Lecture 3: Cytology

Question 1

What types of membranes constantly express and recycle receptors on both their inner and outer surfaces to perform their functions?

Answer 1

Cell membrane

Membrane of all organelles

Question 2

Mitochondrial replication

Answer 2

• Self-replicating
• Uniparental inheritance, therefore little opportunity for genetic recombination between different lineages, although a single mitochondrion can contain 2–10 copies of its DNA

Question 3

Mitochondria structure

Answer 3

Double membrane-enclosed organelle with cristae

Question 4

Is mitochondria visible under LM in ordinary staining?

Answer 4

No

Question 5

Cristae

Answer 5

finger-like projections of the cellular membrane

Question 6

Three roles of mitochondria?

Answer 6

• ATP production
• Necrosis
• Apoptosis initiation

Question 7

How do mitochondria initiate apoptosis?

Answer 7

Release cytochrome C

Question 8

What is the point of no return for apoptosis?

Answer 8

mitochondrial outer membrane permeabilization

Question 9

Are Pancreatic Acinar Cells exocrine or endocrine?

Answer 9

exocrine

Question 10

Endoplasmic reticulum

Answer 10

anastomosing network of intercommunicating

channels

Question 11

What differentiates the RER and the SER

Answer 11

RER has polyribosomes

Question 12

Three functions of the SER

Answer 12

Lipid biosynthesis
Detoxification
Sequestration of calcium ions (sequ = temporarily stored)

Question 13

Four functions of the RER

Answer 13

Segregate proteins not destined to the cytoplasm
Glycosylation of glycoproteins
Synthesis of phospholipids
Assembly of multichain proteins

Question 14

Golgi complex

Answer 14

Collection of membrane-bound flattened sacs ‘cisternae’

Question 15

Purpose of Golgi complex

Answer 15

Modifies and ‘packages’ proteins

Question 16

The Golgi body is best developed in

Answer 16

secretory cells

Question 17

Lysosomes

Answer 17

Membrane-bound dense particles that contain hydrolytic enzymes
Associated with intracellular digestion

Question 18

What two processes are lysosomes associated with?

Answer 18

pinocytosis

phagocytosis

Question 19

Pinocytosis

Answer 19

engulfing small vesicles by invaginations of the cell

Question 20

Lipofuscin

Answer 20

• Wear and tear pigment

- Degraded material that remains permanently

Question 21

Proteasomes

Answer 21

• Small enzymatic complexes for intracellular digestion

- Recycles amino acids from endogenous proteins

Question 22

Intracellular digestion in proteasomes requires a protein known as

Answer 22

Ubiquitin

Question 23

Peroxisomes

Answer 23

• Contain the enzyme ‘catalase’ which can degrade intracellular hydrogen peroxide (protects the cell)
• Degrade toxic molecules and some prescription drugs

Question 24

Cytoskeleton - Three different types of structures

Answer 24

• Microfilaments
• Intermediate filaments
• Microtubules

Question 25

What are microfilaments made out of?

Answer 25

actin and myosin

Question 26

What are intermediate filaments made out of?

Answer 26

keratin

Question 27

What kind of cell is keratin normally found in?

Answer 27

epithelial

Question 28

What are and what is the function of microtubules

Answer 28

hollow thin tubules that move organelles, vesicles, ribosomes; form the mitotic spindle; maintain shape of avian red blood cells (RBCs) and platelets; part of centrioles, cilia and sperm flagella

Question 29

Myosin

Answer 29

thick microfilaments | 15 nm in diameter

Question 30

Actin

Answer 30

Thin microfilaments | 5-7 nm in diameter

Question 31

Size of intermediate filaments

Answer 31

range between 6 and 12nm in diameter

Question 32

Five types of intermediate filaments

Answer 32

- Tonofilaments (cytokeratin) - Vimentin - Desmin - Neurofilaments - Glial filaments

Question 33

Tonofilaments (cytokeratin) location

Answer 33

epithelium

Question 34

Vimentin location

Answer 34

mesenchymal cells (Fibroblasts, chondroblasts, osteoblasts, macrophages, endothelial cells, vascular, smooth muscle cells)

Question 35

Desmin location

Answer 35

muscle

Question 36

Neurofilament location

Answer 36

neurons

Question 37

Glial filament location

Answer 37

Glial cells (astrocytes)

Question 38

In a fluorescing microscope, microtubules appear what color?

Answer 38

light color

Question 39

Lipofuscin

Answer 39

brown

Question 40

Lutein

Answer 40

yellow

Question 41

Hemosiderin

Answer 41

results from the decomposition of red blood cells

Question 42

Why does melanin cover the nucleus?

Answer 42

Acts like an umbrella | Protects it from the UV light

Question 43

Adipocyte

Answer 43

Cell that forms the adipose tissue

Question 44

Yellow/brown in the myocardium is more likely

Answer 44

lipofuscin

Question 45

Yellow/brown in the spleen is most likely

Answer 45

hemosiderin

Question 46

What color does hemosiderin stain in Prussian Blue?

Answer 46

Black

Question 47

How do you find glycogen in hepatocytes?

Answer 47

Stain with best carmine, look under light microscope

Question 48

Microvilli

Answer 48

- very small, absorptive, seen in EM | - Form a brush/striated border when viewed with the light microscope

Question 49

Cilia

Answer 49

motile projections, longer but less numerous than microvilli, come from basal bodies (= modified single centrioles)

Question 50

Stereocilia

Answer 50

nonmotile projections, absorptive (are considered large microvilli)

Question 51

When looking at an intestinal epithelium using PAS, what color will the goblet cells be?

Answer 51

magenta

Question 52

What color are goblet cells when not using PAS?

Answer 52

white/clear

Question 53

Cilia are made up of

Answer 53

9 microtubules and 2 central single tubules

Question 54

From each outer pair of microtubules, a pair of _____ _____ reach towards the next pair of microtubules

Answer 54

dynein arms

Question 55

_____ ______ extend from each outer pair of microtubules towards the inner central tubules

Answer 55

radial spokes

Question 56

____ links also join each outer pair of microtubules with the adjacent outer pair.

Answer 56

Nexin

Question 57

7 cell shapes

Answer 57

Squamous, cuboidal, columnar, spindle, cylindrical, multipolar, round

Question 58

3 nuclear shapes

Answer 58

Round, elongated, polymorphonuclear

Question 59

4 nuclear positions

Answer 59

Central, eccentric/hypolemmal, apical vs. basal

Question 60

3 surfaces of an epithelial cell

Answer 60

Apical (free) surface Lateral surfaces Basal surface