W10 Cellular pathology

Question 1

Cells

Answer 1

Living, more or less self-sufficient entities that may form more complex structures. Cells are surrounded by a membrane

Question 2

Tissues

Answer 2

The “more complex structures”. Interwoven masses of cells and extra cellular material

Question 3

Histology

Answer 3

Study of the “more complex structures” = tissues

Question 4

Organization at 4 different levels

Answer 4

Tissue structure - how cells combine together with extracellular material and each other to form a tissue

Cellular structure - how a cell is shaped, and how the components inside cells are organized to support that cells specific function

Sub-cellular structure - detailed analysis of organelles and inclusions

Histochemical structure - molecular analysis of cellular structure

Question 5

Histopathology

Answer 5

The study of tissues affected by disease

Useful in making a diagnosis and in determining the severity and progression of a disease

Question 6

Epithelial tissue

Answer 6

Is made of cells arranged in a continuous sheet with one or more layers; has apical & basal surfaces

A basement membrane separates the epithelial layer from the underlying connective tissue

Two types of epithelial tissues: 1) Covering & lining epithelia; 2) Glandular epithelium (endocrine and exocrine)

The number of cell layers & the shape of the cells in the top layer are used to classify epithelium

Question 7

Epithelial tissue classification

Answer 7

Number and distribution of cell layers

Simple Epithelium - one cell layer.

Stratified Epithelium - two or more cell layers.

Pseudostratified Epithelium - cells are all anchored to the basement membrane (i.e. one cell layer) but not all cells reach the apical surface (nuclei do not align, does not look like one cell layer).

Shape of the top layer of cells
Cuboidal, columnar, squamous

Question 8

Connective tissue

Answer 8

There are two main groups: 1) Connective tissue proper; 2) Specialised connective tissue.

Contains:

Many different cell types including: fibroblasts, macrophages, mast cells, and adipocytes.

Connective Tissue Matrix made of two materials: 1) ground substance - proteins and polysaccharides; 2) fibres – reticular, collagen and elastic

Question 9

Connective tissue classification

Answer 9

Loose Connective – fibres & many cell types in gelatinous matrix, found in skin & surrounding blood vessels, nerves and organs

Dense Connective – bundles of parallel collagen fibres & fibroblasts, found in tendons and ligaments

Question 10

Cartilage

Answer 10

Made of two main components: 1) collagen & elastin fibres embedded in a matrix of glycoproteins; 2) cells called chondrocytes. There are 3 types

Question 11

Hyaline cartilage

Answer 11

Weakest, most abundant type. Found at end of long bones, & structures like the ear and nose

Question 12

Elastic cartilage

Answer 12

Maintains shape, branching elastic fibers distinguish it from hyaline

Question 13

Fibrous cartilage

Answer 13

Strongest type, has dense collagen & little matrix, found in pelvis, skull & vertebral discs

Question 14

Bone

Answer 14

Composed of bone cells - osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts – suspended in a matrix consisting of collagen fibres and minerals

Question 15

Bone development can be

Answer 15

1) Membranous – as in flat bones, clavicle or mandible; 2) Endochondral – as in limb and vertebral column bones

Question 16

Mature bone may be

Answer 16

1) Compact – concentric circular layers (lamellae) organised in lacunae and a central canal (Harvesian system); 2) Trabecular – slender interlacing parallel lamellae with marrow within the spaces

Question 17

Skeletal muscle

Answer 17

Voluntary, striated, striations perpendicular to the muscle fibers and it is mainly found attached to bones.

Organized in myofibres with nuclei peripherally located. Forms a lined up banding pattern from one cell to another when observed longitudinally

Question 18

Cardiac muscle

Answer 18

Involuntary, striated, branched and has intercalated discs. Cells smaller than skeletal muscle with nuclei centrally located

Question 19

Smooth muscle

Answer 19

Involuntary, non-striated, spindle shaped and is found in blood vessels & the GI tract. Cells vary in size and have a fusiform shape. Nuclei observed in different positions

Question 20

Ectoderm

Answer 20

Develops into nervous tissue and epithelial tissue

Question 21

Mesoderm

Answer 21

Develops into epithelial tissue, connective tissue and muscle tissue

Question 22

Endoderm

Answer 22

Develops into epithelial tissue