Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology > Nutrional disorders & the eye > Flashcards

Nutrional disorders & the eye Flashcards

1
Q

what are the major nutrients that our food is composed of

A
  • carbohydrates
  • protein
  • fats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do carbohydrates supply energy/ATP

A

broken down into glucose (monosaccharides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what types of proteins are in the body

A
  • amino acid chains - for structural support
  • enzymes
  • collagen
  • hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are fats useful for in the body

A
  • help absorb vitamins
  • energy source
  • integral part of cell membranes
  • insulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what do vitamins act as

A

co-enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what two things can co-enzymes be

A
  • fat soluble
    or
  • water soluble
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what will vitamins be useless without

A

carbohydrates, proteins & fats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the fat soluble vitamins

A

A, D, E & K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the water soluble vitamins

A

B & C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the 7 minerals that the body requires moderate amounts of

A
  • calcium
  • phosphorus
  • potassium
  • sulphur
  • sodium
  • chloride
  • magnesium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are minerals not used for

A

not used for energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are minerals used for

A

functions such as:

  • Ca - bone
  • Fe - haemoglobin
  • Ca/Na/K - nerve minerals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which mineral functions for nerves

A

Ca, Na, K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

which mineral functions for bone

A

Ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

which mineral functions for haemoglobin

A

Fe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are most minerals that we need synthesised from within the body

A

the liver from the food we ingest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

give an example of a retinal nutrient which cannot be made by the body and only comes from the diet

A

carotenoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the two sorts of nutritional deficiencies

A

primary & secondary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is primary nutritional deficiency

A

insufficient intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is secondary nutritional deficiency

A

intake normally sufficient, yet cells receive less nutrients as they don’t arrive where they should e.g.

  • failure of intestine to absorb (e.g. crohn’s disease)
  • increased demand (pregnancy, lactation, growth)
  • presence of antagonists (some substances can neutralise nutrients taken in)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is crohn’s disease

A

failure of the intestine to absorb nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what two diseases are the result of protein-energy malnutrition PEM

A
  • marasmus

- kwashiorkor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is protein-energy malnutrition PEM

A

deficiency of proteins and calories

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens as a result of the disease marasmus

A

body compensates for the reduced calorific deficiencies by catabolising body tissues (fat and muscle).
the calories derived from the breakdown of these tissues are used to maintain normal cellular metabolism.
the result of this is extreme body wasting (but alert and recover quickly as normal cell function is retained)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what happens as a result of the disease kwashiorkor

A

body cannot compensate for catabolising tissues.
normal metabolism fails
patients lethargic and difficult to feed
characteristic symptom is the extended belly, caused by failure to maintain serum albumin levels resulting in oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is a characteristic symptom of kwashiorkor disease

A

the extended belly, caused by failure to maintain serum albumin levels resulting in oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are vitamin deficiencies hypovitaminosis

A

Not enough vitamins

Hyper = too many vitamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is an ocular vitamin of vitamin A

A

retinol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

where does retinol come from

A

either directly from the diet or is produced in the body from a provitamin (carotene) which the body can convert to vitamin A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

where does dietary retinol come from

A

dairy products and liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

where does carotene come from

A

leafy green/yellow vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are the ocular symptoms of vitamin A deficiencies

A
  • night blindness (nyctalopia)

- epithelial changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how does night blindness occur as a result of vitamin A deficiency

A

vitamin A is integral part of visual pigments (which are composed of a protein, opsin, bound to 11-cis retinal, which is derived from retinol)
the first photoreceptor to be effected are the rods, which underlie scotopic vision, in severe deficiency, cone mediated photopic vision is also effected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how does epithelial changes occur as a result of vitamin A deficiency

A

squamous epithelium becomes abnormally thickened and excessively keratinised (keratin plaques)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

where does ocular covering epithelia occur

A

in the cornea and conjunctiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is the name of changes in ocular epithelia due to vitamin A deficiency

A

xeropthalmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what happens to the conjunctiva as a result of ocular epithelial changes due to vitamin A deficiency

A

conjunctiva becomes wrinkled and dry and white bitot’s spots (raised keratin plaques) develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is the name of raised keratin plaques

A

Bitot’s spots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what happens to the cornea at a late stage of vitamin A deficiency

