Description: Segment 1 Carr, seated, talks to camera. He introduces the macrophage and the four main points the lecture will cover: appearance of macrophages their location their function and their role. He shows three short film sequences of macrophage cells. The first shows the cells in action, the second shows them digesting carbon particles and the third shows a macrophage digesting in sequence, surrounded by dead cells. Carr then shows a series of electron micrographs detailing the ultrastructure of the macrophage. Time start: 00:00:00:00 Time end: 00:06:24:20 Length: 00:06:24:20 Segment 2 Carr continues to look at electron micrographs showing the ultrastructure of the macrophage. He describes the structure and appearance of macrophage cells in detail, pointing out their vesicles, granules and microtubules, amongst other things. Time start: 00:06:24:20 Time end: 00:09:50:00 Length: 00:03:25:05 Segment 3 Carr shows a diagram of a human body marked to show where macrophages are most likely to be located. This is followed by a series of diagrams focusing on different organ locations of macropahges. He gives, throughout, detailed descriptions of how macrophages function in these various locations. Carr shows an animated illustration of a dendritic reticular cell which is home to a particular kind of macrophage cell he describes this and goes on to describe other less common types of macrophage. Time start: 00:09:50:00 Time end: 00:15:38:00 Length: 00:05:48:00 Segment 4 Carr shows an animated diagram detailing the origin and circulation of the macrophage. He explains how they are usually of bone marrow origin but can also arise from cell division in other locations. He shows an electron micropraph of a macrophage with a broken nuclear membrane, revealing the dividing cell. He then shows an illustration and an electron micrograph of pinocytosis (cell digestion) occurring in a macrophage. He explains in detail the process of phagocytosis, the most common way in which macrophages digest other cells or foreign materials. Time start: 00:15:38:00 Time end: 00:20:47:00 Length: 00:05:09:00 Segment 6 Carr shows a micrograph of a multinucleate giant cell (a cell seen in the early acute stage of an infection) and describes how macropahages attack these. He then refers to illustrations of different cell types and describes their interaction with macrophage cells. Time start: 00:26:26:00 Time end: 00:29:55:15 Length: 00:03:29:15. Segment 7 Carr talks about how macrophages are involved with iron metabolism he shows a micrograph of a splenic sinusoid deforming red blood cell - the sort of cell which might lead to anaemia due to lack of iron. He describes how macrophages, in contrast, are key to the transfer of iron from iron stores in the body, to the marrow. Carr describes further functions of the macrophage such as how they interact with human carcinomas. Carr summarises the lecture with a table showing the biological significance of macrophages. Time start: 00:29:55:15 Time end: 00:37:16:10 Length: 00:07:20:20