically active = change of color to purple

Close-Face Nucleus - not metabolically active = no change of colors

Question 11

Dorsal Root Ganglia

Answer 11

Dog

Collection of neuronal cell bodies of the peripheral nervous system

Question 12

Dorsal Root Ganglia Identification

Answer 12

Nucleus
Nucleolus
Nissl Substance, RER 
Artifact
Satellite Cells

Question 13

Examining Dorsal Root Ganglia Slide

Answer 13

Low Magnification - Note large ganglionic cells surrounded by smaller, darker satellite cells

High Magnification - Ganglionic cells:
Large open-faced nucleus with a prominent nucleolus (not every cell seems to have a nucleus b/c of where the cell was cross-sectioned)
Basophilic stain of cytoplasm = due to rough endoplasmic reticulum = Nissl substance in neurons
Space around ganglionic cells = artifact fixation due to shrinkage from dehydration

can also notice stroma and neuronal cell membrane

Question 14

Rough Endoplasmic Reticulum

Answer 14

Cytoplasmic surface possesses receptor molecules for ribosomes and signal recognition particle (ribophorins and docking proteins)

Continuoues with the outer nuclear membrane

Question 15

Satellite Cells in Neurons

Answer 15

Glial cells that cover cell bodies in sensory, sympathetic and parasympathetic ganglia

Question 16

Liver

Answer 16

Cat

Largest gland in body

Second largest organ

Processes and stores the nutrients absorbed through digestion

Interface between the digestive system and the blood

Question 17

Liver Identification

Answer 17

Hapatocytes (Parenchyma)
Vacuoles
Nucleus
Endothelial Cells
White Blood Cells (Leukocytes)
Red Blood Cells (Erythrocytes)

Question 18

Examination of the Liver Slide

Answer 18

Low Magnification:
Large blood vessels
Septa
Hepatic Cells (Hepatocytes; Parenchyma; lots of activity)

High Magnification:
Sinusoids - spaces containing erythrocytes, leukocytes, and hepatocytes
Hepatocytes with open-faced nuclei and many vacuoles (lipids or glycogen from digestion) in the cytoplasm (pink))
Endothelial Cells
Lipid Droplets (CELL INCLUSIONS)

Also central vein

Question 19

Erythrocytes

Answer 19

Small and ovoid

5-7 micrometers

Viewed in almost all tissues = marker for estimating size of cells

Question 20

Endothelial Cells

Answer 20

Flattened and often elongated

Line all vascular structures

Contain close-faced nuclei (dark = basophilic)

Question 21

Lipid Droplets

Answer 21

CELL INCLUSION in Liver

Question 22

Sympathetic Ganglion

Answer 22

Horse

Question 23

Sympathetic Ganglion Idetification

Answer 23

Nucleus
RER
Nucleoli
Satellite Cells
Lipofuscin (CELL INCLUSION)

Question 24

Examination of Sympathetic Ganglion Slide

Answer 24

Low Magnification:
Ganglionic neuron morphology - neuron cell body (with prominent nucleus and nucleoli and a basophilic cytoplasm) and neuronal fibers

High Magnification:
Surrounding dark satellite cells
Prominent RER (purple, basophilic)
Lipofuscin (CELL INCLUSION) = yellow to brown stain in cell body

Question 25

Lipofuscin

Answer 25

CELL INCLUSION in Sympathetic Ganglion Yellow to brown pigment in symmpathetic cells Insoluble pigment that indicate the wear and tear of the cell digestive remnents of organelles in cell

Question 26

Lots of RER in Sympathetic Ganglion = ?

Answer 26

Nissl Bodies

Question 27

Skin

Answer 27

Horse Epidermis and Dermis

Question 28

Skin Identification

Answer 28

Epidermis Dermis Epithelial Cells Melanin (CELL INCLUSION)

Question 29

Examination of Skin Slide

Answer 29

Low Magnification: Dark stained epidermis Adjacent to lighter stained dermis High Magnification: At the basal layer of the epithelium (epidermis) = darkly stained brown pigment = melanin (CELL INCLUSION)

Question 30

Epidermis vs Dermis

Answer 30

Epidermis - epithelium, created from the ectoderm, small extracellular matrix Dermis - connective tissue, created from the mesoderm, large extracellular matrix

Question 31

Melanin

Answer 31

CELL INCLUSION in Skin Dark brown pigment in cytoplasm of the epithelium created by melanocytes in response to DNA damage Protects nuclei from further damage Melanocytes are derived from neural crest cells (drom ectoderm)

Question 32

Uterus

Answer 32

Lumenal organ of the female reproductive tract Active estrous cycle (Slide 2)

Question 33

Uterus Identification

Answer 33

``` Lumen Uterine Glands Epithelium Mitotic Figures Blood Vessels Endometrium Myometrium Macrophages Hemosiderin (CELL INCLUSION) ``` Blood Vessels as well

Question 34

Examination of Uterus Slide - Slide 1

Answer 34

Low Magnification: Central lumen Epithelial cells line the lumenal surface that invaginates the endometrium to form uterine glands (cross section) Notice the difference between the inner endometrial layer (endoderm) and the outer myometrial layer (thick smooth muscle, mesoderm) Blood vessels High Magnification: Examine the uterine glands - different stages of mitotic activity Mitotic activity = mitotic figures

Question 35

Why is it important to recognize mitotic figures?

Answer 35

Indicative of normal/abnormal growth and tissue repair If not supposed to be reproducing, could = cancer

Question 36

Uterine Glands

Answer 36

Created by invagination of epithelial cells into underlying endometrium Active or quiet depending on phase of reproductive cycle (estrus, proestrus, diestrous, metestrous, anestrous) High estrogen levels = cells proliferate = cells in various stages of mitosis Low estrogen levels = no activity (mitosis) Lowering Progesterone levels - vascular tissue regressing leaving some RBCs in the connective tissue proper

Question 37

Examination of Uterus Slide - Slide 2

Answer 37

``` Low Magnification: Lumen Endometrium Uterine Glands Outer Myometrium ``` High Magnification: Macrophages with yellow/brown pigment (hemosiderin (CELL INCLUSION) and RBCs

Question 38

Macrophages

Answer 38

Between uterine glands large WBCs that have engulfed (phagocytized) erythrocytes Derived from circulating WBCs called monocytes Connective tissue cell "big eater" Hemorrhaging of RBCS around the uterine glands signals the macrophages Contain Hemosiderin from the breakdown of ingested hemoglobin Open-faced nucleus (round and indented)

Question 39

Hemosiderin

Answer 39

CELL INCLUSION of Uterus Indication of the cleaving a the heme molecule from hemoglobin from phagocitzing of RBCs by macrophages Insoluble yellow/brown pigment Macrophages DO NOT have to have hemosiderin Hemosiderin is NOT only found in macrophages (common in macrophages however)

Question 40

Cell Inclusions

Answer 40

``` Zygomagens - Pancreas Lipid Droplets - Liver Lipofuscin - Sympathetic Ganglion Malanin - Skin Hemosiderin - Uterus ```