Brainscape's Knowledge GenomeTM

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


See full index

8. CP - Core Haematology > (42) Paediatric haematology > Flashcards

(42) Paediatric haematology Flashcards

1
Q

The site of haematopoesis varies between children and adults. Explain the differences

A
  • embryos = yolk sac

- then spleen, liver, lymph nodes - bone marrow takes over and forms most RBCs when it develops

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

Haematopoesis occurs in the bone marrow in both children and adults but what are the differences?

A

children = marrow of long bones eg. femur and tibia

adults = mainly in pelvis, cranium, vertebrae and sternum

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

How much of haemoglobin is HbF at birth?

A

55-65%

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

What are the differences in red blood cells between children and adults?

A

In children:

  • larger
  • higher haematocrit
  • greater oxygen affinity

Rapidly reach similar values to adults

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

What is haematocrit?

A

Also known as packed cell volume (PCV) or erythrocyte volume fraction (EVF), is the volume percentage (%) of red blood cells in blood. It is normally 45% for men and 40% for women

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

Which chromosome is responsible for the production of 2 alpha chains?

A

Chromosome 16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which chromosome is responsible for the production of 2 beta chains?

A

Chromosome 11

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

Which chromosome is responsible for the production of gamma chains and delta chains?

A

Chromosome 11

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

What haemoglobin switching occurs to form alpha chains? (chromosome 16)

A

zeta - alpha

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

What haemoglobin switching occurs to form delta chains? (chromosome 11)

A

epsilon - gamma - beta - delta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What types of haemoglobin exist between weeks 4-14 of gestation?

A 
2zeta/2epsilon = Hb Gower-1
2zeta/2gamma = Hb Portland
2alpha/2epsilon = Hb Gower-2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of haemoglobin exists after week 14 of gestation?

A

2alpha/2gamma = HbF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What types of haemoglobin exist at the neonatal stage?

A 
2alpha/2beta = HbA
2alpha/2delta = HbA2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What globin chains is Hb Portland made up of?

A

2zeta/2gamma

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

What globin chains is HbA2 made up of?

A

2alpha/2delta

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

What globin chains is Hb Gower-2 made up of?

A

2alpha/2epsilon

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

What globin chains is HbF made up of?

A

2alpha/2gamma

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

What globin chains is HbA made up of?

A

2alpha/2beta

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

What globin chains is Hb Gower-1 made up of?

A

2zeta/2epsilon

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

How does the number of white blood cells differ in children from adults?

A

Similar numbers - higher lymphocyte counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The immune system is a work in progress. Describe how the immune system is built up in a child

A
  • IgG crosses the placenta
  • IgA/D/E/G/M in breast milk (passive immunity)
  • start producing own antibodies 2-3 months
  • can make satisfactory immune response by 6 months
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which antibodies cross the placenta?

A

IgG

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

How else do babies receive passive immunity from the mother?

A

Breast milk (antibodies IgA, IgD, IgE, IgG, IgM)

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

At what age do babies start producing their own antibodies?

A

2-3 months

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

At what age are babies able to make a satisfactory immune response?

A

6 months

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

When do platelets levels reach that of an adult?

A

By week 18 out of 40 of gestation

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

How are platelets different in the foetus?

A

Initially larger, but slim down to adult size by birth

28
Q

Platelets are functionally different at birth. In what way?

A
  • hyporesponsive to certain agonists

- hyperresponsive to vWF

29
Q

What is haemostasis?

A

The human body’s response to blood vessel injury and bleeding. It involves a coordinated effort between platelets and numerous blood clotting proteins (or factors), resulting in the formation of a blood clot and subsequent stopping of the bleed

30
Q

Is haemostasis present at birth?

A

Present but imperfect at birth

- coagulation proteins do not cross the placenta effectively

31
Q

Which coagulation proteins are normal at birth?

A
  • fibrinogen
  • FV
  • FVIII
  • FXIII
    only these are normal at birth
32
Q

Most haemostatic parameters reach adult values by what age?

A

6 months

33
Q

Which (anti)coagulation factors are vitamin K dependent?

A
  • FII
  • FVII
  • FIX
  • FX
  • protein C
  • protein S
34
Q

Foetal vitamin K is what proportion mother?

A

The placental gradient means that foetal vitamin K is 10% mother

35
Q

What is the function of vitamin K in the body?

A

Required for complete synthesis of certain proteins that are prerequisites for blood coagulation

(needed for normal blood clotting)

36
Q

What is prevented by giving routine neonatal vitamin K?

A

Haemorrhagic disease of the newborn

37
Q

The risk of vitamin K-deficient haemorrhagic disease of the newborn is increased in what circumstances?

