CVS T

0.0(0)
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/603

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

604 Terms

1
New cards
describe the structure of the red cell membrane
-outer hydrophilic region containing glycolipids, glycoproteins and proteins
-central hydrophobic region containing proteins, cholesterol and phospholipids
inner hydrophobic layer of mesh-like cytoskeletal proteins to support the lipid bilayer
2
New cards
what are integral membrane proteins?
proteins that extend from the outer surface and traverse the entire lipid bilayer membrane to the inner surface
3
New cards
what are the two major integral membrane proteins?
glycophorins (A, B and C)
Band 3 (anion transporter)
4
New cards
give 3 other examples of integral membrane proteins
1. sodium/potassium ATPase
2. Aquaporin 1
3. Surface receptors such as TfR
5
New cards
what are peripheral membrane proteins?
proteins that bind to the cytoplasmic surface of the membrane and forms the red blood cell membrane
6
New cards
what is the role of the cytoskeleton?
acts as a framework to support the bilayer, maintains the biconcave shape and is responsible for deformability
7
New cards
name four major peripheral membrane proteins
1. actin
2. spectrin
3. ankyrin
4. protein 4.1
8
New cards
what is the role of spectrin?
Controls biconcave shape and deformability of the cell by binding with other peripheral proteins and forming a cytoskeletal network of microfilaments
9
New cards
what happens if spectrin becomes denatured?
red blood cell becomes spherical and loses its flexibility
10
New cards
what is the role of ankyrin?
anchors lipid bilayer to membrane skeleton by interacting with spectrin and Band 3
11
New cards
what is the role of Protein 4.1?
links the cytoskeleton to the membrane by associating with glycophorin
stabilises the interaction of spectrin and actin
12
New cards
what is the role of actin?
responsible for contraction and relaxation of the membrane
13
New cards
blood group antigens
found on red cell membranes and determine our blood group
14
New cards
what is the function of red blood cells and how do they achieve this?
-main function is to transport respiratory gases to and from tissues
-red blood cells travel the microvascular system without being damaged, retaining a shape that allows gaseous exchange
-red cell membrane should be tough, yet flexible
15
New cards
what determines strength and flexibility of the red cell membrane?
cytoskeletal protein interaction with the membrane lipid bilayer
16
New cards
what happens if there is an increase in free plasma cholesterol?
accumulation of cholesterol in the red blood cell membrane
red blood cells become distorted resulting in the formation of acanthocytes
17
New cards
what can cause hereditary spherocytosis?
Abnormalities or deficiency to: ankyrin, spectrin A or B, Band 3 and Protein 4.2
18
New cards
what can cause hereditary elliptocytosis?
Abnormalities or deficiency to: spectrin A or B, spectrin dimer or spectrin-ankyrin association, as well as Protein 4.1
19
New cards
what is the most abundant haemoglobin in adults?
Alpha 2 Beta 2
20
New cards
what are haemoglobinopathies?
inherited disorders of haemoglobin
21
New cards
what are the two categories of haemoglobinopathies?
thalassemias: reduced synthesis of haemoglobin
sickle cell disease: change of one amino acid in the globin for another
22
New cards
what are the two main sources of energy for the red blood cells?
RBC metabolic pathways and the hexose monophosphate shunt
23
New cards
G6PD
glucose 6 phosphate dehydrogenase
24
New cards
G6PD deficiency
NADPH and GSH (glutathione) generation impaired
25
New cards
What can a G6PD deficiency lead to?
acute haemolysis (bleeding)
26
New cards
what is G6PD commonly known as?
enzymopathy
27
New cards
what is the glycotic pathway?
generates energy i the form of ATP that maintains red blood cell shape and deformability
28
New cards
what does disorder of the glycotic pathway cause?
ATP is depleted meaning cells lose large amounts of potassium and water, becoming dehydrated and rigid
29
New cards
chronic non-spheryotic haemolytic anaemia
deficiency of vital enzymes required for glycolysis and red blood cell nucleotide metabolism
30
New cards
microcytes
small red blood cells with less haemoglobin
31
New cards
macrocytes
large red blood cells with more haemoglobin
32
New cards
anisocytosis
presence of red blood cells of unequal size
33
New cards
poikilocytosis
presence of red blood cells of irregular shape
34
New cards
what is the appearance of blood after centrifugation?
bottom: red blood cells
middle: white blood cells and platelets
top: plasma
35
New cards
describe the nature of red blood cells
biconcave without a nucleus, DNA, RNA or mitochondria
36
New cards
what are red blood cells also known as?
erythrocytes
37
New cards
how does the shape of red blood cells contribute to their function?
allows greater surface area to carry oxygen and squeeze into the narrow lumen of the vascular tissue
38
New cards
what is the lifespan of red blood cells?
120 days
39
New cards
what are white blood cells also known as?
leukocytes
40
New cards
what are the two most common white blood cells?
neutrophils and lymphocytes
41
New cards
describe the nature of neutrophils
polymorphonuclear, granulocyte
42
New cards
polymorphonuclear
irregular, mutli-lobed nucleus
43
New cards
granulocyte
prominent cytoplasmic granules
44
New cards
give two examples of neutrophils
basophil and eosinophil
45
New cards
what is the function of neutrophils?
phagocytose and kill bacteria and fungi
46
New cards
describe the nature of lymphocytes
large, regular nuclei
lack granules
47
New cards
what is the function of lymphocytes?
immune response, produces antibodies and kill virus infected cells
48
New cards
what is the role of eosinophils?
kill parasites
involved in allergic responses
49
New cards
what is the role of basophils?
kill parasites
involved in allergic responses
involved in controlling inflammation
50
New cards
what is the role of monocytes?
phagocytosis of dead cells and pathogens
51
New cards
what are platelets also known as?
thrombocytes
52
New cards
describe the nature of platelets
