What colours do haemotoxylin and eosin stain the cell nuclei an cytoplasm?
- Nuclei = blue - Cytoplasm = pink but colour varies depending on nature of cytoplasmic contents
What do these stains show: - PAS - Van Gieson - Trichrome - Alcian Blue?
- sugars, e.g. goblet cells - elastic tissue - 3 types of cell - mucins
Why do cells vary in size?
Depends on metabolic activity, e.g. lymphocytes smaller than nerve cells as aren’t as metabolically active (need less mitochondria)
What are the 6 types of cell shapes?
- rounded - polygonal - fusiform - squamous (flattened) - cuboidal - columnar
What common feature do metabolically active cells have?
Nucleoli (within nucleus, site of ribosomal RNA formation)
What is chromatin? What are the two types?
Condensed DNA wound around histones. Can’t be transcribed unless decondensed. - Heterochromatin = permanently condensed - Euchromatin = becomes decondensed in the life cycle of the cell
What is the mitochondria?
- powerhouse of cell - site of oxidative phosphorylation - have own nucleus
What is RER?
Site of protein synthesis, lots of ribosomes
What is SER?
- site of membrane lipid synthesis - processes synthesised proteins
What is the Golgi apparatus?
- processes macromolecules synthesised in ER - prominent in plasma cells (called perinuclear ‘hoff’)
What are the 3 parts of the Golgi apparatus?
- cis face = receives transport vesicles from SER, phosphorylase some proteins - medial Golgi = forms complex oligosaccharides by adding sugars to lipids and peptides - trans Golgi network (end) = sorts macromolecules into vesicles which bud from surface
What are vesicles?
Small membrane-bound organelles used for transport, storage and exchanging cell membrane between compartments. An example is a lysosome
How are lysosomes formed?
Hydrolyse vesicles fuse with endosomes to form endolysosomes
What is the cytoskeleton? What does it contain?
- supports cell’s shape - microfilaments (actin) helps this (smallest, 5nm) - intermediate filaments (6 types) spread tensile forces through tissue = cytokeratin, desmin, glial fibrillary acidic, neurofilament, laminin, vimentin - microtubules act as a scaffold for chromosomes during mitosis + meiosis (made of tubulin) (largest, 25nm)
What is lipofuscin and where is it found?
- membrane-bound orange-brown pigment, formed from peroxidation of lipids in older cells - heart and liver
Where are lipids and glycogen found?
- lipids found in adipocytes (fat cells) - glycogen found in cytoplasm
Are all the constituents of the body contained inside cells?
No, there is interstitial fluid, e.g. water + extra cellular material, e.g. tendons
A sample of liver from a patient who has a disease that makes them store excess iron in the liver is examined by a pathologist. Which stain can be used to stain iron blue? A - Alcian blue B - Haemotoxylin C - Iron haemotoxylin D - Perl’s stain E - Periodic acid-Schiff stain
D - Perl’s stain
Different cells have different lifespans. Which of the following cell types lives for the whole life of a person? A - Enterocytes (gut lining cells) B - Erythrocytes (red blood cells) C - Cardiac myocytes (heart muscle cells) D - Fibroblasts (connective tissue cells) E - Keratinocytes (skin cells)
C - Cardiac myocytes (heart muscle cells)
Which stain(s) have been used on this section? A - Alcian Blue B - Giemsa C - Haemotoxylin and eosin D - Periodic acid Schiff E - Perls Prussian Blue
What is the shape of these cells? A - Columnar B - Fusiform C - Polygonal D - Rounded E - Squamous
What is the lifespan of these cells? A - 5 days B - 120 days C - 400 days D - 3600 days E - 21000 days
What is chromatin? A - Mitochondrial DNA B - Nuclear DNA C - Nuclear DNA + proteins D - Nuclear RNA E - Nuclear RNA + proteins
What is the function of the arrowed organelle? A - DNA transcription B - Energy production C - Lipid degradation D - Protein degradation E - Protein synthesis
Which metabolic process takes place here? A - Fatty acid metabolism B - Lipid synthesis C - Kreb’s cycle D - Nucleotide phosphorylation E - Respiratory chain
Which organelle causes this pale area? A - Golgi body B - Lysosomes C - Mitochondria D - Rough ER E - Smooth ER
What is the function of this organelle? A - Form complex oligosaccharides B - Form membrane lipid C - Protein phosphorylation D - Proteolysis E - Synthesise protein
Which of these filaments has the smallest diameter? A - Actin B - Desmin C - Nuclear laminin D - Tubulin E - Vimentin
Which of these intermediate filaments is predominantly found in muscle? A - Cytokeratin B - Desmin C - Neurofilament protein D - Nuclear laminin E - Vimentin
What is this pigment? A - Bilirubin B - Haemosiderin C - Lipofuscin D - Melanin E - Rhodopsin