Session 1 Flashcards
Define tissue
A collection of cells specialised to perform a particular function.
Aggregations of tissues constitute organs.
Define biopsy
The removal of a small piece of tissue from an organ or part of the body for microscopic examination.
What is a smear biopsy?
Collect cells by spontaneous/mechanical exfoliation. Smear on slide.
When are smear biopsys used?
Cervix, buccal cavity.
What is a Curettage biopsy?
Remove tissue by scooping/scraping.
When is a Curettage biopsy used?
Endometrial lining of uterus
What is a needle biopsy?
Put needle into tissue to gather cells.
When is a needle biopsy used?
Brain, breast, liver, kidney, muscle.
What is a direct incision biopsy?
Cut directly into tissue of interest and remove tissue.
When is a direct incision biopsy used?
Skin, mouth, larynx.
What is an endoscopic biopsy?
Removal of tissue via instruments through an endoscope.
When is an endoscopic biopsy used?
Lung, intestine, bladder.
When is transvascular biopsy used?
Heart, Liver
Define fixed biopsy
Macromolecules cross-linked, cellular structure preserved, no autolysis or putrefaction.
Commonly used fixatives include glutaraldehyde and formaldehyde.
Define Shrinkage artifacts
Abnormalities on the final slide due to preparation process involving dehydrated and then rehydrated.
How does Haematoxylin and Eosin (H&E) work?
Haematoxylin stains acidic components of cells, eg Nucleolus (RNA), Chromatin (DNA) purple/blue.
Eosin stains basic components of cells, eg most cytoplasmic proteins and extracellular fibres pink
How does Periodic Acid-Schiff (PAS) work?
Stains carbohydrates and glycoproteins magenta.
What is phase contrast microscopy?
Uses interference effects of two combining light waves
What is the advantage of phase contrast microscopy?
Enhancing the image of unstained cells
What is dark field microscopy?
Exclude unscattered beam (light/electron) from the image
What is the advantage of dark field microscopy?
Live an unstained samples
What is fluorescent microscopy?
Target molecule of interest with fluorescent Ab
What is the advantage of fluorescent microscopy?
Use multiple different fluorescent stains on one specimen
What is Confocal microscopy?
Tissue labelled with one or more fluorescent probes.
What is the advantage of Confocal microscopy?
Eliminates “out of focus flare”, 3D from a series of 2D images, imaging of living specimens.
What does the Ectoderm become?
Epidermis
Corneal epithelium of eye
What does the Mesoderm become?
Epithelium of UG tract
Vessel lining
Pericardial/Pleural sac lining
What does the Endoderm become?
Epithelia of respiratory tract
Epithelia of GI
Epithelia of Liver & glands
Where are simple squamous epithelia found?
Lining of vessels Lining of cavities Respiratory Bowmans capsule Inner ear
What is simple squamous function?
Lubrication
Gas exchange
Barrier
Where are simple cuboidal epithelium?
Thyroid follicles
Small ducts of many exocrine glands
Kidney tubules
Surface of the ovary
What is simple cuboidal function?
Absorption, conduit, secretion, barrier, hormone synthsis/storage
Where are simple columnar epithelium?
Stomach lining & gastric pits Small intestine & colon Gallbladder Large ducts of some exocrine glands Uterus Oviducts Ductuli efferents of testis
What is simple columnar function?
Absorption
Secretion
Lubrication
Transport
Where is pseudostratified epithelium?
Lining of nasal cavity, trachea and bronchi (URT)
Epididymis and ductus deferens
Auditory tube and part of tympanic cavity
Lacrimal sac
Large excretory ducts
What is pseudostratified epithelium function?
Secretion, conduit, absorption, mucus secretion, particle trap/removal
Where is stratified squamous non keratinized epithelium?
Oral cavity Oesophagus Larynx Vagina Part of anal canal Surface of cornea Inner surface of eyelid
What is the function of stratified squamous non keratinized epithelium?
Protection against abrasion (all sites)
Reduces water loss whilst remaining moist
Where is stratified squamous keratinized epithelium?
Surface of skin
Limited distribution in oral cavity
What is the function of stratified squamous keratinized epithelium?
Protection against abrasion and physical trauma
Prevents water loss
Prevents ingress of microbes
Shields against UV light damage
Where is stratified transitional epithelium?
Renal calyces (singular = calyx)
Ureters
Bladder
Urethra
What is the function of stratified transitional epithelium?
Distensibility
Protection of underlying tissue from toxic chemicals
What is the structure of the basement membrane?
It consists of a basal lamina, which is laid down by the epithelial cells and therefore lies closest to them.
Thickness can be increased by reticular fibrils (type III collagen) elaborated by the subtending connective tissue.
What is the function of the basement membrane?
It serves as a strong flexible layer to which epithelial cells adhere. It also serves as a cellular and molecular filter.
The degree to which malignant cells penetrate basement membrane is highly relevant to prognosis.*Think neoplasms
Define microvilli
Apical extensions that greatly increase the surface area for selective absorption of intestinal contents.
Define cillia
Extensions from cells that beat in coordinated waves. Found in the lining of the trachea where they sweep mucus and dirt out of the lungs. Also found in the fallopian tubes, where they move the ovum from the ovary to the uterus. 9+2 configuration.
Define Stereocilia
Very long microvilli, extend from the surface of the ductus deferens and the Epididymis. They may have an absorptive function
