Introduction to Cellular Pathology

Question 1

what are cells?

Answer 1

living, self sufficient entities that may form more complex structures

Question 2

what is tissue?

Answer 2

‘more complex structures’

-interwoven mass of cells and extracellular material

Question 3

what is histology?

Answer 3

the study of tissues and the structure

Question 4

what are the 4 levels of tissue structure?

Answer 4

1) tissue structure: how cells combine together w extracellular material and each other to form a tissue
2) cellular structure: how a cell is shaped and how the components inside the cells are organised to support that cell’s specific function
3) sub-cellular structure: detailed analysis of organelle’s and inclusions
4) histochemical structure: molecular analysis of cellular structure

Question 5

what is histopathology?

Answer 5

the study of tissues affected by disease

Question 6

what is the importance of histopathology?

Answer 6

• useful in making diagnosis and determining severity + progression of disease
• understanding normal structure and function of diff tissues us essential for interpreting the changes that occur during disease

Question 7

describe epithelial tissue

Answer 7

• made of cells arranged in continuous sheet w one or more layers
• has an apical and basal surface
• basement membrane separates the epithelial layer from connective tissue

Question 8

what are the 2 types of epithelial tissue?

Answer 8

1) covering and lining epithelia

2) glandular epithelium

Question 9

how are epithelial tissue classified?

Answer 9

by the number of cell layers and shape of cell in the top layer

Question 10

how are epithelium classified by the number and distribution of cells?

Answer 10

• simple epithelium: 1 cell layer
• stratified epithelium: 2+ cell layers
• pseudostratified epithelium: cells are all anchored to the basement membrane but not all cells reach the apical surface

Question 11

how are epithelium classified by the shape of the cells?

Answer 11

-cuboidal, squamous, columnar shapes

Question 12

give examples of different classifications of epithelial tissue and where they are found

Answer 12

• simple cuboidal: renal collecting ducts
• stratified cuboidal: lining of ducts of the mammary gland
• pseudostratified columnar: lining of epithelium of tranchea

Question 13

what are the 2 main groups of connective tissue? which cells make up connective tissue?

Answer 13

1) connective tissue proper
2) specialised connective tissue

-fibroblasts, macrophages, mast cells, adipose

Question 14

what are connective tissue matrixes made of?

Answer 14

1) ground substance- proteins and polysaccharides

2) fibres- reticular, collagen, elastic

Question 15

what are the 2 classifications of connective tissue?

Answer 15

1) loose connective tissue: fibres and many cell types in gelatinous matrix
- found in skin and surrounding blood vessels, nerves, organs

2) dense connective tissue: bundles of parallel collagen fibres and fibroblasts
- found in tendons and ligaments

Question 16

what is bone made of?

Answer 16

• made of bone cells suspended in the matrix of collagen fibres and minerals
• in development: the bone is endochondral and membranous
• in mature bone: compact and trabecular

Question 17

what is cartilage made of?

Answer 17

-made of collagen and elastin fibres and chondrocytes

Question 18

what are the 3 types of cartilage?

Answer 18

• hyaline cartilage: weakest but most abundant
• elastic cartilage: maintains shape, breaching elastic fibres distinguish from hyaline
• fibrous cartilage: strongest type, dense collagen found in pelvis, skull and vertebrate discs

Question 19

what is the functional unit of muscle tissue?

Answer 19

principally muscle fibre but also has satellite cells to develop into muscle fibres

Question 20

what are the 3 types of muscle tissue?

Answer 20

1) skeletal muscle: voluntary, striated, mainly found attached to bone
- organised in myofibrils w nuclei peripherally located
- forms a lined up banding pattern from one cell to another

2) cardiac muscle: involuntary, striated, branched and has intercalated discs
- cells smaller than SKM w nuclei located centrally

3) smooth muscle: involuntary, non striated, spindle shaped
- found in blood vessels and GI tract
- cells vary in size and has fusiform shape
- nuclei observed in diff positions

Question 21

what is nerve tissue?

Answer 21

constitutes the CNS and PNS

Question 22

what are the 2 cells that make up nerve tissue?

Answer 22

1) neurons: cells that convert stimuli into electrical impulses to the brain
2) neuroglia: collection of diff cell types w a supportive role

Question 23

describe neurons

Answer 23

• made of the cell body, axons and dendrite
• motor neurone: carries impulses from the CNS to the muscles and glands
• interneurone: interprets input from the sensory neurone and end responses to motor neurones
• sensory neurone: receive info from the environment and transmits to the CNS

Question 24

describe neuroglia

Answer 24

• made of astrocytes, oligodendrocytes, ependymal cells, microglia in the CNS
• made of schwann cells and satellite cells in the PNS

Question 25

what do tissues of the body develop into?

Answer 25

-3 primary cell layers that form the embryo

Question 26

what are the 3 primary cell layers that form the embryo?

Answer 26

• ectoderm develops into nerve tissue and epithelial tissue
• mesoderm develops into epithelial tissue, connective tissue and muscle tissue
• endoderm develops into epithelial tissue