Cell biology of tissues

Question 1

Types of human cells

Answer 1

Epithelial cells
Mesenchymal cells
Contractile tissue
Haematopoietic cells
Neural cells

Question 2

Examples of epithelial cells

Answer 2

Layers of cells lining organs and forming boundaries between tissue and compartments

Question 3

Examples of mesenchymal cells

Answer 3

Cells of the connective tissue, fibroblasts, chondrocytes, osteocytes

Question 4

Examples of contractile tissues

Answer 4

Skeletal muscle, cardiac muscle, smooth muscle

Question 5

Examples of haematopoietic cells

Answer 5

Blood cells, immune cells, bone marrow progenitor cells

Question 6

Examples of neural cells

Answer 6

Neurones, glial cells

Question 7

Cell type affected in cancers

Answer 7

Carcinomas - epithelial cells
Sarcomas - mesenchymal cells
Leukaemias - bone marrow cells
Lymphomas - lymphocytes
Neuroblastomas - neural cells
Gliomas - glial cells

Question 8

Function of nucleus

Answer 8

Contains genetic information of the cell and controls activity of the cell

Question 9

Function of nucleolus

Answer 9

Contains genes for rRNA, site of synthesis for ribosomal subunits

Question 10

Function and shape of rough ER

Answer 10

Protein synthesis, flattened sheets with ribosomes studded on OUTER face.

Question 11

Function and shape of smooth ER

Answer 11

Lipid metabolism and synthesis. Tubular, no ribosomes.

Question 12

Function and shape of Golgi apparatus

Answer 12

Modify, sort, package macromolecules for secretion of delivery to other organelles. Stacked, membrane bound sacs.

Question 13

Examples of intracellular membranes

Answer 13

Nuclear envelope, ER, golgi apparatus.

Question 14

Function of mitochondria

Answer 14

Aerobic glucose metabolism, ATP production

Question 15

Function of ribosomes

Answer 15

Site of protein synthesis, two subunits.

Question 16

Function of peroxisomes

Answer 16

Contain and release enzymes involved in lipid and oxygen metabolism (oxidases, catalase, peroxidases)

Question 17

List cell organelles

Answer 17

Nucleus
Nucleolus
Rough ER
Smooth ER
Golgi app.
Intracellular membranes
Mitochondria
Ribosomes
Peroxisomes

Question 18

Cytoskeleton components (descending order of thickness)

Answer 18

Microtubules
Intermediate filaments
Microfilaments

Question 19

Features of microtubules

Answer 19

• Polymers of alpha and beta tubular heterodimers
• 20nm thick
• Involved in cell shape
• Act as “tracks” for organelle and cytoplasmic component movement
• Structural and motor components of cilia/flagellae
• Form mitotic spindle

Question 20

Features of Intermediate filaments

Answer 20

• Group of polymers of filamentous proteins
• Form rope-like structures
• 10-15nm thick
• Give mechanical strength to cell
• Different types of cell have different IFs
• Nuclear lamins are IFs that form a network on the inside of the nuclear envelope to stabilise it.

Question 21

Features of Microfilaments

Answer 21

• Polymers of actin
• Associate with adhesion belts in epithelia and endothelia
• 5-9nm thick
• Involved in cell shape and movement
• Accessory proteins (myosin) act with actin to control cell movement.

Question 22

Types of cells and their Intermediate filaments

Answer 22

Epithelial cells - Cytokeratins
Mesenchymal cells - Vimentin
Neurones - Neurofilament protein
Muscle cells - Desmin

Question 23

Definition of a tissue

Answer 23

A group or groups of cells whose type, organisation and architecture are integral to its function.

Question 24

Components of tissues

Answer 24

Cells
Extracellular matrix
Extracellular fluid