PSC1002/L02 Blood Flashcards

1
Q

What percentage of total body weight is blood?

A

8%

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

Give 3 functions of blood.

A

Gas transport and exchange
Distributing solutes
Immune functions
Maintaining body temperature
Regulates blood clotting
Preserving acid-base homeostasis
Stabilising blood pressure

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

What is blood composed of? (3)

A

Erythrocytes
Leukocytes
Thrombocytes

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

How does blood separate when centrifuged? (3)

A

55% soluble materials (top)
1% buffy coat - white blood cells and platelets
44% haematocrit (bottom)

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

What are the 2 main functions of plasma?

A

Thermoregulation
Transport

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

How does a high percentage of water in plasma affect properties? (3)

A

High specific heat capacity
Heat not needed lost to environment
Precentage of water determines blood viscosity/ bp

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

Describe serum albumins (3)

A

55% of plasma volume
Large protein synthesised in liver
Maintains osmotic pressure of plasma
Transport of lipids & steroid hormones

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

Describe globulins (3).

A

38% of plasma volume
Transport ions, hormones, lipids
Immune proteins made by leukocytes

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

Describe clotting proteins. (3)

A

7% plasma volume
Essential for blood clotting
Synthesised in liver

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

What makes up the final 1% of blood plasma?

A

Regulatory proteins
Enzymes, proenzymes, hormones

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

What does a normal electrophoretic pattern of plasma proteins show? (5)

A

Albumin, a1, a2, B and Y globulins

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

Give 3 causes of cirrhosis.

A

Cancer
Alcoholism
Viral hepatitis

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

What can cirrhosis lead to? (2)

A

Decrease in production of plasma proteins
Decreased colloidal osmotic pressure
Fluid loss to ECS
Severe edema in abdomen
Decline in clotting factor/easy bruising

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

What is the volume of erythrocytes?

A

80-96 femtolitres

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

Where are small/large RBCs found?

A

Small - macrocytic in iron deficiency anaemia
Large - microcytic in folate (vitamin B9)

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

Where does erythropoiesis occur?

A

Bone marrow

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

Describe the 7 steps in erythropoiesis.

A

Hematopoietic cell
Erythrocyte-CFU
Proerythroblast
Early erythroblast
Late erythroblast
Reticulocyte
Erythrocyte

18
Q

In which step of erythropoiesis does the hormone erythropoietin stop being produced?

A

3 - proerythroblast

19
Q

In which step of erythropoiesis is haemoglobin synthesised?

A

4 - early erythroblast

20
Q

In which step of erythropoiesis is the nucleus ejected?

A

5 - late erythroblast

21
Q

In which step of erythropoiesis are organelles ejected?

A

6 - reticulocyte

22
Q

How long after a bleed is homeostasis achieved in the blood?

23
Q

How are erythrocytes disposed of at the end of their life?

A

Phagocytosed in liver and spleen

24
Q

What are heme components recycled into? (2)

A

Heme into biliverdin then bilirubin, secreted in bile from liver
Iron stored by protein ferritin in liver

25
Describe Glucose-6-phosphate dehydrogenase (G6PD).
Predisposes to red blood cell breakdown (haemolytic crisis) when exposed to certain environmental triggers
26
Describe the 2 parts of a haemoglobin molecule.
Globin - 4 protein chains 4 iron containing haem groups
27
Describe the structure of the Haem group.
Porphyrin ring containing 1 iron atom
28
Describe the structure of iron with and without oxygen.
Without: Fe2+ (ferrous) With: Fe3+ (ferric)
29
Give the 4 forms of globin protein.
Alpha, beta, gamma, delta
30
What are the 3 combinations of globin chains in adults?
HbA - 2A, 2B HbA2 - 2A, 2D HbF - 2A, 2Y
31
What are the 2 forms of haemoglobin and where are they found?
r form - high O2 affinity e.g., in lungs t form - low O2 affinity e.g., in peripheral tissues
32
Give 3 other molecules that haemoglobin can bind.
Carbon dioxide Acidic hydrogen portion of carbonic acid Carbon monoxide Nitric oxide
33
What are haemoglobinopathies?
Abnormal haemoglobin chains
34
What are thalassaemias?
Decreased amount of globin chains or absent globin chains due to gene expression defects
35
Describe sickle cell anaemia. (3)
Mutation is B-globin gene Glutamic acid replaced by valine Creates sticky patches and HbS polymerisation
36
How can thalassaemias occur? (2)
Gross deletion of one or more globin genes Gene mutation
37
Describe the 2 classes of thalassaemia.
a - production of a globin is deficient b - production of b globin is deficient
38
What form of haemoglobin is produced in a thalassaemia?
Excess B chains Unstable tetramers of 4 B chains HbH
39
What happens to the oxygen dissociation curve in a thalassaemia?
High O2 affinity, reduced oxygen carrying capacity
40
Why is B thalassaemia more clinically important than a thalassaemia?
Results in iron overload -> organ damage
41
What does an excess of a chains lead to in B thalassaemia? (3)
Do not form tetramers Bind to and damage RBC membranes At high conc. form toxic aggregates RBC are fragile and short-lived