Tissues 1 (Epithelial Cells)

Question 1

What are the 3 connective tissue cells?

Answer 1

• fibroblasts
• chondrocytes (cartilage)
• osteocytes (bone)

Question 2

What are the 3 contractile tissues?

Answer 2

• skeletal muscle
• cardiac muscle
• smooth muscle

Question 3

What are haematopoetic cells?

Answer 3

• blood cells
• tissue-resident immune cells
• bone marrow cells

Question 4

What are the 2 neural cells and their functions?

Answer 4

• neurones (carry electrical signals)

- glial cells (support cells)

Question 5

What are the functions of epithelial cells

Answer 5

• form continuous layers
• line surfaces
• separate tissue compartments

Question 6

What is a mesenchymal cell?

Answer 6

• connective tissue

- fibroblasts, chondrocytes & muscle cells

Question 7

Which cells do carcinomas, sarcomas, leukaemias & neuroblastomas originate from?

Answer 7

• carcinoma: epithelial
• sarcoma: mesenchymal
• leukaemia: haemopoetic
• neuroblastoma: neural

Question 8

What features does a nucleus contain?

Answer 8

• nucleoplasm
• nuclear pores
• nucleolus (site of ribosome production)
• nuclear envelope

Question 9

What is a cisternae?

Answer 9

stack of endoplasmic reticulums

Question 10

What do peroxisomes contain?

Answer 10

enzymes for lipid & oxygen metabolism

Question 11

What comprises a cytoskeleton?

Answer 11

• microtubules
• intermediate filaments
• microfilaments

Question 12

What are microtubules made of and what is the diameter of a microtubule?

Answer 12

• alpha and beta tubulin

- 20nm

Question 13

What are the functions of a microtubule?

Answer 13

• involved in cell shape
• tracks for movement of organelles & other components
• form mitotic spindle

Question 14

What is a major structural & motor component of cilia & flagellae

Answer 14

microtubules

Question 15

Which cytoskeletal filament gives mechanical strength to a cell?

Answer 15

intermediate filament

Question 16

What is an intermediate filament?

Answer 16

group of filamentous proteins forming rope-like filaments

Question 17

What are the different type of intermediate filaments in different cell types?

Answer 17

• epithelial: cytokeratin
• mesenchymal: vimentin
• muscle: desmin
• neurons: neurofilament protein

Question 18

What is the diameter of an intermediate filament?

Answer 18

10-15nm

Question 19

How are desosomes connected?

Answer 19

via intermediate filaments

Question 20

What is a nuclear lamins and its function

Answer 20

type of intermediate filament, stabilises nuclear envelope

Question 21

What is a microfilament?

Answer 21

polymers of globular protein actin

Question 22

What do microfilaments associate with?

Answer 22

• adhesion belts (epithelia)
• endothelia proteins
• plasma membrane proteins

Question 23

What are the functions of microfilaments?

Answer 23

• involved in cell shape & movement

- contraction of non-muscle cells

Question 24

What type of structure does a microfilament have?

Answer 24

helical (actin)

Question 25

What is a tissue?

Answer 25

a group of cells whose type, organisation & architecture are integral to its function

Question 26

What are the 3 major cell-cell junctions?

Answer 26

- zonula adherens - zonula occludens - macula adherens

Question 27

What is a zonula adherens?

Answer 27

- adhesion belt - e.g. cadherin (binds to similar molecules on adjacent cells) - closely associated to actin cytoskeleton

Question 28

Why are cell-cell junctions important?

Answer 28

key to formation & maintenance of epithelial layers

Question 29

What is a zonula occludens?

Answer 29

- tight junction - prevents ion diffusion so allows polarity establishment - blocks paracellular pathways

Question 30

What is a macula adherens?

Answer 30

- cluster of pores formed by membrane proteins - allows passage of ions (relatively small & water) - 1.5nm diameter

Question 31

What happens in the nucleolus?

Answer 31

ribosomal subunits are synthesised

Question 32

What is the organisation of microtubules in cells?

Answer 32

originate from point called the microtubule organising centre (MTOC)

Question 33

What is the definition of extracellular matrix?

Answer 33

the insoluble material found extracellularly

Question 34

What are the four main types of cell-cell junctions (in order of apical to basal)?

Answer 34

- tight - adhesion belt - desmosomes/gap junctions

Question 35

What is the role of gap junctions?

Answer 35

allows transport of small molecules between cells