Pathology 1: role of pathologist and functional histology Flashcards
What is pathology?
- Pathology = the study of disease
What is the difference between a histopathologist and a cytopathologist?
- Histology = the study of tissue and histopathologists study diseases in tissue biopsies, usually using a light microscope
- Cytology = the study of cells and cytopathologists study cells from fluids scrapings/brushings or from fine needle aspirates
How do you distinguish a benign cell from a malignant cell?
- Malignant cells have high nuclear to cytoplasmic ratios, irregular nuclear membranes and an irregular distribution of chromatin within the nucleus
- Benign cells have low nuclear to cytoplasmic ratios, smooth nuclear membranes and evenly distributed chromatin
Into what medium do you place a biopsy for histopathological assessment?
- Tissue biopsies are placed in formalin (a mixture of formaldehyde and saline)
What happens to tissue if you do not do place it in formalin?
- The tissue will rot and will not be able to be examined
- Formalin crosslinks proteins within the tissue stopping its breakdown
What is the stain used most commonly in histopathology?
- H+E (Haematoxylin and Eosin)
- Haematoxylin stains nuclei blue and eosin stains cytoplasm pink
Which cell produces collagen which makes some tumours feel hard on palpation?
- Fibroblasts produce collagen around tumours
- Collagen is a protein which makes tumours and scar tissue hard to palpation
What is the difference between a transudate and an exudate?
- Transudate = a fluid which is low in protein (eg. a pleural effusion caused by heart failure)
- Exudate = a fluid which is high in protein (eg. an effusion caused by infection or malignancy)
What is an adenocarcinoma?
- Adenocarcinoma = a malignant epithelial tumour showing gland formation (glandular differentiation)
What is immunohistochemistry?
- Immunohistochemistry is the application of labelled antibodies to tissue slides in order to detect the presence of certain antigens of interest within the nucleus, cytoplasm or membranes of cells.
- This technique is used to tell pathologists where a tumour has come from or the cell type which is present or what receptors a tumour is expressing.
Role of pathologist quiz Q1…
Answer: cytopathologist
Role of pathologist quiz Q2…
Answer: radiologist, surgeon, clinical nurse specialist, pathologist
Role of pathologist quiz Q3…
Answer: False
Role of pathologist quiz Q4…
Answer: Haemotoxylin and Eosin (H+E)
Role of pathologist quiz Q5…
Answer: image shows correct matches
Role of pathologist quiz Q6…
Answer: third option
What is gastrulation?
- The formation of the 3 germ cell layers in the embryo (ectoderm, mesoderm and endoderm)
List some examples of mature tissues which derive from ectoderm.
- Skin, nerves, eyes and ears, adrenal, medulla and pituitary gland
List some examples of mature tissues which derive from mesoderm.
- Muscle, bone + cartilage, heart + blood vessels, the urogenital system, bone marrow, the lymphatic system and the adrenal cortex
List some examples of mature tissues which derive from endoderm.
- Lining of the gastrointestinal (GI) and respiratory tracts, GI organs (liver + pancreas), larynx, trachea, lungs, thyroid gland, parathyroid glands and thymus
What epithelium covers the skin?
- Stratified squamous keratinising epithelium forms the epidermis of the skin.
Structure of keratin (keratin makes up hair, nails, outer layer of skin)…
What happens to the surface keratin layer of the skin in psoriasis?
- In psoriasis there is an increased rate of epidermal turnover and this causes the keratin layer to get thickened
- Normal keratin has a basket-weave pattern with no nuclei visible but in psoriasis this basket weave is lost, the keratin layer is thickened and nuclei are retained in this layer because the keratinocytes do not have time to fully mature
Which structures provide strong adhesion between keratinocytes in the epidermis?
- Desmosomes
- (image shows desmosomes structure and seen as ladders between the keratinocytes in bottom image)