Tissues

Question 1

Tight Junctions

Answer 1

(zonula occludens)
- occluding junctions
- tightly bound at apical regions
- transmembrane proteins; OCCLUDINS & CLAUDINS
- claudin-1 waterproofing of skin
- claudin-16, kidney permeability to Mg2+

Question 2

Zonula adherens

Answer 2

• anchoring
• strengthens cell attachments at apical region
• links cytoskeletons of cells(actin myofilaments).
• E-CADHERINS
• loss of e-caherins associated with cancer metastisis

Question 3

Desmosomes

Answer 3

• anchoring
• firmly anchors neighboring cells together
• link cytoskeletons of adjacent cells
  conencts to cytokeratin
• CADHERINS such as desmoglein
• autoimmune attack on desmoglein-3 resoults in skin sloughing off

Question 4

Hemidesmosomes

Answer 4

• anchoring
• anchors cell to basement membrane
• modified desmosomes; bind cells to basement membrane.
• bind to cytokeratin
• INTEGRINS

Question 5

Gap junctions

Answer 5

• communicating
• open channels between cell’s cytoplasm
• CONNEXINS

Question 6

hyperplasia

Answer 6

increase in size of tissue/organ
caused by increased cell reproduction rate

adaptation
- breast epithelial tissue changes during pregnancy
pathology
- oestrogen-secreting ovarian tumour causing endometrial cell proliferation

Question 7

Hypertrophy

Answer 7

increase in size of tissue/organ
caused by increase of cell size

adaptation
- breast epithelial tissue changes during pregnancy

Question 8

tissue/cell atrophy

Answer 8

decrease in size

Question 9

metaplasia

Answer 9

reversible transition of a mature cell from one cell type to another

pathology
- transitional epithelium —> strat squam due to bladder stones
- cilia colum epi bronchi –> strat squam due to cigarette smoke
- barrett’s oesophagous squamous –> columnar with goblet

Question 10

dysplasia

Answer 10

presence of abnormal type of cells

pathology
- sunburn
- cervial dysplasia

Question 11

neoplasia

Answer 11

new, uncontrolled cell growth

cancer
- cervical neoplasm
- cancer

Question 12

epithelial tumours

Answer 12

benign:
- squamous & transitional cell papilloma
- renal, thyroid, or hepatic adenoma

malignant
- squamous or transitional cell carcinoma
- thyroid, renal or hepatic adenocarcinoma

Question 13

Connective tissue proper; types

Answer 13

loose;
- areolar(cushioning, lamina propria)
- reticular(supports organs)
- adipose(fat; white or brown)

dense
- regular(parallel fibers)
- irregular(random fibres)

Question 14

Cartilage types

Answer 14

Hyaline
- smooth, translucent
- little collagen
- eg. end of bones, tracheal rings

Fibrocartilage
- lots of collagen
- eg. cartilaginous joints, menisci

Elastic
- elastin and collagen
- eg. ear

Question 15

Bone

Answer 15

• collagen in ECM
• calcification
• cancellous or compact.

Question 16

ECM components

Answer 16

ground substance;
- glycosaminoglycans(GAGs/unbranching polysaccharides, e.g. hyaluronic acid)
- proteogycans - covalently bound to GAGs

fibrillar proteins
- strength(collagen) and elasticity(elastin

Adhesion proteins
- link fibres, ground substanc e and cells(fibronectin & laminin)

Question 17

Collagen types

Answer 17

I: 90%. ligaments, tendons, bones, skin.
II: cartilage
III: reticular tissue
IV: basement membrane

Question 18

(muscle) myofilaments(4)

Answer 18

actin; contains binding sites for thick filaments

tropomysin; covers binding sites in relaxed state

troponin; sits on tropomyosin and responds to signals for contraction

myosin; main thick filament protein. elongated with distinct head. ‘walks’

Question 19

Basement membrane layers

Answer 19

lamina lucida
lamina densa
lamina fibroreticularis

Question 20

RIgor mortis

Answer 20

Ca2+ leaks from sarcoplasm into muscle fibrea, myosin binds to actin; no ATP to unbind myosin.

Question 21

Nermaline myopathy

Answer 21

birth defect; muscle weakness.
gene mutation in;
- NEB(thin filament length), or ACTA1(actin substance)

Question 22

arrythmogenic right ventricular cardiomyopathy

Answer 22

• arhythmia caused by cardiac muscle death and replace meant by adipose
• desmosome dysfunction

Question 23

Multiple sclerosis

Answer 23

autoimmune disorder, attacks CNS myelin sheaths
- visual disturbances,
- muscle weakness
- difficulty with coordination and balance

Question 24

GUillan barre

Answer 24

autoimmune attack on the myelin sheath of the PNS
- tingling & weak limbs
- altered heart rate & BP

Question 25

Myasenthia gravis

Answer 25

autoimmune disease- attacks nicotinic receptor
blocks Ach
- worse eyes, face & swallowing.

Question 26

Epithelia types in the trachea, oesophagus, and small intestine

Answer 26

Trachea;
- pseudostratified ciliated columnar with goblet cells

Oesophagus:
- stratified squamous

Small intestine:
- simple columnar