A

If the mother is on anti-convulsants - the mother needs to take oral vitamin K

38
Q

Name a drug that is teratogenic

A

Warfarin

39
Q

In the neonate, pro-coagulant proteins are reduced such as…

A

FII, FVII, FIX, FXI, FXII, prekallikrein, high molecular weight kininogens

40
Q

In the neonate, there is a reduced concentration of coagulation inhibitors, such as…

A
  • ATIII
  • Heparin
  • cofactor 2
  • TFPI
  • protein C
  • protein S
41
Q

The neonate has unique forms of which proteins?

A
  • fibrinogen

- plasminogen

42
Q

The neonate has raised levels of what? (concerning haemostasis)

A
  • D dimers

- vWF

43
Q

What are the congenital causes of anaemia in children?

A
  • haemoglobin synthesis problem (HAEMOGLOBINOPATHY)
  • bone marrow failure syndromes
  • bone marrow infiltration
  • PERIPHERAL DESTRUCTION
  • BLOOD LOSS
44
Q

What proportion of the worldwide population carry an abnormal gene causing haemoglobinopathy?

A

5%

45
Q

How many babies are born per year with a type of haemoglobinopathy?

A

300,000

46
Q

Name 2 types of haemoglobinopathy

A
  • thalassaemia

- sickle cell disease

47
Q

Where are haemoglobinopathies most common geographically?

A

Middle of Africa (malaria protection)

48
Q

Describe 4 things that can cause peripheral destruction of red blood cells?

A
  • an incompatibility
  • membrane defect
  • enzyme defect
  • infection
49
Q

Give 2 types of incompatibility that can cause RBC peripheral destruction?

A
  • Rh

- ABO

50
Q

What is Rh incompatibility?

A

A condition that occurs during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood

51
Q

ABO incompatibility is more common than Rh incompatibility but why is it rarely a significant problem?

A

As IgM antibodies cannot cross the placenta

52
Q

Name a type of RBC membrane defect that can cause peripheral destruction

A

Hereditary spherocytosis

53
Q

What is hereditary spherocytosis?

A
  • autosomal dominant abnormality of RBC membrane proteins
  • abnormal erythrocytes are sphere-shaped
  • more prone to rupture
  • cells with these dysfunctional proteins are taken for degradation at the spleen = anaemia and jaundice
54
Q

Give 2 clinical features seen in hereditary spherocytosis?

A
  • anaemia

- jaundice (due to breaking down of red blood cells)

55
Q

Give 2 types of enzyme defects that cause peripheral destruction of RBCs

A
  • G6PD deficiency

- PK deficiency

56
Q

Another cause of anaemia in babies is blood loss. Give 2 causes of blood loss in babies

A
  • twin to twin transfusion (one baby bleeding into the other)
  • fetomaternal haemorrhage (loss of foetal blood cells into maternal circulation)
57
Q

What are the acquired causes of anaemia in childhood?

A
  • NUTRITIONAL DEFICIENCY
  • BONE MARROW FAILURE
  • BONE MARROW INFILTRATION
  • peripheral destruction
  • blood loss
58
Q

What nutritional deficiencies cause acquired anaemia in childhood?

A
  • IRON
  • B12
  • folate
59
Q

Do we have larger stores of B12 or folate?

A

B12

60
Q

Give an example of a disease of bone marrow failure

A

Aplastic anaemia

61
Q

What is aplastic anaemia?

A

A rare disease in which the bone marrow and the hematopoietic stem cells that reside there are damaged (bone marrow failure) - this causes pancytopenia

  • aplastic refers to inability of the stem cells to generate mature blood cells
62
Q

Is aplastic anaemia a serious condition?

A

Serious and difficult to manage - child will need bone marrow transplant

63
Q

Give an example of a disease of bone marrow infiltration?

A

ALL leukaemia (signs = pale, frequent nosebleeds etc.)

64
Q

What are the congenital causes of bleeding and bruising in children?

A
  • platelet problem (most common)
  • clotting factor problem
  • connective tissue disorder (more rare)
65
Q

What are the acquired causes of bleeding and bruising in children?

A
  • trauma
  • tumour
  • infection
  • immune disorder
  • bone marrow failure
  • drug related
66
Q

Give examples of infections that can cause bleeding and bruising in children

A
  • meningococcus

- chronic eg. HIV

67
Q

Give examples of immune disorders that can cause bleeding and bruising in children

A 
primary = immune thrombocytopenia, TTP
secondary = SLE, ALPS

8. CP - Core Haematology (11 decks)

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