TOB S1 - Light Microscopy and Epithelia Flashcards Preview

ESA1 Callum's cards > TOB S1 - Light Microscopy and Epithelia > Flashcards

Flashcards in TOB S1 - Light Microscopy and Epithelia Deck (49):
1

What is meant by the term tissue?

A collection of cells specialised to perform a particular function

2

Why is histology valuable to diagnosing disease?

The study of tissues can reveal and be final proof of a range of diseases
Eg cancer

3

What is a smear and what tissues can it be used to sample?

Collection of cells via spontaneous/mechanical exfoliation, then smeared on slide

Cervix or buccal cavity

4

What is Curettage and what tissues can it be used to sample?

Removal of tissue via scooping or scraping

Endometrium of uterus

5

What is Needle biopsy and what is it used to sample?

Needle used to gather cells

Brain, kidney, muscle, breast, liver

6

What is direct incision biopsy and what tissues is it used to sample?

Cut into and remove tissue

Skin, larynx, mouth

7

What is Endoscopic biopsy and what tissues can it be used to sample?

Removal via endoscope instrument

Lung, intestine, bladder

8

What tissues can trans vascular biopsy be used to sample?

Heart, liver

9

Why does biopsied tissue require fixation?

Preserves cellular structure by cross linking macromolecules

No autolysis or putrefaction

10

Commonly used fixatives for tissue include?

Glutaraldehyde, formaldehyde

11

Why do shrinkage artefacts arise in preserved tissues?

Dehydration and rehydration during fixing

12

Why is histological staining useful?

Different types of tissue can be stained different colours/shades to allow differentiation between them

13

Haemotoxylin staining is taken up by _________

Acidic components of cells eg Nucleolus or chromatin

14

What colour is conferred onto tissue that take up haemotoxylin?

Purple/blue

15

Eosin staining is taken up by ________

More basic components of cells eg most cytoplasmic proteins and extra cellular fibres

16

Eosin staining confers what colour?

Pink

17

Periodic acid schiff (PAS) stains what cellular components what colour?

Carbohydrates, glycoproteins

Magenta

18

What is Phase contrast microscopy and what advantages does it have?

Uses interference of two combined light waves

Enhances un-stained cell image

19

What is dark field microscopy and what advantages does it have?

Uses light not directly aimed at objective lens

Enhances contrast in un-stained samples

20

What is confocal microscopy and what advantages does it have?

Tissue labelled with fluorescent probes

Can be used to generate a 3D image from a series of 2D images

21

Define epithelia

Sheet of contiguous cells of varying embryonic origins that cover external and internal surface of the body

22

What external or internal opening to external space does epithelia cover?

Skin
Alimentary tract
Respiratory tract
Genitourinary tract

23

What interior spaces that don't open to exterior are covered by epithelium?

Pericardial sac
Pleural sac
Peritoneum
Blood vessels
Lymphatic vessels

24

Where can simple squamous epithelium be found?

Lining the blood vessels (endothelium)
Lining of body cavities (mesothelium)
Alveoli
Inner and middle ear
Bowman's capsule and Loop of Henle in the kidney

25

Functions of simple squamous epithelia include?
Relate this to location

Lubrication (visceral linings)
Gas exchange (alveoli)
Barrier (Bowman's capsule)
Active transport via pinocytosis (meso/endothelium)

26

Where are simple cuboidal epithelia found?

Thyroid follicles
Ducts of exocrine glands
Kidney tubules
Surface of ovary (germinal epithelium)

27

Function of simple cuboidal epithelia include?
Relate this to location

Absorption and conduit (exocrine glands)
Absorption and secretion (kidney tubules)
Barrier (ovary)
Hormone synthesis, storage and mobilisation

28

Simple columnar epithelium are found where?

Stomach lining
Small intestine and colon
Gallbladder
Large ducts of exocrine glands
Uterus
Oviducts
Ductili efferents of testis

29

Functions of simple columnar epithelia include?
Relate this to location

Absorption (intestines and gallbladder)
Secretion (stomach lining, gastric pits, intestines)
Lubrication (small intestine and colon)
Transport (oviducts)

30

Pseudo stratified epithelia is found where?

Lining of nasal cavity, bronchi and trachea
Epididymis and ductus deferens
Auditory cavity and part of tympanic cavity
Lacrimal sacs
Large excretory ducts

31

Functions of pseudo stratified epithelia include?
Relate this to location

Secretion and conduit (upper resp tract and ductus deferens)
Absorption (epididymis)
Mucus secretion (URT)
Particle trapping and removal (URT)

32

Stratified squamous non keratinised epithelia can be found where?

Oral cavity
Oesophageal
Larynx
Vagina
Part of anal canal
Surface of cornea
Inner surface of eyelid

33

Functions of stratified squamous non keratinised epithelia include?
Relate this to location

Protection against abrasion (all sites)
Reduces water loss while remaining moist.

34

Stratified squamous keratinised epithelia can be found where?

Surface of skin
Limited distribution in oral cavity

35

Functions of stratified squamous keratinised epithelia include?
Relate this to location

Protection from abrasion and trauma
Prevents water loss
Prevents ingress of microbes
Shields from UV damage
(All sites)

36

Stratified transitional epithelia (urothelium) found where?

Renal calices
Ureters
Bladder
Urethra

37

Functions of stratified transitional epithelia include?Relate this to location

Distension
Protection from toxic chemicals
(All sites)

38

Where would you find a basement membrane?

Between epithelia and subtending tissues

39

Describe a basement membrane

Consists of basal lamina
Thickness variable with introduction of type III collagen
Thin, flexible and acellular

40

Function of basement membrane?

Epithelium adheres to it
Cellular and molecular filter (prevents malignant ingress through it)

41

Epithelial cell renewal rate can be described as?

Constant rate for different epithelia

42

Rate of renewal for skin epithelium?

28 days

43

Rate of renewal for small intestine epithelia?

4-6 days

44

Epithelia renewal can be triggered by?

Damage or trauma

45

Epithelial regeneration rate depends on?

Location and function

46

What are microvilli and what is their function?

Apical extensions to increase surface area of intestinal epithelium
Increase surface area for selective absorption

47

What are stereo cilia and what is their function??

Very long microvilli found in Ductus deferens and epididymis
May have absorptive function

48

What are cilia and where are they found? What do they do?

Apical cell extensions on respiratory epithelia and in oviducts
Beat in waves
Sweep mucus and dirt out of respiratory tract
Move the ovum down the oviduct
Feature the 9+2 micro tubule configuration.

49

What is the purpose of microvilli occludin in simple columnar epithelia?

Creates the zona occludens
Binds the cells together tightly in apical portion of cells, restricts proteins to either basal or apical surfaces