
Mucosa: Epithelium
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

Epithelium
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

- Enterocytes
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

- Microvilli
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

- Goblet cells
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

Lymphocytes and macrophages
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x

Lamina propria
The small intestine is lined by a simple columnar epithelium, primarily composed of absorptive enterocytes with microvilli. Scattered goblet cells with their expanded apical portions containing mucinogen are visible. Also present are lymphocytes, macrophages and microfold or M cells. M cells (not visible here) occur among the enterocytes, but lack microvilli; instead having microfolds of their apical surface membrane that endocytose antigens, transporting them to surveilling lymphoid tissue in the lamina propria beneath them. M cells are antigen delivery cells for initiating mucosal immune responses. 1000x