Cell biology of tissues

Question 1

Recall types of human cells

Answer 1

Epithelial = layers that line surfaces and separate tissues and compartments Mesenchymal = connective tissue (fibroblasts/ chondrocytes/ ostercytes/ muscle cells) Haematopoietic = blood and bone marrow cells Neural = nervous system cells, neurons and glial cells

Question 2

Recall the originating cell type in neoplasms

Answer 2

Epithelial = carcinoma Mesenchymal = Sarcoma Haematopoietic = leukaemia (bone marrow) lymphoma (lymphocytes) Neural = Neuroblastoma (neurone precursor) Glioma (glial cells)

Question 3

Summarise the 3 main components that constitute the cytoskeleton

Answer 3

MICROTUBULES = 20nm, cilia and flagella INTERMEDIATE FILAMENTS = 10-15nm, mechanical strength, epithelial(cytokeratin), mesenchymal(vimentin), neurons(neurofilament protein), muscle(desmin) MICROFILAMENTS = actin polymers associated with adhesion belts, monomer (globular actin), microfilaments(filamentous actin), helical structure

Question 4

What is heterochromatin?

Answer 4

Darker regions of the nucleoplasm showing condensed DNA

Question 5

What is the nucleolus?

Answer 5

Site of ribosome subunit production

Question 6

Recall ribosomal sizes

Answer 6

Prokaryote = 70S Eukaryote = 80S Mammalian mitochondrial = 55S

Question 7

Outline the relationship between the nuclear envelope and endoplasmic reticulum

Answer 7

-Physical continuity between the two structures -Nuclear lamina = specialised cytoskeleton on the internal surface of the nuclear envelope. Controls assembly/disassembly of NE in cell division

Question 8

Describe the difference between Smooth and rough ER

Answer 8

RER = flattened sheets w/ ribosomes, membrane bound and packaging proteins SMER = tubular, involved in lipid metabolism/ detoxification/ Ca2+ storage

Question 9

Describe the structure of golgi apparatus

Answer 9