cytoplasmic fragments with no nucleus, membrane bound
contain granules that are important for clotting and modulating inflammation
53
New cards
haemostasis
blood clotting
54
New cards
how does blood clot?
fibrinogen (factor 1) is a major plasma protein that is converted to fibrin, forming a blood clot
clotting factors control the process and the fibrin clot reinforces primary platelet plug
55
New cards
where do blood cells come from?
mature blood cells are produced from stem cells in the bone marrow
56
New cards
haematopoietic stem cells
immature cells within the bone marrow that can develop into all types of blood cells
57
New cards
give four main components of plasma
water
salts
proteins
organic molecules (metabolites, carbohydrates, lipids)
58
New cards
what is the difference between plasma and serum?
plasma is the fluid component of the blood, minus the clotting factors
serum is the fluid remaining after blood has clotted
59
New cards
what percentage of the plasma is protein?
7-9%
60
New cards
what is the main plasma protein?
albumin
61
New cards
what is the role of plasma proteins?
carry substances which are poorly soluble in water such as lipids, hormones and ions
62
New cards
how is plasma involved in the immune response?
1. immunoglobulins transported which are made by B lymphocytes and act as antibodies against pathogens
2. complement proteins kill bacteria and other pathogens by cooperating with immunoglobulins and white blood cells
63
New cards
give three functions of blood
transport
defence
homeostasis
64
New cards
how is blood used for transport?
blood carries oxygen and nutrients to tissues, removing carbon dioxide and waste products
65
New cards
what is the role of red blood cells (erythrocytes)?
transports oxygen from the lungs to tissue and removes carbon dioxide
66
New cards
how is carbon dioxide carried in plasma?
in the form of bicarbonate
67
New cards
what is the role of carbonic anhydrase?
to aid in the transport of carbon dioxide
68
New cards
how does a pulse oximeter work?
measures the colour of haemoglobin and determines if a patient is hypoxic
69
New cards
what is the usual total blood volume for a 70kg male?
~5 litres
70
New cards
what is the usual plasma volume for a 70kg male?
~2.5-3 litres
71
New cards
how do you calculate haematocrit?
volume of cells/total volume
72
New cards
what is the normal haematocrit value?
0.4-0.5
73
New cards
what does a low haematocrit signify?
anaemia and therefore low oxygen
74
New cards
what is a full blood count test?
blood test to determine the number of red blood cells, white blood cells and platelets
75
New cards
how is haemoglobin concentration used?
overall concentration of haemoglobin in the blood- used to diagnose anaemia
76
New cards
what is mean red cell volume?
size of the red blood cells
77
New cards
what is the diameter of a red blood cell?
8 micrometres
78
New cards
what is the thickness of a red blood cell?
2 micrometres
79
New cards
what is mean red cell haemoglobin content?
how much haemoglobin is in each red cell
80
New cards
why is total white blood cell count important?
important for diagnosing infection
81
New cards
what do liver function tests measure?
albumin concentration
liver enzymes released from damaged liver cells
clotting factors
82
New cards
why do we test for urea and electrolyte levels?
test kidney function
metabolic abnormalities
83
New cards
what do we screen for a lipid profile?
triglycerides
cholesterol
LDL and HDL
risk of cardiovascular disease
84
New cards
LDL
low density lipoprotein
inflammatory mediator
85
New cards
HDL
high density lipoprotein
86
New cards
Why does blood clot?
Prevents excessive blood loss and pathogens from entering the body and causing infection
87
New cards
Outline primary haemostasis
1. Endothelium constantly releases VWF, from the Weibel-Palade bodies, into the blood
2. When damage occurs to the endothelium the subendothelial collagen becomes exposed and any VWF circulating in the blood will bind to it
3. Platelets carry receptors for VWF and collagen and so are activated- this activation expresses fibrinogen receptors which are necessary for aggregation
4. Activated platelets can aggregate by binding to fibrinogen, and they release ADP and TXA2
88
New cards
What does primary haemostasis involve?
Platelet aggregation and platelet plug formation
89
New cards
What does secondary haemostasis involve?
Formation of fibrin through conversion by thrombin
90
New cards
Outline secondary haemostasis
1. When damage occurs to the endothelium, tissue factor is exposed alongisde the subendothelial collagen
2. Tissue Factor activates the coagulation cascade when FVIIa binds to it, activating FXa
3. The activation of FXa initiates conversion of prothrombin to thrombin and this causes more platelet aggregation
4. After the initial trickle of thrombin, FVIIIa and FVa form calcium-ion dependent complexes on the surface of platelets with FXa and FIXa
5. These complexes increase production of FXa and amplify production of thrombin
91
New cards
Describe fibrinolysis
Tissue plasminogen activator activates plasmin which is converted from plasminogen, and the plasminogen breaks down fibrin into fibrin fragments
92
New cards
Haemophilia
Lack of ability to clot
93
New cards
Thrombophilia
Tendency to develop blood clots in the wrong locations
94
New cards
Disseminated intravascular coagulation
Widespread clotting and obstruction of blood flow to the tissues
95
New cards
Define cardiovascular system
The heart, blood vessels and approximately 5 litres of blood
96
New cards
Functions of the CVS
Transport of oxygen and substrates to cells
Transport of carbon dioxide and metabolites from cells through excretion
Distribution of hormones
Transport of defence mechanisms
Thermoregulation
97
New cards
Passive diffusion
Random, unidirected, thermal movement of molecules
98
New cards
How is time proportional to distance in passive diffusion?
Time is directly proportional to the distance squared
99
New cards
Convection transport
Movement of fluids and solutes down a pressure gradient created by the heart
100
New cards
How does the heart have dual circulation?
Pulmonary circulation
Systemic circulation