Brainscape's Knowledge GenomeTM

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


See full index

MEH * > S3 Haemopoiesis, the Spleen and Bone Marrow > Flashcards

S3 Haemopoiesis, the Spleen and Bone Marrow Flashcards

1
Q

Where does production of blood cells occur? What is the bone marrow distribution in adults and infants?

A

In the bone marrow

Adults - limited distribution (pelvis, sternum, skull, ribs, vertebrae)

Infants - extensive distribution throughout skeleton

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

What is differentiation of haemopoietic stem cells determined by?

A
  • hormones - erythropoietin and thrombopoietin
  • transcription factors
  • interactions with non-haemopoietic cell types e.g. endothelial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is erythropoietin secreted? What does it stimulate?

A

In the kidneys

RBC production

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

Where is thrombopoietin produced? What does it regulate?

A

The liver and kidney

Production of platelets

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

What are haemopoietic stem cells (HPSCs) able to do more than other adult tissue?

A

Self-renew

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

What are the sources of haemopoietic stem cells (HPSCs)?

A
  • bone marrow aspiration
  • GCSF mobilised peripheral blood stem cells, collected by leucopharesis
  • umbilical cord stem cells, “cord bank”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the reticuloendothelial system (RES)? What is it made up of? Where does it mainly occur?

A

It is part of the immune system.

Made up of monocytes in the blood and a network of tissues that contain phagocytic cells.

Mainly in the spleen and liver

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

What tissues are each, Kupffer cell, tissue histiocyte, microglia, peritoneal macrophage, red pulp macrophage, Langerhans cell, found in?

A
  • Kupffer cell - liver
  • tissue histiocyte - connective tissue
  • microglia - central nervous system
  • peritoneal macrophage - peritoneal cavity
  • red pulp macrophage - spleen
  • Langerhans cell - skin and mucosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the role of macrophages?

A

To remove dead/damaged cells and identify and destroy foreign antigens in blood and tissues

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

What do RES cells in the spleen do?

A

Dispose of blood cells, e.g. damaged/old RBCs

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

Describe the structure of the red pulp in the spleen.

A

Contains sinuses (vessels/tracts) lined by endothelial macrophages and cords

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

Describe the structure of the white pulp in the spleen.

A

Has a similar structure to lymphoid follicles

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

What is the function of the spleen in adults?

A
  • sequestration and phagocytosis
  • blood pooling
  • extramedullary haemopoiesis
  • immunological function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is blood pooling?

A

Platelets and RBCs can be rapidly mobilised during bleeding

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

What is extramedullary haemopoiesis?

A

Haemopoiesis happening outside the bone marrow e.g. in the spleen.

Pluripotent stem cells proliferate during haematological stress/if bone marrow fails

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

What is myelofibrosis?

A

Bone marrow cancer that leads to scarring of the bone marrow

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

What % of T and B cells are present in the spleen?

A

T cells - 25%

B cells - 15%

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

How does blood enter the spleen?

A

Splenic artery

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

What is splenomegaly?

A

Spleen enlargement

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

Why would splenomegaly occur?

A
  • red or white pulp being over worked
  • back pressure from the hepatic portal system (portal hypertension in liver disease)
  • extramedullary haemopoiesis
  • expanding as cells infiltrate e.g. cancer cells or blood origin or cancer metastases
  • expanding as materials infiltrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is hypersplenism?

A

Low blood counts can occur due to pooling of blood in enlarged spleen

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

Why should you avoid contact sports and vigorous activity if you have an enlarged spleen?

A

To avoid the risk of rupture as it is no longer protected by the rib cage

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

What are some major causes of splenomegaly?

A
  • chronic myeloid leukaemia
  • myelofibrosis
  • malaria
  • schistosomiasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are some moderate causes of splenomegaly?

A
  • lymphoma
  • leukaemias
  • myeloproliferative disorders
  • liver cirrhosis and portal hypertension
  • infections e.g. glandular fever
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are some mild causes of splenomegaly?

A
  • infectious hepatitis
  • endocarditis
  • infiltrative disorders e.g. sarcoidosis
  • autoimmune diseases e.g. AIHA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How do you feel for an enlarged spleen?

A

Never normal for the spleen to be palpable below the costal margin

  1. Start to palpate in the right iliac fossa (RIF)
  2. Feel fo spleen edge moving towards your hand on inspiration
  3. Feel for the splenic notch
  4. Measure in cm from the costal margin to midclavicular line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is hyposplenism?

A

Lack of functioning splenic tissue

28
Q

What are some causes of hyposplenism?

A
  • splenectomy
  • sickle cell disease
  • gastrointestinal diseases e.g. coeliacs, crohn’s and ulcerative colitis
  • autoimmune disorders e.g. systemic lupus, rheumatoid arthritis, hashimoto’s disease
29
Q

What are Howell Jolly bodies?

A

DNA remnants in RBCs

Seen on a blood film, usually removed by spleen so appearance of them is a sign of hyposplenism

30
Q

What are patients with hyposplenism at risk of?

A

Sepsis from encapsulated bacteria e.g. streptococcus pneumonia, haemophilus influenzae and meningococcus

31
Q

What do you give the patients with hyposplenism?

