Microscopy And Movement

Question 1

What are the 5 ways to obtain a sample of an organ

Answer 1

Punch
Incisional
Excisional
Needle
Endoscopic
(All biopsies)

Question 2

What are the 3 different specimen types you can obtain

Answer 2

Whole organs/ surgical specimens
Organ samples (biopsies)
Fluid samples

Question 3

How would you prepare a slide of cells to be seen under a light microscope

Answer 3

Fresh tissue delicate and easily damaged
Stabilise/ fix tissue before cutting
Cut into thin slices

Question 4

How would you prepare a tissue sample to be seen under an electron microscope

Answer 4

Freeze tissue- easier to cut- less chance of damage
Infiltrate tissue with liquid that solidifies- paraffin sections
Resin embedding for hard materials like bone

Question 5

How are paraffin sections made (12 steps)

Answer 5

1. Fresh tissue fixed before processing- preserves tissue and protect against processing
2. Tissue put into formaldehyde solution from 6-24 hours
3. Specimens dehydrated by increasing conc. of ethanol- allow paraffin infiltration
4. Clearing agent to remove ethanol and fat- xylene
5. Wax infiltration- paraffin wax and additives- liquid at 60 degrees- solid at 20
6. Block formed after wax infiltration to allow sectioning
7. Placed into mould- filled with molten wax with histology cassette
8. Solidified with cold plate
9. Ribbons of sections cut on microtome- as thin as 2um
10. Flattened on warm water bath
11. Mounted on glass slide
12. Wax removed- dehydration reversed so can be stained

Question 6

Where are frozen sections mostly used

Answer 6

For kidney biopsies

Question 7

Why are frozen sections made instead of paraffin

Answer 7

If needed urgently- quicker process
If sample has high fat

Question 8

How is a frozen section made

Answer 8

1. Tissue froze rapidly at 150 degrees
2. Sections cut on special microtome in cryostat (refrigerated cabinet)

Question 9

What are the two methods used to stain tissues

Answer 9

Histochemical and immunohistochemical

Question 10

What is the most commonly used stain

Answer 10

Haematoxylin and eosin

Question 11

What colour is haematoxylin

Answer 11

Purple/blue

Question 12

What colour is eosin

Answer 12

Pink/ red

Question 13

What does haematoxylin stain

Answer 13

Acidic structure like DNA and RNA- nuclei

Question 14

What stain is used to see acidic structures like nuclei

Answer 14

Haematoxylin

Question 15

What does eosin stain

Answer 15

Stains basic structures like cytoplasm

Question 16

What stain would be used to see basic structures like cytoplasm

Answer 16

Eosin

Question 17

What does periodic acid-shiff stain

Answer 17

Carbohydrates like glycogen, basement membranes, goblet cells and fungi

Question 18

What stain would be used to see glycogen

Answer 18

Periodic acid-shiff

Question 19

What stain would be used to see goblet cells

Answer 19

Periodic acid-shiff

Question 20

What does elastic van Gieson stain and what colour do they appear

Answer 20

Connective tissues
Collagen- appears red
Nuclei- appears blue
Cytoplasm- appears yellow
Elastic fibres- appears brown

Question 21

What is elastic van gieson stain mostly used to see

Answer 21

Vessel structures and connective tissues

Question 22

What stain would we use to see connective tissues or vessels

Answer 22

Elastic van gieson

Question 23

What is immunohistochemistry

Answer 23

Antibodies are added to tissues to bind to their specific antigens
Antibodies have indicator attached- fluorescent or coloured product

Question 25

What 4 types of cells are specialised for movement of body tissues

Answer 25

Muscle cells Myoepithelial cells Myofibroblasts Pericytes

Question 26

Characteristics of skeletal muscle

Answer 26

Striated Responsible for voluntary movement and posture maintenance Referred to as muscle fibres- myofibres Up to 35cm in length Powerful contraction but quick to retire

Question 27

How are skeletal muscles structured

Answer 27

Into compartments/ groups of muscles with similar functions Muscle- fascicle- muscle fibre Each layer surrounded by connective tissue- fascia, epimysium, perimysium, endomysium

Question 28

What 4 connective tissues surround skeletal muscles

Answer 28

Fascia, epimysium, perimysium and endomysium

Question 29

What are the 3 compartments of the thigh and what action do they carry out

Answer 29

Anterior- extension Posterior- flexor Medial- adductor

Question 30

What are the 3 compartments of the leg and what action do they carry out

Answer 30

Anterior- dorsiflexor Posterior- plantarflexor Lateral- Evertor

Question 31

What tissue connects muscles to bones

Answer 31

Tendons

Question 32

Function of a tendon

Answer 32

Connects muscles to bones

Question 33

What is the cell membrane of a skeletal muscle fibre called

Answer 33

Sarcolemma

Question 34

What are contractile proteins arranged into

Answer 34

Myofibrils

Question 35

What are the two myofibrils- which one is thick- which ones thin

Answer 35

Actin- thin Myosin- thick

Question 36

What’s the cytoplasm if skeletal muscles referred to as

Answer 36

Sarcoplasm

Question 37

Where are nuclei located in skeletal muscle fibres

Answer 37

Located peripherally- close to the sarcolemma

Question 38

What are tendons composed of

Answer 38

Collagen fibres and fibroblasts

Question 39

Why do tendons take long to heal

Answer 39

Because they are poorly vascularised

Question 40

What are aponeuroses

Answer 40

Flat sheet-like tendon Provides strength and stability to the skeleton Attaches muscles to bones Attaches muscles to muscles

Question 41

What do aponeuroses do

Answer 41

They attach muscles to bones and muscles to muscles

Question 42

What does a ligament do

Answer 42

Connects bones to bones Increases joint stability

Question 43

Characteristics of a ligament

Answer 43

Flexible bands of collagenous tissue

Question 44

Where is smooth muscle found

Answer 44

Found in locations that require slow or rhythmic contractions Eg. Walls of hollow viscera like bowel, bladder or uterus Blood vessel walls Secretory gland ducts

Question 45

Are smooth muscle cells larger or smaller than skeletal muscle cells

Answer 45

Smaller

Question 46

Describe the structure of a smooth muscle cell

Answer 46

Spindle shaped Tapering at the ends Single, centrally placed nucleus Irregular branching fasiculi

Question 47

Where is the nucleus of smooth muscle cells located

Answer 47

Single nucleus, centrally placed

Question 48

How is smooth muscle contraction stimulated

Answer 48

By autonomic nervous system Neurohormones Conduction from adjacent cell

Question 49

What is the organisation of actin and myosin in smooth muscle

Answer 49

Crisscross cells

Question 50

What is cardiac muscle referred to as

Answer 50

Myocardium

Question 51

What type of muscle is cardiac muscle

Answer 51

Striated

Question 52

How many nuclei do cardiac muscle cells have

Answer 52

One- mononuclear

Question 53

Describe the structure of cardiac muscle

Answer 53

Mononuclear Ends of cells split into branches- connect network of myocytes Intercalated discs

Question 54

Characteristics of cardiac muscle

Answer 54

Not able to regenerate after damage- forms scar tissue Less powerful than skeletal muscle but more resistant to fatigue

Question 55

What are myoepithelial cells

Answer 55

Form secretory glands like breast tissue

Question 56

What is the function of myoepithelial cells

Answer 56

Expel secretions from glandular tissue

Question 57

What is the function of myofibroblasts

Answer 57

Repair defects resulting from tissue death Secrete collagen

Question 58

What is the function of pericytes

Answer 58

Surround blood vessels Help with tissue healing