Module 1: Cardiovascular System Flashcards
1
Q
What is the main role of blood?
A
Body’s transport/distribution medium that is continuously circulated via blood vessels
2
Q
Is blood connective tissue? If so, why?
A
Yes; liquid CT, because it consists of cells, fibres, and amorphous ground substance (AGS)
3
Q
3 main functions of blood?
A
- Regulation: monitors temperature, pH, water distribution
- Protection: houses immune system and facilitates immune communication
- Transportation: transports oxygen, nutrients, gases, hormones, metabolic wastes
Acronym: RPT
4
Q
Consistency of blood?
A
Viscous and slightly sticky, because of RBCs and plasma proteins
5
Q
3 main components of blood?
A
- Plasma
- Buffy coat
- RBCs
6
Q
Temperature of blood in the body?
A
37-38°C
7
Q
pH of blood in the body?
A
Alkaline, with a normal pH range of 7.35-7.45
8
Q
Volume of blood in the body?
A
Variable according to size, etc.
Typically: 4-5L in females, 5-6L in males.
9
Q
What percent of blood is plasma?
A
55%
10
Q
What is plasma comprised of?
A
- 91% water
- 7% blood proteins
- 2% nutrients, hormones, and electrolytes
11
Q
What percent of blood is buffy coat?
A
<1%
12
Q
What is buffy coat comprised of?
A
WBCs and platelets
13
Q
What percent of blood is RBCs?
A
45%
14
Q
What is another name for RBCs?
A
Erythrocytes
15
Q
What is another name for WBCs?
A
Leukocytes
16
Q
Shape and size of erythryocytes?
A
Biconcave disc, diameter of 7-8µm
17
Q
Structure of erythrocytes?
A
No nucleus or organelles; have cytosol packed with haemoglobin
18
Q
Function of haemoglobin?
A
Oxygen transporting vehicle; carries oxygen from lungs and releases it to tissues
19
Q
Where is haemoglobin synthesised? Why?
A
In immature RBCs, because maturation of these cells involves the loss of machinery (e.g. nucleus, organelles) for protein synthesis
20
Q
What type of protein is haemoglobin (Hb)?
A
Metalloprotein
21
Q
Structure of 1 haemoglobin molecule?
A
4 globulin proteins, each of which contains an Fe molecule. Each Fe binds 1 x O2 molecule, meaning Hb binds 4 x O2 molecules max.
22
Q
Main role of leukocytes?
A
Part of the immune system, thus participate in immune responses to injury or pathogens
23
Q
What are neutrophils?
A
- Type of leukocyte
- Engulf and destroy invading microorganisms by means of phagocytosis; capable of phagocytosis in low oxygen conditions
- Increase in bacterial infections
24
Q
What are lymphocytes?
A
- Type of leukocyte; include T and B cells
- Responsible for antibody production, direct cell-mediated killing of virus-infected and tumour cells, and regulation of the immune response
- Bear receptors that bind to a specific antigen
25
What are monocytes?
- Type of leukocyte
- Differentiate into macrophages
- Responsible for phagocytosis and presentation of antigens to lymphocytes
26
What are eosinophils?
- Type of leukocyte
- Phagocytose Ag-Ab complexes, antigens, and release enzymes
- Increase in parasitic infections or allergies
27
What are basophils?
- Type of leukocyte
- Store heparin and histamine
28
What are platelets?
Fragments of megakaryocytic that are formed elements; not cells
29
Structure of platelets?
Disc-shaped; 2-4µm in diameter
30
Functions of platelets?
- Involved in blood clotting; upon activation, adhere a platelet plug
- Secrete: vasoconstrictors, clotting factors, growth factors, and chemical attractants
31
What proteins/clotting factors circulate in blood plasma, and what proportion do they make up? (3-4)
- Albumins: 54-60%
- Globulins: 36-38%
- Clotting proteins: 4-7%
- Other proteins: 1%
32
Role of albumins?
Primarily transport proteins; transport of steroid hormones, thyroid hormones. Also induce blood colloid osmotic pressure.
33
Role of globulins?
α/β: transport iron, lipids, fat-soluble vitamins
γ: antibodies, released mainly by plasma cells
34
Types of clotting proteins and their main role?
Fibrinogen and prothrombin, which play roles in blood coagulation.
35
What is haemostasis?
Cessation of bleeding
36
Why does haemostasis occur?
Prevents significant blood loss after vascular injury
37
Four steps of haemostasis?
1. Vessel injury occurs; epithelium is ruptured
2. Vessel spasm occurs after receiving signal of exiting blood, thus constricting and narrowing the hole
3. Platelets adhere to injury and aggregate to form temporary plug
4. Insoluble fibrin strands form a meshwork and blood coagulation occurs
38
What is haematopoiesis?
