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Science For Med A ellen > Blood > Flashcards

Flashcards in Blood Deck (31):
1

What are the main functions of blood?

-Carriage of biologically active material and gases.
-Clotting
-Defence
-Maintenance of ECF pH
-Thermoregulation

2

What are the three types of plasma proteins?

1. Albumin
2. Globulin
3. Fibrinogen and clotting factors

3

What is meant by colloidal oncotic pressure?

This is the 'pull' created by plasma proteins. It pulls water across the endothelial cells of the capillary wall. Sodium can follow, long with other penetrating components of the ISF.

4

What can Red Blood Cells also be called?

Erythrocytes

5

Describe the structure of erythrocytes.

Biconcave disk shape, without a nucleus. This allows more space for haemoglobin.

6

What is erythropoiesis?

This is the development of erythrocytes from pluripotent stem cells, accelerated by erythropoietin.

7

What is the most abundant blood cell?

Erythrocyte

8

Describe the structure of platelets.

Cell fragments
Megakaryocyte cytoplasm wrapped up in megakaryocyte membrane. No nucleus

9

What are the three types of granulocytes?

Eosinophils
Neutrophils
Basophils

10

What do monocyte cells mature into?

Macrophages

11

What is the function of macrophages?

To engulf and destroy pathogens in phagocytosis

12

What is the function of neutrophils?

-Phagocytosis
-To trap pathogens in NETs (Neutrophil extracellular traps)

13

What is the function of eosinophils?

To attack pathogens which are too large for neutrophils and other defensive cells

14

In what scenario is eosinophil count extremely elevated?

During an allergic reaction

15

What is the function of basophils?

To release histamine and heparin to stimulate inflammation

16

Which is the largest white blood cell?

Monocyte

17

Which is the most abundant white blood cell?

Neutrophil

18

What controls white blood cell formation?

Cytokines

19

Which WBC is used to attack parasites?

Eosinophils

20

Describe the process of haemotaxis.

Infected cells produce a chemical messenger, which diffuses throughout the ECF, staying strongest at site of infection. The chemical enters blood stream and alerts WBCs. The chemical then acts as a trail, leading WBC to site of infection.

21

What is the name given to the process of WBC formation?

Leukopoiesis

22

Describe the process of leucopoiesis.

-Cytokines are released from endothelial cells, fibroblasts and mature WBCs.
-Stimulate mitosis and maturation of leaukocytes
-Composition of cytokine cocktail changes as a result of particular infection
-For example, in the event of a bacterial infection, cytokine cocktail is required to stimulate the synthesis of more neutrophils than usual.

23

What WBC is best for neutralising bacterial pathogens?

Neutrophils

24

What WBC is best for neutralising viral pathogens?

Lymphocytes

25

What protein controls the formation of platelets?

Thrombopoietin

26

What is the function of platelets?

Adhere to damaged vessels and connective tissue to mediate blood clotting

27

What is meant by the viscosity of blood?

How thick it is compared to water

28

What is the role of erythropoietin?

Stimulates the creation of erythroblasts from pluripotent stem cells?

29

What increases the secretion of erythropoietin?

Decreased delivery of oxygen to the kidney (e.g. through haemorrhage, anaemia, lung disease or cardiac dysfunction.

30

What is meant by haematocrit?

The volume percentage of RBCs in blood.
Typically 40-54% in males
Typically 37-47% in females

31

What three factors affect blood viscosity?

Haematocrit, temperature and flow rate