FIGURE 2.1

Nuclei in liver cells stained blue within cytoplasm. Nuclei communicate with cytoplasm, and cells connect intimately with one another through a variety of cell junctions. (Confocal fluorescence microscopy.)

FIGURE 2.2

Mitochondria, visible as rod-like structures lying mostly around the nucleus, are demonstrated by a fluorescence technique. (Courtesy of Dr Rehab Al-Jemal.)

FIGURE 2.3

Lung alveolar epithelium. Nuclei are blue, flattened type 1 alveolar epithelial cells are green and type 2 cells are pink. The green and pink fluorescence depends on the expression of proteins specific to the different cell types identified by particular antibodies labelled with fluorescent dyes. (Courtesy of Dr Gareth Clegg.)

FIGURE 2.4

(A) Liver cells in culture. (B) After treatment with apoptosisinducing injury, one cell has become shrunken and blebbed before completely disintegrating into apoptotic bodies. In vivo these apoptotic bodies are rapidly phagocytosed.

FIGURE 2.5

Summary of mitosis.

FIGURE 2.6

Summary of meiosis.

FIGURE 2.7

The cell cycle. Cells start at rest in G₀ and cycle through to mitosis or meiosis. At a number of steps there are checkpoints where the cycle can be stopped. Failing to activate cycle checkpoints may contribute to mutagenesis, ultimately leading to cancer.

FIGURE 2.8

Apoptosis refers to the morphological form of individual cell death. It can occur as part of normal homeostasis in a variety of settings or as part of a disease. Programmed cell death, for example, when cells die during embryological development, usually occurs by apoptosis. HIV =  human immunodeficiency virus.

FIGURE 2.9

A slice of heart with the left ventricle to the left and right ventricle to the right. There is massive left ventricular hypertrophy. This occurs when an increased load is placed on the ventricle as in systemic hypertension or aortic valve stenosis.

FIGURE 2.10

Normal (lower) and hyperplastic (upper) adrenal glands from different patients. The increased size of the upper glands is due to the presence of increased numbers of glucocorticoid-producing cells in response to sustained stimulation by adrenocorticotropic hormone from a pituitary adenoma.

FIGURE 2.11

Atrophic (upper) and normal (lower) thyroid glands. The atrophy is the result of loss of normal thyroid tissue due to longstanding autoimmune disease.

FIGURE 2.12

Squamous metaplasia. The normal pseudostratified columnar lining of the bronchus has been replaced by stratified squamous epithelium as a consequence of chronic exposure to cigarette smoke. The black flecks among the submucosal inflammatory cells are particles of carbon from the inhaled smoke.

FIGURE 2.13

The typical immunoglobulin unit consists of two heavy (H) and two light (L) chains linked by disulphide bonds. The H and L chains both contribute to the antigen-binding site but the secondary properties reside in the H chain.

FIGURE 2.14

Major histocompatibility complex (MHC) class I and class II molecules present antigen on the cell surface as processed peptide. Class I MHC consists of an α chain and β₂ microglobulin, whereas class II consist of αβ heterodimers.

FIGURE 2.15

Double immunohistochemical staining of islets of Langerhans – insulin-producing cells brown, glucagon-producing cells blue. (A) is a normal islet and (B) from the pancreas of a patient with type 1 diabetes mellitus. There are virtually no surviving insulin-producing cells in (B).

FIGURE 2.16

In the glomerulonephritis associated with systemic lupus erythematosus there is deposition of complement-activating immune complexes – IgG illustrated by immunofluoresence (A), with consequent infiltration by inflammatory cells (B).