A

corneal epithelium is lost over the lower nasal part of the eye. also dry wrinkled conjunctiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what happens to the cornea in advanced keratomalacia

A

the whole cornea becomes softened and opaque

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is the name for corneal ulceration

A

keratomalacia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what two ways is vitamin D (cholecalciferol) obtained

A
  • absorbed by intestine from the diet along with fats

- UV light from the sun transforms a steroid in the skin (7-dehydroxycholesterol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what are vitamin D deficiency usually resulted from

A
  • insufficient dietary intake

- lack of sunlight

44
Q

how can vitamin D deficiencies be eradicated in developed countries

A

adding vit D to milk

45
Q

how can vitamin D deficiencies still occur in developed countries

A
  • older people who rarely go outside

- vegetarians who don’t eat dairy products

46
Q

what is vitamin D known as in Germany and why

A

known as english disease based on assumption the sun never shines in england

47
Q

what is the main function of vitamin D

A

aiding absorption of calcium

48
Q

what is a result of vitamin D deficiency

A

not enough calcium gets absorbed in the blood and there is inadequate calcification of bones

49
Q

what is the name of children whose bones are still developing but have vitamin D deficiency

A

rickets

50
Q

what is the result of a child with rickets

A

overall growth is retarded and because the bones becomes soft you can get a number of deformities.
load bearing bones, such as tibia bow out and children become pigeon-chested as the intercostal muscles pull on the ribs

51
Q

what is the name of vitamin D deficiency in adults

A

osteomalacia

52
Q

what is vitamin K required for

A

synthesis of blood coagulation factors e.g. prothrombin (being converted into thrombin)

53
Q

what is the main source of vitamin K

A

synthesis by intestinal bacteria

some derived from leafy green vegetables and dairy products

54
Q

when can vitamin K deficiency occur

A

after prolonged antibiotic treatment that kills the intestinal bacteria

55
Q

what will lack in vitamin K result in

A

excessive bleeding (rat poison e.g. is a vitamin K antagonist)

56
Q

why is excessive bleeding a result of vitamin K deficiency

A

as blood does not clot

57
Q

what does vitamin E tocopherol act as

A

an antioxidant

58
Q

what do oxidation reactions result in

A

the loss of electrons

59
Q

oxidation reactions are crucial for life, but how can they be damaging

A

they can produce free radicals

60
Q

what are free radicals

A

unstable molecules with unpaired electrons, they are highly reactive and can damage cells by penetrating the cell wall and damaging DNA & cell membranes

61
Q

what is an antioxidant

A

a molecule capable of slowing or preventing the oxidation of other molecules

62
Q

how do antioxidants have a therapeutic value

A

oxidative stress is an important part of many human diseases inc AMD and cataract
antioxidants mop up free radicals

63
Q

what does deficiency of vitamin E result in

A

its rare but can cause haemolytic anaemia (red blood cells rupture)
also some neuromuscular degeneration

64
Q

what is vitamin C ascorbic acid required for

A

the manufacture of connective tissue (collagen & ground substance)

65
Q

what type of collagen is vitamin C important for manufacturing

A

tropocollagen (needed to make scars)

66
Q

what is a consequence of vitamin C deficiency

A

increased fragility of blood vessels (which contain a lot of tropocollagen) leading to bleeding including haemorrhaging of the eye lids, anterior chamber, vitreous cavity and retina

67
Q

what ocular bleeding occurs as a result of vitamin C deficiency

A
  • haemorrhaging of the eye lids
  • anterior chamber
  • vitreous cavity
  • retina
68
Q

which other parts of the body results in bleeding due to deficiency of vitamin C

A

gums

69
Q

what can vitamin C deficiency also lead to apart rom bleeding

A

old scars reopening and bone abnormalities

70
Q

what is the name for a condition of vitamin C deficiency

A

scurvy

71
Q

what is a type of vitamin B1

A

thiamine

72
Q

what is vitamin B1 thiamine

A

a Co-enzyme in the decarboxylation (involved in energy production) of pyruvate (citric acid cycle)

73
Q

what is the result in the lack of vitamin B1 thiamine

A

leads to impaired energy production

74
Q

what secondary role does vitamin B1 thiamine have

A

in the production of acetylcholine

75
Q

what does a deficiency in production of acetylcholine from lack of vitamin B1 thiamine result in

