ToB

Question 0

Define histology

Answer 0

The study of tissue using special stains and electron/light microscopy

Question 1

Define tissue

Answer 1

A collection of cells specialised to perform a function

Question 2

Why is histology important clinically?

Answer 2

Histology and biopsy are often needed for definitive proof of a diagnosis such as Crohn’s or cancer

Question 3

Define biopsy

Answer 3

The removal of a piece of tissue for study under a microscope

Question 4

What is a smear biopsy and what is it used for?

Answer 4

Collect cells by exfoliation and smear on slide. Used for cervix or buccal cavity

Question 5

What is curettage and what is it used for?

Answer 5

Scrape cells. Endometrial lining of the uterus

Question 6

What is a needle biopsy and what is it used for?

Answer 6

Inserting a needle into the tissue to remove the cells. Brain, breast, kidney, liver and muscle.

Question 7

What is direct incision and what is it used for?

Answer 7

Cut directly in and remove tissue. Skin, larynx, mouth

Question 8

What is endoscopic biopsy and what is it used for?

Answer 8

Removal of tissues using an endoscope. Lung, intestine, bladder

Question 9

Name 2 commonly used fixatives

Answer 9

Formaldehyde and glutaraldehyde

Question 10

How can shrinkage artefacts be formed?

Answer 10

During tissue preparation it is dehydrated and rehydrated which can lead to abnormalities

Question 11

What is stained by Haematoxylin and eosin?

Answer 11

H stains acidic parts blue (nucleus)

Eosin stains basic parts pink (cytoplasmic proteins and extra cellular fibres)

Question 12

What is stained by periodic acid schiff?

Answer 12

Stains carbohydrates and glycoproteins magenta (mucous goblet cells)

Question 13

What is phase contrast and the advantage it gives?

Answer 13

Interference of 2 light waves to see an untainted sample

Question 14

What is dark field and the advantage of it?

Answer 14

Exclude unscattered light/electrons from the image. Can be used on live and untainted samples

Question 15

What is fluorescence and the advantage of it?

Answer 15

Tag target molecule with fluorescent stain. Can use multiple stains

Question 16

What is confocal and what is the advantage of it?

Answer 16

Label tissue with fluorescent probes. Can make a 3D image from a series of 2D images. Use on living samples. Removes out of focus flare

Question 17

Define epithelia

Answer 17

Sheets of contiguous tissue of varied embryonic origin that cover external surfaces and line internal surfaces of the body

Question 18

What are the different types of epithelia?

Answer 18

Simple/stratified squamous, columnar, cuboidal. Pseudostratified. Transitional

Question 19

Location and function of simple squamous?

Answer 19

Blood vessels (endometrium), lining body cavities (mesothelium) alveoli, bow and capsule and loop of henle. Lubrication, gas exchange, barrier

Question 20

Location and function of simple cuboidal

Answer 20

Thyroid follicles, exocrine glands, kidney tubules and ovaries. Absorption, secretion, barrier and synthesis of hormones

Question 21

Location and function of simple columnar?

Answer 21

Stomach, small intestine, gall bladder, uterus, large exocrine glands. Absorption, secretion, transportation, lubrication. Note - can have micro villi

Question 22

Location and function of pseudostratified?

Answer 22

Trachea, bronchi, nasal cavity, epididymis. Secretion, absorption, trapping small particles

Question 23

Location and function of stratified squamous keratinised.

Answer 23

Skin, oral cavity. Protect against water loss, abrasion and microbes

Question 24

Location and structure of non keratinised stratified squamous

Answer 24

Oesophagus, vagina, anal cavity, cornea, inner eyelid, larynx. Protect against abrasion and water loss

Question 25

Location and function on transitional epithelium

Answer 25

Ureters, bladder, urethra. Distensibility, protect underlying tissue from toxic substances

Question 26

What is the position, structure and function of the basement membrane

Answer 26

Layer between epithelium and connective tissue. Consists of basal lamina and collagen. Serves as filter and strong layer for epithelium to adhere to

Question 27

Rate of renewal of skin?

Answer 27

28 days

Question 28

Rate of renewal of small intestine epithelia

Answer 28

4-6 days

Question 29

Define glands

Answer 29

An epithelial cell or collection of cells specialised for secretion

Question 30

How can you classify glands by destination of secretion?

Answer 30

Endocrine (directly into the blood) and exocrine (into ducts)

Question 31

How can you classify glands by their structure?

Answer 31

The secretory part can be unicellular or multicellular. They can also be coiled or branched. If multicellular gland branches it is complex, if it doesn't branch it is simple.

Question 32

How can you classify glands by nature of secretion?

Answer 32

Either serous (watery secretion) or mucous.

Question 33

How can you classify glands by the method of secretion?

Answer 33

Holocene, apocrine or merocrine

Question 34

What is merocrine secretion and give an example of glands that do it?

Answer 34

Exocytosis - vesicles containing the substance fuses to the membrane and releases its contents. Plasma membrane becomes slightly larger E.g. Salivary glands and pancreas

Question 35

What is apocrine secretion and what glands use it?

Answer 35

The substance is draped in cytoplasm and surrounded by the cell membrane before pinching off. Membrane becomes slightly smaller E.g. Mammary gland

Question 36

What is holocrine secretion and name a gland that does it?

Answer 36

Cell disintegrates releasing contents | E.g. Sebaceous gland

Question 37

Describe endocytosis and how, when combined with exocytosis, it gives transepithelial transport

Answer 37

Opposite of exocytosis, material is engulfed by the cell. Then moves the length of the cell before being released by exocytosis

Question 38

Where and why does glycosylation occur?

Answer 38

N linked in ER. O linked in Golgi. Makes a cell more specifi

Question 39

What do mucous membranes consist of and where are they found?

Answer 39

Mucus secreting cells, epithelium, lamina propria (CT) and in alimentary track smooth muscle (muscularis mucosae). Found in alimentary, respiratory and urinary tract.

Question 40

What do serous membranes consist of and where are they found?

Answer 40

Serous fluid secreting cells, simple squamous epithelium (mesothelium) and connective tissue. Found in peritoneum (abdomen) pleural sacs (lungs) and pericardial sac (heart)

Question 41

Define the limit of solution

Answer 41

Minimum distance two objects can be distinguished at