Blood cell formation ('p' for production)
39
Active formation of prothrombin?
Thrombin
40
Insoluble version of fibrinogen?
Fibrin
41
Where does haematopoiesis occur? Why?
Within red bone marrow, because this is the home of haematopoietic stem cells; heavily protected by skeleton
42
What is erythropoiesis?
Formation of RBCs
43
What is leukopoiesis?
Formation of WBCs
44
Lifespan of erythrocytes? When do they reach maturity?
120 days, then undergo apoptosis and degradation by macrophages in spleen; mature in 7 days
45
Lifespan of leukocytes?
20 days, then undergo degradation in lymphoid organs;
46
2 types of HSCs?
Myeloid stem cell -> RBCs, platelets, granulocytes (WBCs)
Lymphoid stem cell -> WBCs
47
Universal blood donor type?
O-negative
48
What does ABO blood group system classify types by?
Presence/absence of antigens on RBC surface
49
Correlation between blood transfusions and blood type? Why?
Blood transfusions only possible when conducted between compatible blood types; otherwise, if blood types are incompatible, recipient's blood has antibodies against foreign RBC antigens, so immune reaction occurs
50
How does the ABO blood group system classify blood into types?
Based on the presence/absence of antigens on RBC surface
51
4 main blood types?
A, B, AB, O
52
What does the +/- sign indicate for blood types?
Whether or not RBCs express Rhesus protein
53
Is Rh+ or Rh- more common?
Vast majority of people are Rh+
54
What occurs if blood transfusions between incompatible blood types takes place?
Agglutination (RBC clumping), then haemolysis (RBC destruction via rupturing)
55
Role of blood vessels?
Provide structures for blood to flow to and from the heart, for exchange of nutrients/wastes in tissues
56
Role of arteries?
Take blood from heart to tissues
57
Role of capillaries?
Site of exchange
58
Role of veins?
Take blood from tissues to heart
59
3 types of arteries?
Elastic, muscular, and arterioles
60
4 types of veins?
Small, medium, large, and venules
61
What is the tunica intima?
Most internal layer of blood vessel wall, which is common to all blood vessels
62
Structure of tunica intima?
Endothelium (thin, simple squamous epithelium); smooth endothelial cell
63
What is the tunica media?
Middle layer of blood vessel wall
64
Which of the blood vessel wall layers is typically predominant/thickest?
Tunica media (especially in muscular arteries)
65
Role of tunica media?
Responsible for vasoconstriction and vasodilation, and therefore changes in blood flow and blood pressure; also propulsion of blood through vessels
66
Structure of tunica media?
Largely composed of smooth muscle fibres, as well as elastic tissue
67
What is the lumen?
Hollow passageway through which blood flows
68
What is the tunica adventitia/externa?
Outermost layer of blood vessel wall
69
Structure of tunica adventitia?
Connective tissue (collagenous and elastic fibres); size varies according to amount/type of support blood vessel needs
70
Role of tunica adventitia?
Supports, protects, and prevents over-distension of vessel wall
71
Differences in arterial wall vs venous wall?
Arterial wall:
- Thicker, due to tunica media
- More smooth muscle
- Internal elastic membrane surrounding tunica media
Venous wall:
- Thinner
- Less smooth muscle
- No internal elastic membrane
72
Correlation between lumen/vessel wall size and distance from heart?
Lumen/vessel wall size decreases as we move further away from the heart
73
3 types of arteries?
- Elastic
- Muscular
- Arterioles
74
Characteristics of elastic arteries?
Thicker tunica media, interdispersed with lots of elastic fibres; large diameter and thick walls
75
Location of elastic arteries? What does this mean?
Proximal to heart; so, subject to high pressure
76
Structure of muscular arteries?
Rich in smooth muscle fibres; more muscle fibres than elastic fibres in tunica media, which is the predominant blood vessel layer
77
Role of muscular arteries?
Organisation of muscle adapted for vasoconstriction and vasodilation; so, adjust rate of blood flow
78
Characteristics of arteriole structure?
- Smallest blood vessel where 3 tunics can still be identified
- Thick wall relative to lumen size
79
Role of arterioles?
Protect capillaries from bursting; so, reduce blood pressure and regulate blood flow through capillaries
80
Do arteries or veins work under a lower pressure system? What does this mean?
Veins; so, they have proportionally thinner blood vessel walls
81
What is the predominant blood vessel layer in veins?
Tunica adventitia
82
Where are capillaries extensive?
In tissues of high metabolic activity (brain, muscles, liver, kidneys)