A

(wet and dry) beriberi

76
Q

what do 70% of patients with beriberi have

A

ocular abnormalities associated with changes in the corneal and conjunctival epithelium, producing dry eyes

77
Q

what is a type of vitamin B2

A

riboflavin

78
Q

what is vitamin B2 riboflavin involved in

A

energy production (electron transfer)

79
Q

what are symptoms of vitamin B2 riboflavin deficiency

A

vascularisation of the cornea, followed by corneal opacities, ulceration of the cornea and ultimately blindness

80
Q

what is vitamin B niacin (nicotinic acid) involved in

A

most oxidation-reduction reactions

81
Q

what are the ocular abnormalities of vitamin B niacin deficiency

A

rare but may result in optic neuritis and retinitis

82
Q

what is a type of vitamin B6

A

pyridoxine

83
Q

what is vitamin B6 pyridoxine involved in

A

as a co-enzyme in many of the bodies enzyme systems and has a role in GABA synthesis

84
Q

what can lack of vitamin B6 pyridoxine result in in the eye

A

can cause blepharitis (inflammation of the eyelids)

85
Q

what is a type of folic acid & vitamin B12

A

cyanocobalamin

86
Q

what is folic acid & vitamin B12 cyanocobalamin important in

A

nucleic acid synthesis

87
Q

what does a lack of folic acid & vitamin B12 cyanocobalamin result in

A

causes disrupted DNA synthesis resulting primarily in megaloblastic anaemia (maturation phase of erythropoiesis abnormal)

88
Q

how long can stores of vitamin B12 last for

A

very extensive lasts for up to 10 years for deficiency may not become apparent for a long time

89
Q

what are the minerals & trace elements, sodium, potassium & calcium needed for

A

sodium & potassium - action potential generation

calcium - synaptic transmission and muscle contraction

90
Q

what is the mineral iron a part of

A

haemoglobin

91
Q

what does a lack of iron result in

A

anaemia

92
Q

what does the mineral, iodine deficiency result in

A

decreased thyroid hormone output

93
Q

what is the mineral fluoride important for

A

maintenance of teeth

94
Q

what are the minerals calcium and phosphate major components of

A

bone

95
Q

what are the functions of the minerals, magnesium, zinc, copper and selenium

A
  • being required for enzymatic activity

- zinc - is anti-inflammatory

96
Q

what can high concentrations of zinc cause to the eye

A

toxic to the eye

involved in ARMD, drusen caused by high amount of zinc in the eye

97
Q

what vitamins and minerals prevent vision loss and less likely to develop advanced AMD than control groups

A

antioxidants: vitamin C, vitamin E and beta-carotene

along with: zinc and copper

98
Q

what is the AREDS formulation composed of

A
  • 500mg of vitamin C
  • 400 international units of vitamin E
  • 15 mg of beta-carotene
  • 80mg of zinc
  • 2 mg of copper (to prevent copper deficiency anaemia, a condition associated with high levels of zinc intake)

however later studies suggested that zinc may be harmful to the retina

99
Q

what does the AREDS formulation have no effect on

A

cataract formation

100
Q

what carotenoids of the retinal macular pigment a mixture of

A

zeaxanthin & lutein

101
Q

what type of pigment is the carotenoids, zeaxanthin & lutein

A

yellow pigmentation

102
Q

what does the yellow pigment of the carotenoids, zeaxanthin & lutein remove

A

short wavelengths (absorbs blue light) which serves to reduce the amount of scatter (as short wavelengths are more prone to Rayleigh scatter) and lessen the amount of chromatic aberration. image quality is therefore increased

carotenoids also remove the wavelengths most damaging to the retina and act as antioxidants

103
Q

what do zeaxanthin & lutein decrease with

A

age

104
Q

what can low levels of zeaxanthin & lutein be associated with due to lack of it with age

A

diseases such as, cataract and macular degeneration

105
Q

as carotenoids can only be obtained from the diet, what can increased intake result in

A

higher macular pigment density

106
Q

what is smoking the biggest risk factor of developing AMD

A

smoking

107
Q

what supplement, which protects against AMD increases the risk of lung cancer in smokers and ex-smokers by 24&

A

beta carotene, so can’t be given nutritional supplements if a smoker

Pathology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions