1.2 Tissues

Question 1

What are the 4 basic tissue types?

Answer 1

Nervous
Muscle
Epithelial
Connective

Question 2

What is connective tissue composed of

Answer 2

Made from cells surrounded by an extracellular matrix. The extracellular matrix is made of ground substance and protein fibres.

Question 3

How can connective tissue vary in terms of packing

Answer 3

It can be loosely packed (not many cells and lots of ECM) or tightly packed (lots of cells and not much ECM)

Question 4

What are the 3 types of protein fibre in the ECM of connective tissue

Answer 4

-collagen
-reticular
-elastic

Question 5

What are the properties of collagen fibres in ECM

Answer 5

-have variable thickness
-usually runs parallel
-makes dense connective tissue

Question 6

What are the properties of reticular fibres in ECM

Answer 6

-are a type of collagen with dark fibrils
-has a loose network that allows for molecular movement

Question 6

What are the properties of elastic fibres in ECM

Answer 6

-gives recoil
-is in distensible/contractile organs like lungs

Question 7

Give 4 functions of connective tissue

Answer 7

-structural support
-medium for exchange
-storage
-defence and repair

Question 8

Give an example of CT used for structural support

Answer 8

bones, ligaments, cartilage, tendons (all dense regular collagenous)

Question 9

Give an example of CT used for a medium of exchange

Answer 9

blood or the CT underlying the epithelium

Question 10

Give an example of CT used for storage

Answer 10

adipose (storing vitamins and fats) or bone (storing calcium and phosphate)

Question 11

Give an example of CT used for defence and repair

Answer 11

blood (WBCs) or blast cells

Question 12

What is the difference between fixed and transient connective tissue

Answer 12

Fixed connective tissue stays in place but transient moves areas of the body in response to stimuli

Question 13

Give some examples of fixed connective tissue

Answer 13

cartilage, tendons, bones, mast cells, pericytes, adipocytes

Question 14

Give some examples of transient connective tissue

Answer 14

leukocytes, monocytes, phagocytes, neutrophils, lymphocytes

Question 15

Give the properties of epithelial tissue

Answer 15

-avascular
-highly cellular sheet that covers surfaces
-one nucleus
-come from all 3 germ layers
-have a free apical surface and a basal surface, bot of which are different which makes the cells polar
-cells are bound to each other by junctions
-cells are regenerative

Question 16

Give 4 functions of epithelial tissue

Answer 16

-protection
-secretion
-absorption
-sensory detection

Question 17

Give an example of epithelial tissue used for protection

Answer 17

highly layered stratified squamous (often keratinzed) in skin and oesophagus

Question 18

Give an example of epithelial tissue used for secretion

Answer 18

stratified cuboidal for sweat and salivary glands

Question 19

Give an example of epithelial tissue used for absorption

Answer 19

in the intestine, simple columnar epithelial has microvilli to increase surface area

Question 20

Give an example of epithelial tissue used for sensory detection

Answer 20

olfactory epithelium in the nasal cavity is pseudostratified columnar

Question 21

What is nervous tissue composed of

Answer 21

Neurons (which are the functional unit) and glial cells

Question 22

What are the 3 types of muscle tissue

Answer 22

smooth, cardiac and skeletal

Question 23

Give some general properties of muscle tissue

Answer 23

-heavy and darker due to high protein content
-excitable, contractile, elastic and extensible

Question 24

Which of the 4 tissue types are excitable

Answer 24

Nervous and Muscle

Question 25

What stimuli can excite nervous and muscle tissue

Answer 25

neurotransmitters, hormones ,drugs, mechanical stimuli and external electrical impulses

Question 26

Describe the fixation stage in light microscopy

Answer 26

A neutral buffer is used to inactivate some enzymes so to prevent decay and keep the tissue life like

Question 27

Describe the dehydration and clearing stage in light microscopy

Answer 27

Removing water from the sample so it is easier to handle

Question 28

Describe the embedding stage in light microscopy

Answer 28

When liquid paraffin is injected into the sample then left to dry out, this hardens the sample

Question 29

Describe the sectioning stage of light microscopy

Answer 29

The sample is thinly sliced (15-50 micron length) and mounted on the slide

Question 30

What is hematoxylin and eosin staining

Answer 30

Hematoxylin stains the nucleus purple and eosin stains the cytoplasm pink/red

Question 31

What is silver staining

Answer 31

Targets proteins and nucleotides, turning them brown/orange

Question 32

What is masson trichome staining

Answer 32

A series of 3 stains that turns collagen blue/green, muscle fibres red and nuclei black

Question 33

What is periodic acid schiff staining

Answer 33

Stains polysaccharides red and purple

Question 34

What is wright and giemsa staining

Answer 34

Used on blood smears, stains RBCs pink/red, WBC nuclei purple and platelets light blue

Question 35

What is alcian blue staining

Answer 35

Stains acidic mucopolysaccharides (commonly found in in goblet cells, mucins, connective tissue tumours and cartilage) blue

Question 36

In what order would the procedure be to prepare a sample for microscopy.

Answer 36

Fixation, Dehydration, Embedding, Sectioning , Staining

Question 37

Give examples of the 3 types of collagenous connective tissue

Answer 37

dense regular - tendons and ligaments dense irregular - periosteum loose (areolar) - subcutaneous

Question 38

Give an example of a reticular connective tissue

Answer 38

lymph nodes and bone marrow

Question 39

Give an example of elastic connective tissue

Answer 39

lung walls