A

Life long antibiotic prophylaxis immunisations

32
Q

When does fetal Hb switch to adult Hb

A

About 3-6 months of age

33
Q

What are the membrane proteins of a RBC?

A
  • spectrin (peripheral)
  • ankyrin (peripheral)
  • band 3 (integral)
  • protein 4.2 (peripheral)
34
Q

What organ recognises changes in RBC shape/membrane structure? What does it do? To prevent what?

A

The spleen - it removes them from circulation to prevent haemolytic anaemia occurring

35
Q

What does spectrin do?

A

It links the plasma membrane to the actin cytoskeleton

36
Q

What does ankyrin do?

A

Links integral membrane proteins to the underlying spectrin-actin cytoskeleton

37
Q

What does band 3 do?

A

Facilitates chloride and bicarbonate exchange across the membrane and involved in the physical linkage of the membrane to the cytoskeleton (binds to ankyrin an protein 4.2)

38
Q

What does protein 4.2 do?

A

An ATP-binding protein that may regulate the association of band 3 with ankyrin

39
Q

What is cytopenia?

A

Reduction in the number of blood cells

40
Q

What is …cytosis or …philia?

A

An increase in the number of blood cells

41
Q

What happens when haem is degraded?

A
  1. Senescent RBC engulfed by macrophages in the RES
  2. Haem released, Fe2+ is recycled
  3. Haem breaks down into bilirubin which is transported in blood bound to albumin
  4. Bilirubin is conjugated with glucuronic acid and is secreted in the bile where it is removed via the faeces or urine
  5. If there is excess bilirubin in the blood, jaundice occurs
42
Q

What do you call an increase and decrease in RBCs?

A

Increase - polycythaemia or erythrocytosis

Decrease - anaemia

43
Q

What do you call an increase and decrease in WBCs?

A

Increase - leucocytosis

Decrease - leucopenia

44
Q

What do you call an increase and decrease in lymphocytes?

A

Increase - lymphocytosis

Decrease - lymphocytopenia

45
Q

What do you call an increase and decrease in monocytes?

A

Increase - monocytosis

Decrease - monocytopenia

46
Q

What do you call an increase and decrease in neutrophils?

A

Increase - neutrophilia

Decrease - neutropenia

47
Q

What do you call an increase and decrease in eosinophils?

A

Increase - eosinophilia

Decrease - eosinopenia/low eosinophils count

48
Q

What do you call an increase and decrease in basophils?

A

Increase - basophilia

Decrease - basopenia/low basophil count

49
Q

What do you call an increase and decrease in platelets?

A

Increase - thrombocytosis/thrombocythaemia

Decrease - thrombocytopenia

50
Q

What do you call an increase and decrease in all blood cell types?

A

Increase - panmyelosis

Decrease - pancytopenia

51
Q

What controls the maturation of neutrophils?

A

G-CSF

52
Q

What part of the immune system are neutrophils part of, innate or adaptive?

A

Innate

53
Q

How long to neutrophils live for?

A

1 to 4 days

54
Q

What does G-CSF control?

A
  • neutrophil production
  • chemotaxis
  • phagocytosis and killing of pathogens
55
Q

What is neutrophilia?

A

An increase in the absolute number of circulating neutrophils

56
Q

What causes neutrophilia?

A
  • infection (most common)
  • tissue damage
  • smoking
  • drugs e.g. steroids
  • myeloproliferative diseases (rare)
  • cytokines (G-CSF)
  • cancer
57
Q

What can cause neutropenia?

A
  • reduced production - B12/folate deficiency, aplastic anaemia, radiation, drugs, viral infection, congenital
  • increased removal/use - immune destruction (autoantibodies), sepsis, splenic pooling
58
Q

What are the consequences of neutropenia?

A
  • severe life threatening bacterial infection
  • severe life threatening fungal infection
  • mucosal ulceration
59
Q

How long do monocytes circulate fro before migrating to tissues to differentiate into macrophages/dendritic cells?

A

About 1 to 3 days

60
Q

What are some causes of monocytosis?

A
  • bacterial infection e.g. TB
  • inflammatory conditions e.g. rheumatoid arthritis
  • carcinoma
61
Q

What can cause eosinophilia?

A
  • common - allergic diseases, parasitic infection, drug hypersensitivity, skin diseases
  • rare - Hodgkin lymphoma, acute lymphoblastic leukaemia, acute myeloid leukaemia, eosinophilic leukaemia
62
Q

What do eosinophils do?

A

Responsible for immune response against multicellular parasites like helminths

Mediator of allergic responses

Phagocytosis of antigen-antibody complexes

63
Q

When are basophils active?

A

(Least common)

Active in allergic reactions and inflammatory conditions e.g rheumatoid arthritis, hypersensitivity reactions and ulcerative colitis

64
Q

Where do lymphocytes originate from?

A

Bone marrow

65
Q

What rate the 3 types of lymphocytes?

A

B cells, T cells and natural killer cells

66
Q

What type of immunity, humoral and cellular, are B and T cells involved in?

A

B cells - humoral

T cells - cellular

67
Q

What are some causes of lymphocytosis?

A
  • viral infections
  • bacterial infections e.g. whooping cough
  • post splenectomy
  • smoking
  • T-/NK- cell leukaemia
  • lymphoma

MEH * (22 decks)

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