Pigments

Question 1

Pigments are coloured substances, some of which accumulate in the cell under special circumstances.

● They could be:
○ Normal e.g. ______ or abnormal e.g. ____

Answer 1

melanin; tatoo

Question 2

________ is the most common exogenous
pigment.

Answer 2

Carbon (Coal dust)

Question 3

Carbon(coal dust)

• is inhaled daily as an ______
  • When inhaled, it is ingested by the _______ in the ____ which transport them via _______ to the regional _____

Answer 3

air pollutant

macrophages; alveoli

lymphatic channels

lymph nodes

Question 4

Carbon dust is ubiquitous

T/F

Answer 4

T

Question 5

Coal dust

This pigments forms the ___ coloured patches seen on the _____ surface of the lungs and ______ in the ________

Answer 5

dark; pleural; lymph nodes; tracheobronchial tree.

Question 6

Coal worker’s pneumoconiosis is a disease condition where there is a ______ reaction to the large amounts of coal dust inhaled by workers in this
profession.

Answer 6

fibroblastic

Question 7

Endogenous:
•______ (wear and tear
pigment)
• Hemosiderin
•___________ – deposited in the connective tissues, skin in patients with alkaptonuria. The pigmentation is known as _______.
• Melanin
• Bilirubin

Answer 7

Lipofuscin

Homogentisic acid

ochronosis

Question 8

Lipofuscin

• Granules composed of _______ complexes.
● Found in _______ diseases and are the end products of oxygen radical mediated membrane damage which are not eliminated by intracellular ______

● They subsequently persist in the ______ as collections of _______.

Answer 8

lipid-protein

ageing or debilitating

lipid peroxidation.

Lysosomes; indigestible material

Question 9

Lipofuscin is injurious to the cell

T/F

Answer 9

F

Not injurious to the cell

Question 10

Lipofuscin has no gross features

T/F

Answer 10

T

Question 11

Melanin

• ______ pigment.
● Normally seen in the skin, hair etc
● Synthesized in the _____ and _____ cells by the action of _____ on ______ to form
__________(DHPA).

Answer 11

Brown-black

melanocytes; dendritic

tyrosinase on tyrosine

dihydroxyphenylalanine

Question 12

Melanin is derived from hemoglobin

T/F

Answer 12

F

Question 13

Melanin

Disorders of melanin pigmentation can cause generalised and localised _______/_______

Answer 13

hyperpigmentation/hypopigmentation

Question 14

Generalised hypopigmentation (Albinism)

● Genetic defect in ______
●_______ cases have almost no pigment in the skin and hair and complain of severe ________.
● Chronic sun exposure may lead to ______

Answer 14

tyrosinase

Oculocutaneous; photophobia

skin cancer

Question 15

Focal hypopigmentation
●_________: localised loss of skin pigmentation.

●_____: More common

● Acquired focal hypopigmentation: healing of wounds,_______,_____ etc.

Answer 15

Leucoderma

Vitiligo

leprosy, lupus

Question 16

Alkaptonuria

● Autosomal (dominant or recessive?) disorder
● Deficiency of ____ enzyme which is required to break down ________ which therefore accumulates in the tissues
and is excreted in the urine.
● Urine turns ____ if allowed to stand for a few hours in the air ( ______ of _______).

Answer 16

Recessive

oxidase

homogentisic acid.

black

oxidation of homogentisic acid

Question 17

black pigment in alkaptoneuria is called ______ and is deposited _____cellularly. E.g. Joints, ligaments, skin
tissue.

Answer 17

ochronosis

both inter and intra

Question 18

● Iron in tissues can be stored either as
○________
○________

Answer 18

Ferettin

Haemosiderin

Question 19

● Iron in tissues can be stored either as
○ Ferettin (Fe complexed to ______)
○ Haemosiderin (formed by _______)

Answer 19

Apoferritin

aggregates of ferritin

Question 20

● Excessive storage of haemosiderin occurs when there is increased ______ or ________ overload.

Answer 20

Breakdown of red blood cells

systemic iron

Question 21

Hemosiderin can only be localized

T/F

Answer 21

F

Can be localised or generalised

Question 22

Bilirubin
● Pigment derived from _____, found in bile.
● Excess bilirubin (hyperbilirubinaemia) causes ______
● Aetiology
○ Increased production (excessive _______)
○ Defective conjugation (_____ disease/injury)
○ Defective transport (_________ ducts)

Answer 22

haemoglobin

jaundice

RBC destruction

liver

intra/extrahepatic bile

Question 23

Bilirubin is iron-containing

T/F

Answer 23

F

is non-iron containing

Question 24

Bilirubin Accumulates as _____ pigment in the fluids and tissues of the body e.g. hepatocytes, skin, sclera.

