2) Examining Cells & Tissues

Question 1

What is a tissue?

Answer 1

A collection of specialised cells

Question 2

What are the 4 broad classificationns of tissue?

Answer 2

Epithelial
Connective
Muscle
Nerve

Question 3

What are epithelial tissues?

Answer 3

Tissue found on the surface of all cells, often on the edge of other tissue and surrounding other cells.
Can be tissues found in clusters within other tissue (glands)

Question 4

Describe 5 features of epithelial tissue

Answer 4

Polarised when at the surface
Have a basement membrane on the basal
Often secret substances from the apical surface
Held together by strong anchoring proteins
Communicate via junctions on the basal and lateral surfaces

Question 5

What is a basement membrane made up of?

Answer 5

Basal laminar

Reticular lamina

Question 6

What is often screted from the apical surface and why?

Answer 6

Sugars, as they attract water which will prevent the cells from drying up

Question 7

What is glycocaylx?

Answer 7

Sugar that surrounds the cell membrane to prevent it from drying up by attracting water

Question 8

What is connective tissue?

Answer 8

Tissue consisting of cells and extracellular proteins/glycoproteins and gels

Question 9

What are the 4 main cell types found in connective tissue?

Answer 9

Fibroblasts
Chondrocytes
Osteoblasts/osteoclasts/osteocytes
Stem cells/progenitor cells/bone marrow/blood/adipocytes

Question 10

What is each connective tissues main cell type associated with?

Answer 10

Fibroblasts - tendons & ligaments
Chondrocytes - cartilage
Osteocytes/osteoblasts/osteoclasts - bone
stem cells/bone marrow/blood/progenitor cells/adipocytes - making all cells/making blood/substance transport/repair of cells/sock absorbing & heat retention

Question 11

What are the main compounds of connective tissue?

Answer 11

Fibres
Ground substance
Wax & gel-like materials

Question 12

What is nerve tissue?

Answer 12

Neurones and several support cells

Question 13

What is the main function of nerves?

Answer 13

Fast communication in the body

Question 14

Describe the structure of a spinal nerve

Answer 14

Epineurium (Outer connective tissue layer)
Perineurium (Surrounds the fasicle)
Fasicles (nerve fibre made from a cluster of nerve cells)
Endoneurium (individual neurones within the fasicle)`

Question 15

What is muscke tissue?

Answer 15

Tissue consisting of muscle cells

Question 16

What are the 3 main muscle cells?

Answer 16

Cardiac
Skeletal
Smooth

Question 17

Which of the main muscle cells are striated?

Answer 17

Skeletal

Cardiac

Question 18

What is the main function of muscle cells?

Answer 18

Contraction

Question 19

Why is contraction important?

Answer 19

Movement of the organism
Stability of the organism, organs & tissues by holding organs & blood vessels in the correct orientation
Movement of tissue contents (e.g. peristalsis - movement of gut contents)

Question 20

What is the minor function of muscle tissue?

Answer 20

Hormone secretion

Question 21

What is the limit of resolution?

Answer 21

The smallest distance 2 objects can be separated and still be distinguishable as 2 separate objects

Question 22

What energy source does a ligth microscope use?

Answer 22

Uses light that is transitted through the specimen

Question 23

What energy source does a ligth microscope use?

Answer 23

Uses light that is transitted through the specimen and the image is observed on a projector

Question 24

What energy source does an electron microscope use?

Answer 24

Electrons are fired onto a specimen but bounce off onto an electron detector

Question 25

Name advantages of a light microscope

Answer 25

Easy to prepare and use
Cheap
Displays images in natural colour
Large field of view
Can view living and moving objects

Question 26

Name disadvantages of alight microscope

Answer 26

Low resolution

Low magnification

Question 27

Name advantages of an electron microscope

Answer 27

High resolution

High magnification

Question 28

Name disadvantages of an electron microscope

Answer 28

Can only view images in monochrome colours
Can only view dead and inert objects
Expensive
Difficult to prepare
limited field of vision

Question 29

How does freeze fracture electron microscopy work?

Answer 29

The sample is frozen to -160 and is the hit with a sharp knife edge which fractures the sample through the plasma membrane exposing its interior

Question 30

How does a scanning electron microscope work?

Answer 30

The electrons are reflected back from the sample surface and received by a cathode ray tube

Question 31

What considerations mus be taken into account when preparing a light microscope slide?

Answer 31

Preserving the tissue to prevent putrification
Embeding the tissue in a substance that allows it to be thinly cut
Staining the tissue so that all the cells components can be seen

Question 32

What does only haematoxylin stain?

Answer 32

nucleus blue

Question 33

What does only eosin stain?

Answer 33

cytoplasm & extracellular matrix pink

Question 34

What does haematoxylin & eosin stain?

Answer 34

nuclei (darker purple) & cytoplasm purple

Question 35

What is stained red in Masson’s trichrome?

Answer 35

keratin & muscle fibre

Question 36

What is stained blue and green in Masson’s trichrome?

Answer 36

Collagen & bone

Question 37

What is stained light pink in Masson’s trichrome?

Answer 37

Cytoplasm

Question 38

What is stained dark brown/black in Masson’s trichrome?

Answer 38

nuclei

Question 39

What is stained in Period Acid-Schiff stain?

Answer 39

Glycocalyx - anything with a protein attached to it

Question 40

What are the different methods of aquiring tissue?

Answer 40

Endometrial biopsy
Endometrial curettage
Pipelle
Hysterectomy