Tissues of the Body

Question 1

Define Tissue

Answer 1

A collection of cells specialised to perform a specific function

Question 2

4 types of tissue

Answer 2

Epithelial, connective, muscle, nervous

Question 3

Define biopsy

Answer 3

Remove piece of tissue from organ/body part, for microscopic examination

Question 4

What type of biopsy for cervical cancer?

Answer 4

smear

Question 5

Biopsy for endometrial lining?

Answer 5

Curettage

Question 6

Biopsy for brain

Answer 6

Needle

Question 7

Biopsy for heart

Answer 7

Transvascular

Question 8

Biopsy for skin?

Answer 8

Direct incision

Question 9

Biopsy for gut

Answer 9

Endoscope

Question 10

Why fix tissues before using microscope?

Answer 10

Preserves structure (by forming cross links), prevents autolysis.
Use formaldehyde, may have artefacts

Question 11

Under a microscope, mucus in goblet cells is visible as a magenta colour.
Which stain was used?

Answer 11

Periodic-Acid-Schiff

Question 12

Which two stains are used to visualise elastic fibres?

Answer 12

Weigert’s Elastin and Elastic van Gieson

Question 13

H&E stain, what stains what?

Answer 13

Haemotoxylin - Acidic components such as nucleolus and DNA purple/blue

Eosin - Basic components such as ECM pink

Question 14

Whats the point of phase contrast and differential interference contrast microscopy?

Answer 14

Can visualise living cells

Question 15

Confocal microscopes use…

Answer 15

Fluorescent probes

Question 16

Types of simple ‘Epithelia’

Answer 16

simple squamous - kera: skin, non-kera: vagina
simple cuboidal - pancreatic duct, thyroid follicles
simple columnar - gall bladder, crypts of Lieberkuhn
pseudostratified - epididymis, trachea

Question 17

Types of stratified epithelia

Answer 17

Squa, cub, colum, transitional

Question 18

What is epithelia?

Answer 18

Sheets of contiguous cells with varied embryonic origins. Covers external surfaces and internal linings.

Question 19

Example of epithelia derived from ectoderm

Answer 19

Corneal epithelium, skin

Question 20

Example of epithelia derived from mesoderm

Answer 20

Endothelium and mesothelium, i.e. blood vessels, lymph vessels, pleura, genitourinary tract

Question 21

Example of epithelia derived from endoderm

Answer 21

Respiratory tract, gastrointestinal tract, liver, glands

Question 22

Define basement membrane and describe its structure

Answer 22

Thin, flexible, acellular layer between epithelial cells and connective tissue.
Epithelial cells lay down basal lamina, and the subtending connective tissue lays down the reticular fibres, hence can vary thickness of basement membrane.

Question 23

The epiglottis is an interesting structure in terms of its epithelia. What is so special about it?

Answer 23

One side is stratified squamous cells, the other is pseudostratified cells

Question 24

Where do we find umbrella-like cells that stretch and recoil?

Answer 24

Urothelium, and also blood vessels with connective tissue

Question 25

Rate of renewal of epidermis

Answer 25

28 days

Question 26

Rate of renewal of intestinal cells

Answer 26

4-6 days

Question 27

What is Marfan Syndrome?

Answer 27

A genetic disorder (Auto dom) in the fibrillin gene. Fibrillin is a glycoprotein found in microfibrils of extracellular matrix found in connective tissue. This makes the connective tissue of affected individuals abnormal, resulting in a number of peculiar symptoms: Tall, thin stature, flexible joints, scoliosis, and risk of aortic tear.

Question 28

List 4 types of connective tissue

Answer 28

Proper, adipose, bone, blood

Question 29

What are three features common to all connective tissue?

Answer 29

1) Originate from mesenchymal cells 2) Have different degrees of blood flow 3) Mostly extra-cellular matrix (non-living)

Question 30

What is ground substance?

Answer 30

Amorphous gel-like substance, with proteoglycans. These have protruding glycosaminoglycans that together form a structure that somewhat resembles a brush with bristles, and traps water.

Question 31

Most common loose connective tissue and where it is found

Answer 31

Areolar. (Has few fibroblasts, with a little elastic/collagen fibres here and there). Superficial fascia

Question 32

Reticular connective tissue

Answer 32

Like areolar but with reticular fibres (instead of elastin/collagen). Found in stroma of organs.

Question 33

Dense connective tissue types

Answer 33

1) Regular - collagen in parallel, tendons, ligaments and aponeurosis 2) Irregular - collagen in random arrangement, dermis of skin and deep fascia 3) Dense elastic - Increased elasticity vs rigidity. Vertebrae joints.

Question 34

Types of cartilage

Answer 34

Hyaline, Elastic, Fibro | Nose, Ears, Vertebrae