● In infants, high levels of unconjugated bilirubin may cause ______ injury (________)

Answer 24

yellow

brain

kernicterus

Question 25

Excessive absorption of iron ● Excessive absorption even with normal intake is known as _______ or ______ ● It is an autosomal (dominant or recessive?) disease

Answer 25

idiopathic or hereditary haemochromatosis. Recessive

Question 26

Excessive absorption of iron Characterised by: ○ Pigmented ______ ○____ pigmentation ○ _______ damage resulting in diabetes (‘______ diabetes’)

Answer 26

liver cirrhosis Skin Pancreatic; bronze

Question 27

Excessive iron intake ● First observed in the ____ tribe of _____ due to Consumption of alcohol brewed in _____ vessels. ● Later found in other communities without similar history. ● A gene called _____ has been identified as the predisposing factor to this overload.

Answer 27

Bantu; South Africa ungalvanised iron ferroportin

Question 28

Histology of excessive iron intake ● Intracytoplasmic coarse, _______, granular pigment ● Visualised with _______/______ stain

Answer 28

golden-brown Prussian blue/Perl’s

Question 29

Localised Haemosiderosis ● When there is haemorrhage into the tissue, the red blood cells are ___ releasing their _____ which is then taken up by _____, degraded and stored as ______. Examples are ○ Haemosiderin laden macrophages at sites of ________ ○ Haemosiderin laden alveolar macrophages (______ cells) in the ___ in ______ failure

Answer 29

Lysed; haemoglobin; macrophages; haemosiderin endometriotic deposits heart failure lungs; left ventricular

Question 30

______ is the ageing pigment

Answer 30

Lipofuscin

Question 31

Lipofuscin pigment appears as ______ in tissue segments

Answer 31

Yellow brown

Question 32

Lipofuscin is seen in cells undergoing (slow or rapid?) , (regressive or progressive?) changes and is particularly prominent in the _______ and _____ of ageing patients

Answer 32

Slow Regressive Liver and heart

Question 33

_____/______ is used to stain for iron

Answer 33

Perls stain/ Prussian blue

Question 34

Lipofuscin is to _____ brown as haemosiderin is to _______ brown

Answer 34

Yellow Golden yellow

Question 35

Tattoo pigments are also absorbed by ________

Answer 35

dermal macrophages.

Question 36

In anthracosis, the macrophages which ingest the inhaled carbon particles, also elaborate ______ which encourage the formation of _____ in the lungs. This may result in difficulty in respiration.

Answer 36

cytokines fibrosis

Question 37

Generalised hyperpigmentation ●________ disease: hyperpigmentation of sun exposed areas ●________: seen in pregnancy/oral contraceptive pills. •________ induced hyperpigmentation of the face, nipples, genitalia. ● Chronic _____ poisoining: classic raindrop pigmentation of the skin.

Answer 37

Addison’s Chloasma Oestrogen arsenic

Question 38

Focal hyperpigmentation ● Neurofibromatosis:________ spots ● Peutz-Jeghers syndrome:_______ ● Melanosis coli: _________ ● Melanotic tumours: _____ ● Lentigo:___ ● Dermatopathic lymphadenopathy: Lymph nodes draining _______

Answer 38

Cafe-au-lait ; Peri-oral mucosa of the colon; skin skin skin lesions

Question 39

Leucoderma is an autoimmune condition T/F

Answer 39

T

Question 40

Vitiligo may be familial which means???

Answer 40

Other members of the family may have it

Question 41

Homogentisic acid is converted to _______ by homogentisic acid oxidase

Answer 41

Maleylacetoacetic acid

Question 42

Localised Haemosiderosis ● When there is haemorrhage into the tissue, the red blood cells are lysed releasing their haemoglobin which is then taken up by macrophages, degraded and stored as haemosiderin. Examples are ○ Haemosiderin laden macrophages at sites of _________ ○ Haemosiderin laden ____ macrophages (_____ failure cells) in the _____ in ______ failure

Answer 42

endometriotic deposits alveolar; heart; lungs left ventricular

Question 43

Generalised haemosiderosis Causes are broadly categorised into: ● Increased breakdown of haemoglobin e.g.____________ anaemia, excessive _______ ● Excessive _________ of iron ● Excessive iron _____ e.g. ______, ____ brewed in certain vessels.

Answer 43

chronic hemolytic; blood transfusion intestinal absorption intake; multivitamins alcohol

Question 44

Excessive absorption even with normal intake is known as _________________

Answer 44

idiopathic or hereditary haemochromatosis.

Question 45

idiopathic or hereditary haemochromatosis It is an autosomal (recessive or dominant?) disease ● Characterised by: ○ Pigmented liver _____ ○________ ○ ______ damage resulting in diabetes (‘_______ diabetes’)

Answer 45

Recessive cirrhosis Skin pigmentation Pancreatic bronze