1.introduction to IMMS

Question 1

what colour does Haematoxylin and Eosin (H&E) stain the nucleus, cytoplasm and extra-cellular structures

Answer 1

nucleus - blue
cytoplasm - pink (colour depends on contents)
extra-cellular - pink

Question 2

how is tissue prepared for microscopy

Answer 2

preserved by fixing in formalin (prevents it from rotting)
then embedded in paraffin
thin slices made
for bone it must be de-mineralised or ground down

Question 3

other types of stains

Answer 3

PAS (sugars), Van Gieson (elastic), Trichrome (3 types of cell), Alcian blue (mucins)

Question 4

shapes of cells

Answer 4

rounded 
polygonal (irregularly shaped)
fusiform (spindle shaped/elliptical)
squamous (flattened)
cuboidal 
columnar

Question 5

activity of cells

Answer 5

metabolically inactive (dormant cells) are smaller than metabolically active - needs less machinery so has less cytoplasm metabolically active cells often have nucleoli

Question 6

cell life spans

Answer 6

lining of gut - days
red blood cells - 120 days
cardiac muscle - whole life

Question 7

nucleus ultrastructure

Answer 7

houses DNA
nucleolus - 1-3 microns in diameter, sites of ribosomal RNA formation
Euchromatin is lighter - less electron dense due to transcription than heterochromatin

Question 8

mitochondria

Answer 8

powerhouse, site of oxidative phosphorylation, have their own DNA, double membrane (inner is highly folded)

Question 9

rough endoplasmic reticulum

Answer 9

site of protein synthesis, highly folded flattened membrane sheets with ribosomes

Question 10

smooth endoplasmic reticulum

Answer 10

site of membrane lipid synthesis, processes synthesised proteins, highly folded membrane sheets

Question 11

golgi apparatus

Answer 11

parallel stacks of membrane, processes macromolecules synthesised in the ER, particularly prominent in plasma cells

Question 12

vesicles

Answer 12

small, spherical, membrane-bound organelles used for transport, storage and exchanging cell membrane between compartments

Question 13

lysosomes

Answer 13

derived from golgi apparatus, low internal pH due to H+-ATPase on membrane, contain acid hydrolases that degrade proteins, dangerous to cell so separation between two chemicals, initial hydrolase vesicles fuse with endosomes with the correct membrane proteins to produce endolysosomes

Question 14

peroxisomes

Answer 14

small vesicle, contain enzymes which oxidise long-chain fatty acids

Question 15

cytoskeleton

Answer 15

has lots of different filaments e.g. intermediate filament
desmin-myocytes
neurofilament protein neurons

Question 16

call death

Answer 16

programmed - apoptosis (cell shrinks, becomes fragmented and is ingested by adjacent cells)
unprogrammed cell death occurs as a result of tissue necrosis

Question 17

storage products and inclusions

Answer 17

lipid- non-membrane bound, appear as empty space as dissolve in processing, adipocytes and liver

glycogen - CHO polymer in cytoplasm, seen on electron microscopy, accumulates in some cells and diseases

Question 18

composition of tissues

Answer 18

interstitial fluid (water, salts in solution, peptides and proteins)
extracellular material (fibrillar proteins, inorganic salts and solids)

Question 19

types of tissues

Answer 19

epithelia: protection, adsorption, secretion, form solid glands such as salivary glands
muscle: smooth, skeletal, heart, have contractile properties

supporting tissues: cartilage, bone, tendons, blood

nerves: brain, peripheral, visceral

germ cells: ova . sperm

Question 20

what is chromatin

Answer 20

nuclear DNA + proteins

Question 21

what is the function of the nucleolus

Answer 21

DNA transcription

Question 22

what is the function of rough endoplasmic endoplasmic reticulum

Answer 22

site of protein synthesis

Question 23

what intermediate filament is predominantly found

Answer 23

Desmin

Question 24

where is cytokeratins found

Answer 24

epithelial cells

Question 25

Glial fibrillary acidic protein

Answer 25

astrocytic glial cells

Question 26

neurofilament

Answer 26

neurons

Question 27

nuclear laminin

Answer 27

nuclei of all cells

Question 28

vimentin

Answer 28

mesodermal cells