Histology Pracs Flashcards
Layers of the GIT from inside out?
Lumen, mucosa, submucosa, muscularis propria or externa, adventitia (outer layer merges with surrounding tissues) or serosa (covered by mesothelium in peritoneal cavity)
X= goblet cells
Y = regenerating stem cells
Z = muscularis mucosae
What type of collagen is the main componet of basement membranes
collagen IV
What does desmoplastic stroma do to the malignant tumour?
Fibroblast infliration due to TGF-B -> increased firmness of lesion
In a metastatic malignant epthelial cells are these up or down regulated?
E-cadherin expression
Surface integrins
metalloprotenases
VEGF factor
E-cadherin expression - down regulation
metalloprotenases - increased
VEGF factor - increased
Surface integrins - upregulated
Biochem level main regulator of cell cycle?
Phosphorylation
Gefitinib and Erlontinib are targeted therapies for selected cases of non-small cell lung carcinoma. What type of receptor do they target?
Receptor Tyrosine Kinase
What substances are tissues first placed in to presevre them for histological sections? how does it work?
Formalin
Formalin (formaldehyde) preserves tissue by cross-linking amino groups in proteins with nearby nitrogen atoms in protein or DNA.
Label:
mucosa
submucosa
muscularis propria. This layer is sometimes called the muscularis externa
serosa
yellow: mucosa
green: submucosa
blue: muscularis propria. This layer is sometimes called the muscularis externa
purple: serosa
Label: surface epithelium, glands (glandular epithelium), lamina propria, muscularis mucosae
green: surface epithelium
blue: glands (glandular epithelium) yellow: lamina propria
purple: muscularis mucosae
Which is basement membrane and which is muscularis mucosae? Blue or Black?
Basement membranes lie at the base of epithelia (black). The blue line here is located along the muscularis mucosae.
What type of cells are present in the epithelial layer of the mucosa of the small and large intestines?
Goblet cells, Enterocytes (absorptive cells in large intestine), Enteroendocrine (neuroendocrine) cells, stem cells and lymphocytes
Immune Cells in normal lamina propria?
eosinophils
plasma cells
dendrictic cells
Mast cells
Fibroblasts
Macrophages
Lymphocytes
Endothelial cells
Difference between serosa and adventitia of the GIT?
Serosa is connective tissue covered by a layer of simple squamous cells (known as mesothelial cells) which lines a cavity while adventitia is connective tissue which merges with surrounding tissues.
Which parts are normal mucosa?
muscularis propria?
region of tumour?
metastatic tumour in lymph and pericolonic adipose tissue?
yellow: normal mucosa
blue: normal muscularis propria
green: tumour
purple: lymph node containing metastatic tumour in the pericolonic adipose tissue
Factors relevant for determining Grade of a tumour?
Freq of mitotic figures in tumour cells
similarity of tumour cells to their normal counterparts
degree of variability of nuclear shape and size
What factors are relvant to the stage of a cancer?
metastases in lymph nodes
metastases in distant organs
size and depth of primary tumour